Roles and mechanisms of ginsenoside Rg1 in coronary artery disease: Progress and perspectives

Abstract

Coronary artery disease (CAD) is a leading cause of morbidity and mortality globally, necessitating innovative therapeutic strategies. Panax ginseng Meyer, esteemed in traditional Chinese medicine as the “King of Herbs,” has garnered scientific attention for its cardiovascular benefits. Among its bioactive components, ginsenoside Rg1 stands out as a potent therapeutic candidate. This review consolidates current research on Rg1's multifaceted mechanisms in CAD management, including its roles in enhancing endothelial function, inhibiting smooth muscle cell proliferation, modulating inflammation, regulating lipid metabolism, preventing thrombosis, and promoting angiogenesis. Furthermore, Rg1 exhibits cardioprotective properties by mitigating ischemic myocardial injury, reducing myocardial hypertrophy, and preventing fibrosis. Despite promising preclinical findings, the clinical translation of Rg1 is hindered by challenges such as poor bioavailability, potential drug interactions, and limited clinical trial data. This review underscores the need for rigorous clinical studies to validate Rg1's efficacy and safety, paving the way for its incorporation into CAD therapeutic regimens.

Graphical abstract

1. Introduction

Coronary artery disease (CAD) remains the leading cause of mortality worldwide, with an alarming incidence of nearly 7 million fatalities and 129 million disabilities annually, predominantly in low- and middle-income countries [1]. Despite significant advancements in secondary prevention and revascularization techniques like coronary artery bypass grafting and percutaneous coronary interventions, the long-term incidence of adverse cardiovascular events remains high [2]. This underscores the urgent need for novel cardioprotective agents.

Panax ginseng Meyer (P. ginseng), a cornerstone of traditional Chinese medicine (TCM), is derived from perennial plants of the Panax genus within the Araliaceae family. Documented in the ancient medical text “Shennong Bencao Jing” for its restorative properties, P. ginseng is utilized based on the principle that “qi and blood are interconnected; qi governs blood movement while blood nurtures qi.” Modern pharmacological research has identified various bioactive constituents in P. ginseng, including polysaccharides, ginsenosides, peptides, and fatty acids [3]. Among these, ginsenosides receive particular attention due to their therapeutic potential.

Ginsenoside Rg1, a prominent tetracyclic triterpenoid of the 20(S)-protopanaxatriol type [4], is recognized for its abundance and bioactivity in P. ginseng, contributing significantly to its pharmacological effects [5]. Accumulating evidence [[6], [7], [8], [9], [10]] indicates that Rg1 exerts protective effects against CAD through anti-atherosclerotic properties and cardiomyocyte protection against ischemic injury. This review explores the mechanisms and therapeutic potential of Rg1 in CAD, providing a basis for developing Rg1-based interventions to enhance CAD management and patient outcomes.

2. Mechanism of cardioprotective role in anti-atherosclerosis

Arteriosclerosis is the main pathological process underlying CAD, involving endothelial dysfunction, smooth muscle cell (SMC) proliferation and migration, monocyte recruitment, lipid infiltration, inflammation, and foam cell formation [11]. These processes culminate in plaque formation and lumen narrowing, impairing blood supply. Plaque rupture triggers platelet aggregation and thrombus formation, further exacerbating cardiac function.

Recent advancements in atherosclerosis treatment include medications like evolocumab [12], which reduces lipid accumulation, colchicine, targeting inflammation [13], and ticagrelor, inhibiting platelet aggregation [14]. Ginsenoside Rg1 has shown potential in addressing various aspects of atherosclerosis formation, including endothelial cell damage, SMC proliferation, monocyte recruitment, lipid deposition, inflammation, and thrombus formation, highlighting its prospect for clinical application. Here, we provide a comprehensive review of the mechanisms by which Rg1 exerts its anti-atherosclerotic effects (Table 1; Fig. 1).

Table 1.

Summarized the effects and mechanisms of ginsenoside Rg1 on anti-atherosclerosis.

Primary Action	Experimental models	Specific Effects	Mechanisms	Ref
Enhance endothelial function	STZ-induced diabetic rats; HG-induced HAECs	Improve endothelial function, preserve mitochondrial structure and function, reduced oxidative stress	Inhibit calpain-1/ROS/PKC-β axis	[20]
	CIH-induced HCAECs	Suppress mitoROS, preserve mitochondrial function, increase the release of NO	Inhibit calpain-1/PP2A/eNOS axis	[6]
	PM2.5-induced HUVECs	Decrease ROS and MDA content	Upregulate the expression of HO-1 and Nrf2	[21]
	Ox-LDL-induced HUVECs	Increase SOD activity, reduce the production of reactive species	Stimulate AMPK phosphorylation, increase SIRT3 expression, reduce p53 level.	[8]
	Serum-depleted medium-cultured PAECs	Boost eNOS phosphorylation, stimulate L-arginine transport into ECs	Activate PI3K/Akt pathway, increase CAT-1 expression	[24]
	Shear stress-induced HUVECs	Decrease MCP-1 expression	Inhibit MAPK pathway include ERK, p38, JNK phosphorylation	[26]
Inhibit SMC proliferation	Carotid balloon injury-induced rats	Inhibit VSMCs proliferation	Inhibit ERK2 pathway, elavate MKP-1 expression, reduce c-fos and SMα-actin mRNA expression	[7]
	TNF-α-induced HASMCs	Inhibit HASMCs proliferation	Inhibit ERK and PI3K/PKB, downregulate cyclin D1, upregulate p53, p21 and p27 levels	[28]
	TNF-α-induced VSMC	Prevent VSMCs proliferation cycle progression from G1 to S phase	Decrease PKC-ζ, GRK and N-ras protein, increase p21 expression	[30]
Anti-inflammation	LPS-induced macrophages; mouse peritoneal macrophages	Decrease TNF-α and IL-6 mRNA levels, increase TNF-α protein expression	Reduce the phosphorylation of IκB and NF-κB, upregulate the PI3K/Akt/mTORC1 signaling pathway	[34]
	Hypoxia-induced PAH rats; hypoxia-induced HPAECs	Reduce TNF-α and IL-1β levels	Inhibit the activation of the NF-κB/TGF-β pathway through upregulating CCN1	[35]
	STZ-induced diabetic rats	Decrease the expression levels of IL-1β, IL-6,TNF-α, NF-κB, NLRP3, TLR4, and ASC	Stimulate AMPK phosphorylation, increase Nrf2 and HO-1expression	[36]
Regulate lipid metabolism	High-sugar and high-fat diets-raised rats	Reduce the levels of TC and TG, inhibit the secretion of IL-1, IL-6, IL-8, IL-18, and TNF-α	Promote the expression of PPAR-α, CPT1A, CPT2, and CYP-7A, inhibit the expression of SREBP-1C	[39]
	High-fat diet-induced NAFLD rats;	Reduce TC, TG, LDL-C, free fatty acids, and increase HDL-C	Promote fatty acid oxidation via PPARα activation	[40,41]
	Male db/db mice
	3T3-L1 cells;	Reduce TC and TG levels, decrease lipid droplets accumulation in 3T3-L1 cells	Activate AMPK pathway, reduce the expression of PPARγ, CCAAT/C/EBP and SREBP, suppress ACC activity	[42]
	High fat diet-raised obese mice
Anti-thrombotic effects	Human blood from healthy subjects;	Inhibit platelet aggregation and spreading, decrease platelet adhesion on collagen-coated surface in human blood, reduce platelet adhesion and thrombus formation	Inhibit PKC-MAPK pathway	[47]
	10 % FeCl3- induced mice mesenteric arterial thrombosis
Promote angiogenesis	Diabetes and myocardial infarction rat	Increase arteriolar density	Inhibit the expression of PKCδ, stimulate the activation of the VEGF/PI3K-Akt/eNOS pathway	[55]
	HUVECs	Increase tube-like structure number	Upregulate GR and enhance cooperation between GR and FGFR-1, thereby activating the PI3K/Akt pathway, consequently enhance eNOS, GSK3β and HIF-α expression	[[56], [57], [58]]
	HUVECs	Promote eNOS expression, enhance VEGF-A production, enhance angiogenic capacity	Downregulate miR-23a and miR-214, upregulate MET protein	[[59], [60], [61]]

Fig. 1.

Mechanisms of the anti-atherosclerotic effects of ginsenoside Rg1.

Ginsenoside Rg1 (Rg1) exerts multiple protective effects against atherosclerosis by targeting key cellular components involved in the pathogenesis of the disease. A. Endothelial cells (ECs): Rg1 enhances endothelial function by reducing oxidative stress, promoting the dissociation of the Keap1/Nrf2 complex, and facilitating nuclear translocation of Nrf2. This activation leads to the upregulation of antioxidant enzymes such as SOD and GSH, and increased NO production while reducing ROS and MDA levels. Rg1 also stimulates NO release by increasing ETB receptor expression, facilitating L-arginine transport, and enhancing eNOS phosphorylation. Additionally, Rg1 suppresses the expression of adhesion molecules such as VCAM-1 and ICAM-1, thereby reducing monocyte adhesion and clustering. B. Smooth muscle cells (SMCs): Rg1 inhibits SMC proliferation by modulating the expression of genes through the ERK, PI3K, and PKC pathways, thereby exerting an inhibitory effect on cell proliferation and preventing neointimal hyperplasia.

Abbreviations: ETB, endothelin receptor type B; VCAM-1, vascular cell adhesion molecule-1; ICAM-1, intercellular adhesion molecule-1; Keap1, kelch-like ECH-associated protein 1; Nrf2, nuclear factor erythroid 2-related factor 2; HO-1, heme oxygenase-1; AMPK, AMP-activated protein kinase; SIRT3, sirtuin-3; PKC, protein kinase C; PP2A, protein phosphatase 2A; CAT-1, cationic amino acid transporter 1; PI3K, phosphoinositide 3-kinase; Akt/PKB, protein kinase B; ROS, reactive oxygen species; MDA, malondialdehyde; SOD, superoxide dismutase; GSH, glutathione; NO, nitric oxide; eNOS-P, endothelial nitric oxide synthase phosphorylation; mitoROS, mitochondrial reactive oxygen species; ERK, extracellular signal-regulated kinase; MKP-1, mitogen-activated protein kinase phosphatase-1; c-fos, cellular oncogene fos; SM-α actin, smooth muscle alpha-actin.

2.1. Enhancing endothelial function

The vascular endothelium serves as the initial barrier for blood components and plays a fundamental role in regulating vascular homeostasis, tone, and integrity [15]. Endothelial injury is a primary step in atherosclerotic plaque formation [16]. Rg1 resolves endothelial dysfunction by promoting vasodilation, reducing oxidative stress, and inhibiting leukocyte adhesion.

2.1.1. Improving oxidative stress

Oxidative stress is a critical factor in endothelial dysfunction, resulting from an imbalance between reactive oxygen species (ROS) production and the body's antioxidant defenses [17]. Rg1 has been extensively studied for its antioxidative properties and its potential to mitigate endothelial oxidative stress.

In rat models of carotid artery balloon injury, Rg1 administered intraperitoneally at doses of 4, 8, and 16 mg/kg daily for 14 days significantly increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) levels in the vascular intima, indicating reduced oxidative damage [18]. Similarly, In H₂O₂-induced human umbilical vein endothelial cells (HUVECs), Rg1 (4, 8, and 16 μmol/L for 24 h) enhanced cell viability in a dose-dependent manner [19], confirming its protective effects against oxidative stress.

Mechanistically, Rg1 activates several antioxidative pathways. By using streptozotocin (STZ)-induced diabetic mice, Lu et al. found that Rg1 at doses of 10 and 20 mg/kg for 8 weeks reduced oxidative stress, preserved mitochondrial structure and function, and improved endothelial function. Similar effects were observed in high-glucose-induced human aortic endothelial cells (HAECs), where pretreatment with Rg1 (10, 20 μM) inhibited the calpain-1/ROS/protein kinase C-beta (PKC-β) axis [20]. Furthermore, Rg1 has been demonstrated to preserve mitochondrial function and suppress mitochondrial ROS production in models of chronic intermittent hypoxia (CIH) and human coronary artery endothelial cells (HCAECs). This involves inhibiting the calpain-1 pathway, highlighting Rg1's role in maintaining mitochondrial integrity [6].

Further studies in PM2.5-stimulated HUVECs revealed that preincubation with Rg1 (2.5, 10, 40 μg/mL) increased cell viability, decreased ROS and MDA levels, and upregulated heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2) expression [21]. These effects are mediated through the Nrf2-Keap1 pathway activation, indicating that Rg1 enhances the cellular antioxidant defense system. In HUVECs activated by oxidized low-density lipoprotein (ox-LDL), Rg1 treatment (1, 5, or 10 μM for 24 h) improved cell survival by reducing reactive species production and increasing SOD activity. This was achieved through the stimulation of AMP-activated protein kinase (AMPK) phosphorylation and upregulation of sirtuin 3 (SIRT3), leading to decreased tumor protein p53 expression [8].

Collectively, these findings underscore the beneficial role of Rg1 in mitigating oxidative stress through multiple signaling pathways, including calpain-1, Nrf2/HO-1, and AMPK/SIRT3/p53. These mechanisms highlight the therapeutic potential of Rg1 in managing endothelial dysfunction and oxidative stress associated with cardiovascular diseases.

2.1.2. Promoting nitric oxide (NO) release

NO is a critical signaling molecule in vascular homeostasis, involved in modulating vascular tone, inhibiting platelet aggregation, and reducing inflammation. Impaired NO synthesis contributes to endothelial dysfunction and atherosclerosis progression [22].

Rg1 has been shown to significantly increase NO production by upregulating endothelial nitric oxide synthase (eNOS) expression and activity. In rat models of carotid artery balloon injury, Rg1 treatment increased eNOS mRNA expression and NO levels, demonstrating its ability to enhance endothelial function under oxidative stress conditions [18]. Similarly, in H₂O₂-induced HUVECs, Rg1 enhanced NO production, underscoring its protective effects against oxidative damage [19]. Further studies revealed that pretreatment with Rg1 in tumor necrosis factor (TNF)-induced HUVECs leads to an upregulation of eNOS mRNA and NO levels via increased endothelin type-B (ETB) receptor expression [23]. This suggests that Rg1 enhances NO synthesis via receptor-mediated pathways.

Additionally, in spontaneously hypertensive rats, Rg1 promoted eNOS phosphorylation and increased NO content, improving endothelium-dependent vasodilation. The mechanistic insights were further elucidated using porcine aortic endothelial cells (PAECs). Rg1 was found to boost eNOS phosphorylation by activating the phosphoinositide 3-kinase/protein kinase B (PI3K/PKB) pathway and stimulating L-arginine transport into endothelial cells via increased cationic amino acid transporter-1 (CAT-1) expression [24]. This indicates that Rg1 facilitates NO production through multiple signaling pathways. Moreover, Zhao et al. [6] observed elevated levels of eNOS protein, phosphorylated-eNOS, and NO in both in vivo and in vitro endothelial injury models treated with Rg1. This effect was achieved by inhibiting the calpain-1/protein phosphatase 2A (PP2A) pathway, resulting in increased eNOS phosphorylation at Ser¹¹⁷⁷. In CIH-induced diabetic rats and high glucose-stimulated HAECs, Rg1 increased eNOS protein and NO levels by inhibiting the calpain-1/ROS/PKC-β axis [20].

In summary, Rg1 significantly enhances NO production by upregulating ETB and CAT-1 expression and modulating key signaling pathways, including PI3K/Akt, calpain-1/PP2A/eNOS, and calpain-1/ROS/PKC-β. These mechanisms highlight Rg1's potential in improving endothelial function and preventing atherosclerosis progression through enhanced NO release.

2.1.3. Inhibiting monocyte aggregation

Monocytes play a critical role in atherosclerosis development by adhering to the endothelium, migrating into the intimal layer, and differentiating into macrophages, which contribute to atherosclerotic plaque formation. This process involves multiple steps, including capture, slow rolling, adhesion strengthening, spreading, intravascular crawling, and transmigration, all mediated by chemokines, selectins, integrins, and adhesion molecules. Once within the intima, monocytes differentiate and exacerbate plaque formation, creating a necrotic core that further destabilizes the plaque [25].

Vascular cell adhesion molecule (VCAM) and intercellular adhesion molecule (ICAM) are crucial adhesion molecules expressed on the surface of endothelial cells and leukocytes, facilitating monocyte adhesion to the vascular wall. A study by Lv et al. [23] demonstrated that Rg1 pretreatment significantly reduces the expression of VCAM-1, ICAM-1, and p-selectin in tumor necrosis factor-alpha (TNF-α)-induced HUVECs. Furthermore, in shear stress-induced HUVECs, Rg1 pretreatment led to the inhibition of monocyte chemoattractant protein-1 (MCP-1) gene expression and protein secretion, subsequently reducing monocyte adhesion. This inhibitory effect is attributed to the suppression of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK), and c-Jun N-terminal kinase phosphorylation within the MAPK signaling pathway [26].

These findings suggest that Rg1 effectively attenuates monocyte aggregation by downregulating key adhesion molecules and chemokines, mitigating the inflammatory cascade associated with atherosclerotic progression. This highlights the therapeutic potential of Rg1 in preventing the early stages of atherosclerosis through targeted inhibition of monocyte-endothelial interactions.

2.2. Inhibiting smooth muscle cell proliferation

Vascular smooth muscle cells (VSMCs) are pivotal in atherosclerosis progression, particularly through their shift from a contractile to synthetic phenotype when exposed to stimuli like hypoxia and inflammation [27]. This change in phenotype results in increased proliferation, migration, and secretion of extracellular matrix components, ultimately contributing to neointimal hyperplasia and plaque formation.

Rg1 has demonstrated significant potential in inhibiting VSMC proliferation. In carotid artery balloon injury rat models, administering Rg1 (4, 8, and 16 mg/kg/day) for 2 weeks effectively reduced neointimal hyperplasia. This effect was mediated by the inhibition of ERK2 signaling, increased expression of MAPK phosphatase-1 (MKP-1), and decreased expression of cellular oncogene fos and smooth muscle α-actin mRNA [7]. Further studies have explored the effects of Rg1 on human arterial vascular smooth muscle cells (HASMCs) induced by TNF-α. Incubation with various concentrations of Rg1 resulted in a dose-dependent inhibition of HASMC proliferation. This was achieved through the downregulation of cyclin D1 levels and the upregulation of p53, p21, and p27 levels, indicating the involvement of ERK and PI3K/PKB pathways [28].

Rg1 also inhibits VSMC proliferation induced by platelet-derived growth factor-BB (PDGF-BB) by restricting cell cycle progression from the G0/G1 to S phase. This mechanism is linked to eNOS mRNA expression promotion, resulting in increased NO and cyclic guanosine monophosphate (cGMP) production [29]. Additionally, Rg1 treatment (10–160 mg/L) prevented VSMCs from progressing from the G1 to S phase and decreased the expression of G-protein coupled receptor kinase (GRK), protein kinase C-ζ (PKC-ζ), and N-ras protein. Concurrently, it increased the levels of cell cycle-related protein p21 in TNF-α-induced VSMCs, suggesting that Rg1 inhibits VSMC proliferation via PKC-ζ and p21 pathway regulation [30].

These findings collectively indicate that Rg1 inhibits VSMC proliferation primarily by interfering with cell cycle progression, enhancing NO production, and modulating key signaling pathways such as ERK, PI3K/PKB, and PKC-ζ. These mechanisms underscore the potential of Rg1 as a therapeutic agent for atherosclerosis by targeting smooth muscle cell proliferation and stabilizing vascular plaques.

2.3. Anti-inflammation

Inflammation is a key component in atherosclerosis progression and a significant therapeutic target in CAD management. Rg1 has demonstrated significant anti-inflammatory effects in various models, indicating its potential as a therapeutic agent for CAD [31].

In vivo, studies in naturally aging rats showed that Rg1 at a dose of 0.1 mg/kg/day alleviated age-related inflammation by decreasing TNF-α and increasing interleukin-10 (IL-10) levels [32]. Similarly, in vitro studies reported that Rg1 at concentrations of 12.5, 20, and 50 μM for 6 h significantly reduced TNF-α secretion in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages [33].

However, another study using a similar LPS-stimulation model in RAW 264.7 macrophages and mouse peritoneal macrophages showed that Rg1 treatment (5 and 10 μM for 1 h) significantly decreased TNF-α and interleukin-6 (IL-6) mRNA levels by reducing inhibitor of κB (IκB) and nuclear factor-kappa B (NF-κB) phosphorylation, while paradoxically increasing TNF-α protein expression through PI3K/Akt/mTORC1 signaling pathway upregulation [34]. This inconsistency in TNF-α protein expression is thought to be associated with the concentration of LPS used.

LYU et al. [8] demonstrated that Rg1 therapy (1, 5, or 10 μM for 24 h) reduces IL-6, interleukin-1 beta (IL-1β), and TNF-α levels in ox-LDL activated HUVECs by regulating the AMPK/SIRT3/p53 signaling pathway. Furthermore, Tang et al. [35] found that Rg1 reduces TNF-α and IL-1β expression levels in the lung tissue and serum of hypoxia-induced pulmonary arterial hypertension rats, as well as in human pulmonary artery endothelial cells exposed to hypoxia. The study demonstrated that Rg1 downregulates the expression of p-NF-κB, p65, transforming growth factor-beta 1 (TGF-β1), and p-Smad2/3 while upregulating cellular communication network factor 1 (CCN1). This suggests that the anti-inflammatory effects of Rg1 are achieved by inhibiting the NF-κB/TGF-β pathway activation through CCN1 upregulation.

In a study with STZ-induced diabetic rats, Qin et al. [36] reported that administering Rg1 (20 mg/kg/day for 8 weeks) markedly enhanced cardiac function and reduced inflammation. It also lowered the expression levels of IL-1β, IL-6, TNF-α, NF-κB, NOD-like receptor protein 3 (NLRP3) inflammasome, toll-like receptor 4 (TLR4), and apoptosis-associated speck-like protein containing a caspase recruitment domain. These effects were achieved by promoting AMPK phosphorylation and boosting Nrf2 and HO-1 expression.

Collectively, these findings demonstrate that Rg1 exerts its anti-atherosclerotic effects by decreasing the secretion of inflammatory factors, thereby alleviating inflammation. These mechanisms highlight the potential of Rg1 as a therapeutic agent in managing inflammation-related cardiovascular diseases.

2.4. Regulating lipid metabolism

Low-density lipoprotein (LDL) plays a central role in the initiation and progression of atherosclerosis by depositing in the arterial walls and becoming retained within the intimal layer. Therefore, lipid-lowering therapy remains foundational in managing CAD [37,38].

Recent studies indicate that Rg1 significantly modulates lipid metabolism. Hou et al. [39] demonstrated that administering Rg1 orally (30, 60 mg/kg/day) to rats on a high-sugar and high-fat diet for 4 or 8 weeks reduced total cholesterol (TC) and triglyceride (TG) levels. This effect is attributed to the upregulation of carnitine palmitoyl transferase 1α (CPT1A), carnitine palmitoyl transferase 2 (CPT2), and cholesterol 7α-hydroxylase (CYP-7A), alongside downregulation of sterol regulatory element-binding proteins-1C (SREBP-1C) via increased peroxisome proliferator-activated receptor-α (PPAR-α) expression.

In nonalcoholic fatty liver disease (NAFLD) mice, Rg1 (20 or 40 mg/kg/day for 1 month) decreased TG, TC, high-density lipoprotein cholesterol (HDL-C), and LDL-C levels, improving lipid peroxidation through PPAR-α upregulation [40]. In male db/db mice, Rg1 (10 mg/kg for 15 days) significantly reduced plasma TG and free fatty acids while increasing HDL-C concentrations by promoting fatty acid oxidation via PPAR-α activation [41].

Rg1 also reduced TC and TG levels in obese mice and minimized lipid droplet accumulation in 3T3-L1 cells. Furthermore, Rg1 lowered PPARγ, CCAAT/enhancer-binding protein (C/EBP), and SREBP expression; activated the AMPK pathway; and suppressed acetyl-CoA carboxylase (ACC) activity, enhancing lipolysis and reducing lipogenesis both in vivo and in vitro [42]. In high-fat diet-induced NAFLD rats, Rg1 (5, 10, 20 mg/kg/day for 8 weeks) decreased TC, TG, and LDL-C levels while increasing HDL-C in plasma. Additionally, it promoted hepatic acyl-CoA synthetase 1 (CoASH1), carnitine acyltransferase (CAT1), and acyl-CoA oxidase 1 (ACOX1) expression, indicating enhanced fatty acid oxidation [43].

2.5. Antithrombotic effects

Thrombosis is crucial in the pathogenesis of atherosclerosis-related thrombotic events involving platelet activation, coagulation factor activation, and fibrinolytic system imbalance [44]. Rg1 exhibits potential antithrombotic effects through both antiplatelet and anticoagulant mechanisms.

Rg1 inhibits platelet aggregation in blood samples from healthy individuals and ADP-induced platelet aggregation in rat blood. Zhou et al. [45] reported that both PNS and its component, Rg1 (100 μM), significantly inhibited platelet aggregation and spreading and reduced platelet adhesion on a collagen-coated surface in human blood samples. Additionally, Rg1 at concentrations of 1.5, 2.5, 3, and 4 mmol/L was found to inhibit platelet aggregation in rat blood in vitro [46]. The in vivo effect of Rg1 was further confirmed in a mouse mesenteric arterial thrombosis model, where Rg1 (10 mg/kg, bolus injection) markedly attenuated vessel injury-induced platelet adhesion and thrombus formation. These antiplatelet effects are likely achieved by interference with the platelet PKC-MAPK pathway, as evidenced by decreased ERK and PKC substrate phosphorylation [47]. Despite these promising findings, the precise antiplatelet effects of Rg1 remain controversial, the current in vitro experiments utilize Rg1 treatment concentrations that are significantly higher than the reported peak plasma concentration (Cmax ≈ 1134.4 ± 562.80 ng/mL) observed in pharmacokinetic studies [48], indicating a substantial discrepancy between experimental models and physiological conditions. The use of such supraphysiological concentrations may result in deviations from the true biological effects of Rg1, thereby weakening the relevance of experimental findings to its in vivo functionality. Therefore, further research is needed to clarify its role in antiplatelet, particularly at physiological concentrations.

Additionally, Rg1 exhibits anticoagulant effects in rat blood, prolonging prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) while reducing fibrinogen concentrations [49]. Similar effects were observed in human blood, where Rg1 extended PT, APTT, and TT [50]. Lv et al. [23] also suggested that Rg1 may exert antithrombotic effects by downregulating plasminogen activator inhibitor 1 (PAI-1), which regulates intravascular fibrinolysis and tissue proteolysis.

2.6. Promoting angiogenesis

Angiogenesis, the formation of new blood vessels from preexisting ones, is crucial in both normal physiology and pathological conditions, offering a promising therapeutic strategy for improving ischemia [51,52]. Rg1 has been shown to stimulate angiogenesis effectively both in vivo and in vitro [53].

Sengupta et al. [54] found that Rg1 promotes functional neovascularization in vivo and tube-like structure formation in vitro by upregulating the PI3K/Akt/eNOS pathway. Similarly, Pan et al. [55] showed that Panax Quinquefolium Saponins, which include Rg1, inhibit PKCδ expression and facilitate the activation of the vascular endothelial growth factor (VEGF)/PI3K-Akt/eNOS pathway. Cheung et al. [56] demonstrated that Rg1 increases tube formation and activates the PI3K/Akt/eNOS pathway in PAECs by upregulating glucocorticoid receptor (GR) and fibroblast growth factor receptor-1 (FGFR-1), enhancing synergy between these receptors.

In HUVECs, Rg1 increased β-catenin levels and enhanced nuclear accumulation, promoting VEGF expression and tube formation via the PI3K/Akt pathway and glycogen synthase kinase 3β (GSK3β) phosphorylation [57]. Additionally, Rg1 increased VEGF expression through the PI3K/Akt/p70 pathway mediated by GR, ultimately enhancing hypoxia-inducible factor-α (HIF-α) expression [58]. Moreover, microRNAs (miRNAs) have emerged as important regulators of angiogenesis. A study by Wu et al. found that Rg1 promotes new blood vessel formation by inhibiting miR-23a, increasing Runt-related transcription factor 2 (RUNX2) expression, and enhancing VEGF-A production in HUVECs [59]. Kwok et al. [60] found that Rg1 activates GR, reduces miR-23a expression, and upregulates hepatocyte growth factor receptor protein, promoting angiogenesis. Chan et al. [61] reported that Rg1 downregulates miR-214 in HUVECs, increasing eNOS expression and tube formation. Xiong et al. [62] revealed that Rg1 stimulates endothelial progenitor cells to release exosomes containing angiogenesis-related miRNAs such as miRNA-126–5p, miRNA-146a-5p, miRNA-210, and miRNA-214–5p.

In summary, Rg1 promotes angiogenesis through multiple pathways involving GR and miRNAs. It enhances cooperation between GR and FGFR-1, activates the PI3K/Akt pathway, and modulates the expression of key angiogenic factors such as eNOS, β-catenin, HIF-α, RUNX2, and VEGF.

3. Mechanism of cardioprotective action in myocardium

The progressive formation of atherosclerotic plaques within coronary arteries results in diminished blood supply, leading to insufficient oxygen and nutrient delivery to myocardial cells within the ischemic environment. Consequently, myocardial cells undergo compensatory hypertrophy to sustain normal cardiac function [63]. Prolonged ischemia, however, causes myocardial fibrosis, significantly impairing the heart's elasticity and contractility, thereby affecting its pumping function. Hence, protecting cardiomyocytes is crucial for enhancing CAD progression and prognosis [64]. Rg1 has demonstrated potential in ameliorating ischemic myocardial injury, inhibiting cardiac hypertrophy and fibrosis, thus decelerating CAD progression (Table 2).

Table 2.

Summarized the effects and mechanisms of ginsenoside Rg1 Protective effect on ischemic cardiomyocytes.

Primary Action	Experimental models	Specific Effects	Mechanisms	Ref
Improve myocardial injury	ISO-induced AMI rats	Improve oxidative stress and inflammation, inhibit cardiomyocyte apoptosis	Inhibit PTEN expression thereby activating PI3K/Akt pathway	[69]
	I/R-induced H9c2 cells	Reduce ROS and MDA production, increase antioxidant enzyme levels	Activate Nrf2 and HO-1	[71]
	LPS or H/R-induced H9C2 cells	Inhibit mitochondrial Ca2+ overload, increase MMP, reduce ROS levels	Activate Akt/GSK-3β pathway	[72]
	I/R-induced myocardial injury rats	Inhibit cardiomyocytes apoptosis	Decrease Bax-2/Bcl-2 ratio	[76]
	I/R-induced myocardial injury rats	Modulate energy metabolism, improve myocardial viability	Inhibit RhoA/ROCK pathway, enhance the activity and expression of mitochondrial respiratory chain complexes	[77]
	Nutritional stress-induced H9c2 cell	regulate mitochondrial autophagy and inhibite apoptosis	Activate AMPK and PINK1, dissociate of Bcl-2-Beclin1 complex	[78,82]
	H/R-induced H9c2 cells	Inhibit endoplasmic reticulum stress, reduce cardiomyocyte damage and apoptosis	Activate the PI3K/Akt signaling pathway by phosphorylating Akt	[79]
	H/R-induced H9c2 cells	Increase cellular ATP content, inhibit autophagosomal formation and apoptosis	Prevent AMPK activation, promote mTOR activation	[81]
	Myocardial I/R-induced diabetes rats	Inhibit cardiomyocytes apoptosis	Activate HIF-1α/ERK pathway, decrease Bax-2/Bcl-2 ratio, reduce caspase-3 and caspase-9 activity	[80]
	Hypoxia-induced H9c2 cells	Increase cell viability, decrease cell apoptosis and autophagy	Activate PI3K/AKT/mTOR pathway, upregulate Bcl-2 and p62, downregulate caspase-9, caspase-3, LC3-II/LC3-I, and Beclin-1	[83]
	I/R-induced myocardial injury rats	Decrease infarct size, reduce cardiomyocyte apoptosis, lower levels of TNF-α, IL-1β, and p65 protein.	Inhibit NF-κB pathway, Increase IκB expression	[85]
	LPS-induced cardiac dysfunction mice;	Suppress inflammation, restore cardiac function	Inhibit TLR4/NF-κB/NLRP3 pathway, downregulate TLR4, NF-κB, and NLRP3	[86]
	LPS-induced NRCMs
	I/R-induced rats;	Reduce IL-1β and TNF-α mRNA expression, maintain stable IL-10 expression, reduces cardiac inflammation and fibrosis	Promote macrophage M2 polarization	[87]
	BMDMs
Inhibit cardiac hypertrophy	Angiotensin II and isoproterenol-stimulated neonatal rat cardiomyocytes	Mitigate myocardial hypertrophy, downregulate ANP	Upregulate SIRT1 and PGC-1α expression	[10]
	AAC-induced cardiac hypertrophy rats	Alleviate cardiac hypertrophy, improve cardiac hemodynamic function	Inhibit TNF-α/NF-kB pathway	[90]
	AAC-induced left ventricular hypertrophy rats	Ameliorate left ventricular hypertrophy	Inhibit CaN/MAPK pathway	[91]
	ISO-induced H9c2 cells	Inhibit cardiomyocyte hypertrophy	Inhibit Ca 2+/calpain-1 pathway	[92]
	TAC-induced left ventricular hypertrophy rats	Ameliorate left ventricular hypertrophy, improve cardiac dysfunction	Regulate expression of SIRT1 and PGC-1α, activate Akt, inhibit TNF-α/NF-κB and p38 MAPK signaling pathways	[93]
Improve myocardial fibrosis	LAD ligation-induced MI mice;	Enhance cell viability, reduce apoptosis, attenuate fibrotic remodeling	Activate SIRT1/PINK1/Parkin pathway	[95]
	H2O2-induced H9C2 cells
	AAC-induced rats	Alleviate cardiac fibrosis, improve cardiac decompensation	Inhibit [Ca2+]i increase, activate the CaN/NFAT3 pathway	[97]

3.1. Modulating myocardial injury

Myocardial injury results from restricted blood flow, leading to an imbalance between myocardial oxygen supply and demand. This imbalance is exacerbated by oxidative stress, inflammation, and myocardial necrosis and apoptosis, ultimately leading to cardiac dysfunction [65] (Fig. 2).

Fig. 2.

Mechanisms of ginsenoside Rg1 in protecting ischemic myocardium.

Ginsenoside Rg1 (Rg1) offers significant cardioprotection in ischemic myocardium through multiple mechanisms. A. Anti-apoptotic effects: Rg1 prevents apoptosis in cardiomyocytes by promoting the dissociation of Bcl-2 and Beclin-2, regulating the HIF-α/ERK and PI3K/Akt/mTOR pathways, as well as inhibiting intracellular ATP depletion to suppress AMPK pathway activation. This leads to increased expression of anti-apoptotic proteins Bcl-2 and Beclin-2, and decreased expression of pro-apoptotic proteins Bax, caspase-3, and caspase-9. B. Antioxidant activity: Rg1 enhances oxidative stress response by regulating intracellular Ca²⁺ equilibrium, reducing ROS, and boosting mitochondrial membrane potential, thus preserving mitochondrial structure and function. Key pathways include inhibition of the RhoA/ROCK pathway, suppression of GSTP-1 to facilitate OPA-1 expression, and activation of the Akt/GSK-3β pathway through P2X7 expression inhibition. C. Anti-inflammatory effects: Rg1 attenuates inflammatory responses in myocardial cells by inhibiting the NF-κB/p65 pathway through TLR4 receptor suppression, stimulating the AMPK/Nrf2/HO-1 pathway, preventing the activation of the NLRP-3 inflammasome, and promoting macrophage M2 polarization. Collectively, these mechanisms reduce the secretion of inflammatory cytokines, thereby alleviating inflammation.

Abbreviations: HIF-α, hypoxia-inducible factor alpha; ERK, extracellular signal-regulated kinase; PI3K, phosphoinositide 3-kinase; mTOR, mammalian target of rapamycin; Bcl-2, B-cell lymphoma 2; Bax, bcl-2-associated X protein; RhoA, ras homolog gene family member A; ROCK, Rho-associated protein kinase; GSTP-1, glutathione S-transferase pi-1; OPA-1, optic atrophy 1; GSK-3β, glycogen synthase kinase 3 beta; P2X7, purinergic receptor P2X ligand-gated ion channel 7; MMP, mitochondrial membrane potential; NF-κB, nuclear factor kappa B; NLRP-3, NOD-like receptor protein 3; TLR4, toll-like receptor 4; AMPK, AMP-activated protein kinase; Nrf2, nuclear factor erythroid 2-related factor 2; HO-1, heme oxygenase-1.

3.1.1. Ameliorating oxidative stress

Oxidative stress, characterized by an imbalance between ROS production and antioxidant defenses, is a critical factor in myocardial injury. Excessive ROS generation during ischemia induces cell apoptosis and degrades the extracellular matrix, causing significant myocardial damage [66]. Rg1 has demonstrated considerable potential in mitigating oxidative stress and protecting myocardial cells.

In a rat model of acute myocardial ischemia (AMI), Rg1 was found to reduce myocardial infarction size and tissue damage significantly. This was accompanied by increased activities of SOD and glutathione peroxidase (GSH-Px) alongside decreased levels of MDA, indicating reduced oxidative damage [67,68]. Similarly, in rats with isoproterenol (ISO)-induced AMI, Rg1 pretreatment (20, 30, and 40 mg/kg for 14 days) alleviated myocardial injury, increased SOD activity, and decreased myocardial MDA levels [69].

The protective effects of Rg1 against oxidative stress are closely related to its ability to preserve mitochondrial function. Zhu et al. [70] demonstrated that Rg1 effectively suppressed ROS accumulation and increased GSH levels in primary neonatal rat ventricular myocytes (NRVMs). The mechanism involves Rg1 binding to glutathione S-transferase P1 (GSTP1), inhibiting its kinase activity and maintaining the interaction between optic atrophy 1 (OPA1) and mitofilin by preventing glutathionylation. This action protects the mitochondria from myocardial damage. Li et al. found that Rg1 protects H9c2 cells from simulated ischemia/reperfusion (I/R) injury by activating antioxidant defenses via Nrf2 and HO-1, reducing ROS and MDA production and increasing antioxidant enzyme levels. This also improved mitochondrial function, as evidenced by increased mitochondrial membrane potential (MMP) [71].

Furthermore, Liu et al. [72] showed that Rg1 activates the Akt/GSK-3β signaling pathway via the purinergic 2X7 (P2X7) receptor in cardiomyocytes. This activation inhibits mitochondrial Ca2+ overload, increases MMP, reduces ROS levels, and alleviates myocardial dysfunction in a hypoxia/reoxygenation (H/R) model of H9C2 cells. Treatment with Rg1 (3.125, 6.25, 12.5 μM for 12 h) post-H/R in H9C2 cells enhanced mitochondrial viability, reduced cardiac toxicity, increased ATP production, and decreased ROS production in a dose-dependent manner. These effects are attributed to mitochondrial dynamics balance maintenance through the mitofusin 2 (MFN2)-mediated pathway [73].

A recent study employed a combination of network pharmacology, ligand-based protein docking, proteomics, and Western blot to analyze protein expression changes in H9c2 cells damaged by H₂O₂ and pretreated with Rg1. The study suggests that Rg1 effectively alleviates oxidative stress damage in cardiomyocytes by acting on key proteins such as MAPK1 and adenosine kinase and inhibiting the oxidative phosphorylation pathway [74].

In summary, Rg1 ameliorates oxidative stress and protects myocardial cells through multiple mechanisms. These include enhancing antioxidant enzyme activity, preserving mitochondrial function, and modulating key signaling pathways. The ability of Rg1 to manage oxidative stress and myocardial injury highlights its potential as a cardioprotective agent.

3.1.2. Inhibiting myocardial apoptosis

Protecting cardiomyocytes from necrosis and apoptosis following ischemia is a key therapeutic target in CAD treatment [75]. Several studies suggest that Rg1 significantly inhibits myocardial apoptosis, thus preserving cardiac function.

In an AMI model induced by H/R, pretreatment with Rg1 demonstrated a marked protective effect on myocardial structure and function. This effect was associated with a significant reduction in myocardial apoptosis, as evidenced by decreased infarct size and improved myocardial viability [68]. Shen et al. reported that Rg1 reduced the infarct area in rats subjected to I/R injury. Rg1 effectively inhibited I/R-induced cardiomyocyte apoptosis by increasing Bcl-2 mRNA expression and decreasing Bax mRNA expression. Additionally, Cleaved-Poly (ADP-ribose) Polymerase (PARP), caspase-9, and caspase-3 protein expressions were significantly downregulated [76]. Another study in I/R rats showed that Rg1 treatment improved cardiomyocyte survival by regulating energy metabolism and enhancing the activity and expression of mitochondrial respiratory chain complexes via the RhoA/ROCK signaling pathway [77].

In vitro studies further elucidate the mechanisms underlying Rg1's cardioprotective effects. Pretreatment with Rg1 (50 mg/kg, 7 days) enhanced the expression of aldose reductase, AMPK, and PTEN-induced kinase 1 (PINK1) in fasting mice hearts, promoting mitochondrial autophagy. In vitro, Rg1 improved H9c2 cell viability under nutrient deprivation, reduced apoptosis, and maintained mitochondrial stability by upregulating aldose reductase, activating AMPK and PINK1, and regulating mitochondrial autophagy, ultimately inhibiting apoptosis [78]. Liu et al. established an in vitro ischemia-hypoxia model using H9c2 cells and found that under ischemia-hypoxia conditions, Rg1 activated the PI3K/Akt signaling pathway by phosphorylating Akt, leading to upregulation of HIF-1α and its downstream protective factors. This activation played a protective role in cardiomyocytes. Furthermore, HIF-1α upregulation inhibited the expression of C/EBP Homologous Protein (CHOP), a pro-apoptotic factor mediated by endoplasmic reticulum stress, thereby reducing cardiomyocyte damage and apoptosis [79]. Additionally, Rg1 was found to modulate the expression of apoptosis-related proteins in diabetic myocardial infarction models. Specifically, Rg1 treatment decreased the bcl-2-associated X protein/B-cell lymphoma 2 (Bax-2/Bcl-2) ratio and reduced caspase-3 and caspase-9 activity by activating the HIF-1α/ERK signaling pathway [80].

In cardiomyocytes, autophagy plays a dual role, exhibiting either protective or detrimental effects under varying pathological conditions. In H9c2 cardiomyocytes subjected to H/R, treatment with Rg1 (100 μmol/L for 24 h) significantly inhibited both autophagy and apoptosis. This protective effect was achieved by maintaining cellular ATP levels, preventing AMPK activation, and promoting mTOR activation, as evidenced by the reduced expression of autophagy markers LC3BII and Beclin-1 [81]. Conversely, another study demonstrated that Rg1 induces autophagy in nutrient-deprived H9c2 cells by facilitating the dissociation of Beclin-1 from Bcl-2, thereby increasing free Beclin-1 and Bcl-2 levels in the cytoplasm. This mechanism led to a reduction in apoptosis in a dose- and time-dependent manner [82]. These findings indicate that Rg1 exerts protective effects on cardiomyocytes by modulating autophagy differently, depending on the specific pathological conditions.

Moreover, in an ISO-induced AMI rat model, Rg1 reduced myocardial apoptosis by regulating the PI3K/PTEN/Akt pathway [69]. This regulation resulted in lower Bax-2 levels and higher Bcl-2 levels, indicating a shift toward cell survival. In both in vivo and in vitro models, Rg1's protective effects against myocardial infarction were associated with the upregulation of Bcl-2 and p62, as well as the downregulation of caspase-9, caspase-3, LC3-II/LC3-I. These findings further support its role in activating the PI3K/Akt/mTOR pathway [83].

In conclusion, Rg1 exerts its cardioprotective effects through multiple mechanisms, including modulating apoptosis-related signaling pathways, regulating autophagy, preserving mitochondrial function, and maintaining energy metabolism. These findings highlight Rg1's potential as a therapeutic agent in protecting against myocardial apoptosis and improving cardiac outcomes in patients with CAD.

3.1.3. Alleviating inflammation

Ischemia triggers a potent inflammatory response that significantly contributes to myocardial dysfunction [84]. Studies using ISO-induced AMI models demonstrate that Rg1 pretreatment mitigates this inflammatory response, reducing levels of creatine kinase-MB, lactate dehydrogenase (LDH), IL-6, and TNF-α [69].

In I/R injury models, Rg1 pretreatment (10 mg/kg for 15 days) decreased infarct size, reduced cardiomyocyte apoptosis, and lowered levels of IL-1β, TNF-α, and p65 protein. Notably, increased IκB expression indicates that Rg1 ameliorates myocardial injury by inhibiting the NF-κB pathway [85].

In neonatal rat cardiomyocytes (NRCMs), Rg1 mitigated LPS-induced cardiac dysfunction by reducing the expression of inflammatory cytokines and reversing the upregulation of NF-κB, TLR4, and NLRP3. These findings suggest that Rg1 suppresses inflammation and restores cardiac function by modulating the TLR4/NF-κB/NLRP3 pathway [86]. Additionally, Rg1 treatment decreased TNF-α, IL-6, and IL-1β levels in the myocardium of STZ-induced diabetic rats. This anti-inflammatory effect is linked to inhibiting NF-κB and NLRP3 while activating the AMPK/Nrf2/HO-1 pathway [36].

Another study conducted by Xu et al. reported that Rg1 alleviates myocardial I/R injury in SD rats by reducing IL-1β and TNF-α mRNA expression and stabilizing IL-10 expression. In vitro, Rg1 reverses necrotic DNA-induced changes in macrophage inflammatory protein expression, decreases iNOS, and increases Arginase 1 expression, indicating that Rg1 reduces cardiac inflammation and fibrosis by promoting macrophage M2 polarization [87].

In summary, Rg1 alleviates myocardial inflammation by inhibiting key inflammatory pathways, activating protective signaling cascades, and modulating macrophage polarization. These actions reduce inflammatory cytokine production and improve cardiac function, highlighting Rg1's potential as a therapeutic agent for inflammatory cardiovascular conditions.

3.2. Inhibiting cardiac hypertrophy

Cardiac hypertrophy often develops as a response to increased workload caused by conditions like hypertension and myocardial infarction from CAD [88]. Research indicates that Rg1 effectively inhibits cardiac hypertrophy, thereby preserving cardiac function.

Sun et al. [10] demonstrated that Rg1 significantly reduced cardiomyocyte volume and downregulated atrial natriuretic peptide (ANP) expression in angiotensin II and ISO-stimulated neonatal rat cardiomyocytes. Notably, Rg1 increased the ATP/AMP ratio and elevated the expression of PPAR-gamma coactivator 1-alpha (PGC-1α) and sirtuin-1 (SIRT1). These effects were partly inhibited by a SIRT1 blocker, suggesting that Rg1 mitigates myocardial hypertrophy by upregulating PGC-1α and SIRT1 expression.

Wang et al. [89] found that Rg1 may enhance cellular energy metabolism by regulating PGC-1α expression in hypertrophic cardiomyocytes. In rats with abdominal aortic coarctation (AAC)-induced cardiac hypertrophy, Rg1 administration dose-dependently alleviated cardiac hypertrophy and enhanced cardiac hemodynamic function, possibly by inhibiting the TNF-α/NF-kB pathway [90]. Further in vitro experiments using TNF-induced NRVMs confirmed these findings.

In another AAC-induced rat model, Rg1 (3.75, 7.5, and 15 mg/kg/day for 3 weeks) ameliorated left ventricular hypertrophy in a dose-dependent manner, primarily through inhibition of the calcineurin (CaN) and MAPK signaling pathways [91]. Pretreatment of H9c2 cells subjected to ISO-induced injury with Rg1 showed a comparable inhibitory effect on cardiomyocyte hypertrophy to propranolol. Rg1 also reduced calpain-1 protein expression and intracellular calcium levels, implicating the Ca²⁺/calpain-1 pathway in its protective effects [92]. Additionally, Zhang et al. showed that Rg1 had a protective effect against transverse aortic constriction (TAC)-induced left ventricular hypertrophy and cardiac dysfunction, linked to Akt activation and p38 MAPK pathway inhibition [93].

Collectively, these studies indicate that Rg1 alleviates cardiac hypertrophy by regulating PGC-1α and SIRT1 expression, activating Akt, and inhibiting the TNF-α/NF-κB, Ca²⁺/calpain-1, and p38 MAPK signaling pathways. This highlights the potential of Rg1 as a therapeutic agent for cardiac hypertrophy in patients with CAD (Fig. 3).

Fig. 3.

Mechanisms of ginsenoside Rg1 in modulating myocardial hypertrophy and fibrosis.

Ginsenoside Rg1 (Rg1) inhibits myocardial hypertrophy and fibrosis through Various signaling pathways. A. Inhibiting cardiac hypertrophy: Rg1 inhibits cardiac hypertrophy by activating SIRT1/PGC-1α to regulate FFA and energy metabolism in cardiomyocytes, inhibiting the TNF-α/NF-κB and Ca²⁺/Calpain-1 signaling pathways, and promoting Akt phosphorylation to suppress the MAPK signaling pathway. B. Modulating myocardial fibrosis: Rg1 regulates myocardial fibrosis by activating the SIRT1/PINK1/Parkin pathway, inhibiting the Ca²⁺/CaN/NFAT3 pathway, promoting MMP2 secretion, and reducing MMP9 secretion.

Abbreviations: SIRT1, Sirtuin-1; PGC-1α, PPAR-gamma coactivator 1-alpha; FFA, free fatty acid; NF-κB, nuclear factor kappa B; MAPK, Mitogen-activated protein kinase; PINK1, PTEN-induced kinase 1; CaN, Calcineurin; NFAT3, Nuclear factor of activated T-cells 3.

3.3. Modulating myocardial fibrosis

Chronic ischemia damages myocardial tissue, leading to its replacement with fibrous scar tissue. This process reduces the myocardium's contractile capacity, exacerbating cardiac dysfunction. Rg1 has shown potential in mitigating myocardial fibrosis, thereby preserving cardiac function [94].

In studies involving H9c2 cells, Rg1 (0–80 μM) significantly reduced apoptosis, enhanced cell viability, and attenuated fibrotic remodeling induced by H₂O₂. These effects were mediated through mitophagy modulation via activation of the SIRT1/PINK1/Parkin axis [95]. In a rat model of chronic thromboembolic pulmonary hypertension, Rg1 (100 mg/kg/d for 4 weeks) reduced myocardial fibrosis, increased MMP-2 expression, and decreased MMP-9 expression. There was a negative correlation between the protein expressions of MMP-2, MMP-9, and collagen-I, indicating that Rg1 improved ventricular remodeling through matrix metalloproteinase regulation [96]. In another study, Rg1 alleviated cardiac fibrosis and improved cardiac decompensation induced by AAC in rats by inhibiting [Ca²⁺]i increase and the CaN/NFAT3 pathway activation, both mediated by the calcium-sensing receptor (CaSR) [97].

In summary, Rg1 exerts anti-fibrotic effects by regulating mitophagy, modulating matrix metalloproteinases, and inhibiting calcium-sensing pathways. These mechanisms collectively reduce myocardial fibrosis and improve cardiac outcomes (Fig. 3).

4. Conclusion

In recent years, numerous preclinical studies have demonstrated the promising potential of ginsenosides for treating cardiovascular diseases. Among these, the ginsenoside monomers Rb1, Rd, Rg1, and Rg3 have emerged as research hotspots. These monomers exhibit cardioprotective properties, including anti-inflammatory, antioxidative stress, and anti-cardiomyocyte apoptosis effects [[98], [99], [100], [101]]. Through a summary and synthesis of existing literature, we found that among these ginsenoside monomers, Rg1 exhibits a broader range of pharmacological activities. In addition to the established cardioprotective effects, Rg1 inhibits VSMC proliferation, reduces lipid levels, suppresses platelet aggregation, and promotes angiogenesis, exerting protective effects at various stages of CAD occurrence and development [28,39,45,54]. Based on this, we focused on the protective effects of ginsenoside Rg1 in CAD treatment. This review offers the first systematic summary of the protective effects and potential mechanisms of Rg1 from the perspective of CAD's pathological progression, providing new insights and a theoretical basis for its prevention and treatment.

In atherosclerosis, Rg1 exerts its protective effects by enhancing endothelial function through modulation of Nrf2/HO-1, AMPK/SIRT3/p53, PI3K/Akt, and calpain-1 pathways, thereby improving vasodilation, reducing oxidative stress, and inhibiting leukocyte adhesion. Concurrently, it effectively inhibits VSMC proliferation by interfering with cell cycle progression. The anti-inflammatory properties of Rg1 are primarily mediated through AMPK activation and NF-κB inhibition, resulting in reduced levels of pro-inflammatory factors like IL-1β, IL-6, and TNF-α. Furthermore, Rg1 optimizes lipid metabolism by regulating the expression of specific proteins and genes, while its antithrombotic properties are achieved by downregulating PAI-1 expression. Rg1 also exhibits pro-angiogenic effects via activation of the PI3K/Akt pathway and modulation of key angiogenic factors.

Beyond its anti-atherosclerotic effects, Rg1 demonstrates significant cardioprotective properties through multiple mechanisms. It ameliorates oxidative stress in ischemic myocardium by enhancing antioxidant enzyme activity and preserving mitochondrial function, particularly through the GSTP1, Akt/GSK-3β, and MFN2-mediated pathways. Rg1 inhibits myocardial apoptosis by modulating the RhoA/ROCK, PI3K/Akt/mTOR, HIF-1α/ERK, and AMPK/PINK1 signaling pathways while simultaneously alleviating inflammation by suppressing the NF-κB and TLR4/NF-κB/NLRP3 pathways, activating the AMPK/Nrf2/HO-1 pathway, and regulating macrophage polarization. Moreover, Rg1 mitigates cardiac hypertrophy by regulating SIRT1/PGC-1α expression and inhibiting TNF-α/NF-κB, calpain-1, and Akt/MAPK signaling. Additionally, it improves myocardial fibrosis through the SIRT1/PINK1/Parkin axis and modulation of matrix metalloproteinases. These diverse actions collectively contribute to Rg1's potential as a therapeutic agent in inhibiting atherosclerotic plaque formation and improving overall cardiac function in CAD.

The therapeutic potential of Rg1 in CAD is compelling, yet the journey from “bench to bedside” is fraught with challenges. Bioavailability remains a significant hurdle, as Rg1 exhibits poor oral absorption [102]. Innovative drug delivery systems, such as nanoparticles or liposomes, could enhance its bioavailability and therapeutic efficacy. Additionally, potential interactions between Rg1 and standard cardiovascular medications must be thoroughly investigated to ensure safe and effective combination therapies.

Despite extensive preclinical evidence supporting Rg1's cardioprotective effects, clinical data remain limited. Well-designed clinical trials are imperative to validate the findings from basic research and establish Rg1 as a viable therapeutic option for CAD. These studies should focus on dosing strategies, long-term efficacy, and safety profiles to provide a comprehensive understanding of Rg1's clinical potential. Moreover, the molecular mechanisms underlying Rg1's actions warrant deeper exploration. While current studies highlight its various effects in CAD, the intricate signaling networks involved need further elucidation. Advanced techniques such as proteomics, metabolomics, and CRISPR-based gene editing could offer new insights into Rg1's multifaceted networks.

In conclusion, ginsenoside Rg1 shows significant promise as a therapeutic agent for CAD. Its diverse mechanisms of action address key aspects of atherosclerosis and myocardial protection, positioning it as a multifaceted intervention in cardiovascular disease management. The path forward requires rigorous research, innovative approaches to drug delivery, and comprehensive clinical validation. With continued exploration and collaboration, Rg1 may soon emerge as a cornerstone in the treatment of CAD.

Declaration of competing interest

The authors declare that they have no competing interests.

Abbreviations

AAC

Abdominal aortic coarctation

ACC

Acetyl-CoA carboxylase

AMI

Acute myocardial ischemia

AMPK

AMP-activated protein kinase

APTT

Activated partial thromboplastin time

Bax-2

Bcl-2-associated X protein

Bcl-2

B-cell lymphoma 2

CAD

Coronary artery disease

CaN

Calcineurin

CAT-1

Cationic amino acid transporter-1

CCN1

Cellular communication network factor 1

CHOP

C/EBP Homologous Protein

CIH

Chronic intermittent hypoxia

ERK

Extracellular signal-regulated kinase

ETB

Endothelin receptor type B

FGFR-1

Fibroblast growth factor receptor-1

GR

Glucocorticoid receptor

GRK

G-protein coupled receptor kinase

GSTP1

Glutathione S-transferase P1

H/R

Hypoxia/reoxygenation

HAECs

Human aortic endothelial cells

HASMCs

Human arterial vascular smooth muscle cells

HCAECs

Human coronary artery endothelial cells

HDL-C

High-density lipoprotein cholesterol

HIF-α

Hypoxia-inducible factor-α

HO-1

Heme oxygenase-1

HUVECs

Human umbilical vein endothelial cells

I/R

Ischemia/reperfusion

ICAM

Intercellular adhesion molecule

IL-10

Interleukin 10

IL-1β

Interleukin 1 beta

IL-6

Interleukin 6

IκB

Inhibitor of κB

ISO

Isoproterenol

LDH

Lactate dehydrogenase

LDL

Low-density lipoprotein

LPS

Lipopolysaccharide

MAPK

Mitogen-activated protein kinase

MCP-1

Monocyte chemoattractant protein-1

MDA

Malondialdehyde

MKP-1

Mitogen-activated protein kinase phosphatase-1

MMP

Mitochondrial membrane potential

NAFLD

Nonalcoholic fatty liver disease

NFAT3

Nuclear factor of activated T-cells 3

NF-κB

Nuclear factor kappa B

Nrf2

Nuclear factor erythroid 2-related factor 2

NLRP3

NOD-like receptor protein 3

NO

Nitric oxide

NRVMs

Neonatal rat ventricular myocytes

OPA1

Optic atrophy 1

P. ginseng

Panax ginseng Meyer

PAECs

Porcine aortic endothelial cells

PARP

Poly (ADP-ribose) Polymerase

PDGF-BB

Platelet-derived growth factor-BB

PGC-1α

PPAR-gamma coactivator 1-alpha

PI3K

Phosphoinositide 3-kinase

PINK1

PTEN-induced kinase 1

PKC-β

Protein kinase C-beta

PP2A

Protein phosphatase 2A

PT

Prothrombin time

ROS

Reactive oxygen species

RUNX2

Runt-related transcription factor 2

SIRT1

Sirtuin-1

SIRT3

Sirtuin-3

SMCs

Smooth muscle cells

SOD

Superoxide dismutase

STZ

Streptozotocin

TAC

Transverse aortic constriction

TC

Total cholesterol

TG

Triglyceride

TGF-β1

Transforming growth factor-beta 1

TLR4

Toll-like receptor 4

TNF-α

Tumor necrosis factor-alpha

TT

Thrombin time

VCAM

Vascular cell adhesion molecule

VEGF

Vascular endothelial growth factor

VSMCs

Vascular smooth muscle cells

cGMP

Cyclic guanosine monophosphate

eNOS

Endothelial nitric oxide synthase

miRNAs

MicroRNAs