Table 7.
Biological activity, bioactivity constituents, and clinical studies on medicinal plants reported used by herbalists in Ghana for management of diabetics and hypertension.
| Species | Biological activity | Phytochemical constituents | Clinical studies |
|---|---|---|---|
| Aframomum melegueta | A. melegueta ethyl acetate fraction (AMEF) treatment at 300 mg/kg showed potent anti-diabetic effect in a T2D model of rats [82]. | Gingeredione, oleanolic acid [63]. | Lowering of cardiovascular indices such as systolic blood pressure (SBP), diastolic blood pressure (DBP). The degree of reduction was found to be within safety limits, indicating its potential usefulness in managing hypertension in young and elderly hypertensive patients [47]. |
| Alchornea cordifolia | Administration of Alchornea cordifolia leaf extract to diabetic animals significantly (p < 0.05) decreased the blood glucose level in the group treated with 200 mg/kg b w and decreased by a higher margin (p < 0.01) in animals treated with 400 and 800 mg/kg b w [83]. | Anthranilic acid, protocatechuic acid, ellagic acid [84]. | No previous report |
| Alstonia boonei | Aqueous extract of the stem bark caused about 44 % and 40 % reduction in the activities of hepatic glu-6-phosphatase and fru-1, 6-phosphatase, respectively. This was accompanied by about 30.5 % increase in glu-6-phosphate dehydrogenase [85]. | Akuammicine, echitamidine, Nα-formylechitamidine, boonein, loganin, lupeol, ursolic acid, and β-amyrin [54]. | No previous report |
| Alternanthera pungens | Treatment with 50, 200 and 300 mg kg–1 of A. pungens extract improved and restored rat serum HDL level [57]. | Glycosides, alkaloids, terpenoids, flavonoids carotenoids [57]. | No previous report |
| Anthocleista nobilis | The stem and root bark extracts significantly (p < 0.5) reduced fasting blood glucose concentration of diabetic animals [53]. | Sweroside, secoiridoid, scopoletin [53] | No previous report |
| Azadirachta indica | Aqueous extracts of neem plant showed antihyperglycemic activity in streptozotocin-induced rats and this effect was due to an increase in glucose uptake and glycogen deposition in isolated rat hemidiaphragm [86]. | Nimbidin, β-sitosterol [11] | No previous report |
| Baphia nitida | No previous report | No previous report | No previous report |
| Bryophyllum pinnatum | Both the aqueous and methanolic leaf extracts of B. pinnatum (BP, 50–800 mg/kg iv. or i.p.) produced dose related, significant (P < 0.05 - 0.001) decrease in arterial blood pressure and heart rates of anaesthetized normotensive and hypertensive rats [87]. | Oleic acid, alpha-d-Glucopyranoside [64]. | Using measured hypercapnic-hypoxic breathing training rehabilitation protocol in patients with mild essential hypertension leads to reduction of high blood pressure indexes [88]. |
| Carica papaya | The methanolic extract of C. papaya elicited angiotensin converting enzyme inhibitory activity. The antihypertensive effects elicited by the methanolic extract of C. papaya were similar to those of enalapril, and the baroreflex sensitivity was normalized in treated spontaneously hypertensive rats [89]. | flavonoids quercetin, rutin, nicotiflorin, clitorin, and manghaslin [89]. | No previous report |
| Cinnamomum zeylanicum | Acute intravenous administration of C. zeylanicum extract (5, 10 and 20 mg/kg) to l-NAME-induced hypertensive rats provoked a long-lasting decrease in blood pressure. Mean arterial blood pressure decreased by 12.5 %, 26.6 % and 30.6 % at the doses of 5, 10 and 20 mg/kg, respectively. In chronic administration, MECZ and captopril significantly prevented the increase in blood pressure and organs' weights, as well as tissue histological damages and were able to reverse the depletion in NO tissue's concentration [90]. | Cinnamaldehyde, eugenol [65] | Improves insulin potentiating activity [91]. |
| Cymbopogon citratus | A fresh leaf aqueous extract of Cymbopogon citratus administered in normal rats lowered the fasting plasma glucose and total cholesterol, triglycerides, low-density lipoproteins and very low-density lipoprotein dose dependently while raising the plasma high-density lipoprotein level in the same dose-related fashion, but with no effect on the plasma triglyceride levels [92]. | Esters, aldehyde and fatty acids [55,106] | No previous report |
| Fleurya ovalifolia | No previous report | No previous report | No previous report |
| Gomphrena celosioides | Ethanolic extract of G. celosioides (EEGC) acutely reduced Mean arterial pressure the dose of 100 mg/kg. In the 4-week assay, EEGC acted as diuretic after acute administration after 1, 2, 3 and 4 weeks of treatment. EEGC also acted as an antihypertensive and it showed significant difference already after 1 week (and after 3 and 4 weeks) compared to control, with its MAP close to pre-surgery values at the end of the experiment [93]. | Aurantiamide, aurantiamide acetate [66] | No previous report |
| Gossypium arboreum | Orally administered diethyl ether and ethanolic extracts of Gossypium arboreum significantly decreased blood glucose level [108. | Flavonoids, phenolic compounds, tannins and alkaloids [94]. | No previous report |
| Justicia secunda | Aqueous extract of J. secunda (AEJs) showed a dose dependent glucose reduction of glucose-induced hyperglycemia where a dose of 3 g/kg BW was substantially identical (P > 0.05) to that of glibenclamide at 10-2 g/kg BW. Examination of the liver-released glucose level of control normoglycemic rats and normoglycemic rats treated with AEJs and glibenclamide showed that aqueous extract of Justicia secunda and glibenclamide decreased the glucose released by the liver [58]. | polyphenols, alkaloids, saponosides and sterols and polyterpenes [58]. | No previous report |
| Khaya senegalensis | Treatment of diabetic groups withv organic fractions of K. senegalensis and and metformin in wistar albino rats showed significant decrease in fasting blood glucose (FBS), ameliorated hepatic and renal damages by decreasing the level of AST, ALT, ALP, Urea and creatinine compared to untreated diabetic rats and stimulated insulin secretion by β cells [95]. | methyl 6-ethyl-7-hydroxy-7,8-dihydrophenanthrene-2-carboxylate [95]. | No previous report |
| Kigelia africana | Significant lowering of the blood glucose levels was also expressed in mice following the administration of 50, 100, 200, and 300 mg/kg body weight of K africana [60]. | phenols, flavonoids, alkaloids, tannins, terpenoids, saponins [60]. | No previous report |
| Lantana camara | Ethanolic extract of Lantana camara leaves reduced workload of heart, maintained isotonic levels by negative chronotropic effect, relaxed the smooth muscles in chick and salt hypertensive rats against renal and vascular injuries [96]. | Glycosides, Saponins, Tannins, Flavonoids, Terpenoids and Steroids [96]. | No previous report |
| Luffa cylindrica | No previous report | No previous report | No previous report |
| Mangifera indica | M. indica leaf extract significantly inhibited alpha-amylase activity in a dose-dependent manner. The inhibitory effect was observed up to (51.4 ± 2.7 %) at a concentration of 200 μg/mL [97]. | Mangiferin [98] | No previous report |
| Momordica charantia | M. charantia improved glucose tolerance and suppressed postprandial hyperglycemia in rats [12]. | Charantin, momordicin, oleanolic acid, vicine [13]. | Hypoglycemic effect in only diabetic patients [99,100] |
| Morinda citrifolia | Aqueous extract of M. citrifolia significantly inhibited rat lens aldose reductase (RLAR) activities and improved free radical scavenging activities in vitro as compared to ethanolic and chloroform extracts thereby indicating a potential to inhibit cataract formation and prevent diabetic complications [101]. | Lucidin, morindone [102]. | No previous report |
| Morinda lucida | Administration of aqueous and methanolic extract of M. lucida significantly (p < 0.05) reduced fasting blood glucose of diabetic animals by 73.5 and 39.0 % of their initial values, respectively [103]. | Steroids, anthraquinone Oleanic acid [104]. | No previous report |
| Moringa oleifera | Ethanolic extract of M. oleifera leaves showed a blood pressure lowering effect in rats, mediated possibly through a calcium antagonist effect [105]. M. oleifera extract showed significant decrease in malonaldehyde and improvements in the inflammatory cytokines (TNF-α and IL-6) compared to control animals in STZ-induced diabetic rats fed with equivalent of 250 mg/kg of MO for 6 weeks [106]. | Nitrile, mustard oil glycosides, thiocarbamate glycosides [105]; quercetin [107], chlorogenic Acid [108], and isothiocyanates [109]. | No previous report |
| Musa paradisiaca | M. paradisiaca extracts inhibited angiotensin-I converting enzyme (ACE) activity in a dose-dependent manner (0–25 μg/ml). Unripe plantain peel (UPP) extract showed had a stronger inhibition (IC50 = 14.93 μg/ml) of ACE activity than over ripe plantain peel (OPP) and ripe plantain peel (RPP) extracts (IC50s of 21.80 μg/ml and 21.32 μg/ml, respectively [110]. | cardiac glycosides, terpenes, deoxy sugar [67]. | No previous report |
| Musa sapientum | Forty-five-day treatment with M. sapientum L extract significantly reduced the fasting blood glucose and the concentration of HbA1c in diabetic rats [111]. | Gallocatechin [112] | No previous report |
| Ocimum gratissimum | O. gratissimum leaf extract at a dose of 200 mg/kg bw decreased the blood glucose of diabetic rats by 20.9 %, at 4 h whereas 250 mg/kg bw was able to decrease the blood glucose of diabetic rats by 29.3 % at 4 h [113]. | Steroids, terpenoids, flavonoids and cardiac glycosides [114]. | No previous report |
| Paullinia pinnata | P. pinnata extract (50 mg/kg) and glibenclamide (2 mg/kg) produced a significant (p < 0.05) oral glucose tolerance effect in both normoglycemic and diabetic rats. The extract produced concentration-dependent increase in antioxidant activity and had its optimum effect at 400 μ μg/mL concentration [59]. | Alkaloids, flavonoids, glycosides, tannins, saponins and terpenes/sterols [59]. | No previous report |
| Persea americana | The hydroalcoholic extract of the leaves of Persea americana reduced blood glucose levels and improved the metabolic state of treated animals. Additionally, PKB activation was observed in the liver and skeletal muscle of treated rats when compared with untreated rats [69]. | p-coumaric acid, quercetin and epicatechin [115]. | No previous report |
| Psidium guajava | Significant blood glucose lowering effects of P. guajava extract were observed after intraperitoneal injection of the extract at a dose of 10 mg/kg in both 1- and 3-month-old Lepr (db)/Lepr(db) mice [116]. | Strictinin, isostrictinin, pedunculagin [117]. | No previous report |
| Rauvolfia vomitoria | At 500, 700 and 1000 mg/kg ethyl acetate of R. vomitoria caused a reduction of blood glucose level of treated normoglycemic rats similar to glibenclamide at 10 mg/kg [61]. | Alkaloids (eg. reserpine), flavonoids, and anthrones, anthraquinones, catechin tannins, saponins and monoterpenoids [61]. | No previous report |
| Rosmarinus officinalis | Rosmarinus officinalis extract on blood glucose and serum insulin levels was studied in alloxan-induced diabetic rabbits. Of the three doses of extract, the highest dose (200 mg/kg) significantly lowered blood glucose level and increased serum insulin concentration in alloxan-diabetic rabbits [70]. | Ursolic acid [118]. | Both blood pressure variables of SBP and DBP reflect the clinically significant anti hypotensive effect of Rosemary essential oil that was maintained throughout the treatment period. After validation of the use of the questionnaire (Cronbach's alpha coefficient 40.82), statistically significant differences have been found between pretreatment and post-treatment values of PSC and MSC, which indicate an improvement in these parameters that is directly related to the variation in blood pressure values [119]. |
| Senna alata | The α-glucosidase inhibitory effect of the crude extract of S. alata was far better than the standard clinically used drug, acarbose (IC (50), 107.31 ± 12.31 μg/ml) [120]. | Kaempferol, kaempferol 3-O-gentiobioside [121]. | No previous report |
| Strophanthus hispidus | There was a protective effect in the case of mean arterial blood pressure where, the 500 mg/Kg and 1000 mg/Kg of the plant extract did reduce the hypertension, 60.0 ± 4.80 and 50.50 ± 6.80, respectively [71]. | Alkaloids, flavonoids, saponins, and cardiac and cyanogenic glycosides [122]. | No previous report |
| Tapinanthus banguwensis | It is the first time it being mention for the treatment of hypertension | No previous report | |
| Launaea taraxacifolia | Results showed that one-off oral administration of L. taraxifolia leaf and L. taraxifolia root significantly (p < 0.05) reduced systolic, diastolic and mean arterial blood pressure. In a sub-chronic study L. taraxifolia leaves extract significantly (p < 0.05) prevented an increase in blood pressure throughout the period of treatment [72]. | Saponins, flavonoids, alkaloids, phenols, triterpenoid [123] | No previous report |
| Tetrapleura tetraptera | Polyphenol-rich hydroethanolic extract of Tetrapleura tetraptera (HET) reduced weight gain, fasting blood glucose and plasma insulin levels as well as homeostasis model assessment of insulin resistance (HOMA-IR) and alleviated obesity and T2DM associated oxidative stress and hypertension in rats [73]. | Hytate, triterpenoid, coumarinic (scopoletin), triterpene glycoside [124]. | No previous report |
| Trema orientale | Aqueous stem bark extract of T. orientalis was reported to have hypoglycemic effects in induced diabetic rats by mechanism different from that of sulfonylurea agents [125]. | Flavonoids, phenolic acids [126]. | No previous report |
| Vernonia amygdalina | The aqueous extract of the leaves of V. amygdalina caused a significant reduction in blood glucose levels of extract only, and allocan plus extract treated animals [127]. | Flavonoids, tannins, saponins, and triterpenoids [128]. | No previous report |
| Xylopia aethiopica | The anti-diabetic effect of Xylopia aethiopica has also been studied. A chloroformic extract of the dried fruits of Xylopia aethiopica administered orally at a dose of 250 mg/kg showed an 82 % reduction in the blood glucose concentration of alloxan monohydrate induced diabetic Wistar albino rats while diabetic non-treated rats and glibenclamide treated rats showed a 6.9 % and 74 % reduction respectively [74]. | Methyl ester, 12-octadecanoic acid, hexadecanoic acid [129]. | No previous report |
| Zanthoxylum zanthoxyloides | Z. zanthoxyloides significantly (p < 0.05) lowered blood glucose in treated animals compared to non-treated groups. Total cholesterol and LDL were significantly lower in Z. zanthoxyloides treated groups, with lowest values found in groups treated with higher concentration. It was also observed that LDH, ALP and ALT showed highest activities at 15 % of Z. zanthoxyloide feed with AST activity lowest at the highest concentration of the feed [122]. | No previous report | No previous report |
| Zingiber officinale | 50 mg/kg/day p.o administration of the petroleum ether and 10 mg/kg/day p.o of toluene fraction reduced the blood pressure in unilateral nephrectomized DOCA salt and fructose-induced hypertensive rats [130]. | Gingerol [131] | Increase insulin receptors and enhanceβ-cell function to decrease insulin resistance of diabetic patients [75]. |