TABLE 3.

Recent studies using metabolomics and lipidomic techniques highlighting the beneficial role of carotenoids and their potential impact on relevant health outcomes

Study [reference] and main findings	Model	Technique	Design (approach)	Carotenoid	Dosage (duration)	Tissue	Disease state
In vivo animal studies
Ameliorative effect of spinach on nonalcoholic fatty liver disease induced in rats by a high-fat diet [95]	Sprague-Dawley rats (n=44)	LC-MS	6 groups: -1st group: NC (standard diet, n=6) -2nd group: N2.5 (standard diet + 2.5% spinach, n=8) -3rd group: N5 (standard diet + 5% spinach, n=8) -4th group: HC (high-fat diet, n=6) -5th group: H2.5 (high-fat diet + 2.5% spinach, n=8) -6th group: H5 (high-fat diet + 5% spinach, n=8) (Untargeted)	Spinach powder (1750 μg total carotenoid/g of spinach powder) : 228 μg neoxanthin/g 292 μg violaxanthin/g, 944 μg lutein/g 46 μg α-carotene/g 225 μg β-carotene/g	5% spinach in diet = 53–56 μg of total carotenoids/d (5 wk) 2.5% spinach in diet = 20–24 μg of total carotenoids/d (5 wk)	Liver	Nonalcoholic fatty liver disease
Findings	Consumption of spinach powder and the accumulation of carotenoids in the liver: ↓ SAFA, ↓ ω-6/ω-3 fatty acid ratio, ↓ cholesterol, ↑ MUFA and PUFA
Lycopene and tomato powder supplementation similarly inhibit high-fat diet induced obesity, inflammatory response, and associated metabolic disorders [93]	Male C57BL/6J mice (n=40)	Enzymatic and colorimetric methods	4 groups (n=10/group) -1st group: Control diet -2nd group: high fat diet (HFD 45% fat) -3rd group: HFD + lycopene -4th group: HFD + tomato powder (TP) (Targeted)	Lycopene and TP (lycopene 214 mg/kg of dry TP)	10 mg/kg diet/d (12 wk)	Liver/ epididymal adipose tissue	Inflammation, obesity
Findings	Lycopene and TP supplementation: ↓ serum TAG, ↓ FFA, ↓ 8-iso-prostaglandin GF2α, ↓ NEFA, ↑ glucose homeostasis
Torularhodin alleviates hepatic dyslipidemia and inflammations in high-fat diet-induced obese mice via PPARα signaling pathway [153]	Male C57BL/6J mice	LC-MS	3 groups (n=10/group): -1st group: control -2nd group: HFD (45% high fat diet) -3rd group: HFD-Torularhodin (Untargeted)	Torularhodin	40 mg/kg diet/d (12 wk)	Liver/ adipose tissue	Hepatic dyslipidemia and obesity
Findings	Torularhodin modulates phenotype parameters: ↓ TG, ↓ TC, ↓ LDL, ↓ LPS, ↓ body weight, ↑ HDL
Oral lycopene administration attenuates inflammation and oxidative stress by regulating plasma lipids in rats with lipopolysaccharide-induced epididymitis [249]	Sprague-Dawley rats (n=31)	LC-MS, hybrid quadrupole orbitrap	Four groups: -Control (n=10) -Oil-control (n=10, 5 mL/kg diet/d) Single intraperitoneal injection of lipopolysaccharide in 0.9% sodium chloride, n=5 Continuous intragastric lycopene in oil, n=6 (Untargeted)	Lycopene	5 mg/kg bw/d (4 wk)	Plasma; Cauda epididymis (male reproductive system)	Epididymitis
Findings	Lycopene: ↑ PC, ↓ TAG, ↓ DAG, ↓ phosphatidylethanolamine
Integrated metabolomics, lipidomics, and genomics reveal the presence of a new biomarker, butanediol glucuronide, associated with the activation of liver ketogenesis and lipid oxidation by tomato-based sofrito in obese rats [250].	Obese Zucker rats	LC-HRMS	4 groups (n=5/group): 1st group: lean rats fed chow diet 2nd group: obese rats fed control chow diet 3rd group: lean rats fed chow diet + sofrito 4th group: obese rats fed chow diet + sofrito (Untargeted)	Sofrito (a tomato and olive oil based sauce with high content of carotenoids)	2% w/w supplemented chow diet ad libitum (8 wk)	Adipose tissue, epididymal and visceral	Obesity
Findings	In groups supplemented with sofrito: ↑ expression of esterification enzymes mediating the synthesis of TG from DG, DGAT1 and DGAT2, ↑ expression of CPT1A and PRDM16, ↑ expression of HMGCoA and PKL
Orally administered crocin protects against cerebral ischemia/reperfusion injury through the metabolic transformation of crocetin by gut microbiota [251]	Male specific-pathogen-free Sprague-Dawley rats	GC-MS	2 sham-operated groups and 2 model-operated groups were separately: Intravenous administration: Positive control group: Edaravone Injection (3 mg/kg bw). Model group: Crocin (1 mg/kg bw) Oral administration: Positive control group: free access to food and water. Model group: Crocin (60 mg/kg bw) (Untargeted)	Crocetin	Intravenous administration: 1 mg/kg bw or 60 mg/kg bw (2 h after the onset of ischemia) Oral administration prior to and on the same day of the MCAO procedure (4 d)	Rat transient middle cerebral artery occlusion (MCAO) model	Cerebral ischemic/reperfusion (I/R) injury
Findings	Gut flora plays a key role in the transformation of crocin into crocetin and is the potential target for the cerebral-protection of crocin in MCAO model rats Oral administration of crocin ameliorated the dysfunctional metabolism of the brain to normal status: ↑ MCAO-protective effects than intravenous administration, ↑ concentration of GABA
In vivo human studies
Associations between circulating lipids and fat-soluble vitamins and carotenoids in healthy overweight and obese men [16]	Overweight and obese men with low-grade inflammation (n=35)	LC-MS Linear Trap Quadrupole	Data from the placebo arm of a randomized, double-blind, placebo-controlled, 5-wk intervention trial (Untargeted)	α-Carotene, β-carotene, β-cryptoxanthin, and lycopene	Plasma lycopene 0.62 μM, plasma α-carotene 0.06 μM, plasma β-carotene 0.4 μM, plasma β-cryptoxanthin 0.22 μM (5 wk)	Plasma	Inflammation, obesity
Findings	Interindividual variability in circulating lycopene was explained by low-abundant TGs with 40–52 carbons => lycopene was inversely related to low-abundant TGs. Interindividual variability in circulating of other carotenoids (α-carotene, β-carotene, and β-cryptoxanthin) was not explained by the evaluation of lipids
A multi-omic analysis for low bone mineral density in postmenopausal women suggests a relationship between diet, metabolites, and microbiota [213]	Postmenopausal women (n=92) (≥45 y old, postmenopausal status (12 consecutive months without menstruation)	Electrospray tandem MS	Postmenopausal women classified into: -Normal bone mineral density (normal-BMD, n=34) -Low-BMD (n=58) (Untargeted)	Lycopene from diet	Data and samples collected from [252]	Serum; gut microbiota	Bone mineral density
Findings	The low-BMD group had fewer observed species, higher abundance of γ-Proteobacteria, lower consumption of lycopene, and lower concentrations of leucine, valine, and tyrosine compared with the normal-BMD group. Leucine, valine, and tyrosine correlated positively with the abundance of Bacteroides.

Abbreviations: bw, body weight; CPT1A, carnitine palmitoyltransferase 1A; DAG, diacylglycerol; FFA, free fatty acid; DGAT1/2, diglyceride acyltransferase 1/2; GABA, γ-aminobutyric acud; HMGCoA, (3S)-hydroxy-3-methylglutaryl-CoA; HRMS, high-resolution mass spectrometry; LC, liquid chromatography; LPS, lipopolysaccharide; MS, mass spectrometry; NEFA, non-esterified fatty acids; PC, phosphatidylcholine; PE, phosphatidylethanolamine; PKL, liver-type pyruvate kinase; PRDM16, positive regulatory domain containing 16; SAFA, saturated fatty acid; TAG, triacylglycerol; TC, total cholesterol; TG, triglyceride; UPLC, ultra-performance liquid chromatography.