Metabolic syndrome (MetS) is a cluster of metabolic disturbances, including abdominal obesity, hypertension, hypertriglyceridemia, reduced high-density lipoprotein cholesterol (HDL-C) and hyperglycemia. Adopting a healthier lifestyle and multiple drug-based therapies are current ways to manage MetS, but they have limited efficacy, albeit the prevalence of MetS is rising. Microalgae is a part of the human diet and has also been consumed as a health supplement to improve insulin sensitivity, inflammation, and several components of MetS.
Experiment | Cell Model | Microalgae and Doses | Experimental Groups | Effects | Mechanisms | Reference Number |
---|---|---|---|---|---|---|
Dose-response analysis | COS-1 cells | 0.1% Chaetoceros karianus-derived (7E)-9-OHE or (10E)-9-OHE for 18 h | (1) Positive controls: rosiglitazone or pirinixic acid (2) (7E)-9-OHE or (10E)-9-OHE (3) Negative control: palmitic acid |
(7E)-9-OHE or (10E)-9-OHE: Exhibits PPARα/γ agonist activity |
- | [22] |
Endogenous PPAR target genes activation analysis | Huh7 cells SGBS pre-adipocyte cells |
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(1) DMSO (negative controls) (2) 25 µM (7E)-9-OHE or (10E)-9-OHE (3) 50 µM (7E)-9-OHE or (10E)-9-OHE (4) pirinxic acid (positive control) |
25 or 50 µM of (7E)-9-OHE or (10E)-9-OHE: Fatty acid catabolism is activated in Huh-7 and SGBS cells | Huh-7: (7E)-9-OHE: ↑ ACSL3 gene expression (10E)-9-OHE: ↑ PLIN1 gene expression (7E)-9-OHE or (10E)-9-OHE: ↑ CPT1A and ANGPTL4 gene expressions SGBS: (10E)-9-OHE: ↑ ANGPTL4 gene expression (7E)-9-OHE or (10E)-9-OHE: ↑ CPT1A gene expression |
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Adipocyte differentiation analysis | SGBS pre-adipocyte cells | 25 µM of (7E)-9- OHE or (10E)-9-OHE for 12 days | (1) (7E)-9-OHE or (10E)-9-OHE (2) rosiglitazone (positive control) |
Improvement in the regulation of fatty acid metabolism, transport, storage, adipokine signaling and browning | ↑ PPARG, CEBPA, CEBPB, PLIN1, FABP4, CD36, SCD1 and UCP1 expressions | |
Adipocyte transcriptomics | SGBS pre-adipocyte cells | 25 µM of (7E)-9-OHE or (10E)-9-OHE for 8 days | (1) (7E)-9-OHE or (10E)-9-OHE (2) rosiglitazone (positive control) |
↓ Inflammatory cytokines ↑ Insulin-sensitive adipokines |
↓ IL-6, TNFα, CXCL1, CXCL5 and IL-1B gene expressions ↑ Leptin and insulin sensitizing ADIPOQ genes expressions |
Animal Model | Microalgae and Doses | Experimental Design | Effects on MetS | Mechanisms | Reference Number |
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Male Sprague Dawley rat (7 weeks old) |
Tetraselmis chuii powder (0.17, 1.7, 17 mg/kg BW/d) 8 weeks |
STD-C: Standard diet-control CAF-C: Cafeteria diet- control CAF + 0.17: CAF + 0.17 mg/kg BW/day of T. chuii powder CAF + 1.7: CAF + 1.7 mg/kg BW/day of T. chuii powder CAF + 17: CAF + 17 mg/kg BW/day of T. chuii powder |
CAF + 0.17: ↓ plasma LDL/VLDL-C CAF + 17: ↓ Plasma glucose CAF + 0.17, CAF + 1.7 and CAF + 17: No effects on BW, adiposity index, TG, HOMA-IR index, and HDL-C. |
CAF + 0.17: ↑ plasma NOx ↑ GPx activity in liver CAF + 0.17 and CAF + 1.7: ↑ SOD 1 and SOD2 gene expression in liverCAF + 1.7 and CAF + 17: ↑ GPX1 gene expression in liver ↑ GCLm gene expression in liver CAF + 17: ↓ oxLDL levels in plasma ↑ IL-10 levels in plasma ↑ GSH level in liver ↑ SOD1 gene expression in liver ↑ IL-10 gene expression in MWAT ↑ FOXP3 gene expression in spleen CAF + 0.17, CAF + 1.7 and CAF + 17: ↑ GR and GSH-S gene expressions in liver ↑ SOD1 gene expression in liver ↓HMOX1, TGFβ1 and NFκB1 gene expressions in liver ↓ IL-1β, TNFα and IFNG gene expressions in MWAT ↓ IL-1β agene in thymus and spleen ↓ IFNG gene expressions in MWAT, thymus and spleen ↑ ACDC gene expression in MWAT ↓ TNFα, NRF2, HMOX1, NFκB1, IL-1β and IFNG gene expressions in thymus ↑ IL-10 gene expression in thymus and spleen |
[43] |
Female Sus scrofa pigs(5.6 ± 0.8 months old) | Arthrospira platensis (spirulina, Sp) (20 g/d) tablet 25 weeks |
CTR−: Control diet CTR+: Control diet + Sp tablet WES−: Western diet WES+: Western diet + Sp tablet |
CTR+ and WES+: No effects on BW No effects on visceral adipose tissue proportion No effects on plasma TG No effects on plasma TC ↓ Serum glucose (at late gestation) |
CTR+: ↓ ALT levels ↓ Hepatic necrosis gene expression WES+: ↑ Hepatic lipid accumulation gene expression ↓ Hepatic carbohydrate accumulation gene expression ↑ ALT levels ↑ Hepatic necrosis gene expression CTR+ and WES+: ↓ Plasma insulin levels (at slaughter) ↓ Muscular weight gain gene expression ↓ Liver weight ↓ IR gene expression in liver |
[44] |
Male Wistar rat (3 weeks old) |
Diacronema lutheri powder (12%) 8 weeks |
CTRL: Control diet HF: High fat diet HF-Dia: High fat + D. lutheri powder |
HF-Dia: ↓ BW ↓ AAT and EAT weight/BW ratio ↓ Plasma TG levels ↑ HDL levels ↓ HOMA-IR index Improvement in GT & IT No effects on plasma glucose levels |
HF-Dia: ↓ Plasma insulin levels ↓ AIP ↑ Plasma IL-4 levels ↑ Adipose IL-10 levels ↓ Leptin ↓ TG in liver ↓ TC in liver ↑ ALT ratio |
[45] |
Male Wistar rat (8–9 weeks old) |
Nannochloropsis oceanica powder (5%) 8 weeks |
C: Corn starch diet for 16 weeks H: High-carbohydrate, high-fat diet for 16 weeks CN: Corn starch diet for the first 8 weeks + 5% N. oceanica powder for the last 8 weeksHN: High-carbohydrate, high-fat diet for first the 8 weeks + 5% N. oceanica powder for the last 8 weeks |
HN: ↓ Total abdominal fat and retroperitoneal fat No effects on BW CN and HN groups: No effects on visceral adiposity % No effects on plasma TG No effects on plasma TCNo improvement in GT & IT No effects on systolic BP |
HN: ↓ Hepatic fat vacuole size CN and HN groups: ↑ Abundance of Oxyphotobacteria |
[46] |
Male Wistar rat (3 weeks old) |
Tisochrysis lutea powder (12%) 8 weeks |
CTRL: Standard diet HF: 260 High fat diet with 10% fructose in drinking water HF-Tiso: HF diet + T. lutea powder |
HF-Tiso: ↓ BW ↓ AAT and EAT weight/ BW ratio ↓ Plasma TG ↑ Plasma HDL-C ↓ Plasma LDL-C ↓ Plasma glucose ↓ HOMA-IR index |
HF-Tiso: ↓ Plasma insulin ↓ Plasma TNF-α ↑ Adipose tissue anti-inflammatory IL-10 ↓ AIP ↓ Serum LPS ↓ Leptin ↓ TG in liver ↓ TC in liver |
[6] |
Mixed sex and breed of horse (treatment group is 13.2 ± 4.4 years old and control group is 11.5 ± 2.6 years old) |
DHA-rich microalgae (110 g/horse/d) 46 days |
Control horses Treated horses |
Treated horses: No effects on BW No effect on cresty neck score ↓ Plasma TG No effects on glucose tolerance |
↑ Plasma DHA ↓ TNF-α MFI |
[47] |
Male Wistar rat (3 weeks old) |
Phaeodactylum tricornutum powder (12%) 8 weeks |
CTRL: Control group fed with standard diet HF: 260 High fat diet with 10% fructose in drinking water HF-Phaeo: HF diet + P. tricornutum powder |
HF-Phaeo: ↓ BW ↓ AAT and EAT weight/ BW ratio ↓ Plasma TC ↓ Plasma TG ↑ Serum HDL-C ↓ HOMA-IR index No effects on plasma glucose |
HF-Phaeo: ↓ Plasma insulin ↑ n-3 LC-PUFA levels in plasma, RBC, and liver lipids ↑ ∆9-Desaturase level in liver lipids ↓ Liver weight/ BW ratio ↓ MUFA levels in plasma lipid and liver phospholipids ↓ TG in liver ↓ TC in liver ↓ AIP ↓ Plasma TNF-α and IL-6 ↑ Plasma IL-4 and IL-10 ↓ Plasma leptin |
[10] |
Sprague Dawley rat(8 weeks old) | Coccomyxa gloeobotrydiformis (CGD) (100 mg/kg BW/d) 12 weeks |
Control: Standard chow diet NC: High-energy diet without MetS MS: High-energy diet with MetS MS+CGD: High-energy diet with MetS + CDG MS + CVD: High-energy diet with MetS and CVD MS + CVD + CGD: High-energy diet with MetS and CVD + CGD |
MS + CGD: ↓ BW ↓ AC ↓ Serum glucose level ↓ SBP ↓ Serum TG and LDL-C levels ↑ Serum HDL-C levels MS + CVD + CGD: ↑ Left ventricular systolic and end diastolic pressure, and left ventricular systolic pressure maximum increase rate and diastolic pressure maximum decrease rate |
MS + CGD: ↑ AMPK and PGC-1α gene expressions in heart, adipose and skeletal muscle tissues ↑ MRC coenzymes (ATPase 6, cytochrome b and SDHA) gene expressions in the liver, heart and skeletal muscle ↓ UCP2 gene expression MS + CVD + CGD: ↓ Pro-inflammatory TNF-α and MDA gene expressions in myocardial tissue ↑ SOD gene expression in myocardial tissue ↑ Bcl-2 gene expression ↓ Bax gene and cleaved caspase-3 gene expressions were decreased ↑ TMOD1 gene expression |
[48] |
This entry is adapted from the peer-reviewed paper 10.3390/antiox12020449