Table 2.
Effects of microalgae in animal studies.
| Reference Numbers | Animal Model | Microalgae and Doses | Experimental Design | Effects | Mechanisms |
|---|---|---|---|---|---|
| [9] | Male ICR mice (4 weeks old) |
Spirulina maxima extract (SM70EE; 150 and 450 mg/kg BW/day) 6 weeks |
HFD: high-fat diet (60% of energy from fat) SM150: HFD + SM70EE 150 mg/kg BW/day SM450: HFD + SM70EE 450 mg/kg BW/day |
SM450 group: ↑ Serum HDL-c SM150 and SM450 groups: ↓ Final body weight ↓ Body weight gain ↓ Subcutaneous and abdominal WAT ↓ Serum TG, TC, LDL-c and glucose levels ↓ Adipogenesis in WAT |
SM450 group: ↑ pAMPK, PRDM16 and PGC1α protein expression in WAT ↑ UCP1 protein expression in BAT SM150 and SM450 groups: ↓ C/EBPα, PPARγ, and aP2 protein expression in WAT ↑ UCP1 protein expression in WAT ↑ PRDM16 protein expression in BAT |
| [13] | Male Sprague-Dawley rats (5 weeks old) |
Spirulina maxima (62.5, 125, and 250 mg/kg BW/day) 4 weeks |
LFD: low-fat diet (10% of energy from fat) HFD: high-fat diet (60% of energy from fat) SM 62.5: HFD + 62.5 mg/kg BW/day SM 125: HFD + 125 mg/kg BW/day SM 250: HFD + 250 mg/kg BW/day of |
SM 62.5, 125, and 250 SM groups: ↓ Epididymal adipocyte size ↑ Brown adipose tissue index ↑ Serum adiponectin ↓ Serum TNF-α ↓ HOMA-IR ↑ Serum HDL-c/TC ↓ Serum ALT SM 125 and SM 250 groups: ↓ Body weight gain ↑ Brown adipose tissue ↓ Serum leptin ↓ Serum insulin ↓ Serum TC SM 250 group: ↓ Epididymal adipose tissue index ↓ Serum glucose |
SM 125 and SM 250 groups: ↓ FAS protein expression (epididymal AT) ↓ Fasn gene expression (epididymal AT) ↑ AdipoR gene expression (epididymal AT) ↑ pAMPK protein expression (epididymal AT and skeletal muscle) ↑ AdipoR1, Cpt1 and Ucp2 gene expression (skeletal muscle) ↓ Srebf1 and Nfκβ gene expression (epididymal AT) SM 250 group: ↑ Atgl and Cpt1 gene expression (epididymal AT) The dose is not specified: ↑ pACC, AdipoR1, NAMPT, and SIRT1 protein expression (epididymal AT) ↓ SREBP1 and FAS protein expression (epididymal AT) ↑ AdipoR1, NAMPT and SIRT1 protein expression (skeletal muscle) |
| [11] | Male C75BL/6J mice (6–8 weeks old) |
Phaeodactylum tricornutum (PE) extract (100 and 300 mg/kg BW/day) 26 days |
HFD: high-fat diet 45% of energy from fat) PE100: HFD + PE 100 mg/kg BW/day PE300: HFD + PE 300 mg/kg BW/day |
PE300 group: ↓ Final body weight ↓ Total body fat mass ↓ Epididymal and inguinal tissue ↓ Adiposity index ↑ Energy expenditure PE100 and PE300 group: ↑ % of small adipocytes in inguinal WAT |
PE100 group: ↑ Cd36 and Ppargc1a gene expression in BAT PE300 group: ↓ Lipe, Plin1, and Lpl gene expression in epididymal WAT ↑ Ucp1 and Cpt gene expression in inguinal WAT ↑ BAT activation PE100 and PE300 group: ↓ Lipe and Fasn gene expression in BAT ↑ UCP1 protein expression in BAT |
| [10] | Female C57BL/6J mice (8 weeks old) |
Phaeodactylum tricornutum (PE) extract (0.81, 1.62, and 3.25 mg/kg BW/day) 6 weeks |
HFD: High-fat diet PE-L: HFD + PE 0.81 mg/kg BW/day PE-M: HFD + PE 1.62 mg/kg BW/day PE-H: HFD + PE 3.25 mg/kg BW/day |
PE-H group: ↓ Plasma LDL-c PE-M group: ↓ Plasma TG PE-M and PE-H groups: ↓ Subcutaneous fat volume PE-L, PE-M and PE-H groups: ↓ Body weight gain ↓ inguinal fat depots ↓ Total and abdominal fat volume |
PE-H group: ↓ C/EBPα protein expression in WAT PE-M and PE-H groups: ↑ UCP1 protein expression in WAT PE-L, PE-M, and PE-H groups: PPARγ protein expression in WAT |
| [14] | Male C57BL/6J mice (10 weeks old) |
Euglena gracilis extract (1%) 8 weeks |
Standard diet Standard diet + Euglena gracilis extract |
↓ Total, perinephric, and epididymal adipose tissue | ↑Lipe gene expression in epididymal WAT |
| [15] | Male C57BL/6J mice (10 weeks old) |
Nitzschia laevis extract (10 or 50 mg/kg BW/day) 8 weeks |
HFD (24% of energy from fat) HFD+ 10 mg/kg BW/day of Nitzschia laevis extract HFD+ 50 mg/kg BW/day of Nitzschia laevis extract |
50 mg/kg BW/day: ↓ Body weight ↓ Liver weight and lipid accumulation Improved gut epithelium integrity 10 and 50 mg/kg BW/day: ↓ Epididymal adipose tissue weight and adipocyte diameter ↑ BAT adipocyte number Improved gut microbiota richness and diversity ↑ Firmicutes/Bacteroidetes ratio |
10 mg/kg BW/day: ↑ Pgc-1α gene expression in BAT 50 mg/kg BW/day: ↑ Occludin gene expression 10 and 50 mg/kg BW/day: ↑ Ucp1 gene expression in BAT |
Special note: Doted lines incorporated for separation between different studies. ACC: Acetyl-CoA carboxylase, AdipoR1: adiponectin receptor 1, ALT: alanine aminotransferase, AMPK: AMP-activated protein kinase, AP2: fatty acid binding protein, AT: adipose tissue, ATGL: adipose triglyceride lipase, BAT: brown adipose tissue, BW: body weight, CD36: cluster of differentiation 36, C/EBPα: CCAAT-enhancer-binding protein α, CPT: carnitine palmitoyltransferase, FAS: fatty acid synthase, Fasn: fatty acid synthase (gene), HDL-c: high-density lipoprotein cholesterol, HFD: high-fat diet, HOMA-IR: Homeostatic Model Assessment of Insulin Resistance, ICR: Institute of Cancer Research, IR: insulin resistance, LDL-c: low-density lipoprotein cholesterol, LIPE: hormone sensitive lipase, LPL: lipoprotein lipase, NAMPT: nicotinamide phosphoribosyltransferase, NFκB: nuclear factor kB, PGC-1α: peroxisome proliferator-activated receptor gamma co-activator 1α, PLIN1: perilipin 1, PPARγ: peroxisome proliferator activated receptor γ, PPARGC1a: PPARG coactivator 1 alpha, PRDM16: PR domain-containing16, SIRT1: sirtuin 1, SREBP1: sterol regulatory element-binding protein 1, TC: total cholesterol, TG: triglycerides, TNF-α: tumor necrosis factor α, UCP1: uncoupling protein 1, WAT: white adipose tissue. ↑ significant increase, ↓: significant decrease.