TABLE 2.

The anti-obesity effect of carotenoids.

Compounds	Source	Effects	Mechanism	References
(all-E)- and (5Z)- lycopene 52 μM for 24 h)	Fruits and vegetables	In 3T3-L1 cells, reduced TNFα induced Il-6, MCP-1 mRNA expression Restored the TNFα-blunted uptake of glucose	Transactivated PPARγ and reduce the NF-κB signaling pathway Modulated AKT phosphorylation	(135)
apo-10’-lycopenoic acid (2 μM for 24 h)	Tomato	Prevented inflammation Modulated the transcriptome of 3T3-L1 adipocytes as ATRA Decreased TNFα, IL-6 and IL-1β	Transactivated RAR in vivo, in vitro and modulated transcription of its target genes in adipose tissue	(136)
Astaxanthin (6 or 30 mg/kg body weight) for 8 weeks	Salamon	Reduced hepatic lipogenesis and inflammation, reduced TNF-α and IL-6 in HFD C57BL/6J mice	Activated PPARα and inhibited PPARγ and Akt activity thus decreased SREBP1phosphorylation	(137)
β-cryptoxanthin (provitamin A) 10 mg/kg diet	Paprika	Inhibited the lipogenesis and cholesterol biosynthesis in the liver of BCO1-/BCO2- mice	Upregulated the SIRT1/AMPK pathway Decreased IL6 gene expression	(138)
β-cryptoxanthin 0.05% for 12 weeks	Mandarin oranges	Suppressed body weight gain and mediated thermogenesis in HFD C57BL/6J mice	Induced UCP1 expression in beige adipocytes via the RAR pathway	(139)
Fucoxanthin	Hincksia mitchellae (Harvey) P. C. Silva brown algae	Reduced adipose mass, increased metabolic rate in a high sucrose or a HFD mice	Increased energy expenditure via the upregulation of PGC-1α gene expression	(140)

AKT, protein kinase B; AMPK, adenosine mono phosphate-activated protein kinase; ATRA, All-trans retinoic acid; BCO, β-carotene oxygenase; HFD, high fat diet; IL-6, interleukin-6; MCP1, monocyte chemoattractant protein-1; NBCs, natural bioactive compounds; NF-κB, nuclear factor kappa-B; PGC-1, Peroxisome proliferator-activated receptor-gamma coactivator 1; PPARγ, peroxisome proliferator-activated receptor γ; RA, retinoic acid; RAR, retinoic acid receptors; TNF-α, tumor necrosis factor-alpha; UCP, uncoupling protein.