Unripe Citrus unshiu peel inhibited pre-adipocyte’s differentiation via leptin-PPARγ/FAS pathway and pro-inflammatory cytokines’ release

[Display omitted] •Unripe 30% ethanol extract of C. unshiu peels effectively inhibited pre-adipocyte’s differentiation via PPARγ-C/EBPα pathway.•C. unshiu peels suppressed not only obesity but also inflammation in high fat-induced model through the control of LDL and leptin, the inhibition of fat accumulation, the modulation of PPARγ-C/EBPα-FAS, and the downregulation of inflammatory cytokines such as IL-1β, IL-13, and TNF-α.•The active compounds in C. unshiu peels for anti-obese function were confirmed narirutin and hesperidin and when it will be industrialized they can be used as important constituents for products’ standardization.•In East-Northern Asia C. unshiu peels have been used as culinary material for making tea and then the tea which is made of C. unshiu peels can make the obese to be controlled. By 2030 the obese is prospected 20% of female and 14% of male and obesity induces many diseases. The active compounds in unripe C. unshiu peels were defined and anti-obesity effect was evaluated using with 3T3-L1 cell and high-fat diet mouse. In cell study the anti-obesity effect was analyzed using with oil red O stain and western blot and in animal study that was analyzed using with blood chemistry analysis, H&E stain, immunohistochemistry, RT-PCR, and ELISA. Thirty percentage ethanol extract of C. unshiu peels most effectively inhibited preadipocyte’s differentiation via PPARγ-C/EBPα pathway. In animal study it decreased the levels of LDL and leptin, suppressed fat accumulation, prevented adipogenesis via controlling PPARγ-C/EBPα-FAS, and inhibited inflammation via down-regulation of IL-1β, IL-13, and TNF-α. C. unshiu is a promising candidate for anti-obesity medication and for anti-inflammatory drug via regulating the level of leptin and the active compounds are supposed narirutin and hesperidin.