Berberine exerts anti-adipogenic activity through up-regulation of C/EBP inhibitors, CHOP and DEC2

► Berberine inhibits adipogenesis by down-regulating C/EBPα and PPARγ. ► Berberine up-regulates two different C/EBP inhibitors, CHOP and DEC2. ► CHOP was up-regulated by berberine through ER stress-independent UPR activation. ► DEC2 was up-regulated by berberine due to changes in extracellular environment. ► CHOP knockdown or adjusted environment reduced berberine's anti-adipogenic activity.