Benzo(a)pyrene induces interleukin (IL)-6 production and reduces lipid synthesis in human SZ95 sebocytes via the aryl hydrocarbon receptor signaling pathway

• Benzo(a)pyrene (BaP) could activate AhR signaling pathway in SZ95 sebocytes.
• BaP induced interleukin-6 secretion in SZ95 sebocytes through AhR signaling pathway.
• BaP inhibited lipogenesis of SZ95 sebocytes through AhR signaling pathway.

In this study, we determined the effects of benzo(a)pyrene (BaP) on the expression of aryl hydrocarbon receptor (AhR) and cytochrome P450 1A1 (CYP1A1), and assessed the action of BaP on inflammatory cytokine expression and lipid synthesis in SZ95 sebocytes in vitro. BaP (10−8, 10−7, 10−6 and 10−5 M) was not cytotoxic for SZ95 sebocytes after 24 h exposure. Expression of AhR was promoted in mRNA lever, while was inhibited in protein lever after BaP (10−5 M) exposure. CYP1A1 expression was up-regulated in both mRNA and protein levels. BaP (10−5 M) exerted a stimulatory action on interleukin (IL)-6 secretion, while a dose-dependently inhibitory effect on lipid synthesis from 10−8 M to 10−5 M in SZ95 sebocytes. Both actions were partly antagonized in AhR-knockdowned SZ95 sebocytes. This study demonstrates that BaP can activate AhR signaling pathway, and exhibits pro-inflammatory effects and inhibitory effects on sebum production in human sebocytes.