Anti-adipogenesis mechanism of pterostilbene through the activation of heme oxygenase-1 in 3T3-L1 cells

Background: Pterostilbene is a stilbenoid and major compound and has diverse biological activities, such as antioxidant, anti-cancer, and anti-inflammatory. However, it has not been shown whether pterostilbene affects the mitotic clonal expansion during adipogenesis in 3T3-L1 cells. Purpose: In the present study, we aimed to demonstrate the detailed mechanism of pterostilbene on anti-adipogenesis in 3T3-L1 cells. Methods: Preadipocytes were converted to adipocytes through treatment with MDI (IBMX; 3-isobutyl-1-methylxanthine, DEX; dexamethasone, insulin) in 3T3-L1 cells. Oil Red O staining was performed to measure intracellular lipid accumulation. Western blot analysis was conducted to analyze protein expressions. Results: Our results showed that pterostilbene decreased the lipid accumulation compared to MDI-induced differentiation, using Oil Red O staining. Next, we found that pterostilbene suppressed the expression of C/EBPa, PPAR gamma, and aP2 as well as the mitotic clonal expansion-associated proteins CHOP10 and C/EBP alpha, by western blot analysis. Our results indicated that pterostilbene may repress adipocyte differentiation through the activation of HO-1 expression prior to entering into the mitotic clonal expansion in 3T3-L1 cells. RNA interference was used to determine whether HO-1 acts as a regulator of CHOP10. Conclusion: Our results revealed that pterostilbene induced HO-1 expression which acts as a regulator of CHOP10. Together, we demonstrated that pterostilbene suppresses the initiation of mitotic clonal expansion via up-regulation of HO-1 expression during adipocyte differentiation of 3T3-L1 cells.