Suppression of Sebum Production and Accumulation by β-Cryptoxanthin Due to the Inhibition of the Expression of Diacylglycerol Acyltransferase-1 and Perilipin in Hamster Sebocytes

Background: Acne vulgaris is characterized by the enhancement of sebaceous lipogenesis and sebum secretion, and apart from retinoids and some natural products there are few effective anti-acne agents that directly suppress sebum production and accumulation in sebaceous glands. Objective: We examined the effects of β-cryptoxanthin (β-CRX), which is a carotenoid pigment most abundant in Citrus unshiu Marcovich (Satsuma mandarin orange) and plays a role as a Vitamin A precursor on sebum production and accumulation in hamster sebaceous gland cells (sebocytes). Materials and methods: The regulation of sebum production was examined by the measurement of triacylglycerols (TGs), the major sebum component, and oil red O staining in insulin-differentiated hamster sebocytes. The expression of diacylglycerol acyltransferase-1 (DGAT-1), a rate-limiting enzyme of TG biosynthesis, and perilipin 1 (PLIN1), a lipid storage droplet protein, was analyzed using real-time PCR and Western blotting. Results: Hamster sebocytes constitutively produced TGs during cultivation and the production of TGs was enhanced by insulin treatment. Both constitutive and insulin-enhanced TG productions were doseand time-dependently inhibited by β-CRX as well as 13-cis retinoic acid. In addition, the gene expression of DGAT-1 was suppressed by β-CRX in the sebocytes. Furthermore, the insulin-enhanced sebum accumulation as lipid droplets was reduced in the β-CRX-treated cells. Moreover, β-CRX was found to suppress the gene expression and production of PLIN1 in insulin-differentiated hamster sebocytes. Conclusions: These results provide novel evidence that β-CRX is an effective candidate for acne therapy by its ability to exert dual inhibitory actions against DGAT-1-dependent TG production and PLIN1-mediated lipid-droplet formation in hamster sebocytes.