HSP27 modulates survival signaling in endosulfan-exposed human peripheral blood mononuclear cells treated with curcumin

Endosulfan, a well-known organochlorine pesticide, induces apoptosis and depletion of reduced glutathione (GSH) in human peripheral blood mononuclear cells (PBMC). Thus, for the amelioration of its effect, antioxidant and antiapoptotic potential of curcumin was evaluated. For ascertaining the attenuating effect of curcumin, various biochemical indices of cell damage such as cytotoxicity, oxidative stress, apoptosis (phosphatidylserine externalization, DNA fragmentation, and cytochrome c) in human PBMC was evaluated following endosulfan exposure (0-100 mu M). To assess the role of HSP27 on endosulfan-induced apoptosis, the expression of HSP27 was examined. Curcumin 925 mu M) increased cell viability significantly. As evident from the restoration of GSH, antiapoptotic potential was directly proportional to their antioxidant nature of curcumin. The present study indicates that the beneficial effect of curcumin on endosulfan-induced cytotoxicity is related to the induced synthesis of HSP27, emphasizing its antioxidant and therapeutic potential as well as underscoring the mechanism of pesticide-induced toxicity at cellular level. Taken together, these findings suggest that curcumin protects against endosulfan-induced immunotoxicity in human PBMC by attenuating apoptosis.