immunohistochemical and electron microscopic study of the inhibitory effects of olive oil polyphenol on dexamethasone-induced apoptosis

background: there is accumulating evidence that a polyphenol present in olive oil, oleuropein, has antioxidant, anti-inflammatory and anti-apoptotic effects. this study aimed at determining the anti-apoptotic effect of oleuropein (ole) on dexamethasone-induced apoptosis of mouse thymocytes. method: mice were randomly divided to four groups as follow: dexamethasone (dex)-treated group (20 mg/kg; single dose), ole-treated group (20 mg/kg per day), dex plus ole-treated group, and vehicle group. sections of thymus were taken 16 hours after dexamethasone injection and studied for histopathological and immunohistochemistry assessment. result: further characteristics of degeneration in thymocytes were observed in the dex group compared with the dex plus ole group. compared with the dex group (10.94±3.35), positive staining for bax in thymocytes decreased in dex plus ole group (2.64±1.26), but remained higher than the ole (0.65±0.30) and vehicle (0.67±0.29) groups. compared with the dex group (2.94±0.42), positive staining for bcl-2 in thymocytes increased in dex plus ole group (12.24±1.84) yet was lower than the ole (14.94±1.54) and vehicle (18.93±3.54) groups. conclusion: our results suggest that dexamethasone-induced apoptosis is subsided by oleuropein.