Ellagic acid attenuates oxidative stress on brain and sciatic nerve and improves histopathology of brain in streptozotocin-induced diabetic rats

The aim of this study was to investigate the possible effects of ellagic acid in brain and sciatic nerve tissues of diabetic rats. Also, the impact of ellagic acid on catalase and paraoxonase (PON-1) activities, total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), malondialdehyde (MDA) and nitric oxide (NO) were examined. The rats were randomly divided into four groups, with eight rats each: Normal controls (not diabetic), only ellagic acid treated (ellagic acid controls, not diabetic), Diabetic controls (streptozotocin, diabetic), ellagic acid-treated diabetic (streptozotocin + ellagic acid). After a 4 week experiment, rats were sacrificed, and biomarkers for oxidative stress in the brain and sciatic nerve tissues of the rats were measured. There was significant depletion in the PON-1, catalase, and TAS levels in the brain and sciatic nerve tissues compared to the control groups (for both parameters, p < 0.05). The values of catalase, PON-1 and TAS reversed back to normal levels in ellagic acid-treated diabetic rats compared to untreated diabetic rats (for both parameters, p < 0.05). The levels of MDA, TOS, NO and, OSI in the brain and sciatic nerve tissues were higher in untreated diabetic rats compared to control group (for both parameters p < 0.05). However, MDA, TOS, OSI, and NO levels were found to be significantly reduced in the ellagic acid-treated diabetic group compared to the untreated diabetic group in these tissues (for both parameters, p < 0.05). In conclusion, the results of the present study suggested that ellagic acid exhibits neuroprotective effects against oxidative damage in diabetic rats.