Morphological and biochemical evaluation of the effects of quercetin on the experimantal sciatic nevre damage in rats

The purpose of this study was to evaluate the neuroprotective and antioxidant effectiveness of quercetin in a model of sciatic nerve crush injury using histopathological, morphometric and biochemical methods. Forty-eight male Sprague Dawley rats aged 10-12 weeks were randomly assigned into eight groups; sham (S-7; S-28), quercetin (Q-7 and Q-28; 200 mg/kg/7 days), trauma (T-7 and T-28; 1-min crush of the sciatic nerve with micro vascular clamps) and trauma + quercetin (T+Q-7 and T+Q-28; trauma and quercetin 200 mg/kg/7 days), Animals were sacrificed 7 and 28 days after injury. Oxidant-antioxidant biochemical parameters were analyzed in muscle and nerve tissues from all groups, together with morphological evaluation at histopathological staining with toluidine blue, hematoxylin and eosin and Masson's trichrome. At morphological evaluation, diffuse degeneration was observed in axons and the myelin sheath in groups T-7 and T-28, together with severe impairment of the concentric lamellar structure of the myelin sheath and axonal swelling. Myelin sheath thickness, nerve fiber diameter and myelinated nerve fiber numbers decreased significantly, while apoptotic index (AI) increased. In groups T+Q-7 and T+Q-28, the morphological regeneration process and healing of cellular damage and axonal structure were observed to have begun. AI also decreased significantly. Morphology was close to normal in T+Q-28 compared to S-28. In terms of biochemical parameters, Malondialdehyde and superoxide dismutase activity were increased, when group T-7 was compared with group S-7, this was not statistically significant. A significant decrease was observed in CAT activity in group T-28. When group T+Q-7 was compared with group T-7, malondialdehyde values decreased significantly; catalase activity increased. We concluded that quercetin makes a positive contribution to crush-type injuries of the sciatic nerve and can shorten the healing process by preventing lipid peroxidation and fibrosis in the injured region.