Protective Effects of Citrullus Lanatus Seed Extract on Diclofenac-Induced Splenic Oxidative Stress and Histopathological Alterations in Adult Male Wistar Rats

Diclofenac, a widely used non-steroidal anti-inflammatory drug (NSAID), has been associated with oxidative stress and tissue injury following prolonged administration. Citrullus lanatus (watermelon) seeds contain bioactive phytochemicals with antioxidant properties that may protect against oxidative damage. This study investigated the effect of ethanolic seed extract of Citrullus lanatus on oxidative stress markers and splenic histology in diclofenac-induced splenic injury in male Wistar rats. Twenty-five adult male Wistar rats were randomly assigned into five groups (A–E; n = 5). Group A served as the control; Group B received 100 mg/kg body weight of diclofenac; Group C received 300 mg/kg body weight of C. lanatus extract; while Groups D and E received diclofenac concurrently with 150 mg/kg and 300 mg/kg body weight of the extract, respectively. Treatments were administered orally for 28 days. Body weight, relative spleen weight, serum malondialdehyde (MDA), and superoxide dismutase (SOD) levels were assessed, while splenic histology was evaluated using hematoxylin and eosin staining. Diclofenac administration resulted in reduced body weight gain, elevated MDA levels, decreased SOD activity, and severe splenic alterations characterized by hemorrhage and fibrosis. Treatment with C. lanatus extract reduced MDA levels and significantly improved SOD activity compared with the diclofenac-only group. Histological examination revealed preservation of normal splenic architecture in rats treated with the extract alone and attenuation of splenic lesions in co-treated groups. The findings suggest that ethanolic seed extract of Citrullus lanatus exerts protective effects against diclofenac-induced splenic injury, possibly through its antioxidant activity and enhancement of endogenous antioxidant defenses.