Tramadol, a broadly in recent years, is an effective analgesic agent for the treatment of moderate to acute pain. Its
metabolites are excreted by the kidney which may cause nephrotoxicity. Moringa oleifera leaves are commonly used to
provide herbal and plant-derived medicinal products especially in developing nations. The present study was carried out to
determine the biochemical and histopathological changes in the kidney of tramadol-treated albino mice and to evaluate the
possible protective role of Moringa oleifera leaves against tramadol-induced nephrotoxicity. Twenty adult albino mice
were divided into four groups. Control group (group i) received daily intraperitoneal injection of normal saline only, group
ii received oral dose of Moringa oleifera leaves extract (20 mg/kg/bw) for three weeks, group iii received daily
intraperitoneal dose of tramadol (0.3 mg/kg/bw) for the same period, group iv, received daily oral dose of Moringa oleifera
leaves extract, (20 mg/kg/bw) three hours before injecting intraperitoneal dose of tramadol (0.3 mg/kg/bw), for the same
period. Blood samples were withdrawn at the end of the experiment for kidney function tests and specimens from the
kidney were processed for histological study. No significant differences in the mean values of the kidney function tests
were noticed between Moringa oleifera group and control group. However, there was highly significant increase in the
mean values of serum, urea and creatinine in tramadol-treated group as compared to the control group. Although tramadol
+ Moringa oleifera group revealed significant difference in the mean values of urea and creatinine when compared with
tramadol-treated group. So, Moringa oleifera leaves extract have been shown to attenuate the renal dysfunction, improve
the renal architecture, with nearly normalization of serum urea and creatinine levels which indicate improvement of renal
function. In conclusion, in the light of biochemical results and histological findings, co-administration of Moringa oleifera
leaves lessened the negative effects of tramadol-induced nephrotoxicity; possibly by its antioxidant action. Further
investigation of these promising protective effects of Moringa oleifera leaves against tramadol-induced renal injury may
have considerable impact on developing an adjunct therapy aiming to improve the therapeutic index of some nephrotoxic drugs.