Abstract
The present study was conducted to determine whether an ethanolic extract of Citrus medica 'Otroj' (EEOT) can possibly exert nephroprotective and antioxidant activity against gentamicin-induced renal toxicity in rats. Wistar albino rats of either sex were divided into four groups. Group-1 received normal saline. Group-2 received gentamicin (GM) (80 mg/kg/d, for 8 days intraperitoneally). Group-3 and 4 received EEOT (250 and 500 mg/kg/d, for 21 days orally) plus gentamicin simultaneously. The rats were sacrificed on the twenty first day and kidneys were collected for histopathological assessment. Renal activities were determined in serum for gamma glutamyl transferase (GGT), creatinine, urea and uric acid. Moreover, non-protein sulfhydryl (NP-SH) malondialdehyde (MDA) and total protein (TP) were determined in renal tissues. Additionally, in vitro protection against 2 ',7 '-dichlorofluorescein-induced human nephrotoxicity was carried out with HEK293 cells using MTT assay. GM caused an elevation in serum GGT, creatinine, urea and uric acid, a reduction of the NP-SH and TP levels and an increase the MDA concentration in the kidney tissue. Administration of EEOT significantly protected kidney tissues against nephrotoxic effect of gentamicin as evident from amelioration of the marker enzymes and lipid peroxidation and elevated NP-SH and TP levels, besides some indices of histopathological alterations. The MTT-test showed a 48% protection at a concentration of 1 mg/ml. It is concluded that C. medica could protect the kidney against oxidative stress induced by gentamicin probably through its antioxidant and/or free radical scavenging properties caused by flavonoids and limonene.