Eruca sativa seeds possess antioxidant activity and exert a protective effect on mercuric chloride induced renal toxicity

Mercuric chloride (HgCl2) is a well-known nephrotoxic agent. Increasing number of evidences suggest the role of oxidative stress in HgCl2 induced nephrotoxicity. Eruca sativa is widely used in folklore medicines and has a good reputation as a remedy of renal ailments. In the present study, the antioxidant potential of ethanolic extract of E. sativa seeds was determined and its protective effect on HgCl2 induced renal toxicity was investigated. The extract was found to possess a potent antioxidant effect, with a large amount of polyphenols and a high reducing ability. HPLC analysis of the extract revealed glucoerucin and flavonoids to be the major antioxidants present in it. E. sativa extract significantly scavenged several reactive oxygen species (ROS) and reactive nitrogen species (RNS). Feeding of the extract to rats afforded a significant protection against HgCl2 induced renal toxicity. Subcutaneous administration of 4 mg/kg body weight HgCl2 induced renal injury evident as a marked elevation in serum creatinine and blood urea nitrogen levels, and histopathological changes such as necrosis, oedema and congestion of stroma and glomeruli. Oxidative modulation of renal tissues following HgCl2 exposure was evident from a significant elevation in lipid peroxidation and attenuation in glutathione (GSH) contents and activities of antioxidant enzymes viz., catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD) and glutathione reductase (GR). Oral administration of E. sativa extract to rats at a dose regimen: 50–200 mg/kg body weight for 7 days prior to HgCl2 treatment significantly and dose dependently protected against alterations in all these diagnostic parameters. The data obtained in the present study suggests E. sativa seeds to possess a potent antioxidant and renal protective activity and preclude oxidative damage inflicted to the kidney.