Cadmium (Cd) is one of the most environmentally abundant toxic metals affecting numerous organs of the body.  The pathobiochemical mechanism of this toxic heavy metal is related to oxidative stress injury.  Cleistocalyx nervosum var. paniala or Ma Kiang (MK) is a proanthocyanidin-riched fruit with antioxidant properties.  Since kidney is the main target organ of Cd toxicity, this study was conducted to evaluate the possible beneficial role of MK in chronic Cd exposure using a rat model of Cd-induced nephrotoxicity.  Six groups of male Wistar rats were studied: control, MK (MK fruit extract 2 g/kg, orally), Cd (CdCl2 0.2 mg/kg, i.p.), and CdMK (combination of Cd and MK at 0.5, 1, 2 g/kg, respectively).  After 4 wk treatment, increased blood urea nitrogen and serum creatinine, decreased creatinine clearance, together with histopathological alterations were evident in Cd-intoxicated rats.  Co-treatment with MK, particularly at the doses of 1 and 2 g/kg, significantly reduced these indexes of renal damage and restored all the changes of oxidative indexes (nitric oxide, malondialdehyde, thiols, superoxide dismutase, and catalase) resulting from toxic effect of cadmium.  No significant changes of these parameters from the baseline controls were observed in rats received MK alone.  It is concluded that MK is able to protect against the progression of Cd toxicity in the kidney, mostly via its antioxidant power.  The outcomes also provide essential information regarding health benefits of this naturally occurring antioxidant to combat other conditions elicited by redox alteration.

Keywords: antioxidant, cadmium, Ma Kiang, nephrotoxicity, oxidative stress, toxicity