The present study was conducted to elucidate the protective role of p-coumaric acid, a common dietary polyphenol against cadmium induced nephrotoxicity in rats. For the purpose of comparison, a standard reference drug silymarin (50 mg/kg b. wt) was used. In this experiment, the animals were divided into four groups, with each consisting of six animals. The animals in Group I animals received saline and served as a control group and those in Group II received cadmium chloride (3 mg/kg b. wt) subcutaneously once daily for 3 weeks, but Group III and IV animals received cadmium chloride followed by p-coumaric acid (100 mg/kg b. wt, oral) and silymarin (50 mg/kg b. wt, oral), respectively, daily for 3 weeks. At the end of the treatment, the animals were sacrificed, and the blood and kidney samples were collected. The results obtained in this study revealed the fact that the levels of lipid peroxidation, lysosomal enzymes, glycoprotein, cadmium and metallothionein were increased in the cadmium chloride alone treated rats and antioxidant status was found to be decreased, when compared to the control group. The levels of kidney functional markers (urea, uric acid and creatinine) were also found to be abnormal in serum and urine of cadmium chloride alone treated rats. On the other hand, the administration of p-coumaric acid along with cadmium chloride significantly protected the biochemical alterations as observed in the cadmium chloride alone treated rats as evidenced by histopathology. Thus, the oral administration of p-coumaric acid significantly protected the cadmium-induced nephrotoxicity in rats.

Cadmium, a well-known environmental pollutant and a toxic transitional metal causes severe damage to many organs, such as liver, kidney, lungs, heart, etc. The current study has been designed to assess the impact of p-coumaric acid, a common dietary polyphenol on cadmium chloride-induced renal toxicity in rats. Therefore, the activities of membrane bound ATPases, mitochondrial TCA cycle and electron transport chain enzymes, gluconeogenic and glycolytic enzymes, and glycogen content were estimated in kidney tissue homogenates of control and experimental rats. In addition, the serum levels of glucose and pro-inflammatory cytokines, such as TNF-α and IL-1β were also estimated. The cadmium chloride administered rats (3 mg per kg per b. wt per s.c.) showed significant decrease in the levels of membrane bound ATPases, mitochondrial TCA cycle and electron transport chain enzymes, glycolytic enzymes, and glycogen content as compared with controls. Conversely, the levels of glucose, gluconeogenic enzymes and pro-inflammatory cytokines (TNF-α, and IL-1β) were found to be increased. However, the administration of p-coumaric acid (100 mg per kg per b. wt per s.c.) along with the cadmium chloride significantly modulated these biochemical and immunological changes to near normal, as compared to cadmium chloride treated rats. Thus, the results provide strong evidence that p-coumaric acid has a protective action against cadmium-induced renal toxicity in rats.