Common onion (Allium cepa) extract reverses cadmium-induced organ toxicity and dyslipidaemia via redox alteration in rats

Background: Cadmium (Cd) remains an important environmental pollutant of public health concern as it causes organ toxicity, and cardiovascular diseases (CVD), but the roles of common foods such as onion (Allium cepa) need further clarification. The aims of this study were to clarify whether or not Cd-induced organ dysfunction was associated with blood protein, lipid and lipid peroxidation and the effects of onion extract AcE in a rat model. Methods: Control and Cd-treated rats were maintained on control diet, while AcE+Cd-treated rats were also orally administered AcE (1 ml/100 g body weight). Cd-treated and AcE+Cd-treated rats also received cadmium as CdSO4 (1.5 ml/kg body weight of 0.3 mg/L of CdSO4) via drinking water. Results: It was found that Cd significantly increased total cholesterol, triglycerides, LDL-cholesterol, serum albumin, and reduced HDL-cholesterol, total plasma protein, and plasma testosterone. Administration of AcE restored the liver and kidney toxicities and blood protein and lipid profiles. Moreover, AcE improved Cd-induced decrease in urinary volume and renal clearance, and also protected against Cd-induced oxidative stress by normalizing redox status. However, AcE did not affect Cd-induced altered plasma testosterone. Conclusion: Our study suggests that Cd-induced CVD was associated with altered blood dysproteinemia, dyslipidaemia, and oxidative stress. It also provided the first evidence of the therapeutic efficacy of AcE against atherosclerotic conditions and organ toxicity in Cd-intoxicated rats via a mechanism independent of the circulating testosterone level.