Antioxidant effects of thiamine hydrochloride, n-acetyl-dl-methionine and garlic on cadmium induced oxidative stress to the liver, kidney and brain in sheep

Cadmium is a nonessential trace element with no biological function. It accumulates rapidly by most living organisms and exerts its toxicity at different molecular levels. The present study was undertaken to study the tissue accumulation of cadmium and changes in oxidative stress indices due to this ubiquitous environmental pollutant following experimental daily oral administration and to examine the ameliorative property of thiamine, methionine and garlic extract on cadmium-induced oxidative damage. Twenty five adult sheep weighing 20-30 kg were maintained in experimental animal shed and provided with standard ration and ad.lib drinking water. The experimental sheep were randomly divided into two groups i.e. group-I and group-II. Group-I, consisting of five sheep, served as healthy control and received only normal saline solution @1ml/10 kg B.W. Animals of group-II were again divided into four subgroups i.e. IIA, IIB, IIC, IID and they were given different treatments. All the animals belonging to these subgroups were given Cd@5mg/kg body weight as aqueous solution of CdCl2 orally, through orogastric tube, daily in the morning for 8 weeks. Simultaneously, animals of group-IIB, IIC and IID received thiamine hydrochloride @25mg/kg B.W., N-acetyl-DL-methionine @25 mg/kg B.W. subcutaneously and garlic juice (crude extract) 100 mg/kg B.W. orally daily for 8 weeks, respectively. Animals of Group-IIA did not receive any treatment and served as positive (untreated) controls. Blood samples were collected from all the animals before the commencement of the experiment (day 0) and thereafter at weekly interval till end of the study i.e. 8 week. Animals of both groups were scarified at the end of the cadmium exposure, and a portion of liver, kidney and brain were excised, and immediately transported to laboratory for analyzing Lipid Peroxide (LPO) level, Superoxide Dismutase (SOD), Catalase (CAT) and sulphydryl groups. There were tissue specific changes in the oxidative stress indices parameters, and cadmium accumulation was the highest in kidney followed by liver. It is suggested that environmental exposure to this toxic heavy metals in a polluted environment results in oxidative damage and higher accumulation of this toxic metal in the edible components of food producing animals. Thiamine hydrochloride, N-acetyl-DL-methionine and garlic extract significantly reduced the cadmium induced oxidative damage. Thiamine and methionine significantly reduced cadmium burden from tissues and erythrocytes as compared to untreated group, but garlic extract did not cause any significant reduction.