Betaine as a methyl donor and an antioxidant agent in levodopa-induced hyperhomocysteinemia and oxidative stress in rat's kidney

Abstract

BACKGROUND: Betaine has been shown to be antioxidant<br />and methyl donor effects in our recent studies. OBJECTIVES: In<br />the present study, the antioxidant and methyl donor properties of<br />betaine in levodopa/benserazide-mediated hyperhomocysteinemia<br />and levodopa-induced oxidative stress in rat's kidney were<br />examined. METHODS: Sprague-Dawley male rats were divided<br />into levodopa (LD), Betaine (Bet.), levodopa plus betaine<br />(LD/Bet.), levodopa plus benserazide (LD/Ben.), levodopa plus<br />betaine-benserazide (LD/Bet.-Ben.), and control groups. The<br />experimental groups received LD (3 × 100 mg/kg), Bet. (1.5%<br />w/w of the total diet), Ben. (3 × 25 mg/kg), and distilled water<br />was given to controls for 10 consecutive days, orally by gavage.<br />RESULTS: Plasma total homocysteine (tHcy) concentration<br />decreased significantly in Bet.-, LD/Bet.-, and LD/Bet.-Ben.-<br />treated rats compared to LD/Ben. group. Thiobarbituric acid<br />reactive substances concentration (as a lipid peroxidation<br />marker) in renal tissue reduced statistically in betaine group in<br />comparison with LD and LD/Ben. groups. Renal catalase<br />activity increased significantly in LD-treated rats when<br />compared to controls. Renal superoxide dismutase activity<br />significantly decreased in LD-treated group when compared to<br />LD/Ben. group. However, there was not any significant<br />difference in renal glutathione peroxidase (GPx) activity among<br />the groups. CONCLUSIONS: These findings indicate that LD and<br />LD/Ben. have side effects in kidney due to induction of<br />hyperhomocysteinemia and oxidative stress. In contrast, betaine<br />acts as a promising antioxidant and methyl donor agent versus<br />LD-induced complications.