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

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