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 antioxidantand methyl donor effects in our recent studies. objectives: inthe present study, the antioxidant and methyl donor properties ofbetaine in levodopa/benserazide-mediated hyperhomocysteinemiaand levodopa-induced oxidative stress in rat's kidney wereexamined. methods: sprague-dawley male rats were dividedinto levodopa (ld), betaine (bet.), levodopa plus betaine(ld/bet.), levodopa plus benserazide (ld/ben.), levodopa plusbetaine-benserazide (ld/bet.-ben.), and control groups. theexperimental groups received ld (3 × 100 mg/kg), bet. (1.5%w/w of the total diet), ben. (3 × 25 mg/kg), and distilled waterwas given to controls for 10 consecutive days, orally by gavage.results: plasma total homocysteine (thcy) concentrationdecreased significantly in bet.-, ld/bet.-, and ld/bet.-ben.-treated rats compared to ld/ben. group. thiobarbituric acidreactive substances concentration (as a lipid peroxidationmarker) in renal tissue reduced statistically in betaine group incomparison with ld and ld/ben. groups. renal catalaseactivity increased significantly in ld-treated rats whencompared to controls. renal superoxide dismutase activitysignificantly decreased in ld-treated group when compared told/ben. group. however, there was not any significantdifference in renal glutathione peroxidase (gpx) activity amongthe groups. conclusions: these findings indicate that ld andld/ben. have side effects in kidney due to induction ofhyperhomocysteinemia and oxidative stress. in contrast, betaineacts as a promising antioxidant and methyl donor agent versusld-induced complications.