Abstract

Hyperhomocysteinemia is a hypothesis for the association of homocysteine with cerebrovascular diseases, neurodegenerative diseases and depression of mood. Thus, we examined whether oral betaine can act as a preventive agent in ethanol-induced hyperhomocysteinemia on the monoaminergic system. A total of 32 New Zealand White rabbits were divided into four groups (n=8); the Control group (C). The Ethanol group (E) was administered ethanol at a dosage of 4 g/kg daily. The Betaine group (B) received betaine at a dosage 1.5% (w/w) of the diet daily, and the Betaine and Ethanol group (B&E) was administered with the betaine group diet; after one hour the rabbits received ethanol at a dosage of 4 g/kg daily. Blood samples were taken in the morning of the day before beginning treatment (0.0 day) and on the 30th, 60th and 90th day of the treatment. Serum folate and vitamin B12 levels were determined using a radioimmunoassay, total plasma homocysteine (tHcy) level was determined by homocysteine EIA kit, and 5- hydroxyindoleacetic acid (5-HIAA) of plasma was measured with HPLC-ECD. There was a significant negative correlation between 5-HIAA and tHcy in the E group (r=-0.473, P=0.02), and compared to the E group the concentrations of 5-HIAA in the B&E group increased considerably (p<0.05). In contrast to the E group, significantly high concentrations of 5-HIAA were observed in the B and C groups. While the serum concentrations of vitamin B12 showed no significant difference in the B&E group on the 90th day compared to the control group, the serum concentrations of folate on the 90th day differed significantly (p<0.05) . However, no significant difference was observed between tHcy and gender. Overall, oral pretreatment with betaine significantly prevented ethanol-induced hyperhomocysteinemia, subsequently increasing 5-HIAA in the plasma as well as vitamin B12 and folate in the serum. Thus, betaine may be recommended as a pretreatment method for depressive patients with alcoholism.

Key words: Betaine, hyperhomocysteinemia, 5-HIAA, ethanol, vitamin B12, folate.