Inhibition of nicotine-induced behavioral tolerance by ascorbic acid in female mice

Administration of nicotine leads to incentive and behavioral tolerance in human and animals. Ascorbic acid administration inhibits some effects of nicotine. In the present study, the effects of ascorbic acid administration on the expression and development of nicotine-induced behavioral tolerance in female Swiss-Webster mice (20-25 g) was investigated. Animals were injected with nicotine (0.5 mg/kg, i.p.) once daily for 12 days in order to induce tolerance. At 13th day, an effective dose of nicotine (1 mg/kg, i.p.) was administered to the mice and activity of the animals was recorded for 20 min in an activity monitoring system (30 x 30 x 20 cm). Different doses of ascorbic acid (1-1000 mg/kg, i.p.) were administered to the animals in two ways: first group; the animals received ascorbic acid at days 1-12 of the experiments 10 min before the administration of nicotine (development). Second groups received ascorbic acid only at 13th day of the experiments (Expression). The results showed that administration of nicotine (0.5 mg/kg, i.p.) for 12 days to the mice induced behavioral tolerance in the animals. Injection of ascorbic acid (1-1000 mg/kg, i.p.) inhibits the development of nicotine-induced behavioral tolerance in the female mice. Administration of ascorbic acid (1-1000 mg/kg, i.p.) was ineffective to alter the expression of behavioral tolerance induced by nicotine. In conclusion, administration of ascorbic acid may inhibit the development of nicotine-induced behavioral tolerance, but it is ineffective to inhibit the effect of the expression of nicotine-induced behavioral tolerance.