Effect of Hydro-Alcoholic Root Extract of Delphinium Denudatum Wall on Mecamylamine-Precipitated Nicotine-Withdrawal and Corticosterone Levels in Rats

Abstract

This study evaluates the effects of hydro-alcoholic root extract of Delphinium denudatum Wall (Jadwar, family; Ranunculaceae) for its ability to attenuate the nicotine-withdrawal in nicotine-dependent rats. The physical dependence on nicotine was induced in male adult Wistar albino rats (175-250 g) by subcutaneous implantation of Alzet mini osmotic pumps which supplied nicotine at 9.0mg/kg/day, while control rats received saline via osmotic pumps. For seven days four separate test doses of hydro-alcoholic root extract of Delphinium denudatum Wall (200, 400, 800, 1600 mg/kg) were given orally. On the 7th day, a mecamylamine injection (1 mg/kg, s.c.) was given to precipitate nicotine-withdrawal. The global Gellert’s–Holtzman rating scale was used to rate somatic signs of withdrawal for 15 minutes, followed by a measurement of motor activity. Drug Bupropion was used as a positive control. Serum levels of nicotine (cotinine) and corticosterone were done by ELISA. In nicotine-dependent rats, oral administration of Delphinium denudatum Wall root extract suppressed the hyper-locomotion and decreased the corticosterone levels at all dosages. Higher doses (800 and 1600 mg/kg) of extract, significantly attenuated nicotine withdrawal whereas, lower doses (200 and 400 mg/kg) had no significant effect. These results suggest that hydro-alcoholic root extract of Delphinium denudatum Wall may prove to be a potential therapeutic agent to attenuate nicotine dependence and facilitate tobacco smoking cessation.