Tropical Journal of Pharmaceutical Research

Original Research Article | OPEN ACCESS

Antidepressant effect of methanol extract of smokeless tobacco and identification of its bioactive components

Siddig I Abdelwahab¹ , Syam Mohan², Manal ME Taha², Waquar Ahsan³, Mohammed Al Bratty³, Hassan A Alhazmi^1-3

¹Substance Abuse Research Centre; ²Biomedical Research Unit, Medical Research Centre; ³Department of Pharmaceutical Chemistry, College of Pharmacy, Jazan University, Jazan, Saudi Arabia.

For correspondence:- Siddig Abdelwahab Email: siddigabdelwahab.sarc@gmail.com Tel:+966506612390

Accepted: 20 April 2019 Published: 31 May 2019

Citation: Abdelwahab SI, Mohan S, Taha MM, Ahsan W, Bratty MA, Alhazmi HA. Antidepressant effect of methanol extract of smokeless tobacco and identification of its bioactive components. Trop J Pharm Res 2019; 18(5):1083-1088 doi: 10.4314/tjpr.v18i5.24

© 2019 The authors.
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Abstract

Purpose: To investigate the antidepressant effect of methanol extract of smokeless tobacco and identify its bioactive compounds.

Methods: Adult Wistar rats were randomly assigned to five groups of five rats each: normal control group, standard (reference) control group as well as 100, 200 and 500 mg/kg extract group. The extract, standard drug (imipramine) and normal saline were administered via the intraperitoneal (i.p.) route. The rats were subjected to forced swim test (FST) and tail suspension test (TST) to assess the antidepressant effect of methanol extract of smokeless tobacco. Gas chromatography–mass spectrometry (GC-MS) was used to identify the bioactive compounds of the extract.

Results: The oral LD₅₀ of the extract was > 2000 mg/kg. Significant decrease in immobility time was observed after single administration of imipramine (p < 0.05). The extract significantly and dose-dependently decreased the immobility time, but increased climbing and swimming times, when compared with normal control group (p < 0.05). The immobility time of stressed rats regardless of sex was significantly and dose-dependently lowered, relative to normal control group (p < 0.05). Four major compounds were identified in the extract: nicotine (45.88 %); 1,5-dimethyl-2-pyrrolidinone (23.00 %), n-hexadecanoic acid (11.31 %) and vitamin A aldehyde (9.38 %).

Conclusion: These results demonstrate that the methanol extract of smokeless tobacco possesses antidepressant and mood-elevating effects in rats. However, its use should be discouraged since it contains a number of hazardous and carcinogenic components such as N-nitroso compounds and benzo(a)pyrene which are categorized as Class-I carcinogens.

Keywords: Smokeless tobacco, Extract, Rats, Antidepressant, Imipramine, Immobility