CYTOTOXICITY EFFECT OF SMOKELESS TOBACCO EXTRACT ON FIBROBLAST CELL LINE

Abstract

Introduction: The use of smokeless tobacco is prevalent among Asians. Nicotine, a constituent of tobacco, is known as carcinogenic and a risk factor for oral cancer. The effect of smokeless tobacco extract is not much studied in Malaysia. Objectives: This study's aims to evaluate the cytotoxicity effects of locally produced smokeless tobacco aqueous extract and investigate the cytotoxicity level of different concentrations of aqueous tobacco extract on mouse fibroblast cell line, L929. Methodology: The tobacco purchased from the local market was blended with deionised water (1:2;w:v) followed by freeze-drying. The freeze-dried powder was dissolved in Dulbecco’s Modified Eagle’s Medium (DMEM) followed by dilution in seven concentrations of aqueous tobacco extract (100%, 50%, 25%, 12.5%, 6.25%, 3.125% and 1.56%). The mouse fibroblast cell line, L929, was incubated with different concentrations of the prepared aqueous tobacco extract. Cytotoxicity of the treated cell line was assessed using MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium] assay, and the half-maximal inhibitory concentration (IC50) was determined after 24, 48 and 72 hours incubation. Data were collected analysed by one-way ANOVA (Analysis of Variance). Results: Increasing concentrations of aqueous tobacco extract (1.56%, 3.125%, 6.25%, 12.5%, 25%, 50% and 100%) resulted in decreasing viability of mouse fibroblast cell L929 for all incubation times compared to the control. The IC₅₀ value of areca nut extract on L929 was 52%, 34% and 28% at 24, 48 and 72 hours, respectively. Conclusion: This study portrayed that tobacco is cytotoxic to L929 with increasing concentrations.

Keywords: smokeless tobacco, mouse fibroblast cell line, cytotoxicity, MTT assay, oral cancer.