Anti-inflammatory Effect of the Aqueous Fruit Pulp Extract of Tamarindus indica Linn in Lipopolysaccharide-Stimulated Macrophages

Aim: The aim of the present study was to evaluate the effect of the aqueous fruit pulp extract of Tamarind indica Linn on NO production and iNOS expression in LPS stimulated RAW 264.7 macrophages. Material and Method: The efficacy of tamarind extract on nitric oxide production was determined using RAW macrophages. RT - PCR was used to examine the expression of the iNOS gene in activated macrophages. The Statistical analysis for multiple comparisons was evaluated by one way ANOVA followed by the Dunnett’s test when significant differences were detected. The data were considered to be statistically significant at p < 0.001, p < 0.01 and p < 0.05. Results: LPS stimulated RAW macrophages strongly up regulated the iNOS gene expression levels. The iNOS levels were significantly suppressed in the presence of different concentrations of tamarind extract, compared to LPS treatment alone. The tamarind extract also exhibited dose – dependent decrease in the production of NO. The IC₅₀ was found to be 35.69 μg/ml. LPS stimulated group showed 89.61 ± 0.47 % of NO. Conclusion: Nitric oxide production is found to be more in conditions such as periodontitis, oral squamous cell carcinoma and many other diseases. This study could prove the ability of tamarind fruit pulp extract to inhibit the production of nitric oxide and the iNOS gene expression. Hence, Tamarind indica Linn pulp extract may be used as a good anti-inflammatory agent in periodontitis as well as in conditions associated with over production of nitric oxide in different cancers such as oral squamous cell carcinoma.