Anti-Salmonella activity of Terminalia belerica: in vitro and in vivo studies

To search for an herbal remedy for protection against and treatment for typhoid fever, a number of plants were screened. Anti-Salmonella activity of Terminalia belerica, an ingredient of Ayurvedic preparation 'triphala' used for treatment of digestive and liver disorders, has been reported. Fruits of T. belerica were extracted with petroleum ether, chloroform, acetone, alcohol and water and efficacy of extracts against Salmonella typhi and Salmonella typhimurium was evaluated. Alcoholic and water extracts of T. belerica showed significant anti-Salmonella activity and MIC was 12.5 mg/ml against S. typhimurium. Aqueous extracts of Picrohiza kurroa and Vitits vinefera also showed low anti-Salmonella activity where as aqueous extracts of Asparagus racemosus and Zingiber officinale showed no anti-Salmonella activity. Extracts of T. belerica, Picrohiza kurroa and Vitits vinefera with other solvents such as chloroform and petroleum ether showed insignificant activity. Results showed that aqueous extract of T. belerica was bactericidal at high concentrations where as low concentrations showed bacteriostatic property. In vitro cellular toxicity studies showed no cyto-toxicity associated with T. belerica extracts. Pretreatment of mice with aqueous extract of T. belerica conferred protection against experimental Salmonellosis and 100% survival of animals has been reported when challenged with lethal doses of S. typhimurium.