In vitro Antisalmonellal and Antioxidant Activities of the Crude Extracts and Fractions from the Stem Bark of Albizia gummifera (J. F. Gmel.) C. A. Sm.

摘要

Aims: Typhoid fever is an infectious disease, which continues to be a serious health problem and remains a major cause of morbidity and mortality in the developing country. Considering the ethnopharmacological relevance of Albizia gummifera (Leguminosae/Fabaceae), this study was designed to investigate the in vitro antisalmonellal and antioxidant activities of various extracts and fractions of this plant against five Salmonella species. Study Design: Extraction, fractionation, antibacterial and antioxidant evaluation, phytochemical screening. Place and Duration of the Study: Department of Biochemistry, Faculty of Science, University of Dschang, Cameroon, between October 2013 and November 2014. Methods: Antimicrobial activity was evaluated by the broth microdilution method, whereas the evaluation of antioxidant properties, quantitative determination of total phenols and flavonoids, phytochemical screening were performed by other standard methods. Results: The data obtained showed that minimal inhibitory concentration (MIC) values ranged from 64 to 512 μg/ml. Crude extract, ethyl acetate and hexane fractions showed significant antibacterial activity (MIC = 64 μg/ml). The extracts and fractions exhibited moderate antioxidant properties (IC₅₀ values obtained ranged from 48.80 to 61.90 μg/mL for the aqueous extracts, and from 28.10 to 34.10 μg/mL for the MeOH/CH₂Cl₂ extract and fractions). Ethyl acetate fraction at 200 μg/ml showed the highest hydroxyl radical scavenging and ferric reducing power activity. Phytochemical screening showed the presence of alkaloids, flavonoids, saponins and phenols in all the extracts and fractions. Conclusion: The results suggest that stem extract of A. gummifera contains antisalmonellal and antioxidant substances, which could be developed for the treatment of typhoid fever and other salmonellosis.