In vitro Antisalmonellal and Antioxidant Activities of Leaves Extracts of Tectona grandis L. F. (Verbenaceae)
Gabriel Tchuente Kamsu
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Richard Simo Tagne
Department of Biomedical Sciences, University of Ngaoundéré, P.O. Box 454, Ngaoundéré, Cameroon.
Siméon P. C. Fodouop
Department of Biomedical Sciences, University of Ngaoundéré, P.O. Box 454, Ngaoundéré, Cameroon.
Louis-Claire Ndel Famen
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Norbert Kodjio
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Steve Endeguele Ekom
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
Donatien Gatsing *
Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon.
*Author to whom correspondence should be addressed.
Abstract
Aim: Study aimed to evaluate the in vitro antisalmonellal and antioxidant properties of Tectona grandis, a medicinal plant commonly used in traditional Cameroonian medicine for the treatment of typhoid fever.
Study Design: In vitro Antimicrobial and antioxidant analyses of plant extract using established protocols.
Place and Duration of Study: Plant materiel collection at Loum (Moungo Division, Littoral region of Cameroon), identification at the National Herbarium of Cameroon, extraction of plant and all analyses at the Research Unit of Microbiology and Antimicrobial Substances, Department of Biochemistry, University of Dschang-Cameroon, between August 2018 and April 2019.
Methodology: In vitro antisalmonellal activity of Tectona grandis extracts was evaluated by the liquid microdilution method as well as their antioxidant activity using by standard methods of H2O2 trapping, FRAP, DPPH radical trapping and OH radical trapping. Quantification test of total phenols and flavonoids and phytochemical screening of extract were also done.
Results: The results showed that most of the Tectona grandis extracts had minimal inhibitory concentrations (MICs) ranging from 64 to 1024 μg/mL. Ethanolic extract, 70% ethanol extract and aqueous decoction are the most effective compared to aqueous extracts with activities between 64 and 128 μg/mL on the bacteria tested. Antioxidant tests showed that all extracts except macerated and aqueous infused extracts exhibited high DPPH trapping activities. The antioxidant activities of the extracts are proportionally linked in most cases to their flavonoid and total phenol contents at a concentration of 200 µg/mL. Aqueous decoction showed better H2O2 trapping activity at concentrations less than or equal to 25 µg/mL.
Conclusion: These results show that the ethanolic extract and decocted aqueous of Tectona grandis leaves can be used as an alternative to treat salmonellosis.
Keywords: Tectona grandis extract, antisalmonellal and antioxidant activities