Antibacterial Activity of Ethanolic Extracts of Acacia nilotica var. adansonii (Pods and Bark) against Pathogenic Bacteria: A Promising Therapeutic Alternative in Chad
Abderahman Moussa
University Hospital Center (CHU), P.O. Box V 123, Abéché, Chad and Adam Barka University of Abéché (UNABA), P.O. Box 1173, N'Djamena, Chad and Department of Microbiology, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon.
Steve Henri Voundi Olugu *
Biotechnologies Laboratory, University Institute of Technology, University of Douala, P.O. Box 8698, Douala, Cameroon.
Victor Moussango Davy
Biotechnologies Laboratory, University Institute of Technology, University of Douala, P.O. Box 8698, Douala, Cameroon and Laboratory of Biochemistry, Department of Biochemistry, Faculty of Sciences, University of Douala, Cameroon, P. O. Box 24 157, Douala, Cameroon.
Yacub Mahamat Allamine
University Hospital Center (CHU), P.O. Box V 123, Abéché, Chad.
Franck Alain Tchinda Fonkou
Appalachian College of Pharmacy, P.O. Box 24631, Virginia, USA.
Landry Kengne Gounmadje
Department of Biochemistry, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon.
Alian Désire Afagnigni
Department of Biochemistry, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon.
Emmanuel Nnanga Nga
Department of Galenical Pharmacy and Pharmaceutical Legislation, Faculty of Medicine and Biological Sciences, the University of Yaoundé I. PO. Box: 1364, Yaoundé, Cameroon and Department of Pharmaceutical Science, Faculty of Medicine and Pharmaceutical Science, The University of Douala, PO. Box: 2701, Douala, Cameroon and Institute of Medical Research and Medicinal Plants Studies, PO. Box:6163, Yaoundé, Cameroon.
Abdelsalam Adoum Doutoum
Adam Barka University of Abéché (UNABA), P.O. Box 1173, N'Djamena, Chad.
Maximilienne Ascencion Nyegue
Department of Microbiology, Faculty of Sciences, University of Yaounde I, Yaounde, Cameroon.
*Author to whom correspondence should be addressed.
Abstract
Aims: Acacia nilotica var. adansonii is a medicinal plant widely used by Chadian populations to treat various ailments, including bacterial and fungal infections. Despite this widespread traditional use, few scientific studies have confirmed its antibacterial properties. The present study aimed to evaluate the antibacterial activity of ethanolic extracts from the pods and bark of this plant and to identify the secondary metabolites responsible for this activity.
Methodology: Pods and bark of Acacia nilotica var. adansonii were collected in Abéché (Chad), dried, powdered, and extracted by ethanolic maceration. Antibacterial activity was assessed against five pathogenic strains (Escherichia coli, Staphylococcus aureus, Bacillus cereus, Shigella spp. and Salmonella enteritidis) using the agar diffusion method and broth microdilution to determine minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs).
Results: Ethanolic extraction yielded 62.47% for the pods and 22.93% for the bark. Inhibition zone diameters ranged from 13.66 ± 0.57 to 15.00 ± 1.41 mm for the pods and from 12.00 ± 1.00 to 14.66 ± 2.56 mm for the bark. MIC values ranged from 0.39 to 1.56 mg/mL for the pods and from 0.19 to 1.56 mg/mL for the bark. MBC/MIC ratios revealed a bactericidal effect (MBC/MIC < 4) for most strains, with an MBC/MIC ratio of 1 for the bark against E. coli, Salmonella enteritidis, and Shigella spp. Phytochemical tests highlighted the combined presence of polyphenols, flavonoids, and gallic tannins in both extracts.
Conclusion: These results scientifically confirm the traditional use of this plant and justify further investigations towards the development of phytomedicines.
Keywords: Acacia nilotica var. adansonii, antibacterial activity, ethanolic extract, pods, bark, minimum inhibitory concentration, minimum bactericidal concentration, phytochemical screening, medicinal plants