Synergistic Antibacterial Activity of Bark Extracts from Tamarindus indica, Adansonia digitata and Vitellaria paradoxa against Some Selected Clinical Pathogens

Abstract

The emergence of antibiotic resistance poses a significant threat to global health, necessitating the exploration of alternative antimicrobial agents. This study investigates the antibacterial activities of the bark extracts of Tamarindus indica, Adansonia digitata, and Vitellaria paradoxa against Escherichia coli, Staphylococcus aureus, Streptococcus pneumoniae, and Salmonella typhi, using hot aqueous, methanol, and ethanol as solvents for extraction. The antimicrobial activity was analysed by agar well diffusion assay, and their phytochemical properties were assessed using various standard phytochemical methods. A 0.5ml of hundred percentage (100%) concentration of each extract was used against each bacterial isolate at 37°C for 24 hours. For positive control, 0.5mg/mL of Ciprofloxacin and negative control, 0.5ml of water were used. The findings reveal substantial antibacterial activity, particularly from the hot aqueous extract of Tamarindus indica, Adansonia digitata, and Vitellaria paradoxa; and combined extracts exhibited the highest zones of inhibition, ranging from 23.0 to 31.5mm. The combinations of these plant extracts demonstrated enhanced antimicrobial efficacy, indicative of synergistic interactions among the constituents. The phytochemical results of all the extracts showed the presence of mostly Saponins, Tannins, Flavonoid, Phenol, Glycosides and partly Alkaloids. This research highlights the potential of these plant-derived extracts as alternative sources for new antimicrobial agents to combat resistant strains of bacteria.