Antibacterial activity of Kigelia Africana Methanolic, Ethanolic, and Aqueous extracts against Pseudomonas Aeroginosa and Staphylococcus Aureus isolated from the wounds of the diabetic patients attending care in Mulago Hospital

Abstract

African plant Kigelia africana belonging to the family Bignoniaceae is widely distributed in South, Central, and West Africa. Different parts of K. africana have been used for various medicinal purposes by ethnic groups in different parts of the world for the treatment of common skin diseases such as fungal infections, cancer gynecological complaints, constipation, tapeworm infection, jaundice, ulcers, sores, pneumonia, malaria, diabetes, and waist pain among the others. Therefore, the aim of this study was to evaluate the antimicrobial activity of Kigelia africana leaves and bark extracts on Pseudomonas aeruginosa and Staphylococcus aureus isolated from diabetic wounds. Methodology: In vitro antibacterial activity of extracts was tested against two bacterial strains Pseudomonas aeruginosa and Staphylococcus aureus by agar diffusion method. Ethanol and sterile distilled water were used as negative control and oxytetracycline was used as a positive control. Methanolic extracts of bark of Kigelia africana showed remarkable activity against both bacterial strains as compared to aqueous and ethanolic extracts. Results: Overall, the comparative analysis revealed that bark and leaves extract exhibited the most remarkable antibacterial activity against the tests bacteria as compared to flowers extracts. For bark highest zone of inhibition for P. aeruginosa was 10mm for methanolic extract and staphylococcus aureus 24mm for methanolic extract the highest minimum inhibition concentration was 0.125g/ml, and 0.25g/ml for P. aeruginosa, and staphylococcus aureus respectively. For the flower, the Highest zone of inhibition for P. aeruginosa was 6 mm for methanolic extract and staphylococcus aureus 12mm for methanolic extract and the highest minimum inhibition concentration was 0.5g/ml, and 0.5g/ml for P. aeruginosa, and staphylococcus aureus respectively. For leaves Highest zone of inhibition in P. aeruginosa was 4mm for methanolic extract and staphylococcus aureus 14mm for aqueous extract and the highest minimum inhibition concentration was 0.125g/ml, and 0.25g/ml for P. aeruginosa, and staphylococcus aureus respectively. Conclusion and recommendations: All Kigelia africana methanolic, ethanolic, and aqueous extracts showed the antibacterial effects against pseudomonas aeruginosa and staphylococcus aureus. Generally, the bark extract has a high antimicrobial effect compared to flower and leaves extract on the organisms tested and it was found that Staphylococcus aureus trended to be more ix susceptible than P. aeruginosa. The finding that the plant has an antibacterial effect showed that the Kigelia africana extracts can be used as an alternative in management of pseudomonas aeruginosa and staphylococcus aureus infections in a diabetic patient. This however needs further investigation to determine Toxicity of Kigelia to establish the safety levels for use as an antibiotic.