Antimicrobial Activity of Ethanolic and Aqueous Extracts of Fresh and Dried Leaves of Azadirachta indica (Neem’s leaf)

The leaves of Azadirachta indica (Neem), commonly called Dogonyaro are used in parts of Nigeria right before now as antimicrobial medicine. This study was designed at investigating the antimicrobial activities of the crude ethanolic and aqueous extracts of both the fresh and dried Neem’s leaf on strains of bacteria viz; Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Proteus vulgaris with one of the opportunistic fungi which is Candida albican’s, using agar well diffusion methods. The qualitative and quantitative phytochemical screening of the sample were done using the standard methods and showed a variety of phytoconstituents. The fresh Neem’s leaf of aqueous and ethanolic gave zones of inhibition diameter (ZIDs), ranging from 10 – 20mm and 9 – 18mm each, while the aqueous extrac and ethanolic of from the dried neem leaves gave zone of inhibition diameter of 9 – 13mm and 9 – 14mm respectively. From the results, the organisms showed a statistically significant difference (p<0.0001) in ZIDs according to the concentration levels of the extract. The ethanolic extracts of fresh neems leaf when compared with the dried extracts gave a statistically significant difference (p<0.05) in most of the tested organisms. But when compared with the standard antibiotics discs, there was no statistically significant difference (p>0.05) proving that it could b used in place of the synthetic antibiotics to inhibit (Bacteriostatic) the organisms. It is recommended that the active biological ingredients in the Neem should be extracted and purified with more sophisticated techniques and used in combination with other drugs in treatment of microbial infections to avoid much resistance.

Keywords: Antimicrobial Activity, Azadirachta indica (Neem’s leaf), Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Proteus vulgaris, Candida albican.