Antimicrobial potential of the extracts of the twigs of Azadirachta indica (Neem): an in vitro study

Abstract

Objective: Various medicinal plants have been used since ancient times in daily life to treat diseases all over the world. Almost every part of the Azadirachta indica A. Juss (syn. Melia azadirachta) tree commonly known as neem has been used for years to treat a number of human diseases. As neem is known to possess antimicrobial activity against a number of organisms, the present study was carried out to reveal the antibacterial effect on common oral cariogenic and periodontal pathogens and antifungal activity against Candida albicans. Methods: The twigs of Azadirachta indica were collected and different solvents were used for the preparation of the extract namely petroleum ether, dichloromethane, ethyl acetate, methanol and aqueous solvent. The antibacterial potential was evaluated using the agar well diffusion assay. Sodium hypochlorite and dimethyl sulfoxide were used as positive and negative controls, respectively. Results: Methanol extract of neem exhibited the highest antimicrobial activity at 500 mg/ml concentration, whereas the aqueous extract did not demonstrate any antibacterial and antifungal activities at any concentration tested. Conclusion: Evidence of antimicrobial activities of neem twig extract against cariogenic and periodontal pathogens indicates the presence of bioactive compounds which need to be isolated and identified for the incorporation in the modern oral health care system.