Antibacterial activity of garlic extract on cariogenic bacteria: An in vitro study

BACKGROUND: Garlic (Allium Sativum) is ubiquitous, small and commonly used spice for processing food. There are many types of garlic and differ in shape, size, color, taste, number of cloves per bulb and storability. OBJECTIVES: To determine and compare the antibacterial activity of soft neck and hard neck species of garlic against cariogenic bacteria (Streptococcus mutans and Lactobacillus acidophilus). MATERIALS AND METHODS: The well diffusion method was used to evaluate the antibacterial activity of garlic against Streptococcus mutans and Lactobacillus acidophilus. After incubation in an appropriate culture medium, diameter of zone of inhibition was measured to assess the antibacterial efficacy of garlic extract. Chlorhexidine mouthwash (ICPA HEALTH PRODUCTS LTD.) was kept as control group. Results were statistically analyzed using Kruskal Wallis test and independent ’t’ test. Thus, zone of inhibition (in mm) was analyzed using mean of all the readings obtained and the level of significance at <0.05 was considered statistically significant at 5% of level of significance. RESULTS: Maximum zone of inhibition was found with hard neck garlic extract (24mm) followed by soft neck garlic extract (18mm) and Chlorhexidine (17mm) against Streptococcus mutans and Lactobacillus acidophilus. CONCLUSION: Action of garlic against Streptococcus mutans and Lactobacillus acidophilus raises the possibility that it can be used for dental caries and other oral infections possibly.