RESUMEN
Introduction Madhuca longifolia is one of the important folklore medicinal plants with a plethora of established pharmaceutical properties. Its twigs are used as chewing sticks (toothbrushes), and it is believed that if a person uses it daily, it will make their gum healthy and strong. No study has ever been conducted to evaluate the antibacterial effect of M. longifolia extracts against oral microorganisms. Materials and methods Fresh stem twigs (Madkam Kaarkad) of M. longifolia were collected and dried. The dried stem was cut into small pieces, 5 g of which was mixed with 50 ml distilled water (in the ratio 1:10) and kept for two days for maceration. After two days, the liquid was filtered and the final filtrate was obtained, from which dry pellets were made and stored in the refrigerator at 4°C. Brain heart infusion agar was used as a medium to grow the lyophilized bacteria. Pure strains of Streptococcus mutans 890 were obtained from the Microbial Type Culture Collection (MTCC) and MTCC-suggested protocol was followed for the revival of lyophilized bacteria. The agar well diffusion method was used to determine the zone of inhibition. The extract of stems with different concentrations (10%, 7.5%, 5.0%, and 2.5%) and at different volumes (100 µl, 150 µl, 200 µl, and 250 µl) was transferred to the agar plates. Chlorhexidine 0.2% was used as a control and it was also transferred to agar plates, which were incubated aerobically at 37°C for 24 hours. Antibacterial activity was interpreted from the size of the diameter of zones of inhibition measured in millimeters using a measuring scale in all the agar plates. Results The minimum zone of inhibition of 11 mm at 2.5% concentration and 100 µl volume of M. longifolia extract and the maximum zone of inhibition of 20 mm at 10% concentration and 250 µl volume was notified. While for chlorhexidine at 0.2% concentration, the zone of inhibition obtained was 9.5 mm at 40 µl volume. The minimum inhibitory concentration (MIC) value of M. longifolia was found to be 35 mg/ml. Conclusion M. longifolia showed marked antibacterial activity against S. mutans and has a high MIC value. Therefore, this plant can be considered an effective agent against oral diseases like dental caries.