The antimicrobial and antibiofilm effects of three herbal extracts on compared with Chlorhexidine 0.2% ( study).

There is a special focus on using natural materials and herbal plants to prevent dental caries. Previous studies showed that some herbal plants have antimicrobial effects on oral pathogens. Thus we investigated the antimicrobial effects of three herbal extracts (, , and ) on the growth of , as the most important bacteria causing dental caries. First, plant methanolic extracts were prepared. Then, to evaluate the antimicrobial activity of the three herbal extracts, the agar well diffusion method and MIC were performed. The biofilm formation was carried out using a broth dilution method with 2% glucose-supplemented BHIS in sterile 96-well microplates. Serial dilutions (50, 25, 12.5, 6.25, 3.12 mg/ml) of extracts were prepared. Next, a 0.5 McFarland Suspension of was added to wells. The inhibitory effect on biofilm formation was measured by the ELISA reader apparatus. The assay was repeated three times, and the average was calculated as 3. The results were compared with those of Chlorhexidine 0.2%. showed a better effect in the agar well diffusion method than others. MIC of the extracts of Carum coptimum, , and were 3.12, 6.25, and 12.5 mg/ml, respectively. Overall, the highest activity belonged to extract. For the anti-biofilm effect, the OD values of and were significantly different from that of . Although all of the methanolic herbal extracts can inhibit growth and remove the biofilm, the effect of was better than and . Further studies are recommended to indicate how these extracts perform against the bacteria.