With the rise in bacterial resistance to antibiotics, there is considerable interest in the development of other classes of antimicrobials for the control of infection. Garlic (Allium sativum Linn.) has been used as medicine since ancient times and has long been known to have antibacterial, antifungal, and antiviral properties. This study was undertaken to assess the inhibitory effect of garlic on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans, to assess the time-kill curve of P. gingivalis and A. actinomycetemcomitans, and to determine the antiproteolytic activity of garlic on P. gingivalis. Ethanolic garlic extract (EGE) and aqueous garlic extract (AGE) were prepared and the inhibitory effects of these extracts for two periodontal pathogens (P. gingivalis and A. actinomycetemcomitans) were tested. Antiproteolytic activity on protease of P. gingivalis was determined. 25 microliter (μl), 50 μl, and 75 μl of AGE showed 16 mm, 20 mm, and 25 mm zone of inhibition, respectively, on P. gingivalis. The AGE showed greater bacteriostatic activity against the P. gingivalis with minimum inhibitory concentration determined at 16.6 μl/ml. The time-kill assay of AGE and EGE were compared for P. gingivalis and A. actinomycetemcomitans. AGE showed better antiproteolytic activity on total protease of P. gingivalis compared to the EGE. Thus, the study concludes the antimicrobial activity of garlic extract against periodontal pathogens, P. gingivalis, A. actinomycetemcomitans. Its action against P. gingivalis includes inhibition of total protease activity, and this raises the possibility that garlic may have therapeutic use for periodontitis and possibly other oral infections.

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This study aimed to investigate the antibacterial [minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)] and antibiofilm activity [log10 colony forming unit/mL (CFU/mL) and biofilm disruption] of copper-doped phosphate glass (CDPG) against Streptococcus oralis, Enterococcus faecalis, Lactobacillus casei, Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Methods: the antibacterial activity was determined using microbroth dilution and time-kill assay. The antibiofilm activity was investigated using crystal violet and confocal laser scanning microscopy. Bacteria growing in absence of CDPG were used as controls. Results: the MIC was ≥125 mg of CPDG/mL; the log10 CFU/mL reduction ranged from 2.66–3.14 to 6.23–9.65 after 4 and 24 h respectively. Generally, no growth was observed after 24 h of treatment with CDPG; the MBC was 250 mg/mL for L. casei and S. oralis while 500 mg/mL for the rest of the bacteria. The highest and lowest antibiofilm activity was observed against S. oralis and E. coli respectively. Three patterns of complete biofilm disruption were seen: (i) large areas with E. fecalis and S. oralis, (ii) medium-size pockets with S. aureus and P. aeruginosa, or (iii) small areas with E. coli and L. casei. Conclusion: CDPG can be potentially used as an antibacterial and an antibiofilm agent against oral biofilm-forming bacteria.

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Background: The role of Gram-negative anaerobic periodontal pathogens in periodontal diseases has led to the loss of tooth-supporting structures. These diseases can be prevented by the inhibition of bacterial biofilm on the tooth surfaces. Many treatment modalities have been tried to prevent periodontal diseases. With the rise in resistance to synthetic antimicrobials, there is a requirement to develop natural antimicrobials for the control of periodontitis. Aim: The aim of the study was to evaluate and compare the efficacy of garlic (Allium sativum) and guava (Psidium guajava) extracts on Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans using time-kill assay. Materials and Methods: Aqueous garlic extract (AGaE), ethanolic garlic extract (EGaE), aqueous guava extract (AGuE), and ethanolic guava extract (EGuE) were prepared. Time-kill assays were performed on P. gingivalis and A. actinomycetemcomitans. The aqueous and ethanolic extracts of guava and garlic were compared to assess the maximum bactericidal potency. Results: The comparison of time-kill assay of AGaE and AGuE on P. gingivalis showed a statistically significant difference at 2 h (t = 5.29, P < 0.01), 4 h (t = −4.867, P < 0.01), and 6 h (t = −3.647, P < 0.001). The comparison of time-kill assay of EGaE and EGuE on A. actinomycetemcomitans showed a statistically significant difference at 2 h (t = 4.54, P < 0.01) and highly significant difference at 4 h (t = 6.57, P < 0.001). Conclusions: The, judicious use of these phytomedicinal products could be cost-effective and also the adverse effects caused due to the long-term usage of synthetic antimicrobials can be avoided.