Antibacterial Action of Curcumin Nanocrystals on Streptococcus Mutans

The present study aimed to investigate the antibacterial and antibiofilm properties and adhesion inhibitory effect of curcumin nanocrystals compared to bulk curcumin against Streptococcus mutans.

S. mutans is the main aetiological factor in tooth decay. Curcumin has been used in various studies as an antimicrobial agent due to its wide traditional uses and low side effects. Despite having multiple therapeutic effects, its inherent properties, for example, poor aquas solubility, low bioavailability, photodegradation, chemical instability, rapid metabolism, and short half-life, limit its pharmaceutical significance. Recently, newer strategies have been tried to overcome these pharmacological issues and improve curcumin's therapeutic efficacy. The nanoformulation can enhance the effectiveness of curcumin in a wide range of diseases, especially infectious diseases.

The present study evaluated the Minimum Inhibitory Concentration (MIC), biofilm inhibitory, and adhesion inhibitory actions of curcumin nanocrystals compared to bulk curcumin against S. mutans.

The results showed that curcumin nanocrystals were more effective than curcumin against S. mutans. The MICs spectrum of bulk curcumin and curcumin nanocrystals was 256-512 µg/mL and 125-256 µg/mL, respectively. Both bulk curcumin and curcumin nanocrystals inhibited the formation of S. mutans biofilm (p<0.05), and bacterial adhesion was significantly decreased compared to bulk curcumin and control (p<0.05).

These findings showed that using curcumin nanocrystals in mouthwashes and toothpaste can be useful in preventing dental plaque. Further research is required to determine the stability of curcumin nanocrystals in formulation with other dental product ingredients and to assess their safety and efficacy in human clinical trials.