Curcumin Mediated Gold Nanoparticles and Analysis of its Antioxidant, Anti-inflammatory, Antimicrobial Activity Against Oral Pathogens

ABSTRACT Objective: To green synthesise gold nanoparticles using curcumin and to analyse its antioxidant, anti-inflammatory, and antimicrobial activity among oral pathogens. Material and Methods: Biosynthesised Curcumin Gold nanoparticles (CuAuNP) were evaluated by UV-visible spectrophotometer (UV-Vis), Transmission Electron Microscopy (TEM), and evaluation of antioxidant, anti-inflammatory and antibacterial activity against oral pathogens. Results: Synthesized CuAuNP were characterized using UV-visible spectrophotometry and showed peak absorption at 530nm. CuAuNp showed a 90.3% maximum scavenging ability of DPPH at a concentration of 50 μg/mL. CuAuNP exhibited 79.6 % of the highest anti-inflammatory activity at 50μg/mL than the standard drug diclofenac. TEM image clearly showed uniformly dispersed spherical-shaped gold nanoparticles with a size of about 20 nm. The biosynthesized nanoparticle was tested for its antimicrobial effect, and it showed a potent effect against S. aureus, E. faecalis, and C. albicans at 100µg/ mL. Enterococcus faecalis has a maximum zone of inhibition of 14 mm at 100µg/ mL of CuAuNp. Among gram-positive bacteria, a maximum zone of inhibition of 12 mm at 100µg/ mL was seen in S. aureus compared to S mutans. Candida albicans showed a maximum zone of inhibition of 18 mm at 25 μg/mL of CuAuNp. Conclusion: Curcumin-mediated gold nanoparticles with 20 nm size were effective and had strong antioxidant and anti-inflammatory activity at 50µg/ mL, antimicrobial action inhibiting microbes at 100µg/mL concentration that can be used in treating various Oral mucosal lesions.

Comparative Evaluation of Antimicrobial Efficacy of Silver, Titanium Dioxide and Zinc Oxide Nanoparticles against Streptococcus mutans

Objective: To determine the antimicrobial efficacy of silver, titanium dioxide and zinc oxide nanoparticles against Streptococcus mutans. Material and Methods: Serial dilution method was employed for preparing 1%, 0.5%, 0.25% concentrations of the three test compounds. ATCC 25175 strain of streptococcus mutans was used to assess the antimicrobial activity of test compounds. Equal quantity of BHI broth was dispensed in test tubes containing sectioned tooth and to this the prepared bacterial inoculum was added. Prepared concentrations of test compounds were added accordingly and incubated for 24hrs at 370C. Then, the sectioned tooth was removed and the adherent bacteria were transferred into saline solution by vortexing. These suspensions were transferred onto sterile blood agar plate to make lawn culture and were further incubated at 370C for 24hrs to determine viable bacterial count. The number of colonies were counted manually from each plate and recorded for further analysis. Decrease in number of colonies represents the effective concentration of the test compound against the inhibition of biofilm formation. Results: A significant difference in the colony forming units among all three concentrations of silver (Ag), titanium dioxide (TiO2) and zinc (ZnO) nanoparticles was noted and the antimicrobial effect of nanoparticles was concentration dependent. Inter group comparison of colony forming units with 1%, 0.5% and 0.25% of the test compound revealed that the colony forming units on the ZnO nanoparticles demonstrated highest value followed by TiO2 and the least were with that of the Ag nano particles. Conclusion: Silver, Zinc oxide and Titanium dioxide showed significant antimicrobial effects and the antimicrobial effect of nanoparticles was concentration dependent.