ANTIBACTERIAL ACTIVITY AND CYTOTOXICITY OF AMLA SEED MEDIATED GRAPHENE OXIDE, SILVER NANOPARTICLE & Go-Ag NANOPARTICLE - AN in vitro STUDY

Aim: The aim of the study was to prepare Amla seed mediated silver nanoparticles, Graphene oxide nanoparticles and GO-Ag nanocomposite and assess its antibacterial activity against Streptococcus mutans, Lactobacillus & Candida albicans. This is followed by determining the cytotoxicity of amla seed mediated graphene oxide nanoparticles & silver nanoparticles, and GO-Ag nanocomposite using Brine shrimp lethality assay.

Materials and Methods: Amla seed extract was prepared. The filtrate was used in biosynthesis of Silver, Graphene oxide nanoparticles and GO-Ag nanocomposites. After 24 hours of incubation, the samples were measured for its maximum absorbance using UV-Visible spectrophotometry. All the samples were then heat dried to obtain the synthesized silver nanoparticles, graphene oxide nanoparticles and GO-Ag nanocomposite. Antibacterial activity of various concentrations of biosynthesized Amla seed mediated silver nanoparticles, graphene oxide nanoparticles and GO-Ag nanocomposite (50,100,150 μg/ml) against Streptococcus mutans, Lactobacillus and Candida albicans was assessed. Cytotoxicity of various concentrations of the nanoparticles was assessed using Brine Shrimp Lethality Assay.

Results: AgNPs showed colour change from colorless to reddish brown, GO NPs showed color change from brown to black, whereas GO-Ag nanocomposite turned from black to darker intensity of black. This color change confirms the formation of their respective nanoparticles. Silver nanoparticles has good antibacterial activity against Streptococcus mutans

(150 ug/ml – 17 mm Zone of Inhibition) and Lactobacillus (150 ug/ml – 20 mm zone of Inhibition) and showed 20% lethality at 25 ul concentration. Graphene oxide nanoparticles have good antibacterial activity against lactobacillus (150 ug/ml – 20 mm zone of Inhibition) and showed 40% lethality at 25 ul concentration. GO-Ag nanocomposite has minimal antibacterial activity against all the test organisms and showed 10% lethality at 20 and 25 ul. All three nanoparticles showed minimal antibacterial activity against C. albicans (9 mm Zone of Inhibition).

Conclusion: The silver nanoparticles, graphene oxide nanoparticles and GO-Ag nanocomposites were synthesized from seed extracts of Amla fruit. Silver, Graphene oxide nanoparticles and GO-Ag nanocomposite showed good antibacterial effect against oral pathogens with minimal cytotoxicity.