Green Synthesis of Antibacterial Silver Nanoparticles against Drug Resistant Bacteria

Background: Nanotechnology brings a massive revolution in the domain of medical biotechnology. Plants possess thousands of antimicrobial compounds; these compounds can be extracted and utilized in the production of medicines. Objective: The aim of this research is to design an economical method for the formation of nanoparticles from plants and explore their antibacterial activity. Methods: In the present study, we used the plants Aloe barbadensis, Azadirachta indica, Carica papaya, Mentha arvensis and Catharanthus roseus. Ethanolic, methanolic and aqueous extracts of the above mentioned plants were used to prepare silver nanoparticles. Antimicrobial activities of the nanoparticles of extracts were determined against pathogenic strains of bacteria. Results: Results showed that silver nanoparticles are formed from the ethanolic and methanolic extracts of Azadirachta indica, Carica papaya, Mentha arvensis and Catharanthus roseus and from the aqueous extracts of Aloe barbadensis and Mentha arvensis. It was observed that nanonoparticles of ethanolic extracts of Azadirachta indica, Carica papaya, Mentha arvensis and Catharanthus roseus exhibited the highest antibacterial activity against Pseudomonas specie, E.coli, Pseudomonas specie and S.typhi, respectively. On the other hand, the nanoparticles of methanolic extracts of Carica papaya, Mentha arvensis and Catharanthus roseus showed the highest inhibition against E.coli, whereas, maximum zone of inhibition of Pseudomonas was observed by the action of methanolic extract of Azadirachta indica. It is also found that nanoparticles of the aqueous extracts of Aloe barbadensis and Mentha arvensis inhibited the pathogenic strains and showed maximum activity against Pseudomonas and E.coli, respectively. Conclusion: The above results indicate that the nanoparticles formed from the extracts of the tested plants have high antimicrobial potential and could be utilized in the preparation of medicines to treat various disorders.