Green Synthesis of Silver Nanoparticles from Medicinal Plants and Their Biological Applications: A Review

Abstract

The manufacture of metal nanoparticles using plant extracts is one of the simplest, most useful, economical and environmentally advantageous approaches to decrease the usage of hazardous substances. Since the earliest days of human history, silver and silver salts have been employed, but silver nanoparticles (Ag NPs) have just recently reached light. Particularly in agriculture and medicine, these have been used as antibacterial, antifungal, and antioxidants. The current research on the environmentally friendly manufacture of silver nanoparticles (AgNPs) utilising various plant extracts and their potential use as antibacterial agents is summarised and explained in this review. The main objective is to provide a comprehensive and systematic review of how various factors affect the synthesis of green Ag NPs with antimicrobial properties. These factors include the type and concentration of plant extracts and phytochemicals, the solvent and temperature of extraction, and the temperature, pH, time, and concentration of the reaction. Recent advances in using different plants to yield Ag NPs with different sizes, shapes, and stabilities have been presented. It is currently demonstrated that Ag NPs prevent many bacteria and fungi from growing and multiplying by combining Ag/Ag+ with the biomolecules found inside the microbial cells. Antioxidants and reactive oxygen species that might be produced by Ag NPs, which, by preventing cell replication, cause apoptosis and cell death. SEM and TEM images of the nanoparticle-pathogen solution show that Ag NPs may enter cells and break through the cell wall since they are smaller than microorganisms. It has similarly been established that lesser Nps present additional risks than superior ones. Additionally, Ag NPs are used in packaging to prevent microbial contamination of food products. Ag NPs' toxicity is influenced by the size, concentration, pH of the media, and length of pathogen exposure. Comprehensive details have also been provided on the biogenic AgNPs' shape- and size-dependent antibacterial properties as well as the improved antimicrobial activities caused by the synergistic interaction of AgNPs with well-known commercial antibiotic medicines.