[117] by using Odontosoria Chinensis extract, which resulted in the formation of spherical AgNPs of diameter 22.3-48.2 nm. used Parthenium hysterophorus extract to to synthesize spherical AgNPs having average size of 10.3±1.7 nm. In this the hydroxy group was responsible for the reduction of Ag + and formation of AgNPs. The obtained AgNPs portrayed antibacterial activity and anti-cancer activity. This process is highly dependent on the plant extract composition and parameters such as pH, temperature and concentration ratio. The process is simple, cost-effective, environmentally friendly and had low reaction time. However, the mechanism for affecting the synthesis of process is unknown . The examples of different plant extracts to synthesize AgNPs is given in Table .