Biosynthesis of silver nanoparticles using gamma irradiated of Iranian propolis extract

Silver nanoparticles have many applications in medicine, pharmacy, and industry. Biosynthesized silver nanoparticles are suitable for medical purposes. In this study, scanning electron microscope (SEM) analysis of biosynthesized silver nanoparticles by Iranian propolis’ alcoholic extract shows that AgNPs sizes in gamma-irritated group are about 50–90 nm, and 100–580 nm in the non-irradiated group. Moreover, AgNPs in the irritated group are spherical in shape and homogeneous. DPPH analysis shows that antioxidant activity is significantly increased by raising the concentration of alcoholic extracts in both irradiated and non-irradiated states (P < 0.05). Regenerative properties of propolis alcoholic extract at both gamma-irradiated and non-irradiated states against three bacteria: Staphylococcus aureus (a Gram-positive round-shaped bacterium and food poisoning agent), E. coli (gram-negative, food poisoning agent) and B. subtilis (gram-positive), were examined. As a result, the AgNPs antioxidant properties in the irradiated group have significantly increased compared to the non-irradiated state. Studies on AgNPs antibacterial activity against Gram-positive B. subtilis and S. aureus and Gram-negative E. coli have shown that AgNPs are lethal rather than inhibitory against B. subtilis and S. aureus, and in both irradiated and non-irritated types the rate of MIC and MBC is same against Gram-negative E. coli; hence, due to green synthesis and lack of toxic substances in this method, nanoparticles can be used in medical applications.