Therapeutic effects of silver nanoparticles on Escherichia coli-induced endometritis in rats

Abstract

Background Silver nanoparticles (AgO-NPs) have shown antimicrobial effects against a broad spectrum of microorganisms. Objectives To assess the antimicrobial effects of AgO-NPs prepared using an eco-friendly green method against multidrug-resistant Escherichia coli in vivo after inducing endometritis in rats. Materials and methods In female mice, LD50 of AgO-NPs was determined, followed by a chronic toxicity in female rats by oral administration of 0, 20, 30, and 40 mg of AgO-NPs daily for 4 weeks. The induced endometritis model in female rats was performed by inoculating two doses of E. coli (100 μl of 10×105 CFU) intravaginally. Seven days later, vaginal swabs were stained with Wright stain to confirm the development of endometritis and used to re-isolate the inoculated microorganism. Two doses of 100 μl containing 10 mg AgO-NPs were inoculated intravaginally. Estradiol, progesterone, liver and kidney functions, oxidants and antioxidants, and zinc were measured in collected blood samples of chronic toxicity and induced endometritis model. Results and conclusion LD50 of AgO-NPs was 800 mg/kg body weight (BW). The use of 40 (1 : 20 LD50), 30 (1 : 26.67 LD50), and 20 (1 : 40 LD50) mg/kg BW during the chronic toxicity experiment was safe as indicated by blood biochemical analyses. The chronic toxicity experiment resulted in normal liver and kidney functions, oxidant–antioxidant status, acute-phase proteins, and ovarian hormones. The green method-synthesized AgO-NPs showed efficacy against E. coli-induced endometritis, and rats responded to the treatment as indicated by the uterine cytology and the clinical analysis with mild adverse effects on both liver and kidney. In conclusion, AgO-NPs showed treatment of experimental uterine infections induced by E. coli in rats and were safe for longer administration in concentrations lower than 50 mg/kg BW.