In vitro, in vivo, and anticytotoxic effects of silver nanoparticles green synthesized by Astragalus baba-alliar against Giardia lamblia infection

Abstract

Now, numerous synthetic medications are available for managing giardiasis, such as metronidazole, furazolidone, and tinidazole. These pharmaceuticals are associated with various adverse effects. The present experimental investigation aims to assess the in vitro and in vivo effects of silver nanoparticles (SNP) synthesized Astragalus baba-alliar extract against Giardia lamblia. The precipitation technique was utilized for the eco-friendly synthesis of SNP by reducing silver ions. An in vitro study was conducted on G. lamblia cysts and trophozoites following exposure to varying concentrations of SNP (10–200 µg/mL) for durations ranging from 10 to 360 min. The impact of SNP on trophozoite plasma membrane integrity and its cytotoxic effects on both normal and colon cancer cells were evaluated. In the subsequent in vivo experiment, BALB/c mice infected with Giardia were administered SNP at doses of 10, 15, and 20 mg/kg/day for a duration of one week. Stool examinations were conducted on the 8th day post-infection to assess the presence of Giardia cysts and determine the reduction rate. The study found that the size of synthesized SNP ranged from 10 to 90 nm, with the highest concentration of particles falling within the 35–45 nm range. The administration of SNP significantly elevated the mortality rate of G. lamblia cysts in a dose-dependent manner. Specifically, at concentrations of 100 and 200 ?g/mL, SNP effectively eradicated G. lamblia cysts after 120 and 240 h, respectively. In an in vivo setting, the treatment of infected mice with SNP at doses of 10, 15, and 20 mg/kg likewise led to a dose-dependent reduction in the viability of G. lamblia cysts. Exposing G. lamblia trophozoites to SNP led to a dose-dependent elevation in the permeability of trophozoite plasma membranes. The 50% cytotoxic concentrations (CC50) values of SNP for colon cancer and normal cell lines were measured at 361.7 ?g/mL and 769.9 ?g/mL, respectively. The calculated selectivity index value, which exceeds 2 (2.13), suggests that the SNP demonstrates a higher safety profile for normal cells compared to cancer cells. The experimental investigation demonstrated that SNP produced using A. baba-alliar exhibited significant anti-Giardia activity both in laboratory settings (in vitro) and in living organisms (in vivo), suggesting its potential as a treatment for Giardia infections. However, further studies are needed to elucidate the precise mechanisms of action and thoroughly evaluate the toxicity profile of this type of SNP. © Indian Society for Parasitology 2025.