Biosynthesized selenium nanoparticles as a promising antischistosomal agent: modulation of oxidative stress and pro-inflammatory cytokines in mice.

The genus Schistosoma is the most medically important species responsible for schistosomiasis in humans. The primary anthelmintic medication for schistosomiasis is praziquantel (PZQ), which is effective against adult worms and may confer an immune-mediated advantage by enhancing resistance to reinfection; however, it has limited efficacy against juvenile stages. Recently, natural remedies for parasitic infections have drawn more attention. The present study aimed to evaluate the anthelmintic, antioxidant, and immunomodulatory effects of bio-synthesized selenium nanoparticles (Bio-SeNPs) prepared from Capsicum annuum extract on the liver of Schistosoma mansoni-infected mice. Five groups of mice were used; the first group was kept as a control. Bio-SeNPs (0.5 mg/kg) were given to the second group. The three other groups were each injected with 60 ± 10 cercariae; the third group was kept as a positive control, and the fourth group was treated with bio-SeNPs (0.5 mg/kg). Praziquantel (500 mg/kg) was given to the last group. The results demonstrated that oxidative stress and nuclear factor kappa B (NF-κB) were significantly reduced in the hepatic tissue of mice given bio-SeNPs (0.5 mg/kg). Furthermore, it decreased the expression of cytokines TNF-α, IFN-γ, IL-1β, and IL-10 in the hepatic tissue of infected mice. Additionally, the number of adult worm burdens in the liver was reduced by 48% accompanied by a reduction in histopathological changes, including attenuation of hepatic fibrosis as evidenced by reduced collagen deposition, in contrast to the infected group. Study of the worms by scanning electron microscopy in bio-SeNP-treated mice revealed severe tegumental abnormalities, including erosion and body coiling. Physicochemical characterization confirmed the successful biosynthesis of Bio-SeNPs, as demonstrated by UV-visible spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) analyses. In conclusion, biosynthesized selenium nanoparticles (Bio-SeNPs) are a promising therapeutic option for reducing schistosomiasis-induced liver damage in mice through combined antiparasitic, antioxidant, and immunomodulatory mechanisms.