Protective effects of Sphaeranthus indicus floral extract against BPS induced testicular damage in rats occurs through downregulation of RIPK1/3-MLK-driven necroptosis and Fas-FasL-mediated apoptosis

Abstract

Bisphenol S (BPS) is one of the monomers preferred in the manufacturing of polycarbonate plastics. Unfortunately, its estrogenic and genotoxic effects are similar to those of bisphenol A. The protective effects of Sphaeranthus indicus floral extract (SFE) against reprotoxic effects of BPS (50 µg/kg per body weight) in rats exposed to it via drinking water was investigated. Different SFE doses (25, 50, and 100 mg/kg) were administered via oral gavage for 10 weeks. High performance liquid chromatography (HPLC) results indicated that SFE was rich in polyphenols, with rutin and quercetin being important bioactive molecules modulating BPS-induced necroptosis and apoptosis. Biochemical analyses unveiled that rats administered BPS only exhibited considerable elevation of biomarkers of nitro-oxidative stress, necroptotic (RIPK1/RIPK3 and MLKL), and apoptotic mediators (Fas/FasL and caspase 3/caspase-8). These events caused changes in sperm characteristics (sperm motility, sperm head, and sperm viability), sperm count, and hormonal profile (thyroid stimulating hormone, luteinizing hormone, and follicle-stimulating hormone) of the rats. Histological analysis suggested that there was pronounced sloughing of Sertoli cells, reduced spermatogenic cell density, increased levels of seminiferous tubules, and disorganized morphometric parameters related to seminiferous tubules. The SFE supplementation in rats with BPS-containing water restored nitro-oxidative stress biomarkers, which led to the reduction of necroptosis and apoptosis. Reinstatement of all the biomarkers of oxidative stress, inflammation, necroptosis, and apoptosis after SFE supplementations restored the hormonal profile and normal histoarchitecture of the testes. Virtual screening elucidated that the key regulators of the necroptosis are RIPK3-rutin and RIPK1-quercetin complexes. Further studies are needed to assess its pharmacodynamics, kinetics, and effective concentration for daily use in humans.