Paricalcitol, an active vitamin D analog, mitigates dexamethasone-induced hepatic injury: Role of autophagy, pyroptosis, and PERK/Nrf2/HO-1 signaling pathway.

Drug-induced toxicity is considered a crucial clinical affair, as some adverse effects could be severe or life threatening. Drugs may have adverse effects by altering biological pathways that aren't always involved in the drug's reaction. From this perspective, the purpose of the current study was to assess the impacts of paricalcitol, a synthetic, active, and selective vitamin D receptor activator, on dexamethasone-induced liver injury, and discover the probable implicated signaling pathways as well. Male Wistar rats were treated with paricalcitol at a dose of 0.2 μg/kg, daily, i.p for 12 days and injected with 8 mg/kg dexamethasone i.p daily over the last 6 days. Administration of paricalcitol improved liver function markers, lipid profile, reduced histopathologic changes in hepatic sections, and restored normal oxidative status. Moreover, paricalcitol markedly decreased hepatic collagen deposition as confirmed by Masson's trichrome staining. Paricalcitol effectively inhibited endoplasmic reticulum stress through decreasing expression of tissue PERK and Chop, increasing hepatic Nrf2, and HO-1 activity. Besides, paricalcitol decreased levels of NLRP3 and IL-1β as well as decreased expression of active caspase-1 p20, GSDMD-N-terminal indicating suppression of NLRP3/caspase-1/GSDMD pyroptosis pathway. Paricalcitol can protect against dexamethasone-induced liver injury showing a promising therapeutic value in drug-induced liver injuries.