Purpose A multitude of inflammatory cells and chemical mediators initiate a complex cascade that ultimately leads to hepatocyte death and a systemic inflammatory response. This research aimed to investigate the potential effects of sildenafil and neem (Azadirachta indica) extract, in both conventional and nanoparticle (NP) forms, in the treatment of moderate acute liver damage induced by orogastric carbon tetrachloride (CCL4).

Methods To induce moderate acute hepatic damage a single oral dosage of CCL4 (2.5 mL/kg body weight) was provided 24 h before euthanasia. In liver damage-induced CCL4, sildenafil and neem extract were given in conventional and nanoparticle (PLGA or niosome) forms. To find histological anomalies and hepatic changes, behavioral, biochemical, histopathological, and immunohistochemical methods were used.

Results The findings indicated that sildenafil and/or neem extract, especially in NP combination, significantly mitigated CCL 4-induced acute moderate liver damage. Indicators of liver function, including aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), albumin, bilirubin and gamma-glutamyl transferase (GGT), shown improvement, particularly with the nanoparticulation of both therapies. Treatment, particularly in NP forms, improved the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase activity (GPx) in liver tissues. A significant reduction in NF-κB expression in hepatic tissue was shown in treatment groups. Also, medication resulted in lower levels of interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), caspase-3, and transforming growth factorbeta (TGF-β) in the liver tissue homogenates. Liver function was more significantly improved by the drug-NP combination. Conclusions This study verified the beneficial therapeutic effects of the combination of sildenafil and neem extract, particularly in NP forms, using biochemical, histological, and immunohistochemical analyses in a rat model of liver damage