Viburnum opulus protects against acetaminophen-induced splenic injury through coordinated antioxidant and anti-inflammatory responses

Abstract

Acetaminophen (APAP) overdose induces systemic oxidative and inflammatory responses, yet its effects on splenic homeostasis remain poorly characterized. We investigated whether prophylactic Viburnum opulus L. protects against APAP-induced splenic injury and the molecular pathways potentially underlying this protection. Forty female Wistar rats were allocated to control, APAP, N-acetylcysteine (NAC), V. opulus 100 (VO-100), and 300 mg/kg (VO-300) groups. NAC or V. opulus was administered orally for seven days, followed by a single oral APAP dose of 3 g/kg. Splenic histomorphology and immunohistochemical expression of cleaved Caspase-3, Ki-67, NF-κB, iNOS, SOD1, NRF2, and GPX4 were evaluated; network pharmacology and independent splenic transcriptomic analyses contextualized the experimental findings. APAP disrupted white- and red-pulp organization, induced lymphoid depletion, follicular disorganization, congestion, and sinusoidal dilatation, and significantly altered all seven markers, increasing cleaved Caspase-3, NF-κB, and iNOS immunoreactivity while reducing Ki-67, SOD1, and NRF2. GPX4 also decreased, but the control-APAP comparison lost significance after multiple-testing correction. VO-300 markedly attenuated the histomorphological alterations, reduced inflammatory and apoptosis-associated marker expression, and increased proliferative and antioxidant markers toward control levels. Network pharmacology identified 44 shared targets between major V. opulus constituents and APAP-toxicity-associated genes, with AKT1, NFKB1, PTGS2, and STAT3 as key hub proteins linked to oxidative-stress, apoptotic, and NF-κB-related pathways; 28 of these targets were confirmed in independent spleen transcriptomic data. Prophylactic V. opulus, particularly at 300 mg/kg, therefore, limits APAP-induced splenic injury by preserving tissue architecture, proliferative activity, and antioxidant defenses while attenuating inflammatory and apoptosis-associated responses.