Diosbulbin B aggravates doxorubicin-induced hepatotoxicity with PI3K/AKT signaling and redox-inflammatory stress responses

Objective This study evaluated whether diosbulbin B (DB) affects doxorubicin (DOX)-induced hepatotoxicity. It further characterized the associated changes in redox-related biochemical indices, mitochondrial membrane potential, inflammatory stress-related proteins, and DNA damage-response-related proteins. Methods ICR mice were treated with DOX and/or DB to assess liver injury and serum biochemical changes. LO2 hepatocyte-like cells were used as a simplified in vitro model to evaluate cell viability, nuclear morphology, lactate dehydrogenase release, and mitochondrial membrane potential. Bulk RNA sequencing and Western blotting were performed to characterize transcriptomic and protein-expression changes associated with combined DB and DOX exposure. Results DB co-administration was associated with lower body weight, comparable hepatic histopathological alterations, and higher serum alanine aminotransferase and aspartate aminotransferase activities in DOX-treated mice. Redox-related biochemical indices showed a non-classical pattern, including increased glutathione levels, decreased malondialdehyde levels, and reduced superoxide dismutase activity in the treatment groups. These changes are indicative of altered redox-related biochemical status rather than direct evidence of a specific oxidative cell-death mechanism. In LO2 cells, DB further reduced cell viability, increased lactate dehydrogenase release, altered nuclear morphology, and enhanced mitochondrial membrane depolarization during DOX exposure. Comparison of the DOX + DB and DOX groups identified 1,221 differentially expressed genes, including 130 upregulated and 1,091 downregulated genes. Enrichment analyses showed terms and pathways related to DNA repair, cell-cycle regulation, chromatin organization, and stress-response processes. Combined treatment was also associated with increased phospho-PI3K/PI3K, phospho-AKT/AKT, p38, TXNIP, IL-6, and IL-8 levels, as well as reduced p53 and GADD45A levels. Conclusion DB co-treatment was associated with enhanced DOX-related hepatotoxicity and cytotoxic changes in LO2 cells. Combined exposure was accompanied by mitochondrial membrane depolarization, non-classical redox-related biochemical alterations, increased inflammatory and stress-related protein expression, and reduced p53 and GADD45A abundance. Because direct assays of lipid peroxidation-dependent cell death, ferroptosis, oxytosis, necroptosis, and DNA damage were not performed, the present data do not establish a specific oxidative cell-death mechanism.