Ambroxol mitigates cyclophosphamide-induced liver injury by suppressing TLR-4/NF-κB signaling and oxidative stress and upregulating cytoglobin, TXNRD1 and HMGB1.

Background: Cyclophosphamide (CP) is a potent chemotherapeutic and immunosuppressant agent, but its hepatotoxicity remains a significant concern. Ambroxol (ABX) is a mucolytic agent with emerging beneficial effects against oxidative stress and inflammation.

Aim: To investigate the hepatoprotective effects of ABX against CP-induced liver injury, focusing on oxidative stress, inflammation, and the possible role of cytoglobin, thioredoxin reductase 1 (TXNRD1) and high-mobility group box 1 (HMGB1).

Methods: ABX (20 mg/kg) was orally administered for 7 days, and the rats received a single injection of CP (100 mg/kg) on day 5. Blood and liver samples were collected for analyses, and the affinity of ABX towards cytoglobin, TXNRD1, and HMGB1 was evaluated using molecular docking.

Results: CP administration significantly elevated alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase, reduced albumin, and caused multiple histopathological alterations in the liver. ABX effectively restored liver function biomarkers and attenuated histopathological alterations. CP-induced oxidative stress was evidenced by increased malondialdehyde and decreased glutathione and antioxidant enzyme activities, all of which were ameliorated by ABX. CP upregulated toll-like receptor 4 (TLR-4), nuclear factor-kappaB (NF-κB) p65 and pro-inflammatory cytokines, while downregulating cytoglobin, TXNRD1 and HMGB1. ABX suppressed TLR-4/NF-κB signaling and pro-inflammatory cytokines, and upregulated cytoglobin, TXNRD1 and HMGB1. In silico molecular docking revealed the affinity of ABX to bind with cytoglobin, TXNRD1, and HMGB1.

Conclusion: ABX protects against CP hepatotoxicity by mitigating oxidative stress, suppressing TLR-4/NF-κB signaling, and upregulating cytoglobin, TXNRD1 and HMGB1. ABX showed binding affinity towards cytoglobin, TXNRD1 and HMGB1. These findings suggest that ABX has therapeutic potential in alleviating hepatotoxicity associated with CP treatment.