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

Abstract

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.

Keywords: Chemotherapy; Ambroxol; Oxidative stress; Inflammation; Hepatotoxicity; Cyclophosphamide; Acute liver injury

Core Tip: Cyclophosphamide (CP) is a cornerstone chemotherapeutic and immunosuppressive agent, but its hepatotoxicity limits its clinical utility. While oxidative stress and inflammation are known contributors to CP-induced liver injury, effective therapeutic strategies to counteract these effects remain limited. This study is the first to demonstrate that ambroxol exerts potent hepatoprotective effects against CP hepatotoxicity. Our findings not only elucidate the molecular mechanisms underlying the hepatoprotective effects of ambroxol but also position it as a promising adjunct therapy to mitigate CP hepatotoxicity. Given the lack of effective hepatoprotective agents against CP toxicity, this study has significant translational implications.