Repurposing the antimalarial chloroquine: a potential therapy for hepatic injury in a rat model of hindlimb ischemia–reperfusion by modulating apoptosis, autophagy, inflammation, and oxidative stress

Abstract

Background

Besides its local injurious effect, hindlimb hypoxia/reperfusion (HL-H/R) can escalate leading to multiple organ dysfunction syndrome.

Purpose of the study

This study explores chloroquine’s therapeutic potential in protecting liver tissue from collateral damage caused by HL-H/R, focusing on its effects on inflammation, oxidative stress, autophagy, and apoptosis.

Methods and results

Male Wistar rats were apportioned into three distinct groups, control, HL-H/R model (90 min/8 days), and HL-H/R + chloroquine (7 days). Western blot, ELISA, immunohistochemical, and histopathology techniques revealed that post-administration of chloroquine caused an upturn in liver architecture and function. The antimalarial drug also abated the hepatic content of the surrogate inflammatory marker TNF-α and downregulated the protein expression of p-MAPK p38. This was allied with a reduction in NF-κB p65 the transcription factor but increased the anti-inflammatory marker interleukin (IL)-10. Moreover, chloroquine amended the interrupted redox balance by reducing the HL-H/R induced increase in reactive oxygen and nitrogen species. Chloroquine leveled off hepatic levels of the lipid peroxide marker MDA, the DNA damage parameter 8-OHdG, as well as NO while enhancing the antioxidant capacity by increasing TAC. These beneficial effects entailed the inhibition of apoptotic cell demise by enhancing the anti-apoptotic marker Bcl-2 and reducing the apoptotic markers Bax and caspase-3. Finally, chloroquine succeeded in curbing the autophagy process where it decreased Beclin-1 and LC3-II, two autophagosome markers, along with the lysosomal parameter cathepsin-D.

Conclusion

To recapitulate, chloroquine post-administration improved the injurious remote actions of HL-H/R on the liver by its anti-inflammatory (MAPK p38/NF-κB p65/TNF-α, IL-10) and antioxidant (MDA, 8-OHdG, NO, TAC) properties as well as halting the autophagy (Beclin-1, LC3-II, cathepsin-D) and apoptosis (Bcl-2, Bax, caspase-3)-mediated hepatic death to improve liver function (ALT, AST) and structure.