Protective Effect of Thymol-loaded Chitosan Nanoparticles against Bile Duct Ligation-induced Liver Fibrosis in Rats

Abstract

INTRODUCTION: Liver fibrosis is a critical disorder associated with elevated morbidity and mortality rates globally, leading to many organ dysfunctions. Thymol is a phenolic aromatic chemical extracted from thyme oil. It possesses biochemical, oxidative, anti-inflammatory, and anticancer properties. This results in its widespread applications across various domains, including cosmetics, medicine, and pharmacology. This study aims to assess the efficiency of thymol-loaded chitosan nanoparticles (CS-thymol NPs) in the bile duct ligation (BDL) model of liver fibrosis. METHODS: Thirty male Wister rats were divided into five groups: Sham, BLD, and cholestasis rats treated with chitosan NPs (60 mg/kg body weight, orally), thymol (30 mg/kg body weight, orally), and CS-thymol NPs (60 mg/kg body weight, orally). RESULTS: The administration of CS-thymol NPs markedly enhanced liver function, evidenced by reduced hepatic enzyme activity and elevated albumin level. Furthermore, CS-thymol NPs induced an elevation in glutathione and reduced catalase levels, and along with the reduction in malondialdehyde and nitric oxide production. Furthermore, CS-thymol NPs therapy diminished DNA damage in cholestatic rats and partially restored the normal architecture of hepatic tissues in these subjects. Immunohistochemistry analysis revealed a significant reduction in inflammation and apoptosis by decreasing levels of TNF-α and caspase-3 expression. DISCUSSION: The anticholestatic mechanisms of thymol may depend on its anti-inflammatory activity through the inhibition of TNF-α release, its antioxidative properties by decreasing MDA and NO levels while enhancing CAT and GSH, and its anti-apoptotic effects, likely associated with the down-regulation of activated caspase-3 and DNA damage. CONCLUSION: The incorporation of thymol into chitosan NPs boosts its antioxidant, antiinflammatory, and anti-apoptotic properties, thereby improving liver function and structure of cholestatic rats.