Investigation of alpha smooth muscle actin changes in the liver of cholestatic rats following the consumption of L-theanine

Cholestatic liver disease represents a major global health threat, resulting in significant morbidity and mortality. Cholestasis can be induced in laboratory animals using Bile Duct Ligation (BDL) technique. Activated Hepatic Stellate Cells (aHSCs) express Alpha Smooth Muscle Actin (α-SMA), which is correlated with experimental liver fibrogenesis. The Camellia sinensis plant produces L-Theanine, an amino acid (AA), in its roots. This research endeavored to conduct a comprehensive assessment of the anti-fibrotic effects of L-Theanine alongside α-SMA changes in the liver of cholestatic rats. Rats were classified into eight experimental groups, each consisting of five animals, including; 1) normal control group, 2) BDL control group, 3-5) healthy experimental groups, 6-8) BDL + L-Theanine groups. L-Theanine solution (100, 200 or 400 mg kg -1 ) was administered to the animals by Intragastric gavage (once a day) for 30 successive days. BDL significantly elevated the enzymatic activity of Gamma-glutamyl transferase (GGT), Alanine aminotransferase (ALT), Alkaline phosphatase (ALP), Aspartate aminotransferase (AST) and elevated the amount of total bilirubin. These biochemical alterations were ameliorated when L-Theanine was administered. Masson`s Trichrome and Immunohistochemical (IHC) staining revealed that BDL expanded the collagen deposition and α-SMA expression in hepatic tissue. Administration of L-Theanine, remarkably alleviated these alterations. L-Theanine attenuates hepatic fibrosis through decreasing the production of α-SMA. • L-Theanine alleviated hepatic injuries • L-Theanine diminished the expression of α-SMA in hyperplastic bile duct cells • L-Theanine decreased collagen accumulation in cholestasis • L-theanine reduced the increase of biochemical parameters in cholestasis