Hepatoprotective Effect of Probiotic Lactic Acid Bacteria on Thioacetamide-Induced Liver Fibrosis in Rats

Hepatic fibrosis is a reversible wound-healing response characterized by the accumulation of extracellular matrix. Probiotics have been used to prevent and treat various disorders. The aim of the present study was to investigate the hepatoprotective effects of probiotic lactic acid bacteria (mixture of Lactobacillus paracasei, Lactobacillus casei, and Weissella confusa) on thioacetamide (TAA)-induced liver fibrosis in rats. Thirty-five male Wistar rats were randomly divided into five groups: (1) control, (2) TAA, (3) TAA+probiotics, (4) TAA+silymarin, and (5) probiotics. Group 1 rats received a standard diet. In groups 2-4, fibrosis was induced by intraperitoneal injection of TAA (200 mg/kg BW) 3 times weekly for 8 consecutive weeks. Group 4 received TAA plus 100 mg/kg BW of silymarin 2 times weekly. Groups 3 and 5 were fed 10⁹ CFU/mL viable microbial cells daily by gavage. The rats were sacrificed after 8 weeks of treatment. Liver tissues were collected immediately and processed for histopathological, lipid peroxidation, and Western blot analyses of TNF-α, TGF-β1, and α-SMA. Blood serum was collected to measure liver enzymes. Rats in the TAA groups suffered from hepatic injury (increased serum enzyme levels, liver inflammation, and increased concentration of TNF-α, TGF-β1, and α-SMA proteins) and extensive liver fibrosis. In contrast, TAA-treated rats receiving probiotics or silymarin had significantly lower serum enzyme levels, less inflammation, and less fibrosis. Liver damage was lower in the TAA+probiotics-treated group. Consumption of a mixture of probiotic lactic acid bacteria attenuates the development of liver fibrosis.

Protective effect of alpha-mangostin on thioacetamide-induced liver fibrosis in rats as revealed by morpho-functional analysis

Liver fibrosis is an excessive accumulation of scar tissue resulting from inflammation and cell death. Thioacetamide (TAA) is a well-known hepatotoxin that induces liver fibrosis. A marker of injured hepatocytes is transforming growth factor-beta 1 (TGF-β1), while alpha-smooth muscle actin (α-SMA) and tissue inhibitor of metalloproteinase 1 (TIMP-1) are markers of activated hepatic stellate cells. Alpha-mangostin, a major xanthone derivative from the mangosteen pericarp, has been shown to have anti-oxidant and anti-inflammatory activities. The objective of this study was to determine whether alpha-mangostin has a protective effect on TAA-induced liver fibrosis in rats. The rats were treated by intraperitoneal injection of compounds for eight weeks. For the control group a mixture of dimethyl sulfoxide and phosphate buffered saline was administered. Two hundred mg/kg BW of TAA was administered three times weekly. Alpha-mangostin was administered at 5 mg/kg BW and silymarin at 100 mg/kg BW, both twice weekly. TAA induced histologically recognizable liver damage and fibrosis, as anticipated. Furthermore, it increased immunohistochemically detectable TGF-β1, α-SMA and TIMP-1. Co-administration of alpha-mangostin or silymarin with TAA prevented or ameliorated the effects of TAA administration alone. The anti-fibrotic effect of alpha-mangostin was stronger than that of silymarin.