RETRACTED: Sinapic Acid Attenuate Liver Injury by Modulating Antioxidant Activity and Inflammatory Cytokines in Thioacetamide-Induced Liver Cirrhosis in Rats

Abstract

Sinapic acid (SA) is a natural pharmacological active compound found in berries, nuts, and cereals. The current study aimed to investigate the protective effects of SA against thioacetamide (TAA) fibrosis in rats by histopathological and immunohistochemical assays. The albino rats (30) were randomly divided into five groups (G). G1 was injected with distilled water 3 times/week and fed orally daily with 10% Tween 20 for two months. G2-5 were injected with 200 mg/kg TAA three times weekly for two months and fed with 10% Tween 20, 50 mg/kg silymarin, 20, and 40 mg/kg of SA daily for 2 months, respectively. The results showed that rats treated with SA had fewer hepatocyte injuries with lower liver index (serum bilirubin, total protein, albumin, and liver enzymes (ALP, ALT, and AST) and were similar to that of control and silymarin-treated rats. Acute toxicity for 2 and 4 g/kg SA showed to be safe without any toxic signs in treated rats. Macroscopic examination showed that hepatotoxic liver had an irregular, rough surface with micro and macro nodules and histopathology expressed by Hematoxylin and Eosin, and Masson Trichrome revealed severe inflammation and infiltration of focal necrosis, fibrosis, lymphocytes, and proliferation bile duct. In contrast, rats fed with SA had significantly lower TAA toxicity in gross and histology and liver tissues as presented by less liver tissue disruption, lesser fibrosis, and minimum in filtered hepatocytes. Immunohistochemistry of rats receiving SA showed significant up-regulation of HSP 70% and down-regulation of alpha-smooth muscle actin (α-SMA) protein expression compared to positive control rats. The homogenized liver tissues showed a notable rise in the antioxidant enzymes (SOD and CAT) actions with significantly lower malondialdehyde (MDA) levels compared to that of the positive control group. Furthermore, the SA-treated rats had significantly lower TNF-a, IL-6, and higher IL-10 levels than the positive control rats. Thus, the findings suggest SA as a hepatoprotective compound due to its inhibitory effects on fibrosis, hepatotoxicity, liver cell proliferation, up-regulation of HSP 70, and downregulation of α-SMA expression, inhibiting lipid peroxidation (MDA), while retaining the liver index and antioxidant enzymes to normal.

Keywords: TAA; histology; immunohistochemistry; liver cirrhosis; sinapic acid.

Figure 1

Effect of SA on sections of liver and kidney tissues from rats under acute toxicity test. (A,B), control group; (C,D), rats received 2 g/kg of SA; (E,F), rats received 4 g/kg of SA. The microscopic observation showed non-significant changes in the tissue composition of the livers and kidneys between the experimented rats and control rats (Hematoxylin and Eosin stain, 20×).

Figure 2

Histopathological tissue views of the liver. Hematoxylin and Eosin (H & E) and Mason Trichrome stains (MT), and Gross appearance (GA) of liver from (A), control group; (B), TAA group; (C), silymarin group; (D), 20 mg/kg SA; (E), 40 mg/kg SA. The colored hepatic tissues were observed by Nikon microscope (Y-THS, Japan). 20× magnification.

Figure 3

Shows score for deposited collagens in liver tissues stained with Mason trachoma. Values indicated significant as ns, non-significant; *, p < 0.5; ***, p < 0.001; ****, p < 0.0001.

Figure 4

Effect of SA on HSP 70 protein expression in TAA-induced liver cirrhosis in rats. (A) Control rats showed normal liver tissue distribution without HSP 70 expression. (B) Positive control rats had severe liver damage presented by significantly lower HSP 70 protein expression in TAA-induced cirrhosis in rats (B,F). (C) Silymarin rats experienced mild liver injury and up-regulated the HSP 70 in TAA-induced cirrhosis in rats (C,F). (D) SA 20 mg/kg treated rats had moderate hepatocyte damage and up-regulated the HSP 70 staining in TAA-induced liver cirrhosis in rats (D,F). (E) SA 40 mg/kg treated rats presented mild hepatocellular damage and up-regulated the HSP 70 expression in TAA-induced liver cirrhosis in rats (E,F). (HSP 70 stain, magnification 100×). The data are presented as means ±  SEM. The antigen site appears as a brown color. ****, mean significant at p < 0.0001.

Figure 5

Effect of SA on Alpha-smooth muscle actin (α-SMA) expression in the liver of TAA induced liver cirrhosis in rats. Control group (A,F); Positive control rats (B,F); Silymarin group (C,F); SA 20 mg/kg group (D,F); SA 40 mg/kg group (E,F). The colored liver tissues were observed by Nikon microscope (Y-THS, Japan). 100× magnification. *, p < 0.5; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001.

Figure 6

Effect of SA on the SOD (a), CAT (b) and MDA (c) levels of liver homogenate in TAA-induces liver cirrhosis in rats. Values are presented as mean ± SEM. (n = 6 rate/group). ns, non-significant; *, p < 0.5; **, p < 0.01; ***, p < 0.001; ****, p < 0.0001.

Figure 7

Effect of SA on TNF a (a), IL-6 (b) and IL-10 (c) in TAA-induced liver cirrhosis in rats. G1, control group; G2, TAA group; G3, silymarin group; G4, SA 20 mg/kg group; G5, SA 40 mg/kg group. ns, non-significant; *, p < 0.5; **, p < 0.01; ****, p < 0.0001.