Role of Arctiin in Fibrosis and Apoptosis in Experimentally Induced Hepatocellular Carcinoma in Rats

Abstract

Background and objectives Hepatocellular carcinoma (HCC) is a highly aggressive malignant tumor with a poor prognosis. It is currently the second most common cause of cancer-related mortality. Arctiin, a compound found in plants commonly used as a vegetable in Asian countries and as an ingredient in traditional European dishes, possesses various properties, including anti-proliferative, anti-senescence, anti-oxidative, anti-tumor, toxic, anti-adipogenic, and anti-bacterial effects. Our study aims to investigate the potential antitumor activity of arctiin against HCC in rats by inhibiting cell fibrosis and apoptosis. Methods Rats were induced with HCC by administering thioacetamide. Arctiin was orally administered to some rats twice a week for 16 weeks at a dose of 30 mg/kg. The liver impairment was evaluated by measuring serum α-fetoprotein (AFP) and examining liver sections stained with Masson trichrome or anti-hypoxia-induced factor-1α (HIF-1α) antibodies. The hepatic expression of messenger RNA and protein levels of HIF-1α, protein kinase C (PKC), extracellular signal-regulated kinase (ERK), β-catenin, and mothers against decapentaplegic homolog 4 (SMAD4) were analyzed. Results Our study demonstrated that arctiin can potentially increase the survival rate of rats. This is achieved through a reduction in serum AFP levels and hepatic nodules. We also observed that arctiin has the ability to inhibit the formation of fibrotic tissues and necrotic nodules in HCC rats. Additionally, arctiin can significantly decrease the expression of HIF-1α, PKC, ERK, β-catenin, and SMAD4. Conclusion Arctiin has demonstrated potential anti-tumor properties that could ameliorate HCC. Studies have shown that it may increase survival rates and reduce the number of tumors and AFP levels. Arctiin works by inhibiting HCC-induced hypoxia, thus blocking the expression of HIF-1α. It also helps to slow down tumor fibrosis by decreasing the expression of β-catenin and SMAD4. Furthermore, arctiin has been found to downregulate PKC and ERK, reducing hepatic tissue apoptosis.

Keywords: extracellular signal-regulated kinase (erk); hepatocellular carcinoma (hcc); hypoxia-induced factor-1α (hif-1α); mothers against decapentaplegic homolog 4 (smad4); protein kinase c (pkc); β-catenin.

Figure 1. Effect of HCC and 30 mg/kg arctiin on rats’ survival (a), the average number of nodules (b), and serum AFP (c).

*Significant difference as compared with the control group at p<0.05. #Significant difference as compared with the HCC group at p<0.05. AFP, alpha-fetoprotein; C, control; HCC, hepatocellular carcinoma

Figure 2. Hepatic sections stained with Masson trichrome in the control group (a), control group treated with arctiin (b), hepatocellular carcinoma group (c), and hepatocellular carcinoma group treated with arctiin (d).

Yellow arrows indicated areas of fibrosis. Scale bar represents 100 μm.

Figure 3. Effect of HCC and 30 mg/kg arctiin on hepatic gene expression of HIF-1α (a) and its hepatic protein level (b). Hepatic sections stained with anti-HIF-1α antibodies in the control group (c), control group treated with arctiin (d), HCC group (e), and HCC group treated with arctiin (f).

*Significant difference as compared with the control group at p<0.05. #Significant difference as compared with the HCC group at p<0.05. Scale bar 50 μm. C, control; HCC, hepatocellular carcinoma; HIF-1α, hypoxia induced factor-1α

Figure 4. Effect of HCC and 30 mg/kg arctiin on hepatic gene expression of β-catenin (a) and SMAD4 (c), as well as protein expression of β-catenin (b) and SMAD4 (d).

*Significant difference as compared with the control group at p<0.05. #Significant difference as compared with the HCC group at p<0.05. C, control; HCC, hepatocellular carcinoma; SMAD4, mothers against decapentaplegic homolog 4

Figure 5. Effect of HCC and 30 mg/kg arctiin on hepatic gene expression of PKC (a) and ERK (c), as well as protein expression of PKC (b) and ERK (d).

*Significant difference as compared with the control group at p<0.05. #Significant difference as compared with the HCC group at p<0.05 C, control; ERK, Extracellular signal-regulated kinase; HCC, hepatocellular carcinoma; PKC, protein kinase C

Figure 6. Schematic presentation of the protective effects of arctiin in HCC.

ERK, extracellular signal-regulated kinase; HCC, hepatocellular carcinoma; HIF-1α, hypoxia-induced factor-1α; SMAD4, mothers against decapentaplegic homolog 4; PKC, protein kinase C The image was created by the authors of this study.