Total Saponin from Root of Actinidia valvata Dunn Inhibits Hepatoma 22 Growth and Metastasis In Vivo by Suppression Angiogenesis

Inhibiting Angiogenesis by Anti-Cancer Saponins: From Phytochemistry to Cellular Signaling Pathways

Saponins are one of the broadest classes of high-molecular-weight natural compounds, consisting mainly of a non-polar moiety with 27 to 30 carbons and a polar moiety containing sugars attached to the sapogenin structure. Saponins are found in more than 100 plant families as well as found in marine organisms. Saponins have several therapeutic effects, including their administration in the treatment of various cancers. These compounds also reveal noteworthy anti-angiogenesis effects as one of the critical strategies for inhibiting cancer growth and metastasis. In this study, a comprehensive review is performed on electronic databases, including PubMed, Scopus, ScienceDirect, and ProQuest. Accordingly, the structural characteristics of triterpenoid/steroid saponins and their anti-cancer effects were highlighted, focusing on their anti-angiogenic effects and related mechanisms. Consequently, the anti-angiogenic effects of saponins, inhibiting the expression of genes related to vascular endothelial growth factor (VEGF) and hypoxia-inducible factor 1-α (HIF-1α) are two main anti-angiogenic mechanisms of triterpenoid and steroidal saponins. The inhibition of inflammatory signaling pathways that stimulate angiogenesis, such as pro-inflammatory cytokines, mitogen-activated protein kinase (MAPKs), and phosphoinositide 3-kinases/protein kinase B (PI3K/Akt), are other anti-angiogenic mechanisms of saponins. Furthermore, the anti-angiogenic and anti-cancer activity of saponins was closely related to the binding site of the sugar moiety, the type and number of their monosaccharide units, as well as the presence of some functional groups in their aglycone structure. Therefore, saponins are suitable candidates for cancer treatment by inhibiting angiogenesis, for which extensive pre-clinical and comprehensive clinical trial studies are recommended.

The Chinese medicine Sini-San inhibits HBx-induced migration and invasiveness of human hepatocellular carcinoma cells

Background

Sini-San (SNS) is a formulation of four Traditional Chinese Drugs that exhibits beneficial therapeutic effects in liver injury and hepatitis. However, there are no reports describing its effects on the hepatitis B X-protein (HBx)-induced invasion and metastasis in hepatoma cells, and the detailed molecular mechanisms of its actions are still unclear.

Methods

In this study, we investigated the mechanisms underlying SNS-mediated inhibition of HBx-induced cell invasion and the inhibition of secreted and cytosolic MMP-9 production, using gelatin zymography and Western blot analysis in a human hepatoma cell line (HepG2). Relative luciferase activity was assessed for MMP-9, NF-κB, or AP-1 reporter plasmid-transfected cells.

Results

SNS suppressed MMP-9 transcription by inhibiting activator protein (AP)-1 and nuclear factor-κ B (NF-κB) activity. SNS suppressed HBx-induced AP-1 activity through inhibition of phosphorylation in the extracellular signal-related kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling pathways. SNS also suppressed HBx-induced inhibition of NF-κB nuclear translocation through IκB and suppressed HBx-induced activation of ERK/phosphatidylinositol 3-kinase/Akt upstream of NF-κB and AP-1.

Conclusions

SNS suppresses the invasiveness and metastatic potential of hepatocellular carcinoma cells by inhibiting multiple signal transduction pathways.

Hepatoprotective Activity of the Total Saponins from Actinidia valvata Dunn Root against Carbon Tetrachloride-Induced Liver Damage in Mice

The protective activity of the total saponins from Actinidia valvata Dunn root (TSAV) was studied against carbon-tetrachloride- (CCl₄-) induced acute liver injury in mice. Mice were orally administered TSAV (50, 100, and 200 mg/kg) for five days and then given CCl₄. TSAV pretreatment significantly prevented the CCl₄-induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, and ALP). Parallel to these changes, TSAV also prevented CCl₄-induced oxidative stress by inhibiting lipid peroxidation (MDA) and restoring the levels of antioxidant enzymes (SOD, CAT, GR, and GPX), GSH and GSSG. In addition, TSAV attenuated the serum TNF-α and IL-6 levels and inhibited the serum iNOS and NO levels. Liver histopathology indicated that TSAV alleviated CCl₄-induced inflammatory infiltration and focal necrosis. TSAV (200 mg/kg) also significantly decreased Bak, Bax mRNA and Fas, FasL, p53, and NF-κB p65 protein expressions and increased Bcl-2 mRNA and protein expressions. Meanwhile, TSAV significantly downregulated caspase-3 and caspase-8 activities and prevented CCl₄-induced hepatic cell apoptosis. In addition, TSAV exhibited antioxidant activity through scavenging hydroxyl and DPPH free radicals in vitro. These results indicated that TSAV could protect mice against CCl₄-induced acute liver damage possibly through antioxidant, anti-inflammatory activities and regulating apoptotic-related genes.