Ginsenoside Rh2 inhibits human A172 glioma cell proliferation and induces cell cycle arrest status via modulating Akt signaling pathway

Metabonomic profiling of clubroot-susceptible and clubroot-resistant radish and the assessment of disease-resistant metabolites

Plasmodiophora brassicae causes a serious threat to cruciferous plants including radish (Raphanus sativus L.). Knowledge on the pathogenic regularity and molecular mechanism of P. brassicae and radish is limited, especially on the metabolism level. In the present study, clubroot-susceptible and clubroot-resistant cultivars were inoculated with P. brassicae Race 4, root hairs initial infection of resting spores (10⁷ CFU/mL) at 24 h post-inoculation and root galls symptom arising at cortex splitting stage were identified on both cultivars. Root samples of cortex splitting stage of two cultivars were collected and used for untargeted metabonomic analysis. We demonstrated changes in metabolite regulation and pathways during the cortex splitting stage of diseased roots between clubroot-susceptible and clubroot-resistant cultivars using untargeted metabonomic analysis. We identified a larger number of differentially regulated metabolites and heavier metabolite profile changes in the susceptible cultivar than in the resistant counterpart. The metabolites that were differentially regulated in both cultivars were mostly lipids and lipid-like molecules. Significantly regulated metabolites and pathways according to the P value and variable important in projection score were identified. Moreover, four compounds, including ethyl α-D-thioglucopyranoside, imipenem, ginsenoside Rg1, and 6-gingerol, were selected, and their anti-P. brassicae ability and effects on seedling growth were verified on the susceptible cultivar. Except for ethyl α-D-thioglucopyranoside, the remaining could inhibit clubroot development of varing degree. The use of 5 mg/L ginsenoside Rg1 + 5 mg/L 6-gingerol resulted in the lowest disease incidence and disease index among all treatments and enhanced seedling growth. The regulation of pathways or metabolites of carbapenem and ginsenoside was further explored. The results provide a preliminary understanding of the interaction between radish and P. brassicae at the metabolism level, as well as the development of measures for preventing clubroot.

Gallic Acid Suppressed Tumorigenesis by an LncRNA MALAT1-Wnt/β-Catenin Axis in Hepatocellular Carcinoma

Gallic acid (3,4,5-trihydroxybenzoic acid; GA), a natural phenolic acid, is abundantly found in numerous natural products. Increasing evidence have demonstrated that GA plays anti-cancer roles in multiple cancers. However, its anti-tumor effects on hepatocellular carcinoma (HCC) and the underlying mechanism remain obscure. In the present study, we found that GA suppressed the in vitro cell viability and metastasis and inhibited the in vivo tumor growth of HCC cells. The underlying mechanism was further to investigate and it was showed that GA suppressed the expression of β-catenin and led to the functional inactivation of Wnt/β-catenin signaling. As a kind of significant regulators, the long noncoding RNA molecules (lncRNAs) have attracted widespread attentions for their critical roles in diverse biological process and human diseases. To further identify which lncRNA participated this GA-mediated process, several lncRNAs related to Wnt/β-catenin signaling were chosen for examination of their expression profiling in the GA-treated HCC cells. Of which, Metastasis-Associated Lung Adenocarcinoma Transcript 1 (MALAT1) was the most promising candidate. And moreover, MALAT1 was significantly down-regulated by GA. Its overexpression partially reversed the GA-induced the inhibitory effects on cell proliferation and metastasis; and successfully abolished the suppressive effect of GA on Wnt/β-catenin signaling. In conclusion, our results indicated that GA suppressed tumorigenesis in vitro and in vivo by the MALAT1-Wnt/β-catenin signaling axis, suggesting that GA has great potential to be developed as a chemo-prevention and chemotherapy agent for HCC patients.

20(S)-ginsenoside Rh2 induces caspase-dependent promyelocytic leukemia-retinoic acid receptor A degradation in NB4 cells via Akt/Bax/caspase9 and TNF-α/caspase8 signaling cascades

Background

Acute promyelocytic leukemia (APL) is a hematopoietic malignancy driven by promyelocytic leukemia–retinoic acid receptor A (PML-RARA) fusion gene. The therapeutic drugs currently used to treat APL have adverse effects. 20(S)-ginsenoside Rh2 (GRh2) is an anticancer medicine with high effectiveness and low toxicity. However, the underlying anticancer mechanisms of GRh2-induced PML-RARA degradation and apoptosis in human APL cell line (NB4 cells) remain unclear.

Methods

Apoptosis-related indicators and PML-RARA expression were determined to investigate the effect of GRh2 on NB4 cells. Z-VAD-FMK, LY294002, and C 87, as inhibitors of caspase, and the phosphatidylinositol 3-kinase (PI3K) and tumor necrosis factor-α (TNF-α ) pathways were used to clarify the relationship between GRh2-induced apoptosis and PML-RARA degradation.

Results

GRh2 dose- and time-dependently decreased NB4 cell viability. GRh2-induced apoptosis, cell cycle arrest, and caspase3, caspase8, and caspase9 activation in NB4 cells after a 12-hour treatment. GRh2-induced apoptosis in NB4 cells was accompanied by massive production of reactive oxygen species, mitochondrial damage and upregulated Bax/Bcl-2 expression. GRh2 also induced PML/PML-RARA degradation, PML nuclear bodies formation, and activation of the downstream p53 pathway in NB4 cells. Z-VAD-FMK inhibited caspase activation and significantly reversed GRh2-induced apoptosis and PML-RARA degradation. GRh2 also upregulated TNF-α expression and inhibited Akt phosphorylation. LY294002, an inhibitor of the PI3K pathway, enhanced the antitumor effects of GRh2, and C 87, an inhibitor of the TNF-α pathway, reversed NB4 cell viability, and GRh2-mediated apoptosis in a caspase-8-dependent manner.

Conclusion

GRh2 induced caspase-dependent PML-RARA degradation and apoptosis in NB4 cells via the Akt/Bax/caspase9 and TNF-α/caspase8 pathways.

Inhibitory Effects of Ginsenoside Ro on the Growth of B16F10 Melanoma via Its Metabolites

Ginsenoside Ro (Ro), a major saponin derived and isolated from Panax ginseng C.A. Meyer, exerts multiple biological activities. However, the anti-tumour efficacy of Ro remains unclear because of its poor in vitro effects. In this study, we confirmed that Ro has no anti-tumour activity in vitro. We explored the anti-tumour activity of Ro in vivo in B16F10 tumour-bearing mice. The results revealed that Ro considerably suppressed tumour growth with no significant side effects on immune organs and body weight. Zingibroside R1, chikusetsusaponin IVa, and calenduloside E, three metabolites of Ro, were detected in the plasma of Ro-treated tumour-bearing mice and showed excellent anti-tumour effects as well as anti-angiogenic activity. The results suggest that the metabolites play important roles in the anti-tumour efficacy of Ro in vivo. Additionally, the haemolysis test demonstrated that Ro has good biocompatibility. Taken together, the findings of this study demonstrate that Ro markedly suppresses the tumour growth of B16F10-transplanted tumours in vivo, and its anti-tumour effects are based on the biological activity of its metabolites. The anti-tumour efficacy of these metabolites is due, at least in part, to its anti-angiogenic activity.

Natural Product Triterpenoids and Their Semi-Synthetic Derivatives with Potential Anticancer Activity

Triterpenoids are distributed widely in higher plants and are of interest because of their structural diversity and broad range of bioactivities. In particular, there is a very large literature on the propensity of a variety of triterpenoids to act as potential anticancer agents. In the present review, the anticancer potential is summarized for naturally occurring triterpenoids and their semi-synthetic derivatives, including examples of lupane-, oleanane-, ursane-, and cucurbitane-type pentacyclic triterpenoids, along with dammarane-type tetracyclic triterpenes including ginsenosides and their sapogenins and dichapetalins, which have been characterized as antitumor leads from higher plants. Preliminary structure-activity relationships and reported mechanisms of the antineoplastic-related activity are included. Prior studies for triterpenoids of plant origin are supportive of additional work being conducted on the more detailed biological and mechanistic evaluation for the progression of this type of natural products as possible cancer chemotherapeutic agents.

Reversal effect of ginsenoside Rh2 on oxaliplatin-resistant colon cancer cells and its mechanism

Chemotherapy is an important treatment modality for colon cancer, however, drug resistance is the main factor leading to treatment failure. Ginsenoside Rh2 (G-Rh2), the main bioactive metabolite of ginseng, is known to possess the ability to potently induce cell apoptosis, inhibit cell proliferation and reverse multidrug resistance in a variety of cancer cells. The present study examined the effect of G-Rh2 on oxaliplatin (L-OHP)-resistant colon cancer cells and its potential mechanism. L-OHP-resistant colon cancer cells (LoVo/L-OHP) and LoVo cells were used in the present study. The effect of G-Rh2 on LoVo/L-OHP and LoVo cell proliferation was measured using a 3-(4,5 dimethylthiazol-z-yl)-3,5-diphenyltetrazolium bromide assay. The effects of G-Rh2 on LoVo/L-OHP and LoVo cell apoptosis were detected by flow cytometry. The mRNA and protein expression of apoptosis-related genes Bax, Bcl-2 and caspase-3, drug resistance-related genes P-glycoprotein (P-gp) and Smad4, were determined in LoVo/L-OHP and LoVo cells treated with G-Rh2 by reverse transcription-quantitative polymerase chain reaction and western blot analyses. G-Rh2 treatment significantly inhibited the proliferation and induced the apoptosis of LoVo/L-OHP and LoVo cells. In addition, G-Rh2 treatment resulted in a significant increase in pro-apoptotic factors, Bax and caspase-3, and decrease in anti-apoptotic factor Bcl-2 in the LoVo/L-OHP and LoVo cells. Furthermore, G-Rh2 treatment significantly decreased the levels of P-gp and increased the levels of Smad4 in the LoVo/L-OHP and LoVo cells. It was found that L-OHP had no significant effects on LoVo/L-OHP cell proliferation or apoptosis, whereas G-Rh2 + L-OHP treatment significantly inhibited LoVo/L-OHP cell proliferation and induced apoptosis. L-OHP had no significant effects on the expression of P-gp, Smad4, Bcl-2, Bax or caspase-3 in LoVo/L-OHP cells. Treatment with G-Rh2 + L-OHP significantly reduced the expression of P-gp and Bcl-2, and enhanced the expression levels of Smad4, Bax and caspase-3. These findings demonstrated that G-Rh2 reversed the drug resistance of LoVo/L-OHP cells to L-OHP, and this may be mediated by inhibiting cell proliferation and promoting apoptosis and regulating the expression of drug resistance genes. These results suggest that G-Rh2 may function as a potent anticancer drug for drug resistance in colon cancer treatment.