The anti-tumor effect of ginsenoside Rh4 in MCF-7 breast cancer cells in vitro and in vivo.

Breast cancer is a tremendous threat to humans in many countries, and thus we need to find safe and effective drugs for treatment. Ginsenoside Rh4 has been reported to be present in processed ginseng. However, few studies have focused on its anti-tumor activity. In this study, we investigated the inhibitory effects of ginsenoside Rh4 on MCF-7 breast cancer cells and the pathways that promote apoptosis in vitro. To study the effect of ginsenoside Rh4 in vivo, xenograft models were randomly divided into 3 groups (the control group, 10 mg/kg/d Rh4, 20 mg/kg/d Rh4, n = 10 per group), the ginsenoside Rh4 injection method was i.p. The results showed that ginsenoside Rh4 effectively inhibited proliferation, arrested the cell cycle in S phase and induced apoptosis in MCF-7 cells by flow cytometry. Morphological changes caused by ginsenoside Rh4-induced apoptosis were also observed by Hoechst 33342 staining. Western-blot analyses indicated that the apoptosis-inducing effects of ginsenoside Rh4 were associated with the external pathway by decreasing Bcl-2, increasing Bax, and activating caspase-8, -3 and PARP. Moreover, ginsenoside Rh4 significantly inhibited the growth of MCF-7 tumor cells in vivo. These results suggested that ginsenoside Rh4 could be a potentially effective anti-tumor drug for breast cancer.

Engineered ß-glycosidase from Hyperthermophilic Sulfolobus solfataricus with Improved Rd-hydrolyzing Activity for Ginsenoside Compound K Production.

Hyperthermophilic Sulfolobus solfataricus ß-glycosidase (SS-ßGly), with higher stability and activity than mesophilic enzymes, has potential for industrial ginsenosides biotransformation. However, its relatively low ginsenoside Rd-hydrolyzing activity limits the production of pharmaceutically active minor ginsenoside compound K (CK). In this study, first, we used molecular docking to predict the key enzyme residues that may hypothetically interact with ginsenoside Rd. Then, based on sequence alignment and alanine scanning mutagenesis approach, key variant sites were identified that might improve the enzyme catalytic efficiency. The enzyme catalytic efficiency (kcat/Km) and substrate affinity (Km) of the N264D variant enzyme for ginsenoside Rd increased by 60% and decreased by 17.9% compared with WT enzyme, respectively, which may be due to a decrease in the binding free energy (∆G) between the variant enzyme and substrate Rd. In addition, Markov state models (MSM) analysis during the whole 1000-ns MD simulations indicated that altering N264 to D made the variant enzyme achieve a more stable SS-ßGly conformational state than the wild-type (WT) enzyme and corresponding Rd complex. Under identical conditions, the relative activities and the CK conversion rates of the N264D enzyme were 1.7 and 1.9 folds higher than those of the WT enzyme. This study identified an excellent hyperthermophilic ß-glycosidase candidate for industrial biotransformation of ginsenosides.

Anticancer effects of ginsenoside Rk3 on non-small cell lung cancer cells: in vitro and in vivo.

Ginsenoside Rk3 (Rk3) is present in the roots of processed Panax notoginseng herbs and it exerts anti-platelet aggregation, pro-immunogenic and cardioprotective effects. However, little is known regarding the anticancer activities of this compound, especially in lung cancer. This study was designed to investigate the anticancer effects of Rk3 on non-small cell lung cancer (NSCLC) cells and in an H460 xenograft tumor model. Our results showed that Rk3 reduced cell viability, inhibited both cell proliferation and colony formation, and induced G1 phase cell cycle arrest by downregulating the expression of cyclin D1 and CDK4 and upregulating the expression of P21. Rk3 also induced apoptosis in a concentration-dependent manner in H460 and A549 cells by Annexin V/PI staining, TUNEL assay and JC-1 staining, resulting in a change in the nuclear morphology. Moreover, Rk3 induced the activation of caspase-8, -9, and -3, promoted changes in mitochondrial membrane potential, decreased the expression of Bcl-2, increased the expression of Bax, and caused the release of cytochrome c, which indicated that the apoptosis-inducing effects of Rk3 were triggered via death receptor-mediated mitochondria-dependent pathways. Furthermore, Rk3 significantly inhibited the growth of H460 xenograft tumors without an obvious effect on the body weight of the treated mice. Histological analysis indicated that Rk3 inhibited tumor growth by altering the proliferation and morphology of tumor cells. In addition, we confirmed that Rk3 inhibited angiogenesis via CD34 staining and chick embryo chorioallantoic membrane (CAM) assay in vivo. Taken together, our findings revealed not only the anticancer effect of Rk3 on NSCLC cells but also a new promising therapeutic agent for human NSCLC.