Potentiation of etoposide-induced apoptosis in HeLa cells by co-treatment with KG-135, a quality-controlled standardized ginsenoside formulation.

Our previous studies demonstrated that KG-135, a quality-controlled red ginseng-specific formulation containing approximately equal amounts of three major ginsenosides (Rk1, Rg3 and Rg5), down-regulated G1 cyclin-dependent kinase in HeLa cells. In the present work, we have found that KG-135 potentates cytotoxicity of etoposide by modulating apoptotic signaling. Co-treatment of etoposide and KG-135 markedly elevated the expression and phosphorylation at the serine 15 residue of p53 as well as the cellular levels of Bax and p21(Waf1/Cip1). The increased accumulation and phosphorylation of p53 (Ser15) were attenuated by treatment of cells with wortmannin, a pan-phosphatidylinositol-3 kinase inhibitor. Moreover, co-treatment of etoposide and KG-135 enhanced mitochondrial localization of Bax. Our results indicate that etoposide-induced apoptosis in HeLa cells can be potentiated in the presence of KG-135 through a mechanism that involves the stabilization of p53 and the stimulation of Bax- and p21-mediated apoptotic signaling pathways. These findings suggest that KG-135 represents a useful candidate adjuvant for the treatment of cancers that could potentially minimize the adverse effects of current clinical chemotherapeutics.

Heat-processed neoginseng, KG-135, down-regulates G1 Cyclin-dependent kinase through the proteasome-mediated pathway in HeLa cells.

High temperature heat treatment of ginseng (Panax ginseng, C.A. Meyer) generates KG-135 (heat-processed neoginseng) which contains a mixture of three major ginseng saponins, ginsenosides Rk1, Rg3 and Rg5. Ginsenosides, particularly of the diol-type including Rk1, Rg3 and Rg5, have been shown to induce cell growth arrest in various cell types of human cancer. Herein, we report that KG-135 is able to arrest the cell cycle in human cervix adenocarcinoma HeLa cells. KG-135 arrests cells at the G1 phase of the cell cycle with an IC50 value of 69 microg/ml. The G1 phase arrest is associated with down-regulation of Cyclin D1/Cdk4 and Cyclin B1/Cdc2 activities in cells after treatment with KG-135. Furthermore, down-regulation of G1 Cyclin-dependent kinase activities is kinetically well related to the decreased intracellular protein levels of these kinases. In addition, the decrease in the levels of Cyclin D1/Cdk4 and Cyclin B1, but not of Cdc2, is similarly prevented by co-treatment of cells with MG-132, a potent proteasome inhibitor. Thus, the KG-135-induced arrest of the cell cycle at G1 phase in HeLa cells represents a novel mechanism that involves proteasome-mediated degradation of the Cyclins (Cyclin D1 and B1) and Cdk4 proteins.

Effects of acupuncture at GV01 on experimentally induced colitis in rats: possible involvement of the opioid system.

Oriental medicine uses acupuncture at the GV01 acupoint with great success to treat diarrhea. It significantly reduced the colonic motility and inflammation in colitic rats. Naloxone pretreatment blocked these effects. The therapeutic effects of acupuncture at GV01 in colitis may involve endogenous opioid pathways.

Inhibitory effects of the ginsenoside Rg3 on phorbol ester-induced cyclooxygenase-2 expression, NF-kappaB activation and tumor promotion.

Our previous studies demonstrated the anti-oxidant and anti-tumor promotional properties of the methanol extract of heat-processed Panax ginseng C.A. Meyer [Cancer Lett. 150 (2000) 41]. In the present work, we have evaluated anti-inflammatory as well as anti-tumor promoting effects of Rg(3), a major ginsenoside derived from heat-processed ginseng. Pretreatment of dorsal skins of female ICR mice with Rg(3) significantly inhibited 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ornithine decarboxylase activity and 7,12-dimethylbenz[a]anthracene-initiated papilloma formation. In another experiment, Rg(3) pretreatment abrogated the expression of cyclooxygenase-2 in TPA-stimulated mouse skin. Rg(3) also inhibited the TPA-induced activation of the eukaryotic transcription factor, NF-kappaB in both mouse skin and cultured human pro-myelocytic leukemia (HL-60) cells. Moreover, Rg(3) exerted potent inhibitory effects on the activation of another transcription factor, activator protein-1 (AP-1) that is responsible for c-jun and c-fos oncogenic transactivation. Based on these findings, it is likely that the anti-tumor promoting activity of Rg(3) is mediated possibly through down-regulation of NF-kappaB and AP-1 transcription factors.

Inhibition of 5alpha-reductase activity by diarylheptanoids from Alpinia officinarum.

The acetone extract from the rhizomes of Alpinia officinarum was evaluated for activity against 5alpha-reductase which had been prepared from rat prostate. The fraction responsible for the inhibition of the enzyme was purified, analyzed, and the active constituents were identified as four diarylheptanoids, 1,7-diphenylhept-4-en-3-one, dihydroyashabushiketol (1,7-diphenyl-5-hydroxy-3-heptanone), 5-hydroxy-7-(4"-hydroxy-3"-methoxyphenyl)-1-phenyl-3-heptanone and 5-hydroxy-7-(4"-hydroxyphenyl)-1-phenyl-3-heptanone.

Ginsenoside-Rb1 acts as a weak phytoestrogen in MCF-7 human breast cancer cells.

Ginseng has been recommended to alleviate the menopausal symptoms, which indicates that components of ginseng very likely contain estrogenic activity. We have examined the possibility that a component of Panax ginseng, ginsenoside-Rb1, acts by binding to estrogen receptor. We have investigated the estrogenic activity of ginsenoside-Rb1 in a transient transfection system using estrogen-responsive luciferase plasmids in MCF-7 cells. Ginsenoside-Rb1 activated the transcription of the estrogen-responsive luciferase reporter gene in MCF-7 breast cancer cells at a concentration of 50 microM. Activation was inhibited by the specific estrogen receptor antagonist ICI 182,780, indicating that the estrogenic effect of ginsenoside-Rb1 is estrogen receptor dependent. Next, we evaluated the ability of ginsenoside-Rb1 to induce the estrogen-responsive gene c-fos by semi-quantitative RT-PCR assays and Western analyses. Ginsenoside-Rb1 increased c-fos both at mRNA and protein levels. However, ginsenoside-Rb1 failed to activate the glucocorticoid receptor, the retinoic acid receptor, or the androgen receptor in CV-1 cells transiently transfected with the corresponding steroid hormone receptors and hormone responsive reporter plasmids. These data support our hypothesis that ginsenoside-Rb1 acts a weak phytoestrogen, presumably by binding and activating the estrogen receptor.

Angiogenic activity of beta-sitosterol in the ischaemia/reperfusion-damaged brain of Mongolian gerbil.

Aloe vera continues to be used for wound healing as a folk medicine. We previously reported that A. vera gel has angiogenic activity. In this study, we report upon the isolation of an angiogenic component beta-sitosterol from A. vera and examination of its effect upon damaged blood vessels of the Mongolian gerbil. In a chick embryo chorioallantoic membrane assay, beta-sitosterol was found to have an angiogenic effect. It enhanced new vessel formation in gerbil brains damaged by ischaemia/reperfusion, especially in the cingulated cortex and septal regions, in a dose-dependent fashion (up to 500 microg/kg, p < 0.05, n = 34 - 40). beta-Sitosterol also enhanced the expressions of proteins related to angiogenesis, namely von Willebrand factors, vascular endothelial growth factor (VEGF), VEGF receptor Flk-1, and blood vessel matrix laminin (p < 0.05, n = 6). In addition, the intraperitoneal administration of beta-sitosterol at 500 microg/kg/day for a period of 19 days significantly improved the motion recovery of ischaemia/reperfusion-damaged gerbils as assessed by rota-rod testing (p < 0.001, n = 10). Our results suggest that beta-sitosterol has therapeutic angiogenic effects on damaged blood vessels.