Ginsenoside Rb1 inhibits proliferation and inflammatory responses in rat aortic smooth muscle cells

Ginsenoside Rb1, a known phytoestrogen, is a major pharmacologically active component in ginseng. The present study was designed to investigate the effect of ginsenoside Rb1 on fetal bovine serum (FBS)-induced proliferation and tumor necrosis factor-α (TNF-α)-evoked inflammatory responses in cultured rat aortic vascular smooth muscle cells (VSMCs). The data showed that Rb1 potently inhibited VSMC proliferation and cell growth induced by 5% FBS. These inhibitory effects were associated with G(1) cell cycle arrest and down-regulation of cell cycle proteins. Treatment with Rb1 reduced FBS-induced extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation. Furthermore, TNF-α-evoked inflammatory responses were inhibited by Rb1. Reporter gene assay indicated that Rb1 could transactivate ERβ especially. Moreover, Rb1-mediated inhibition of VSMCs proliferation was greatly blocked by transfection of ERβ siRNA. These results suggest that Rb1 inhibits FBS-induced proliferation and TNF-α-evoked inflammatory responses in VSMCs. The findings presented here highlight the possible therapeutic use of Rb1 in cardiovascular disease.     

Effect of black soybean extract on the suppression of the proliferation of human AGS gastric cancer cells via the induction of apoptosis

Black soybean is known to have a health-promoting effect because of its high content of polyphenolic compounds and antioxidant activities. The objective of the present study was to investigate the chemopreventive effects of black soybean extract against human AGS gastric cancer cells and its possible mechanism in inducing apoptosis. Black soybean extract was obtained by extracting black soybean with acidified aqueous acetone, and its phytochemical constituents, as determined by HPLC-DAD methods, were demonstrated to contain various phenolics. The black soybean extract inhibited AGS cell growth in a dose-dependent manner with an IC(50) of 3.69 mg/mL as measured by the MTT assay. This growth inhibition effect was further confirmed by the CFDA-SE assay. Flow cytometry analysis showed that black soybean extract dose-dependently induced apoptosis of AGS cells. Moreover, the involvement of black soybean extract in inducing apoptosis was confirmed by the expression of Bax, Bcl-2, caspase-3, and PARP. The results of the present study indicated that black soybean extract could be used as an apoptosis inducer in AGS cells and a natural chemopreventive agent in the treatment of human gastric cancer.     

A commercial extract of fruits and vegetables, Oxxynea, acts as a powerful antiatherosclerotic supplement in an animal model by reducing cholesterolemia, oxidative stress, and NADPH oxidase expression

The effects of fruit and vegetable extract (Oxxynea) on plasma cholesterol, early atherosclerosis, cardiac production of superoxide anion, and NAD(P)H oxidase expression were studied in an animal model of atherosclerosis. Thirty six hamsters were divided into two groups of 18 and fed an atherogenic diet for 12 weeks. They received by gavage either water or Oxxynea in water at a human dose equivalent of 10 fruits and vegetables per day. Oxxynea lowered plasma cholesterol and non-HDL cholesterol, but not HDL-cholesterol, and increased plasma antioxidant capacity. It also strongly reduced the area of aortic fatty streak deposition by 77%, cardiac production of superoxide anion by 45%, and p22phox subunit of NAD(P)H oxidase expression by 59%. These findings support the view that chronic consumption of antioxidants supplied by fruits and vegetables has potential beneficial effects with respect to the development of atherosclerosis. The underlying mechanism is related mainly to inhibiting pro-oxidant factors and improving the serum lipid profile.     

Cancer chemopreventive effects of lycopene: suppression of MMP-7 expression and cell invasion in human colon cancer cells

Clinical studies indicate that high blood levels of leptin or matrix metalloproteinase-7 (MMP-7; matrilysin) proteins are associated with tumor progression of human colorectal cancer (CRC). Leptin could play an important role in cell migration and invasion of cancer cells. Our previous study indicated that lycopene could inhibit the proliferation of human colon cancer cells in vitro. However, the inhibitory effects of lycopene on the progression of human colon cancer cells have not been demonstrated yet. In this study, we investigated the inhibitory effects of lycopene on tumor progression including cell invasion and MMP-7 expression in leptin-stimulated human colon cancer cells in vitro. Our results demonstrated that lycopene significantly inhibited leptin-mediated cell invasion and MMP-7 expression in human colon cancer HT-29 cells. Lycopene could augment the expression and stability of E-cadherin proteins. Our results showed that MAPK/ERK and PI3K/Akt signaling pathways played important roles in leptin-mediated MMP-7 expression and cell invasion. Lycopene could effectively inhibit the phosphorylation of Akt, glycogen synthase kinase-3β (GSK-3β) and ERK 1/2 proteins. The molecular mechanisms of lycopene were in part through decreases in nuclear levels of AP-1 and β-catenin proteins. These novel findings suggested that lycopene could act as a chemopreventive agent to suppress MMP-7 expression and leptin-mediated cell invasion in human colon cancer HT-29 cells.     

4-acetylantroquinonol B isolated from Antrodia cinnamomea arrests proliferation of human hepatocellular carcinoma HepG2 cell by affecting p53, p21 and p27 levels

The 4-acetylantroquinonol B isolated from the mycelium of Antrodia cinnamomea could inhibit proliferation of hepatocellular carcinoma cells HepG2 with IC(50) 0.1 μg/mL. When the HepG2 cells were treated with 4-acetylantroquinonol B for 72 h, the proportion of cells in the G1 phase of the cell cycle increased and that in the S phase decreased significantly, and the proportion of G2/M phase cells were not obviously changed. In addition, the 4-acetylantroquinonol B treatment resulted in the decreases of CDK2 and CDK4, and an increase of p27 in a dose-dependent manner. The protein levels of p53 and p21 proteins were also increased when the cells were treated with low dosage (0.1 μg/mL) of 4-acetylantroquinonol B. Higher dosages, however, decreased the expression of p53 and p21 proteins. Assay of RT-PCR indicated that, corresponding to the increases of p53 and p21 proteins at the dosage of 0.1 μg/mL, the mRNAs of p53 and p21 showed 1.66- and 1.61-fold upregulations, respectively. Corresponding to the decreases of CDK2 and CDK4 proteins, the mRNAs of CDK2 and CDK4 showed -1.02- and -1.13-fold downregulations, respectively. However, level of p27 mRNA showed -1.2-fold downregulation in spite of the increase in p27 protein. This observation, again, confirms the fact that the p27 gene rarely undergoes homozygous inactivation in cancer cells. Our finding suggested that the 4-acetylantroquinonol B inhibits proliferation of HepG2 cells via affecting p53, p21 and p27 proteins, and can be considered as a potential cancer drug.