Comparison of the chemical profiles and inflammatory mediator-inhibitory effects of three Siegesbeckia herbs used as Herba Siegesbeckiae (Xixiancao).[Pubmed: 29720145]

Herba Siegesbeckiae (HS, Xixiancao in Chinese) is a commonly used traditional Chinese medicinal herb for soothing joints. In ancient materia medica books, HS is recorded to be the aerial part of Siegesbeckia pubescens Makino (SP) which is also the only origin of HS in the 1963 edition of the Chinese Pharmacopeia (ChP). The aerial parts of Siegesbeckia orientalis L. (SO) and Siegesbeckia glabrescens Makino (SG) have been included as two additional origins for HS in each edition of ChP since 1977. However, chemical and pharmacological comparisons among these three species have not been conducted.

New cytotoxic sesquiterpenoids from Siegesbeckia glabrescens.[Pubmed: 25690283]

Two new sesquiterpenoids, siegenolides A (1) and B (2), and two known sesquiterpenes 3 and 4 were isolated from Siegesbeckia glabrescens. Their structures were elucidated by spectroscopic analyses, and they were further evaluated for their cytotoxic activities against human cancer cells (MCF-7, AsPC-1, SW480, HCT 116, HepG2, HeLa). Compounds 1-4 showed differential cytotoxic effects on the target cancer cells with IC50 values in the range of 0.9-33.3 μM.

Anti-angiogenic effects of Siegesbeckia glabrescens are mediated by suppression of the Akt and p70S6K-dependent signaling pathways.[Pubmed: 25434554]

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of allergic and inflammatory diseases. In the present study, we report the effects and molecular mechanism of an ethanolic extract of SG on cell proliferation, migration and tube formation in vascular endothelial growth factor-A (VEGF-A)-treated human umbilical vein endothelial cells. SG treatment inhibited VEGF-A-stimulated endothelial cell proliferation through downregulation of cyclin D and upregulation of cyclin-dependent kinase inhibitors such as p27Kip1 and p21WAF1/Cip1. In addition, SG inhibited VEGF‑A-stimulated endothelial cell migration and tube formation. These anti-angiogenic activities of SG were mediated by inactivation of the Akt- and p70S6K-dependent signaling pathways. Collectively, our findings demonstrate the pharmacological roles and molecular mechanism of SG in regulating angiogenic responses and support further evaluation and development of SG as a potential therapeutic agent for the treatment and prevention of angiogenesis-related diseases including cancer.

Siegesbeckia glabrescens attenuates allergic airway inflammation in LPS-stimulated RAW 264.7 cells and OVA induced asthma murine model.[Pubmed: 25066761]

Siegesbeckia glabrescens (SG) is a plant growing in Korea that is used as a traditional medicine for various inflammatory diseases. In this study, we investigated the protective effects of SG extract on allergic asthma in an ovalbumin (OVA)-induced asthma murine model and lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Female BALB/c mice were sensitized by intraperitoneal injection of OVA on days 0 and 14 and then challenged with OVA from days 21 to 23. SG (30mg/kg) was administered by oral gavage 1h before the OVA challenge. LPS-stimulated RAW264.7 cells were evaluated to determine their levels of nitric oxide (NO). The SG significantly reduced the number of inflammatory cells in bronchoalveolar lavage (BAL) fluid and also reduced IL-4, IL-5, IL-13, eotaxin and immunoglobulin E in OVA-sensitized/challenged mice. SG also effectively reduced airway inflammation and mucus overproduction in lung tissue in addition to decreasing the expression of iNOS and COX-2. In LPS-stimulated RAW264.7 cells, SG treatment significantly reduced the levels of NO. These findings indicate that SG effectively suppressed inflammatory responses, and its effects appear to be related to reduction in iNOS and COX-2 expression. Therefore, we suggest that SG may have potential use as a therapeutic agent for inflammatory diseases such as allergic asthma.

Regulatory effects of Siegesbeckia glabrescens on non-small cell lung cancer cell proliferation and invasion.[Pubmed: 24707874]

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of allergic and inflammatory diseases. In the present study, we examined the effects and molecular mechanism of the ethanol extract of SG on cell proliferation and invasion in p53 wild-type A549 and p53-deficient H1299 non-small cell lung cancer (NSCLC) cells. SG treatment markedly inhibited the proliferation and invasion in both cell lines, independently of p53 expression. The anti-proliferative effect of SG on A549 cells was mediated by the inactivation of Akt and p70(S6K) as evidenced by treatment with LY294002 and rapamycin, respectively. In addition, anti-invasive activity of SG in A549 cells was found to be associated with the inhibition of p70(S6K). In contrast, in H1299 cells the inactivation of p38(MAPK) appeared to be involved in SG-mediated inhibition of cell proliferation and invasion. Collectively, these findings suggest that SG modulates cellular fates such as proliferation and invasion by differential regulation of signaling pathways, depending on the status of p53 expression in NSCLC, and support the development of SG as a potent therapeutic agent for the treatment of NSCLC.

The in vitro antitumor activity of Siegesbeckia glabrescens against ovarian cancer through suppression of receptor tyrosine kinase expression and the signaling pathways.[Pubmed: 23673404]

Siegesbeckia glabrescens (SG) Makino (Compositae) has been used as a traditional medicine for the treatment of a variety of diseases such as allergy, inflammation, acute hepatitis and hypertension. The primary aim of this study was to determine whether the ethanol extract of SG has antitumor activity against ovarian cancer and to identify molecular mechanisms and targets involved in the regulation of cell growth and progression. We demonstrate that SG treatment inhibits proliferation, adhesion, migration and invasion of SKOV-3 human ovarian cancer cells. The anti-proliferative effect of SG on SKOV-3 cells is accompanied by reduced expression of cyclin E and enhanced expression of the cyclin-dependent kinase inhibitor p27(Kip1), leading to inhibition of pRb phosphorylation. We also show that these antitumor activities are found to be mediated through suppression of FAK, ERK, Akt and p70(S6K)-dependent signaling pathways and downregulation of receptor tyrosine kinases such as EGFR, VEGFR-2 and FGFR-1 as well as the cell adhesion molecule N-cadherin. Taken together, our findings suggest further development and evaluation of SG for the treatment of ovarian cancer.

Combined effects of plant extracts in inhibiting the growth of Bacillus cereus in reconstituted infant rice cereal.[Pubmed: 23290233]

A study was done to determine the potential use of plant extracts to inhibit the growth of Bacillus cereus in reconstituted infant rice cereal. A total of 2116 extracts were screened for inhibitory activity against B. cereus using an agar well diffusion assay. The minimal inhibitory concentrations (MIC) and minimal lethal concentrations (MLC) of 14 promising extracts in tryptic soy broth (TSB) were determined. Dryopteris erythrosora (autumn fern) root extract showed the lowest MIC (0.0156 mg/ml), followed by Siegesbeckia glabrescens (Siegesbeckia herb) leaf (0.0313 mg/ml), Morus alba (white mulberry) cortex (0.0313 mg/ml), Carex pumila (sand sedge) root (0.0625 mg/ml), and Citrus paradisi (grapefruit) seed (0.0625 mg/ml) extracts. The order of MLCs of extracts was D. erythrosora root (0.0156 mg/ml)