Isolation and identification of polyphenols from Marsilea quadrifolia with antioxidant properties in vitro and in vivo.

Marsilea quadrifolia is an edible aquatic medicinal plant used as a traditional health food in Asia. Four new polyphenols including kaempferol 3-O-(2″-O-E-caffeoyl)-ß-d-glucopyranoside (1), kaempferol 3-O-(3″-O-E-caffeoyl)-α-l-arabinopyranoside (3), 4-methy-3'-hydroxypsilotinin (4) and (±)-(E)-4b-methoxy-3b,5b-dihydroxyscirpusin A (18) together with 14 known ones (2, 5-17) were isolated from the ethanol extract of M. quadrifolia. Structures of the new compounds were elucidated by extensive spectroscopic analyses. In DPPH and oxygen radical absorbance capacity antioxidant assays, some compounds showed stronger antioxidant activities and quercetin (9) was the most potent antioxidant in both assays. In a restraint-induced oxidative stress model in mice, quercetin significantly attenuated the increase in plasma ALT and AST levels as well as liver MDA content of restrained mice. Liver SOD activity was also significantly increased by quercetin, indicating a significant in vivo antioxidant activity. As a rich source of polyphenols with strong antioxidant activities, M. quadrifolia may be developed to a product for relieving oxidative stress.

Novel PI3K/AKT targeting anti-angiogenic activities of 4-vinylphenol, a new therapeutic potential of a well-known styrene metabolite.

The pneumo- and hepato-toxicity of 4-vinylphenol (4VP), a styrene metabolite, has been previously reported. Nevertheless, the present study reported the novel anti-angiogenic activities of 4VP which was firstly isolated from the aqueous extract of a Chinese medicinal herb Hedyotis diffusa. Our results showed that 4VP at non-toxic dose effectively suppressed migration, tube formation, adhesion to extracellular matrix proteins, as well as protein and mRNA expressions of metalloproteinase-2 of human endothelial cells (HUVEC and HMEC-1). Investigation of the signal transduction revealed that 4VP down-regulated PI3K/AKT and p38 MAPK. Besides, 4VP interfered with the phosphorylation of ERK1/2, the translocation and expression of NFkappaB. In zebrafish embryo model, the new blood vessel growth was significantly blocked by 4VP (6.25-12.5 µg/mL medium). The VEGF-induced blood vessel formation in Matrigel plugs in C57BL/6 mice was suppressed by 4VP (20-100 µg/mL matrigel). In addition, the blood vessel number and tumor size were reduced by intraperitoneal 4VP (0.2-2 mg/kg) in 4T1 breast tumor-bearing BALB/c mice, with doxorubicin as positive control. Together, the in vitro and in vivo anti-angiogenic activities of 4VP were demonstrated for the first time. These findings suggest that 4VP has great potential to be further developed as an anti-angiogenic agent.

Rapid authentication of Cordyceps by lateral flow dipstick.

Cordyceps (Dongchongxiacao), a valuable traditional Chinese medicine, is composed of the fruiting body of Ophiocordyceps sinensis (Family: Ophiocordycipitaceae) on a caterpillar of ghost-moth species (Family: Hepialidae). Owing to its multiple potential functions, Cordyceps are in great demand and represent significant economic value. Adulterants or substitutes named Cordyceps or Chongcao from related fungi have been reported. In this study, polymerase chain reaction (PCR) coupled with a lateral flow dipstick (LFD) system was developed to distinguish genuine herb O. sinensis from its common adulterant Cordyceps gunnii and Cordyceps militaris. Specific primers (EF-CS-F1-Biotin, EF-CG-F1-Biotin and EF-CM-F1- Biotin) were designed to differentiate the three Cordyceps species. Internal control (EF-F1-b-DIG and EF-R1-FITC) was included to minimize the false signal due to PCR inhibitors or DNA degradation. LFD was then successfully employed for speedy and accurate detection of the respective PCR products.

Application of novel loop-mediated isothermal amplification (LAMP) for rapid authentication of the herbal tea ingredient Hedyotis diffusa Willd.

Hedyotis diffusa Willd. (Baihuasheshecao) is an ingredient of herbal teas commonly consumed in the Orient and tropical Asia for cancer treatment and health maintenance. In the market, this ingredient is frequently adulterated by the related species Hedyotis corymbosa (L.) Lam. The objective of this study is to develop a novel loop-mediated isothermal amplification (LAMP) technique to differentiate H. diffusa from its adulterant H. corymbosa. A set of four internal control primers (F3, FIP, BIP and B3) were designed based on six loci in the internal transcribed spacer (ITS) for LAMP of both H. diffusa and H. corymbosa. Two specific primers (S_F3 and S_FIP) were designed for specific LAMP detection of H. diffusa only. Our data showed that LAMP was successful for both H. diffusa and H. corymbosa in internal control. In contrast, only H. diffusa was detected in specific LAMP using the specific primers S_F3 and S_FIP. This study showed that LAMP was useful to differentiate H. diffusa from its adulterant H. corymbosa. This study is significant for the verification of the authenticity for better quality control of this common herbal tea ingredient. The strategy of including an internal control assures the quality of the concerned DNA region for LAMP.

Anti-angiogenesis and immunomodulatory activities of an anti-tumor sesquiterpene bigelovin isolated from Inula helianthus-aquatica.

Bigelovin is a sesquiterpene lactone isolated from the plant Inula helianthus-aquatica which was traditionally used in cancer treatment in Yunnan, China. The potent apoptotic activities of bigelovin in human leukemia U937 cells were shown in our previous study. The present study investigated the anti-angiogenic and immunomodulatory effects of bigelovin using transgenic zebrafish Tg(fli1a:EGFP)y1 with fluorescent blood vessels and human peripheral blood mononuclear cells (PBMCs), respectively. Furthermore, the inhibitory activities of bigelovin on the human endothelial cell adhesion molecules (CAMs) were also examined. Our results showed that the growth of subintestinal vessels of the bigelovin-treated zebrafish embryos was significantly inhibited and the gene expressions in angiogenesis signaling pathways (e.g. Ang2 and Tie2) of the zebrafish were down-regulated after bigelovin treatment. Besides, the proliferation and Th1 cytokines productions (e.g. IFN-γ, IL-2 and IL-12) were suppressed in bigelovin-treated PBMCs. On the other hand, bigelovin was shown to significantly inhibit the human monocyte adhesion to human endothelial cells and the gene expressions of inflammation-related CAMs (e.g. ICAM-1, VCAM-1 and E-selectin) were significantly down-regulated in bigelovin-treated human endothelial cells. In summary, our data provide the first evidence that bigelovin possesses anti-angiogenic and immunomodulatory activities, suggesting bigelovin may exert multi-target functions against cancer in animal models.