Recent progress in nanomaterial-based assay for the detection of phytotoxins in foods.

Phytotoxins refers to toxic chemicals derived from plants. They include both secondary metabolites that are dose-dependently toxic and allergens that can cause anaphylactic shock in sensitive individuals. Detecting phytotoxins in foods is increasingly important. Conventional methods for detecting phytotoxins lack sufficient sensitivity and operational convenience. Nanomaterial-based determination assays show great competence in fast and accurate sensing of trace substances. In the present review, representative phytotoxin categories of alkaloids, cyanides, and proteins are discussed. Application of notable nanomaterials, e.g. carbon nanotubes, graphene oxide, magnetic nanoparticles, metal-based nanotools, and quantum dots, in specific sensing strategies to fit the physiochemical properties of the target toxins are summarized. Nanomaterials mainly play four roles in phytotoxin detection: 1) analyte enricher; 2) sensor structure mediator; 3) target recognizer or reactant; 4) signaling agent. Great achievements have been made in the detection of trace plant-derived toxins in food matrices, yet there are still challenges awaiting further investigation.

Concise Synthesis of Natural Phenylphenalenone Phytoalexins and a Regioisomer.

Concise total syntheses of the natural phytoalexins 2-hydroxy-8-(4-hydroxyphenyl)phenalen-1-one (1), 2-hydroxy-8-(3,4-dihydroxyphenyl)phenalen-1-one (2), and hydroxyanigorufone (4), together with regioisomer 3 are accomplished in 11 or 12 steps. The synthetic strategy features a Friedel-Crafts acylation to construct the 1H-phenalen-1-one tricyclic core followed by a Suzuki cross-coupling to obtain the target compounds.

Qing-dai powder promotes recovery of colitis by inhibiting inflammatory responses of colonic macrophages in dextran sulfate sodium-treated mice.

BACKGROUND: Qing-dai powder (QDP), comprising Indigo naturalis (Qing-dai) and dried alum (Ku-fan), was used in Chinese medicine to treat the conditions associated with mucosal hemorrhage, such as ulcerative colitis (UC). This study aims to investigate the effects and potential mechanism of QDP on dextran sulfate sodium (DSS)-induced acute colitis in mice and to examine the regulatory effects of QDP on macrophages. METHODS: Seven- to eight-week-old male C57BL/6 mice were challenged with 2.0 % DSS in drinking water for 5 days and then the colitic mice were arbitrarily allocated into five groups (n = 10 for each group). QDP (0.77, 1.54 and 3.08 g/kg) and sulfasalazine (SASP) (0.20 g/kg) were orally administered for 7 days. The disease activity index was determined by scores of body weight loss, diarrhea and rectal bleeding; histological signs of damage was analyzed by H&E staining; myeloperoxidase activity was measured by colorimetric method, levels of proinflammatory cytokines were determined by ELISA; changes in macrophages in the colon were analyzed by immunohistochemistry (IHC) and flow cytometry. Lipopolysaccharide (LPS)-induced RAW264.7 cells were treated with or without QDP, then the production of TNF-α and IL-6 were measured by ELISA; and protein molecules such as COX-2, iNOS, IкB-α were determined by Western blot. RESULTS: Oral administration of QDP at dosages of 1.54 and 3.08 g/kg significantly reduced disease activity index on day 12 (P < 0.001 for 1.54 g/kg and P < 0.0008 for 3.08 g/kg), colon shortening (P = 0.012 for 1.54 g/kg, P = 0.001 for 3.08 g/kg), histological damage (P < 0.001 for 1.54 g/kg, P < 0.001 for 3.08 g/kg) and colonic myeloperoxidase activity (P = 0.002 for 1.54 g/kg, P < 0.001 for 3.08 g/kg) of DSS-treated mice. Moreover, QDP treatment (1.54 and 3.08 g/kg) significantly decreased DSS-induced infiltration of macrophages, and production of TNF-α (P = 0.005 for 1.54 g/kg, P = 0.002 for 3.08 g/kg), IL-1ß (P = 0.008 for 1.54 g/kg, P = 0.002 for 3.08 g/kg) and IL-6 (P = 0.011 for 1.54 g/kg, P = 0.004 for 3.08 g/kg) in colonic tissues, and also reduced serum MCP-1 levels (P = 0.001 for 1.54 g/kg, P < 0.001 for 3.08 g/kg). In RAW264.7 cells, QDP significantly suppressed LPS-induced production of TNF-α and IL-6 (Both P < 0.001 for 1.0 µg/mL QDP treatment) and expression levels of COX-2 (P = 0.002 and P = 0.001 for 1 and 3 µg/mL QDP treatment, respectively) and iNOS (P < 0.001 for 3 µg/mL QDP treatment) by inhibiting IкB-α degradation (P = 0.007 and P = 0.004 for 1 and 3 µg/mL QDP treatment, respectively) and NF-кB p65 nuclear translocation. CONCLUSION: QDP suppressed the inflammatory responses of colonic macrophages in DSS-induced UC in mice and LPS-induced RAW264.7 cells.

Traditional Chinese medicine formulas for irritable bowel syndrome: from ancient wisdoms to scientific understandings.

Traditional Chinese Medicine (TCM) serves as the most common alternative therapeutic approach for Western medicine and benefits IBS patients globally. Due to the lack of scientific evidence in the past, TCM formulas were not internationally well recognized as promising IBS remedies. In this review, firstly, we present the etiology and therapy of IBS in terms of traditional Chinese medical theory. Secondly, we summarize the clinical randomized controlled trials (RCTs) of TCM formulas for IBS patients that are available in the literature (from 1998 to September 2013), in which 14 RCTs conducted of high quality were discussed in detail. Of the 14 selected trials, 12 of those concluded that TCM formulas provided superior improvement in the global symptoms of IBS patients over the placebo or conventional medicines. As well, all 14 RCTs suggested that TCM formulas have good safety and tolerability. Last but not least, we explore the pharmacological mechanisms of the anti-IBS TCM formulas available in the literature (from 1994 to September, 2013). Collectively, in combating IBS symptoms, most TCM formulas exert multi-targeting actions including the regulation of neurotransmitters and hormones in the enteric nervous system (ENS), modulation of smooth muscle motility in the gastrointestinal (GI) tract, modulation of the hypothalamic-pituitary-adrenal (HPA) axis, attenuation of intestinal inflammation and restoration of intestinal flora, etc. In conclusion, TCM formulas appear to be promising for IBS treatment. This review provides a useful reference for the public in furthering a better understanding and acceptance of TCM formulas as IBS remedies.

Inhibitory effect of the gallotannin corilagin on dextran sulfate sodium-induced murine ulcerative colitis.

The therapeutic effect of corilagin (1) was evaluated in an acute colitis model induced by dextran sulfate sodium (DSS) in mice, and the mechanism of action was investigated in this study. Animals were challenged with 2% DSS drinking water for 5 consecutive days and then intraperitoneally treated with 1 (7.5, 15, and 30 mg/kg) daily for 7 days. It was found that 1 significantly decreased the disease activity index, inhibited the shortening of colon length, reduced colon tissue damage, and suppressed myeloperoxidase activity. Moreover, 1 greatly suppressed the secretion of TNF-α, IL-6, and IL-1ß, inhibited the degradation of IκB α, and down-regulated expression of cleaved caspase-3 and cleaved caspase-9 in colon tissues of DSS-treated mice. These findings demonstrated that 1 exerts a protective effect on DSS-induced colitis, and its underlying mechanisms are associated with inhibition of the NF-κB pathway that mitigates colon inflammatory responses and apoptosis of intestinal epithelial cells.

A bioactivity-guided study on the anti-diarrheal activity of Polygonum chinense Linn.

ETHNOPHARMACOLOGICAL RELEVANCE: Polygonum chinense Linn., a folk medicine, has long been used for the treatment of diarrhea and enteritis in southwestern China. However, the components responsible for its anti-diarrheal activity are still poorly understood. AIM OF THE STUDY: To determine anti-diarrheal activities of Polygonum chinense L. and to identify its active components through bioactivity-guided isolation technique. MATERIALS AND METHODS: Animals were orally administered with the extract of Polygonum chinense L. The anti-diarrheal effects of 75% ethanol extract, four fractions with different polarities from 75% ethanol extract, different eluates collected from Diaion HP-20 macroporous resin chromatography, ellagic acid and corilagin, were examined based on mouse models of castor oil- and magnesium sulfate-induced diarrhea. RESULTS: The results showed that the 75% ethanol extract of Polygonum chinense L. exhibited significant anti-diarrheal activities in a dose-dependent manner in two mouse models. Through in vivo bioactivity-guided fractionation processes, n-butanol and aqueous fractions were found to exhibit prominent anti-diarrheal activities, and two major compounds, ellagic acid and corilagin, from these active fractions were found to possess anti-diarrheal effects. CONCLUSION: Present study provides evidence of the utilization of Polygonum chinense L. for diarrhea, and ellagic acid and corilagin are two components contributing to the anti-diarrheal effect.