Determination of trace potassium permanganate in tap water by solid phase extraction combined with spectrophotometry.

A simple solid phase extraction (SPE) coupled with spectrophotometric method was developed for determination of trace permanganate (MnO4 -) in water. Commercial reagent polyamined-6 powder was used as SPE stationary phase to retain MnO4 - which is based on the fact that MnO4 - can be adsorbed on polyamide 6 (PA-6) sorbent as water samples flow through the SPE cartridge. 3,3',5,5'-tetramethylbenzidine (TMB) were used both as eluent solution and chromogenic agent to convert the adsorbed MnO4 - into Mn2+ and generate blue oxidized product with high molar absorptivity. Quantification of MnO4 - could be obtained by spectrophotometric detection of the resulting solution flow out of the SPE cartridge. The extraction and detection variables was optimized to maximize the absorbance of the TMB oxidized product. Under optimized conditions, this method provided linear dynamic ranges of 0.01-1 µmol L-1 for MnO4 - with preconcentration of 100 mL water sample. The limits of detection (3Sb/m) of this method in deionized water were calculated to be 5.1 nM, and the relative standard deviations were determined to be 3.2% (C = 0.1 µmol L-1, n = 5). This method has been applied to the determination of MnO4 - in spiked tap waters and satisfactory recovery was obtained.

Requirement of transcription factor NME2 for the maintenance of the stemness of gastric cancer stem-like cells.

Cancer stem cells (CSCs), which can self-renew and produce heterogeneous cancer cells, are the key factors during tumorigenesis. Transcription factors take essential effects on CSCs. However, the role of transcription factors in regulating the stemness of gastric cancer stem-like cells has not been well explored. In this investigation, it was found that transcription factor NME2 (NME/NM23 nucleoside diphosphate kinase 2) was upregulated in gastric cancer stem-like cells that sorted from the solid tumors of patients with gastric cancer and gastric cancer cell lines. NME2 could preserve the stemness of gastric cancer stem-like cells via suppressing their apoptosis. In vitro and in vivo data revealed that NME2 was crucial for maintaining the stemness of gastric cancer stem cells by enhancing the expression of anti-apoptosis genes. Consequently, our data contributed a new perspective to the relationship between transcription factor and the stemness maintenance of gastric cancer stem cells.

Wei Chang An pill regulates gastrointestinal motility in a bidirectional manner.

CONTEXT: Wei Chang An (WCA) is a commercial prescription developed for the coordination of gastrointestinal movement. OBJECTIVE: To investigate the role of WCA in the regulation of diarrhoea and constipation in rats. MATERIAL AND METHODS: The diarrhoea and constipation models were prepared by gavage of Folium senna and diphenoxylate hydrochloride. Rats were randomized equally (n = 6) into the normal group given saline daily, the positive group given Pinaverium Bromide (13.5 mg/kg) or Sennoside A (0.1 mg/kg) and three WCA-treated groups (22, 44, and 88 mg/kg) by gavage daily for 7 consecutive days. The effects of WCA were assessed by a series of faecal symptoms and histopathology. Gastrointestinal parameters were determined by ELISA. The effect of WCA on gastrointestinal tissues was evaluated by strip assay. Expression of ROCK-1 and MLCK was measured by RT-PCR and Western blotting. RESULTS: Data from Bristol stool form scale, diarrhoea index, visceral sensitivity, defaecation time, and intestinal propulsive rate showed that WCA protected rats against diarrhoea and constipation (p < 0.01). The up-regulation of Substance P and 5-hydroxytryptamine in diarrhoea rats and down-regulation of Substance P and vasoactive intestinal polypeptide in constipation rats were inhibited by WCA (p < 0.05). WCA stimulated the gastrointestinal strip contractions but inhibited ACh-induced contractions (p < 0.01). The decreased ROCK-1 and MLCK expression in diarrhoea rats and increased in constipation rats were suppressed by WCA (p < 0.01). CONCLUSIONS: WCA has both antidiarrhea and anti-constipation effects, suggesting its bidirectional role in gastrointestinal modulation, and providing evidence of WCA for irritable bowel syndrome treatment.

Bakuchiol suppresses oestrogen/testosterone-induced Benign Prostatic Hyperplasia development through up-regulation of epithelial estrogen receptor ß and down-regulation of stromal aromatase.

Estrogens and androgens play critical roles during benign prostatic hyperplasia (BPH) development. Estrogen receptors (ERs), androgen receptor (AR) and aromatase, the key conversion enzyme of androgen to estrogen, are thought to be the effective targets for BPH treatment. Bakuchiol (Ba)-containing herb Psoralea corylifolia has been long-termed used for BPH patients in traditional Chinese medicine while the role and regulatory mechanism of Ba involved remain unclear. Human prostatic cell lines WPMY-1 and BPH-1 and oestrodial/testosterone-induced BPH rats were used as the in vitro and in vivo models. Ba significantly inhibited the proliferation of WPMY-1 and BPH-1 cells. In E2/T-induced BPH model, Ba treatment also significantly inhibited the enlargement of prostate, decreased PI values, reduced the thickness of periglanular smooth muscle layer, and down-regulated the expressions of PCNA and smooth muscle cell marker α-SMA, all of which were highly induced in BPH rats. Moreover, the basal and PGE2-induced expressions of aromatase were reduced in Ba-stimulated WPMY-1 cells, while the expression of ERß was highly increased in Ba-stimulated BPH-1 cells, both of which are consistent with the findings in Ba group in vivo. Ba induced ERE activity in BPH-1 cells as E2 did; however, silence of ERß not ERα, blocked Ba-induced ERE activity while E2 still exhibited the significant ERE activity, indicating the regulation of estrogen signaling by Ba is particularly via ERß. In conclusion, by down-regulation of stromal aromatase and up-regulation of epithelial ERß, Ba contributes to the balance of estrogen and androgen signaling and further inhibits BPH development.

Inhibitory mechanism and molecular analysis of furoic acid and oxalic acid on lipase.

Lipase hydrolyzes fat to free fatty acid and monoacylglycerol, which can be absorbed. Lipase inhibitors reduce the absorption of fat by intestinal cells. In this paper, we explored a novel treatment for obesity. Lipase was strongly inhibited by furoic acid and oxalic acid (IC50 of 2.12 ±â€¯0.04 and 15.05 ±â€¯0.78 mM, respectively). The inhibition by furoic acid was non-competitive, while that of oxalic acid was competitive (inhibition constant 2.12 ±â€¯0.04 and 10.6 ±â€¯0.17 mM, respectively). Quenching was static. With increasing concentration of inhibitor, the peaks of enzyme fluorescence declined. Docking results suggested that furoic acid and oxalic acid could interact with the amino acid residues of the active center of lipase.