Facile synthesis of non-modified yellow emission silicon quantum dots and their visualization of hydrogen sulfide in living cells and onion tissues.

Yellow fluorescent silicon quantum dots (y-SiQDs) with 22.2% fluorescence quantum yield were synthesized by a simple hydrothermal method using 3-glycidoxypropyl triethoxysilane (GOTS) and m-aminophenol. The excitation wavelength is 550 nm with an emission wavelength of 574 nm, which effectively avoids the interference of biological autofluorescence. Notably, the synthesis approach does not require any post-modification and the y-SiQDs can be directly used for hydrogen sulfide (H2S) quantification due to static quenching. It exhibits high sensitivity and excellent selectivity for H2S with a 0.2-10 µM (R2 = 0.9953) linear range and detection limit of 54 nM. y-SiQDs have excellent stability and biocompatibility and can be used for H2S imaging in living cells and onion tissues.

A new strategy to improve the water solubility of an organic fluorescent probe using silicon nanodots and fabricate two-photon SiND-ANPA-N3 for visualizing hydrogen sulfide in living cells and onion tissues.

A small-molecule fluorescent probe offers unique advantages for the detection of hydrogen sulfide (H2S) and other reactive small molecules including high sensitivity, cell permeability and high spatiotemporal resolution. Generally, in order to obtain good cell permeability, fluorescent probes are liposoluble, which in turn leads to poor water solubility. Thus, it is regrettable that most of these fluorescent probes cannot be used in fully aqueous systems and hence, organic solvents are used, which may cause negative effects on living cells. Silicon nanodots (SiNDs) have been widely used in many fields due to good water solubility, benign nature, biocompatibility and low toxicity. Herein, we proposed a two-photon SiND-ANPA-N3 fluorescent probe with good water solubility, excellent biocompatibility and low toxicity; it is suitable to detect H2S in totally aqueous media and living cells. This strategy may provide a technically simple and facile approach for designing fluorescent probes with excellent solubility, benign nature, and biocompatibility for use in fully aqueous systems and in vivo.

A fluorescent probe for carbon monoxide based on allyl ether rather than allyl ester: A practical strategy to avoid the interference of esterase in cell imaging.

Pd0-mediated Tsuji-Trost reaction is a practical strategy to design fluorescent probes for carbon monoxide (CO) sensing, and in such reaction CO can reduce Pd2+ to Pd0 in-situ and remove allyl groups on fluorophores. In most of these probes, esters are commonly used to link allyl on fluorophores. We found that the ester groups could be hydrolyzed by esterase activity of fetal bovine serum (FBS), while FBS is a requisite in cell culture, and the hydrolysis could interfere the Pd0-mediated Tsuji-Trost reaction. In this study, we synthesized a fluorescent probe (Cou-CO) using allyl ether as reaction site rather than allyl ester. Cou-CO is non-fluorescence, and could react with CO under the presence of Pd0 to form Cou with strong fluorescence, and the maximum excitation and emission wavelengths of Cou are 464 nm and 495 nm respectively. Cou-CO shows excellent selectivity to CO and could avoid the effect of FBS with the limit of detection for CO is 78 nm. Finally, Cou-CO was successfully applied for imaging of CO in living cells.

Effect of substituents on Stokes shift of BODIPY and its application in designing bioimaging probes.

BODIPY-based probes have excellent fluorescence properties. However, small Stokes shifts approximately 5-15 nm greatly affect their detection sensitivity. In this study, we compared the Stokes shifts of reported BODIPY-based probes with various of substituents, and found that the phenyl groups on the specific position of BODIPY core could expand the Stokes shift of BODIPY-based probes, and methoxy groups on these phenyl substituents could enhance such effects. Then, by quantum chemical calculations, we found that the number of methoxy groups might also have obvious effect on the Stokes shift of BODIPY. Taking nitric oxide (NO) as analyte, 4,4-difluoro-8-(3,4-diaminophenyl)-3,5-bis(2,4-dimethoxyphenyl)-4-bora-3a,4a-diaza-s-indancene (DMOPB) with diaminophenyl substituents has been designed and synthesized. Compared with monomethoxy-phenyl substituted BODIPY-based probes (MOPBs) in our previous work, Stokes shift of DMOPB was expanded by 10 nm when using dimethoxyphenyl instead of monomethoxyphenyl, which is basically consistent with the quantum chemistry calculation of 11 nm. DMOPB can react with NO in only 2 min to form the triazole DMOPB-T with a fluorescence quantum yield of 0.32. An excellent linear relationship was observed in the range of NO concentration from 0.5 µM to 4 µM and the detection limit was 1 nM. The experimental results indicate that DMOPB with high sensitivity, excellent selectivity, low toxicity and dark background can be a great candidate for imaging NO in cells and tissues. Considering the lack of practical way to increase Stokes shift of small-molecule fluorescent probes based on specific fluorophore, the proposed strategy has great potential for the designing of probes with large Stokes shift.

Sucrose fed-batch strategy enhanced biomass, polysaccharide, and ganoderic acids production in fermentation of Ganoderma lucidum 5.26.

Ganoderma, as a Chinese traditional medicine, has multiple bioactivities. However, industrial production was limited due to low yield during Ganoderma fermentation. In this work, sucrose was found to greatly enhance intracellular polysaccharide (IPS) content and specific extracellular polysaccharide (EPS) production rate. The mechanism was studied by analyzing the activities of enzymes related to polysaccharide biosynthesis. The results revealed that sucrose regulated the activities of phosphoglucomutase and phosphoglucose isomerase. When glucose and sucrose mixture was used as carbon source, biomass, polysaccharide and ganoderic acids (GAs) production was greatly enhanced. A sucrose fed-batch strategy was developed in 10-L bioreactor, and was scaled up to 300-L bioreactor. The biomass, EPS and IPS production was 25.5, 2.9 and 4.8 g/L, respectively, which was the highest biomass and IPS production in pilot scale. This study provides information for further understanding the regulation mechanism of Ganoderma polysaccharide biosynthesis. It demonstrates that sucrose fed-batch is a useful strategy for enhancing Ganoderma biomass, polysaccharide and GAs production.

Nrf2 pathway activation contributes to anti-fibrosis effects of ginsenoside Rg1 in a rat model of alcohol- and CCl4-induced hepatic fibrosis.

AIM: To investigate the anti-fibrosis effects of ginsenoside Rg1 on alcohol- and CCl4-induced hepatic fibrosis in rats and to explore the mechanisms of the effects. METHODS: Rats were given 6% alcohol in water and injected with CCl4 (2 mL/kg, sc) twice a week for 8 weeks. Rg1 (10, 20 and 40 mg/kg per day, po) was administered in the last 2 weeks. Hepatic fibrosis was determined by measuring serum biochemical parameters, HE staining, Masson's trichromic staining, and hydroxyproline and α-SMA immunohistochemical staining of liver tissues. The activities of antioxidant enzymes, lipid peroxidation, and Nrf2 signaling pathway-related proteins (Nrf2, Ho-1 and Nqo1) in liver tissues were analyzed. Cultured hepatic stellate cells (HSCs) of rats were prepared for in vitro studies. RESULTS: In the alcohol- and CCl4-treated rats, Rg1 administration dose-dependently suppressed the marked increases of serum ALT, AST, LDH and ALP levels, inhibited liver inflammation and HSC activation and reduced liver fibrosis scores. Rg1 significantly increased the activities of antioxidant enzymes (SOD, GSH-Px and CAT) and reduced MDA levels in liver tissues. Furthermore, Rg1 significantly increased the expression and nuclear translocation of Nrf2 that regulated the expression of many antioxidant enzymes. Treatment of the cultured HSCs with Rg1 (1 µmol/L) induced Nrf2 translocation, and suppressed CCl4-induced cell proliferation, reversed CCl4- induced changes in MDA, GPX, PCIII and HA contents in the supernatant fluid and α-SMA expression in the cells. Knockdown of Nrf2 gene diminished these actions of Rg1 in CCl4-treated HSCs in vitro. CONCLUSION: Rg1 exerts protective effects in a rat model of alcohol- and CCl4-induced hepatic fibrosis via promoting the nuclear translocation of Nrf2 and expression of antioxidant enzymes.

Novel B,O-chelated fluorescent probe for nitric oxide imaging in Raw 264.7 macrophages and onion tissues.

A novel fluorescent probe based on B,O-chelated dipyrromethene chromophore in far-visible and near-infrared spectral region (600-900 nm), boron chelated 8-(3,4-diaminophenyl)-3,5-bis(2-hydroxyphenyl)-4-bora-3a,4a-diaza-s-indancene (BOPB), has been first developed for nitric oxide (NO) imaging. BOPB, a turn-on fluorescent probe, can react with NO rapidly under physiological condition. The reaction product of BOPB with NO, BOPB-T, emits bright red fluorescence at 643 nm when excited at 622 nm. Meanwhile, BOPB-T displays high fluorescent quantum yield of 0.21 and good photostability. The selectivity for NO over other reactive oxygen/nitrogen species and ascorbic acid has been investigated and BOPB has good specificity for the detection of NO. MTT assay shows that the toxicity of BOPB (below 10 µM) to living cells can be neglected. Based on these investigations, BOPB has been used for NO imaging in Raw 264.7 cells and onion tissues. Meanwhile, mechanical injury to onion tissues results in a brighter fluorescence around the wound, which indicates that more NO has been produced in plant tissues in response to external stimuli. Our studies illustrate that BOPB has advantages of high sensitivity, low background interference and little photo damage on fluorescence imaging of NO.

Determination of fatty acids in bio-samples based on the pre-column fluorescence derivatization with 1,3,5,7-tetramethyl-8-butyrethylenediamine-difluoroboradiaza-s-indacene by high performance liquid chromatography.

1,3,5,7-Tetramethyl-8-butyrethylenediamine-difluoroboradiaza-s-indacene (TMBB-EDAN) has been designed and synthesized as a highly fluorescent labeling reagent for carboxylic acids. By using TMBB-EDAN, a sensitive and rapid method based on high performance liquid chromatography-fluorescence detection for the determination of twelve fatty acids (FAs) in bio-samples has been developed. Under optimized conditions, these FAs were tagged with TMBB-EDAN in the presence of 1-ethyl-3-(3-dimethyla-minopropyl) carbodiamide at 20°C for 30min and then the baseline separation was achieved on a C18 column with a linear gradient elution in 26min. With fluorescence detection at λex/λem=490nm/510nm, the linear ranges of FAs were from 3.0 to 300nM and the detection limits with a signal-to-noise ratio of 3 were in the 0.2-0.4nM range. The proposed method offers advantages of milder derivatization condition and much better sensitivity for the determination of FAs, when compared to the reported fluorescence derivatization-based methods.

Ultrasensitive determination of jasmonic acid in plant tissues using high-performance liquid chromatography with fluorescence detection.

An ultrasensitive and selective high-performance liquid chromatographic method for the volatile signaling hormone, jasmonic acid, has been developed based on precolumn derivatization with 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide). The derivatization reaction was carried out at 60 °C for 30 min in the presence of phosphoric acid. The formed jasmonic acid derivative was eluted using a mobile phase of methanol/pH 6.50 ammonium formate buffer/tetrahydrofuran (67:30:3, v/v/v) in 10 min on a C(18) column and detected with fluorescence detection at excitation and emission wavelengths of 495 and 505 nm, respectively. The detection limit (signal-to-noise ratio = 4) reached 1.14 × 10(-10) M or 2.29 fmol per injection (20 µL), which is the lowest of the existing methods. The proposed method has been successfully applied to the direct determination of trace jasmonic acid in the crude extracts of soybean leaves from soybean mosaic virus-infected and normal plants with recoveries of 95-104%.

[Acupuncture combined with Chinese herbal medicine Plantain and Senna Granule in treatment of functional constipation: a randomized, controlled trial].

BACKGROUND: Functional constipation is one of the most common gastrointestinal diseases. Currently, there is no effective Western medical therapy for functional constipation and it significantly impacts the quality of life of the patients. Integrated traditional Chinese and Western medicine therapies were reported to have better therapeutic effects than routine Western medicine therapies. OBJECTIVE: To explore the efficacy of acupuncture combined with Chinese herbal medicine Plantain and Senna Granule in the treatment of functional constipation. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: A total of 390 patients with confirmed functional constipation enrolled from the Department of Gastroenterology, the First Affiliated Hospital of Xinxiang Medical College in China from February 2008 to January 2010 were randomly divided into three groups, with 130 cases in each group. Acupuncture group was treated with puncture of point Tianshu (ST25), Shangjuxu (ST37), Zusanli (ST36), Dachangyu (BL25) and Zhigou (SJ6) twice daily for four weeks, while Plantain and Senna Granule group was treated with 5 g of Plantain and Senna Granule once daily, and the combination group was given above-mentioned acupuncture and Plantain and Senna Granule. MAIN OUTCOME MEASURES: The defecation cycle, stool property, constipation symptom, accompanying symptoms, gastrointestinal transit time, including total gastrointestinal transit time, mouth-intestine transit time, colonic transit time, right colonic transit time, left colonic transit time and rectosigmoid colonic transit time, and adverse reactions of the three groups were evaluated before treatment, at the end of treatment and 64 weeks after treatment, respectively. RESULTS: Compared with before treatment, the scores of defecation cycle, stool property, constipation symptoms and accompanying symptoms, and gastrointestinal transit time all decreased significantly at the end of treatment in each group (P<0.01), and the combination group showed better results than the other groups (P<0.05). Compared with the end of treatment, the above-mentioned indexes recurred insignificantly in the combination group and acupuncture group after 64 weeks of follow-up (P>0.05), but all recurred significantly in the Plantain and Senna Granule group (P>0.05). Both short- and long-term total response rates of the combination group showed significant differences compared with those of the other two groups (P<0.05 or P<0.01). No serious adverse reactions occurred in all the three groups. CONCLUSION: Acupuncture plus Plantain and Senna Granule can significantly decrease gastrointestinal transit time and defecation cycle in patients with functional constipation; it can also change stool property and alleviate constipation symptom and accompanying symptoms, with good security and tolerance.

Simultaneous determination of phytohormones containing carboxyl in crude extracts of fruit samples based on chemical derivatization by capillary electrophoresis with laser-induced fluorescence detection.

An efficient and sensitive capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) method has been developed for the simultaneous determination of phytohormones containing carboxyl group, including gibberellic acid, indole-3-acetic acid, abscisic acid, jasmonic acid, indole butyric acid, 1-naphthalene acetic acid and 2,4-dichloro-phenoxy acetic acid, based on the chemical derivatization with 6-oxy-(acetypiperazine) fluorescein. Using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide as the condensing reagent, the derivatization reaction completed at 60°C in 60 min and the derivatization limits could reach 20 nmol L(-1). The formed derivatives of seven phytohormones have been separated and quantified within 20 min. The linearity was found in the range of 0.01-1 µmol L(-1) and the limits of detection were 1.6-6.7 nmol L(-1) (S/N=3). The proposed method has been applied to analyze the crude extract of 0.5 g banana samples directly without further purification and the recoveries varying from 90.7 to 106.1%.

Determination of phytohormones in plant samples based on the precolumn fluorescent derivatization with 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene by HPLC for routine use.

Six phytohormones including indole butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichloro-phenoxy acetic acid (2,4-D), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) in crude plant extractions have been quantitated by means of high-performance liquid chromatography (HPLC) with fluorescence detection based on the precolumn derivatization using 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), a fluorescent reagent synthesized in our lab recently. The optimization of derivatization conditions was carefully studied by an L(25) (5(6)) orthogonal array design (OAD) with five factors at five levels that are important influence parameters in the improvement of derivatization efficiency. The separation conditions were also studied in detail. Under the optimal conditions, the detection limits (S/N=3) of the six phytohormones were found from 0.12 to 0.75 nM. The proposed method was the first investigation of aminozide for the analysis of phytohormones and has been successfully applied to the determination of phytohormones in plant samples such as cucumber and tomato with recoveries of 94-105%.

[Long-term efficacy and safety research on functional dyspepsia treated with electroacupuncture and Zhizhu Kuanzhong capsule].

OBJECTIVE: To observe the long-term efficacy and safety on functional dyspepsia treated with electroacupuncture and Zhizhu Kuanzhong capsule and explore the therapeutic mechanism. METHODS: Three hundreds and twenty patients with confirmed diagnosis as functional dyspepsia were randomly divided into 4 groups: an electroacupuncture group, a Zhizhu Kuanzhong capsule group, a combined therapy group and a western medication group, 80 cases in each group. In electroacupuncture group, acupuncture was applied to Zusanli (ST 36), Zhongwan (CV 12), Neiguan (PC 6), Taichong (LR 3) and Gongsun (SP 4), twice per day, continuously for 5 days each week. In Zhizhu Kuanzhong capsule group, Zhizhu Kuanzhong capsule, 1.29 g was administered for oral application, three times each day. In combined therapy group, the therapeutic programs in the above-mentioned groups were applied in combination. In western medication group, Mosapride 5 mg, three times per day; Omeprazole 20 mg, twice per day and Amitriptyline 25 mg, twice per day were administered for oral application. Six weeks treatment was required in each group. The symptoms score, the Nepean Dyspepsia Symptom Index (NDSI), the Nepean Dyspepsia Life Quality Index (NDLQI), Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), electrogastrography, plasma motilin, gastric emptying by B-sonography and adverse reactions were observed before and after treatment, as well as 4 weeks after treatment separately. RESULTS: Compared with those before treatment, the symptom score and NDSI decreased apparently after treatment (all P < 0.01), NDLQI, SF-36, electrogastrographic frequency, plasma motilin and gastric emptying were up-regulated apparently (all P < 0.01) after treatment in each group. The results of the above-mentioned indices in combined therapy group were superior to the other groups (all P < 0.05). As compared with the condition at the end of treatment, in 4 weeks after treatment, the above indices were not rebound apparently in electroacupuncture group and combined therapy group (all P > 0.05). But they were rebound obviously in Zhizhu Kuanzhong capsule group and western medication group (all P < 0.05). The short-term and long-term efficacies in combined therapy group were significantly higher than the total effective rates in the other groups (P < 0.05, P < 0.01). No serious adverse reaction was reported in each group. CONCLUSION: Electroacupuncture and Zhizhu Kuanzhong capsule all up-regulate plasma motilin and electrogastrographic frequency, promote gastric emptying, alleviate the symptom of functional dyspepsia and improve NDLQI. But the combined medication achieves much better efficacy and presents better safety and long-term therapeutic effect.