[Liujunzi Decoction treats 4NQO-induced esophageal cancer in mice: a study based on serum metabolomics].

This study aims to explore the mechanism of Liujunzi Decoction in the treatment of 4-nitroquinoline-N-oxide(4NQO)-induced esophageal cancer in mice. One hundred mice of 35-45 days were randomized into blank, model, and low-, medium-, and high-concentration(18.2, 36.4, and 54.6 g·kg~(-1), respectively) Liujunzi Decoction groups. The mice in other groups except the blank group had free access to the water containing 100 µg·mL~(-1) 4NQO for 16 weeks for the modeling of esophageal cancer. The mice in the Liujunzi Decoction groups were fed with the diets supplemented with corresponding concentrations of Liujunzi Decoction. The body weight and organ weights were weighed for the calculation of organ indexes. The pathological changes of the esophageal tissue were observed by hematoxylin-eosin(HE) staining. Ultra performance liquid chromatography-mass spectrometry(UPLC-MS/MS) was employed to collect metabolites from mouse serum samples, screen out potential biomarkers, and predict related metabolic pathways. Compared with the blank group, the model group showed decreased spleen and stomach indexes and increased lung, esophagus, and kidney indexes. Compared with the model group, Liujunzi Decoction groups had no significant changes in the organ indexes. The HE staining results showed that Liujunzi Decoction inhibited the invasive growth and cancerization of the esophageal cancer cells. A total of 9 potential biomarkers of Liujunzi Decoction in treating esophageal cancer were screened out in this study, which were urocanic acid, 1-oleoylglycerophosphoserine, 11-deoxy prostaglandin E1, Leu-Glu-Lys-Glu,(±) 4-hydroxy-5E,7Z,10Z,13Z,16Z,19Z-docosahexaenoic acid, ureidosuccinic acid,(2R)-2,4-dihydroxy-3,3-dimethylbutanoic acid, kynurenic acid, and bicyclo prostaglandin E2, which were mainly involved in histidine, pyrimidine, alanine, aspartate, glutamate, pantothenate and tryptophan metabolism and coenzyme A biosynthesis. In summary, Liujunzi Decoction may exert the therapeutic effect on the 4NQO-induced esophageal cancer in mice by regu-lating the amino acid metabolism, inflammation, and immune function.

Double-strand DNA-templated formation of copper nanoparticles as fluorescent probe for label free nuclease enzyme detection.

The double-strand DNA (dsDNA) can act as an efficient template for the formation of copper nanoparticles (Cu NPs) with high fluorescence, whereas the single-strand DNA (ssDNA) cannot support the formation of Cu NPs. This difference in fluorescent signal generation can be used for the detection of nuclease cleavage activity. Thus, a label-free strategy for sensitive detection of nuclease has been developed. The sensor contains a complete complementary dsDNA which acts as a template for the formation of Cu NPs and generation of fluorescence signal. The enzyme S1 nuclease was taken as the model analyte. Upon addition of S1 nuclease into the sensing system, the DNA was cleaved into fragments, preventing the formation of the Cu NPs and resulting in low fluorescence. In order to achieve the system's best sensing performance, a series of experimental conditions were optimized. Under the optimized experimental conditions, the sensor exhibits excellent performance (e.g., a detection limit of 0.3 U mL⁻¹ with high selectivity). This possibly makes it an attractive platform for the detection of S1 nuclease and other biomolecules.

[Determination of the cucurbitacins from Cucubita pepo cv dayangua by HPLC].

OBJECTIVE: To establish an HPLC method for the simultaneous determination of four bioactive cucurbitacins in Cucubita pepo cv Dayangua. METHODS: The HPLC chromatography was carried out with a lineal gradient programming and detection wavelength at 215 nm. Kromasil C8 column (150 mm x 4.6 mm ID, 5 microm)was used. The mobile phase was acetonitrile-water (containing 2.0% HAc) and the flow rate was 1.0 ml/min. RESULTS: The linear range of 23, 24-dihydrocucurbitacin F was 0.28-5.6 microg/ml (r = 0.9978), 23, 24-dihydrocucurbitacin D 0.39-7.8 microg/ml (r = 0.9986), cucurbitacin B 0.304-6.08 microg/ml (r = 0.9983), cucurbitacin E 2. 52 -50. 4 microg/ml (r = 0.9998). The method was accurate with variation less than 5% and recovery more than 95%. CONCLUSION: The method is successfully applied to determination of the four cucurbitacins from Cucubita pepo cv dayangua.