A highly sensitive and selective method was developed for both UV-vis spectrophotometric and fluo-rimetric determination of organophosphorus pesticides(OPs).This method used silver nanoparticles(AgNPs)modified with graphitic carbon nitride(g-C3N4).The AgNPs reduced the fluorescence intensity of g-C3N4.Acetylthiocholine(ATCh)could be catalytically hydrolyzed by acetylcholinesterase(AChE)to form thiocholine,which induces aggregation of the AgNPs.This aggregation led to the recovery of the blue fluorescence of g-C3N4,with excitation/emission peaks at 310/460 nm.This fluorescence intensity could be reduced again in the presence of OPs because of the inhibitory effect of OPs on the activity of AChE.The degree of reduction was found to be proportional to the concentration of OPs,and the limit of fluorometric detection was 0.0324 μg/L(S/N = 3).In addition,the absorption of the g-C3N4/AgNPs at 390 nm decreased because of the aggregation of the AgNPs,but was recovered in presence of OPs because of the inhibition of enzyme activity by OPs.This method was successfully applied to the analysis of parathion-methyl in real samples.

Objective Effect of hawthorn and melanoidins on the in-vitro growth of Bifidobacterium and E.coli. Methods According to methods of the Chinese pharmacopoeia (2015),the charred hawthorn was prepared. The melanoidins in charred hawthorn were separated and purified by the macroporous resin extraction process. Ultraviolet spectrophotometry was used to detect melanoidins. The gas chromatography was used to detect the effects of hawthorn, charred hawthorn and melanoidins on the content of the acetic acid in Bifidobacterium and E.coli during growth, stable and decay period. Results In the early stage, the effects of hawthorn and charred hawthorn on bacteria were greater than melanoidins. In the middle and late stage, melanoidins inhibited the growth and metabolism of E.coli by changing the generation of acetic acid, and contributed to that of Bifidobacterium and also promoted the generation of acetic acid and regulate the intestinal flora. Conclusion Hawthorn, charred hawthorn and melanoidins all promote digestion by promoting the growth and metabolism of intestinal flora. Among them, charred hawthorn has a better effect on intestinal flora.

Objective: To investigate the in vitro and in vivo effects of 5-aminolevulinic acid (5-ALA)-mediated photodynamic therapy against oral squamous cell carcinoma (OSCC) and preliminarily explore the possible mechanisms. Methods: SCC25 cells were divided into the control group (5-ALA of 0 mg/L) and the experimental group (5-ALA of 10, 25, 50, 100 and 150 mg/L). The production of protoporphyrin Ⅸ (PpⅨ) induced by 5-ALA in SCC25 cells was detected using the flow cytometry. SCC25 cells were divided into the control group (5-ALA of 0 mg/L), lazer alone group, 5-ALA alone group (5-ALA of 100 mg/L) and the 5-ALA combined with laser irradiation group (5-ALA of 5, 10, 25, 50 and 100 mg/L), the cytotoxicity of 5-ALA combined with laser irradiation (wave length 635 nm, power density 87 mW/cm² and laser dose 10.4 J/cm²) was evaluated in SCC25 cells using the methyl thiazolyltetrazolium assay (incubation times of 4, 8 and 12 h in each group) and the induction effect of combination treatment on the cell apoptosis was assessed by the flow cytometry (incubation time of 12 h in each group). The intracellular production of reactive oxygen species (ROS) triggered by 5-ALA combined with laser irradiation was determined using a fluorescence probe method (incubation time of 12 h in each group). A mouse OSCC xenograft model bearing SCC25 tumor was built, and the mice were divided into control group (saline), 5-ALA group (5-ALA of 50 mg/kg) and 5-ALA combined with laser irradiation group (5-ALA of 10, 25 and 50 mg/kg). Antitumor effect of 5-ALA combined with laser irradiation (wave length 635 nm, power density 158 mW/cm² and laser dose 94.8 J/cm²) was further measured. Results: 5-ALA induced the production of PpⅨ in SCC25 cells in a drug concentration (0-150 mg/L)-and incubation time (0-24 h)-dependent manner. When the 5-ALA concentration was 100 mg/L, the intracellular PpⅨ production was in a relatively stable state. Cell viability and apoptosis rate of 5, 10, 25, 50, 100 mg/L 5-ALA combined with laser irradiation are, respectively, (82.3±5.2)%, (3.13±0.38)%; (74.6±9.3)%, (5.38±0.55)%; (38.3±9.7)%, (17.97±2.72)%; (9.2±3.8)%, (24.47±3.37)%; (7.2±0.8)%, (43.01±5.96)%, which indicated that 5-ALA combined with laser irradiation notably inhibited the growth of SCC25 cells and also induced significant cell apoptosis compared with the control group [(96.3±6.0)%, (0.35±0.13)%, P<0.05]. After combination treatment (5-ALA of 5, 10, 25, 50 and 100 mg/L combined with laser irradiation, the mean fluorescence intensity of dichlorofluorescein is (1.46±0.12)×10⁴, (2.16±0.30)×10⁴, (3.57±0.34)×10⁴, (81.70±13.05)×10⁴, (113.00±7.35)×10⁴, respectively, a large amount of ROS was produced in SCC25 cells compared with the control group [(0.96±0.15) ×10⁴, P<0.05], which was in positive correlation with the intracellular PpⅨ content. 5-ALA (concentration of 10, 25 and 50 mg/kg) combined with laser irradiation greatly suppressed the tumor growth in SCC25 tumor-bearing mice compared to the control group (P<0.05). Conclusions 5-ALA-mediated photodynamic therapy can trigger the generation of intracellular ROS that has significant cytotoxicity and apoptosis induction effect, and thus inhibit the tumor growth both in vitro and in vivo.

OBJECTIVE: To investigate the molecular mechanism underlying the inhibitory effect of aloin on the proliferation and migration of gastric cancer cells. METHODS: Human gastric cancer MGC-803 cells treated with 100, 200 and 300 μg/mL aloin were examined for changes in cell viability, proliferation and migration abilities using CCK-8, EdU and Transwell assays. HMGB1 mRNA level in the cells was detected with RT-qPCR, and the protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 were determined using Western blotting. JASPAR database was used to predict the binding of STAT3 to HMGB1 promoter. In a BALB/c-Nu mouse model bearing subcutaneous MGC-803 cell xenograft, the effect of intraperitoneal injection of aloin (50 mg/kg) on tumor growth was observed. The protein expressions of HMGB1, cyclin B1, cyclin E1, E-cadherin, MMP-2, MMP-9 and p-STAT3 in the tumor tissue was examined using Western blotting, and tumor metastasis in the liver and lung tissues was detected using HE staining. RESULTS: Treatment with aloin concentration-dependently inhibited the viability of MGC-803 cells (P < 0.05), significantly reduced the number of EdU-positive cells (P < 0.01), and attenuated the migration ability of the cells (P < 0.01). Aloin treatment dose-dependently down-regulated HMGB1 mRNA expression (P < 0.01), lowered the protein expressions of HMGB1, cyclin B1, cyclin E1, MMP-2, MMP-9 and p-STAT3, and up-regulated E-cadherin expression in MGC-803 cells. Prediction based on JASPAR database suggested that STAT3 could bind to the promoter region of HMGB1. In the tumor-bearing mice, aloin treatment significantly reduced the tumor size and weight (P < 0.01), lowered the protein expressions of cyclin B1, cyclin E1, MMP-2, MMP-9, HMGB1 and p-STAT3 and increased the expression of E-cadherin in the tumor tissue (P < 0.01). CONCLUSION Aloin attenuates the proliferation and migration of gastric cancer cells by inhibiting the STAT3/HMGB1 signaling pathway.
Humans ; Animals ; Mice ; Stomach Neoplasms ; Cyclin B1 ; Matrix Metalloproteinase 2 ; Matrix Metalloproteinase 9 ; HMGB1 Protein ; Signal Transduction ; Cell Proliferation ; STAT3 Transcription Factor