Simultaneous GC-MS determination of sixteen pesticide residues and safety assessment for Lycii Fructus / 中成药

AIM To establish a GC-MS method for the simultaneous content determination of sixteen pesticide residues in Lycii Fructus and perform safety assessment.METHODS The analysis was performed on DB-5MS chromatographic column(30 m×0.25 mm,0.25 μm)subjected to the programmed heating,with splitless injection of 1.0 μL dissolved sample at a flowing rate of 1.0 mL/min.Other parameters were as follows:injection port temperature of 250℃,electron impact ionization(EI),electron energy of 70 eV;ion source temperature of 230℃,multi-reaction monitoring mode,and collision gas.of high-purity N2.Pesticide residues with relatively high dietary risk were analyzed and discussed with regard to residue levels,dietary intake risk,risk ranking and cumulative exposure assessment.RESULTS Sixteen pesticides showed good linear relationships within their own ranges(r≥0.994 4),whose average recoveries were 70%-114%,with the RSDs of less than 2%.The highest average cyfluthrin residue of 0.999 2 mg/kg in Lycii Fructus of production regions and the highest average cypermethrin residue of 0.088 4 mg/kg in Lycii Fructus commodities were both detected.In Lycii Fructus of production regions with chronic hazard index(HI)value of 0.012 9 and acute HI value of 0.065 5 and their commodities with chronic HI of 0.001 2 and acute HI of 0.005 4,the pesticide residue of cypermethrin was the leading cause of chronic and acute dietary risk,and additionally,pyridaben within maximum residue limit(MRL)was the only detectectable highly toxic pesticide among the other most concerning pestcides of deltamethrin,pyridaben,chlorpyrifos,dichlorvos and methidathion.CONCLUSION There exist pesticide residues within MRL values in some samples of Lycii Fructus and the use of cypermethrin should be well-controlled.

Isobavachalcone induces cell death through multiple pathways in human breast cancer MCF-7 cells / 南方医科大学学报

OBJECTIVE@#To explore the effects of isobavachalcone (IBC) on cell death of human breast cancer MCF-7 cells and explore the possible mechanism.@*METHODS@#MCF-7 cells were treated with different concentrations of IBC, and the changes in cell proliferation were assessed using MTT assay. Apoptosis of MCF-7 cells following treatment with 10, 20, and 40 μmol/L IBC was analyzed using flow cytometry with annexin V-FITC/PI double staining and fluorescence microscopy, and the expressions of apoptosis- and autophagy-related proteins (Bax, Bcl-2, Akt, p-Akt, p62, and LC3) were detected with Western blotting. Electron microscopy was used to observe the changes in submicrostructure of the cells following treatment with 40 μmol/L IBC. JC-1 assay kit, ATP assay kit, and reactive oxygen species (ROS) kit were used to determine the effect of IBC on mitochondrial function of the cells.@*RESULTS@#MTT assay showed that IBC significantly inhibited the proliferation of MCF-7 cells in a concentration- and time-dependent manner, with IC50 values of 38.46, 31.31, and 28.26 μmol/L at 24, 48, and 72 h, respectively. IBC also concentration-dependently induced apoptosis of MCF-7 cells. IBC-induced cell death was inhibited by z-VAD-fmk, a caspase inhibitor (P < 0.05), but not by the necroptosis inhibitor necrostatin-1 (Nec-1). Western blotting showed that IBC-induced MCF-7 cell apoptosis by increasing Bax expression and down-regulating the expressions of Bcl-2, Akt and p-Akt-473 (all P < 0.05). With the increase of IBC concentration, the expression of autophagy-related protein p62 and the LC3-II/I ratio increased progressively. Electron microscopy revealed the presence of autophagic bodies in IBC-treated MCF-7 cells. IBC treatment also resulted in decreased mitochondrial membrane potential and intracellular ATP level and increased ROS accumulation in MCF-7 cells (P < 0.05).@*CONCLUSION@#IBC is capable of inducing both apoptosis and autophagy in MCF-7 cells, suggesting the potential value of IBC as a lead compound in the development of anti-breast cancer agents.

Effect on the expression of key enzymes DS and P450 genes in the medicinal composition synthesis of Panax notoginseng under Cadmium stress / 中草药

Objective: To learn the effect on the expression of key enzymes DS and P450 genes in the medicinal composition synthesis of Panax notoginseng under exogenous Cadmium (Cd). Methods: Nine treatments of Cd (0.0, 0.1, 0.3, 0.6, 1.0, 3.0, 6.0, 10.0, and 30.0 mg∙kg-1) was added to the cultivated soil of Panax notoginseng, respectively. Two years later, mature Panax notoginseng was sampled. The expression of DS and P450 genes in root was detected using qRT-PCR method, and GAPDH gene was taken as the reference genes to calculate the relative expression of DS and P450 genes. The correlation between expression of key enzymes genes and main medicinal composition (notoginsenoside R1, ginsenoside Rb1, ginsenoside Rg1, and total saponins) was determined by correlation analysis. Results: Cd increased DS expression in low concentration, and inhibited in high levels, while with the adding Cd increasing, the P450 expression decreased significantly. However, the expression of DS and P450 genes didn't show good correlation with notoginsenoside R1, ginsenoside Rb1, ginsenoside Rg1, and total saponins (P > 0.5). Conclusion: Cd can affect the expression of DS and P450 genes in different ways and for the same gene, the expression is also various in different Cd levels. However, the main medicinal composition content wasn't influenced consequently.

Intervention of Huayu Qutan Recipe on liver SREBP-2 signal pathway of hyperlipidemia rats of pi deficiency syndrome / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the intervention of Huayu Qutan Recipe (HQR) on liver SREBP-2 signal pathway of hyperlipidemia rats of Pi deficiency syndrome (PDS).</p><p><b>METHODS</b>Totally 100 SPF grade SD rats were randomly divided into the blank control group, the hyperlipidemia group, the hyperlipidemia treatment group, the PDS hyperlipidemia group, and the PDS hyperlipidemia treatment group, 20 in each group. Common granular forage was fed to rats in the blank control group. High fat forage was fed to rats in the hyperlipidemia group and the hyperlipidemia treatment group. Rats in the PDS hyperlipidemia group and the PDS hyperlipidemia treatment group were treated with excessive labor and improper diet for modeling. They were administered refined lard by gastrogavage (3 mL each time, twice per day) and fed with high fat forage on the odd days, and fed with wild cabbage freely on even days. The modeling lasted for 30 days. Rats in the hyperlipidemia treatment group and PDS hyperlipidemia treatment group were administered with Huayu Qutan Recipe (20 mL/kg) by gastrogavage, once a day, for 30 successive days. Levels of serum cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), and serum amylase (AMY) were detected by automatic biochemical analyzer. D-xylose excretion rate was determined using phloroglucinol method. Morphological changes of liver and the lipid deposition in liver were observed using HE stain and oil red O stain respectively, mRNA and protein expression levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR), cholesterol 7α-hydroxylase 1 (CYP7A1), LDL-R, and sterol regulatory element binding protein-2 (SREBP-2) were detected using real time RT-PCR and Western blotting.</p><p><b>RESULTS</b>Compared with the blank control group, serum levels of TC (1.84 ± 0.19 mmol/L, 2.23 ± 0.43 mmol/L) and LDL-C (0.99 ± 0.24 mmol/L, 1.13 ± 0.56 mmol/L) were higher in the hyperlipidemia group and the PDS hyperlipidemia group, serum levels of HDL-C (0.41 ± 0.66 mmol/L, 0.41 ± 0.11 mmol/L) and AMY activities (351 ± 45 mmol/L, 153 ± 30 mmol/L) were lower, and urinary D-xylose excretion rates were lower (26.9 ± 2.1 ng/mL, 15.0 ± 1.7 ng/mL) (all P < 0.05). Lipid deposition occurred in liver cells. Much fat vacuoles occurred in the cytoplasm. Expression levels of HMGCR, CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver significantly decreased (P < 0.01). Compared with the hyperlipidemia group, serum levels of TC and LDL-C significantly increased (P < 0. 05), AMY activities and urinary D-xylose excre- tion rates significantly decreased in the PDS hyperlipidemia group (P < 0.01). A large amount of lipid deposition occurred in liver. The atrophy of liver cells was obviously seen. Expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly lower (P < 0.01, P < 0.05). Serum levels of TC and LDL-C significantly decreased (P < 0.05), AMY activities and urinary D-xylose excretion rates significantly increased in the hyperlipidemia treatment group (P < 0.01). Expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly increased (P < 0.01, P < 0.05). Compared with the PDS hyperlipidemia group, serum level of TC significantly decreased (P < 0.05), HDL-C levels, AMY activities and urinary D-xylose excretion rates significantly increased in the PDS hyperlipidemia treatment group (P < 0.01),expression levels of CYP7A1, LDL-R, and SREBP-2 mRNA and proteins in liver were significantly increased (P < 0.01). Similar changes occurred in the two treatment groups.</p><p><b>CONCLUSIONS</b>Pi deficiency exacerbates abnormal serum TC level and the lipid deposition in liver. These might be related to regulating expression levels of LDL-R, HMGCR, and CYP7A1 genes in the SREBP-2 signal pathway. HQR could regulate this pathway to intervene abnormal metabolism of TC.</p>