[Determination of three new herbicide residues in soil, sediment and water by liquid chromatography-tandem mass spectrometry].

Herbicides play an important role in preventing and controlling weeds and harmful plants and are increasingly used in agriculture, forestry, landscaping, and other fields. However, the effective utilization rate of herbicides is only 20%-30%, and most herbicides enter the atmosphere, soil, sediment, and water environments through drift, leaching, and runoff after field application. Herbicide residues in the environment pose potential risks to ecological safety and human health. Therefore, establishing analytical methods to determine herbicide residues in environmental samples is of great importance. In this study, an analytical method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive electrospray ionization mode (ESI+) was developed for the determination of isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water. The instrumental detection parameters, including electrospray ionization mode, mobile phase, and chromatographic column, were optimized. The mobile phases were methanol (A) and 0.1% formic acid aqueous solution (B). Gradient elution was performed as follows: 0-1.0 min, 60%A; 1.0-2.0 min, 60%A-90%A; 2.0-3.0 min, 90%A; 3.0-4.0 min, 90%A-60%A; 4.0-5.0 min, 60%A. The samples were salted after extraction with acetonitrile and cleaned using a C18 solid-phase extraction column. Different solid-phase extraction columns and leaching conditions were investigated during sample pretreatment. Working curves in the neat solvent and matrix were constructed by plotting the measured peak areas as a function of the concentrations of the analytes in the neat solvent and matrix. Good linearities were found for isoxaflutole, metazachlor, and saflufenacil in the solvent and matrix-matched standards in the range of 0.0005-0.02 mg/L, with r≥0.9961. The matrix effects of the three herbicides in soil, sediment, and water ranged from -10.1% to 16.5%. The limits of detection (LODs, S/N=3) for isoxaflutole, metazachlor, and saflufenacil were 0.05, 0.01, and 0.02 µg/kg, respectively. The limits of quantification (LOQs, S/N=10) for isoxaflutole, metazachlor, and saflufenacil were 0.2, 0.05, and 0.05 µg/kg, respectively. The herbicides were applied to soil, sediment, and water at spiked levels of 0.005, 0.1, and 2.0 mg/kg, respectively. The average recoveries for isoxaflutole, metazachlor, and saflufenacil in soil, sediment, and water were in the ranges of 77.2%-101.9%, 77.9%-105.1%, and 80.8%-107.1%, respectively. The RSDs for isoxaflutole, metazachlor, and saflufenacil were in the ranges of 1.4%-12.8%, 1.2%-7.7%, and 1.5%-11.5%, respectively. The established method was used to analyze actual samples collected from four different sites in Zhejiang Province (Xiaoshan, Taizhou, Dongyang, and Yuhang) and one site in Heilongjiang (Jiamusi). The proposed method is simple, rapid, accurate, stable, and highly practical. It can be used to detect isoxaflutole, metazachlor, and saflufenacil residues in soil, sediment, and water and provides a reference for monitoring the residual pollution and environmental behavior of herbicides.

Anti-Hepatoma activity of wogonin on HepG2 cell in vitro / 中国药学杂志

OBJECTIVE: To study the growth inhibitory and apoptosis-inducing effect of wogonin on hepatocarcinoma cell line HepG2. METHODS: HepG2 cell line was treated with various concentrations of wogonin. Proliferation was determined by MTT test and morphology observation. Flow cytometry was applied to detect the wogonin-induced apoptosis and to analyse the cell cycle. Western blot was used to detect HDAC1 and HDAC2 expression. RESULTS: Wogonin had a growth inhibitory and apoptosis-inducing effect on HepG2 cell. The cell showed G2/M arrest by cell cycle analysis. A characteristic apoptosis change including nuclear disintergration and chromatin agglomerate was displayed. Western blot results show increase of cleave PARP, but not change in HDAC1, HDAC2 expression. CONCLUSION: Wogonin has a growth inhibitory and apoptosis-inducing effect on hepatocarcinoma cell line HepG2.

The suppression effects of desacetyluvaricin on hepatocellular carcinoma and its possible mechanism.

OBJECTIVE: To investigate the anticancer effects of desacetyluvaricin (DES) on hepatocellular carcinoma (HCC) in vitro, and to study its mechanism. MATERIALS AND METHODS: Using DES and cisplatin (DDP) to intervene the cell lines of hepatocarcinoma G2.2.15 (HepG2.2.15) and HepG2, by detecting the expression of HBxAg by immunofluorescence method, the cell cycle and apoptosis by flow cytometry method (FCM), and expression of NF-κB protein by ELISA. RESULTS: DES and DDP showed to suppress proliferation of HepG2.2.15 and HepG2; they increase the S-phase cells and decrease G2/M phase cells. DES and DDP both could promote the apoptosis and reduce the expression of NF-κB on the cell line. DES and DDP both can suppress the expression of HbxAg in HepG2.2.15. There were no statistical differences of the above results between these two drugs (P > 0.05). CONCLUSIONS: DES possesses anticancer effect on hepatocarcinoma. The possible mechanism might be due to promotion the apoptosis of the cancer cells, and downregulate the expression of HBx andNF-κB protein. DES is a kind of natural products, Because of the lighter clinical side effects; our observations suggest that DES has the potential to be explored as an effective anticancer agent for HCC.

Carboxymethylpachymaran enhances immunologic function of dendritic cells cultured in two kinds of hepatoma carcinoma cell line's supernatant via nuclear factor κ B/Rel pathway.

OBJECTIVE: To study the immunologic function of dendritic cells (DCs) cultured in two kinds of hepatoma cell line's supernatant and the enhancing effects of carboxymethylpachymaran (CMP) on DCs. METHODS: DCs were harvested after stimulation by granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 from umbilical cord blood using density-gradient centrifugation method. Cultured supernatant of two hepatoma cell lines (HepG2 and HepG2.2.15) were collected for condition medium (CM) according to a volume ratio of supernatant to incomplete RPMI-1640 medium, which was 3:1. CMP was dissolved in incomplete RPMI-1640 medium. Experimental groups were divided according to the culture medium, either CM or with CMP in it. DCs subsets CD83, CD86, CD1a, and d-related human leukocyte antigens (HLA-DR) were analyzed by flow cytometry. The proliferation ability of allogeneic T cells in mixed lymphocyte reaction (MLR) stimulated by DCs was examined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis. IL-12p70, interferon-γ (IFN-γ), and nuclear factor κB (NF-κB) were detected by enzyme-linked immunosorbent assay analysis. RESULTS: The proliferation of lymphocytes and secreting level of IL-12 and expression of phenotype of DCs cultured in two kinds of CM were lower than those of normal group (P <0.01). Compared with the normal group, groups treated with CMP showed a higher expression level of DCs subsets, lymphocyte reproductive activity, as well as IL-12 and IFN-γ secretion levels. Groups treated with CMP also demonstrated higher levels of DCs phenotype expression and IL-12 and IFN-γ secretion in supernatant of MLR and higher lymphocyte reproductive activity compared with CM group (P <0.05). Compared with the normal group, the expression level of NF-κB in DCs nuclear was higher in CMP groups but lower in two CM groups (P <0.05). After CMP was added, the NF-κB expression levels of two CM groups were increased compared with levels before CMP was added (P <0.05). However, there was no significant difference between the two CM groups (P >0.05). CONCLUSIONS: Two kinds of hepatoma cell line's supernatant can inhibit the immunologic function of DCs. This suppressive effect may be related to the inhibition of NF-κB/Rel pathway. CMP may up-regulate the DCs function by activating the NF-κB/Rel pathway.