ABSTRACT
Aim To study the inhibitory effect of isoquercitrin on Raf/MEK/ERK signaling pathway in HepG2 cells.Methods MTT was used to detect the proliferation of human liver cancer HepG2 cells after the treatment of isoquercitrin.The morphology and growth of cells were observed under inverted microscope after the different concentrations of isoquercitrin(0, 40, 80, 160, 320 μmol·L-1) to treat HepG2 cells for 24 and 48 h.Cell cycle was assessed by flow cytometry.Ras, Raf, MEK, ERK expression was assayed by Western blot, and mRNA expression was detected by quantitative fluorescence PCR.Results Isoquercitrin could inhibit the growth of HepG2 cells in a concentration-and time-dependent manner.Typical morphological changes of apoptosis were observed by inverted microscopy after HepG2 cells were treated with different concentrations of of isoquercitrin for 24 h or 48 h.The cell cycle assay showed that with the increasing concentration of isoquerditrin, the number of cells that was arrested in G1 phase gradually increased.Compared with the blank group, the expressions of Ras, Raf, MEK, ERK mRNA were down-regulated, and related proteins expression were also down-regulated(P<0.05), and these results had statistical significance.Conclusion Isoquercitrin can induce the apoptosis of HepG2 cells, which may be related to the Raf/MEK/ERK signaling pathway.
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Objective To investigate the influence of isoquercitrin on the inflammatory factors in LPS-induced RAW264.7 cells.Methods MTT method was used to detect inhibition ratio of RAW264.7 cells induced by isoquercitrin.The level of TNF-α in culture medium was measured by ELISA.Nitric oxide (NO) was detected by Nitrate Assay Kit.Western blotting was used to investigate the influence on the productions of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2).Results The half inhibitory concentration (IC50) of isoquercitrin was 65.73 μmol·L-1.LPS had no inhibitory effect on the cells.Compared with LPS group,the level of TNF-α was decreased to 74.80% and 60.57% in isoquercitrin (20,10 μmol·L-1) groups in a dose-dependent manner.The results measured by Nitrate Assay Kit revealed that isoquercitrin (20,10 μmol·L-1) could suppress production of NO,the level of NO decreased to 79.34% and 68.81%(P<0.05).The Western blotting results showed that isoquercitrin (20,15,10 μmol·L-1) inhibited the productions of iNOS and COX-2 (P<0.05).Conclusion Isoquercitrin has anti-inflammatory effects by inhibiting the productions of TNF-α,NO,iNOS and COX-2,and the most effective dose for the inhibition is 10 μmol·L-1.
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Objective To investigate whetherthe extract of HUANGPI inhibitthe secretion of TNF-αvia TLR4/MyD88/TRAF6 signaling pathway. Methods ELISA assay was performed to determine TNF-α level in cell culture medium. MTT assay was used to detect the effects of the extract of HUANGPI and LPS on the viabilities of RAW 264.7 cells. Proteinexpressions of TLR4 and TRAF6 were detected by Western blotting assay. Results The extract of HUANGPI inhibited the secretion of TNF-αin a dose-dependent manner. Compared to LPS group , were TNF-αwas significantly suppressed in the cells in LPS+MyD88 inhibitor group , LPS+extract group and LPS+extract+MyD88 inhibitor group,with the corresponding reductions of TLR4 and TRAF6 protein expression at74% and21%,70% and27%,44% and8.5%, respectively. Conclusion MYD88-dependent signaling pathway might be involved in the mechanism underlying the effect of the extract of HUANGPI on suppressing LPS-induced inflammation.
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Objective To observe the targeting effect of curcumin gelatin microsphere in rats in vivo. Methods Injections of curcumin gelatin microsphere and curcumin were injected via tail vein, respectively. HPLC was used to determine the content of curcumin in different organs. The pharmacokinetic parameters were calculated on the basis of compartment models by using DAS 2. 0 program. Targeting efficiency was used to evaluate tissue distribution of curcumin. Results Targeting efficiency of curcumin gelatin microsphere in heart, liver, spleen, lung and kidney was 0. 875, 0. 121, 1. 182, 5. 834 and 0. 896, respectively. Conclusion Curcumine gelatin microspheres can improve lung-targeting efficiency, and benefit for study on lung targeting therapeutic effect.