Alkannin inhibits growth and invasion of glioma cells C6 through IQGAP/mTOR signal pathway.

OBJECTIVE: This study aims to explore the effect of alkannin on the growth and invasion of glioma cells and its mechanism. METHODS: The effects of alkannin on the growth and invasion of glioma cells were detected with MTT assay, clone forming test and transwell assay. The effects of alkannin on the cell cycle were detected with flow cytometry assay. The changes of cyclin, MMPs and IQGAP/mTOR signal pathway related proteins were detected with western blotting methods. RESULTS: Alkannin (1 µM, 3 µM and 10 µM) can significantly inhibit the growth, proliferation, migration and invasion of glioma cells C6 with dose dependent. Alkannin can block cell cycle in G1 phase with the increased concentration, which was related with the down-regulation of cyclinA1, cyclinA2 and cyclinD1 expression. Alkannin can also down-regulate the expression of MMP 2, MMP 9 and IQGAP. Alkannin has no effect on mTOR but can inhibit the phosphorylation of mTOR. CONCLUSIONS: Alkannin can inhibit the growth and invasion of glioma cells C6 through IQGAP/mTOR signal pathway.

[Effect of ginkgolide B on the production of NO, IL-6 and RANTES from astrocytes].

This study is to explore the effect of ginkgolide B (BN52021) on the production of nitric oxide (NO), interleukin (IL)-6 and regulated upon activation normal T cell expressed and secreted (RANTES) from astrocytes induced by stimulators. Primary cultured rat astrocytes were stimulated with lipopolysaccharides (LPS), the production of NO was assayed using Griess reaction; U251 cells were stimulated with IL-1 beta, the contents of IL-6 and RANTES in the supernatant were measured using ELISA. The mRNA expressions of IL-6 and RANTES were detected using RT-PCR. LPS (10 ng mL(-1) to 10 microg mL(-1)) could stimulate rat astrocytes to produce NO in a dose-dependent manner. Ginkgolide B at the concentrations of 0.1-10 micromol L(-1) were shown to decrease NO production significantly. IL-1 beta could induce the mRNA expression and protein secretion of IL-6 from U251 cells, as well as RANTES. Ginkgolide B at concentrations of 0.1-10 micromol L(-1) were shown to inhibit RANTES secretion, and to inhibit mRNA expression of IL-6 and RANTES at concentration of 10 micromol L(-1). Ginkgolide B has inhibitory effect on the production of NO, IL-6 and RANTES from astrocytes treated with inflammatory stimulators.

[Synthesis and antiinflammation activity of aromatic aminoketone compounds, a new type of PAF-receptor antagonist].

A series of aromatic aminoketones were synthesized by Mannich reaction. Structures of these compounds were confirmed by 1H NMR, MS and HRMS or element analysis. Pharmacological screening showed that most target compounds inhibited the release of beta-glucuronidase in polymorphonuclear leucocytes by PAF (platelet activating factor) and compounds MA12, MA13, MA18, MA21 and MA33 were more active. The study suggests that target compounds are potential PAF receptor antagonists and their anti-inflammatory activities are due to the inhibition of release of lysosomal enzyme.

[Effects of ginkgolide B on lipopolysaccharide-induced TNFalpha production in mouse peritoneal macrophages and NF-kappaB activation in rat pleural polymorphonuclear leukocytes].

AIM: To study the effects of ginkgolide B on lipopolysaccharide (LPS)--induced TNFalpha production in mouse peritoneal macrophages and NF-kappaB activation in rat pleural polymorphonuclear leukocytes. METHODS: L929 crystal violet staining assay was used to show the level of TNFalpha released from mouse peritoneal macrophages induced by LPS. Electrophoretic mobility shift assay (EMSA) was used to determine NF-kappaB binding activities. RESULTS: Ginkgolide B (1, 10 micromol x L(-1)) was shown to significantly inhibit LPS (10 mg x L(-1))-induced TNFalpha production in mouse peritoneal macrophages, the IC50 was 0.26 micromol x L(-1); LPS (1 mg x L(-1)) and PAF (1 nmol , L(-1)) were shown to increase the NF-kappaB binding activities in rat pleural polymorphonuclear leukocytes; ginkgolide B (10 micromol x L(-1)) was found to inhibit LPS (1 mg x L(-1))-induced NF-kappaB activation in rat pleural polymorphonuclear leukocytes; ginkgolide B (1, 10 micromol x L(-1)) was shown to inhibit PAF (1 nmol x L(-1))-induced NF-kappaB activation in rat pleural polymorphonuclear leukocytes. CONCLUSION: The inhibition of NF-kappaB activation and TNFalpha production might be considered to be part of the mechanisms underlying the antiinflammatory action of ginkgolide B; PAF is involved in activation of the NF-kappaB pathway stimulated with LPS.

[Effect of ginkgolide B on platelet-activating factor induced activation of rat polymorphonuclear leukocytes].

AIM: To investigate the effect of ginkgolide B on PAF-induced adhesion, chemotaxis and degranulation of rat polymorphonuclear leukocytes (PMNs). METHODS: The adhesion of rat PMNs to rat synovial cells (RSC) was measured with MTT colorimetry. The chemotaxis of PMNs was quantified with Boyden chamber method. The degranulation of rat PMNs was evaluated by determining the activity of released beta-glucuronidase. RESULTS: In comparison with control, ginkgolide B at the concentration of 10 mumol.L-1 significantly inhibited the adhesion of PMNs to RSC by 71.74%. At the final concentration of 1-1,000 nmol.L-1, ginkgolide B dose-dependently inhibited the chemotaxis of PMNs stimulated with 10 nmol.L-1 platelet-activating factor (PAF), the IC50 was 4.84 nmol.L-1. At the final concentration of 0.01-10 mumol.L-1, ginkgolide B decreased the release of beta-glucuronidase in PMNs induced by 1 mumol.L-1 PAF in dose-dependent manner. The IC50 was 3.56 mumol.L-1. CONCLUSION: Ginkgolide B was found to significantly inhibit PAF-induced adhesion, chemotaxis and degranulation in rat polymorphonuclear leukocytes. These effects might be considered a part of the mechanisms underlying the antiinflammatory action of ginkgolide B.