A novel flavanone from Thymus przewalskii / 中国中药杂志

This study was to investigate the chemical constituents from the aerial parts of Thymus przewalskii. The chemical consti-tuents were separated and purified by column chromatography on silica gel, ODS, Sephadex LH-20 and semi-prepared HPLC, and their structures were determined by physicochemical properties and spectroscopic data. Four flavanones were isolated from the ethanol extract of the aerial parts of T. przewalskii, and identified as(2S)-5,6-dihydroxy-7,8,4'-trimethoxyflavanone(1), 5,4'-dihydroxy-6,7-dimethoxyflavanone(2),(2S)-5,4'-dihydroxy-7,8-dimethoxyflavanone(3), sakuranetin(4), respectively. Compound 1 was a new compound and its configuration was determined by CD spectrum, compound 3 was natural product which was isolated for the first time and their configurations were determined by CD spectra. Compound 2 was isolated from the genus Thymus for the first time and compound 4 was isolated from T. przewalskii for the first time. Furthermore, cytotoxicity test was assayed for the four flavanones. They exhibited weak cytotoxicity against human lung cancer cells(A549), with the IC_(50) from 74.5 to 135.6 μmol·L~(-1).

Effect of dihydroartemisinin on permeability of human erythrocyte membrane infected plasmodium / 中国中药杂志

In view of the fact that the antimalarial effects of artemisinins are significant but the mechanism has not yet been clarified and there are many different opinions, it is possible that artemisinins can produce high anti-malarial efficacy through various mechanisms and multiple pathways. In addition, the researches on the pathogenesis of malaria "erythrocyte membrane plasmodial surface anion channel (PSAC)" in the past few years have provided more positive findings, which may confirm and discover the new antimalarial mechanism of artemisinins. This paper was as to study the effect of dihydroartemisinin (DHA) in vitro on erythrocyte membrane permeability of HB3 plasmodium infection, with using the mechanism of 5% sorbitol can be used to kill the Plasmodium falciparum in red blood cell membrane selectively, the effectual difference of sorbitol on the killing of P. falciparum with adding DHA or not was detected, so as to investigate whether DHA can affect the permeability of the erythrocyte membrane. Result showed that, Pre-stimulation with 10 nmol·L⁻¹ DHA (the final concentration of plasmodium in vitro culture system) for 30 min could significantly decrease the killing effect of sorbitol on the HB3 plasmodium in the P. falciparum erythrocytic cycle, and DHA may inhibit the permeability of the erythrocyte membrane for preventing sorbitol through the red blood cell membrane, thereby reducing the killing effect of sorbitol on the P. falciparum.

Progress in influence factors on drug induced liver injury / 中国药学杂志

Drug-induced liver injury (DILI) is a hot topic for clinicians, academia, drug companies and regulators. It is essential to understand risk factors of idiosyncratic DILI in order to accurately predict and prevent this problem. However, the role of factors on the pathogenesis of DILI is poorly understood. Indeed, both drug properties and host factors are likely interact at multiple levels to determine individual risks and clinical outcome of DILI. In this review, cross-disciplinary view over drug characteristics associated with hepatotoxicity is provided, and various host factors influencing individuals' DILI risks at updating the current knowledge to stimulate future investigation are discussed.

Protective effects of three phenylallyl compounds from Guizhi decoction ox-LDL-induced oxidative stress injury of human brain microvascular endothelial cells / 中国中药杂志

The main objective of this research is to observe protective effects of three phenylallyl compounds(cinnamyl alcohol,cinnamaldehyde and cinnamic acid)from Guizhi decoction against ox-LDL-induced oxidative stress injury on human brain microvascular endothelial cells(HBMEC).In this study,the toxicity and optimal protective concentration of three phenylallyl compounds from Guizhi decoction were determined by MTT assay.The HBMEC were divided into control group(DMSO),model group(ox-LDL),tert-butylhydroquinone (t-BHQ) group,cinnamyl alcohol group, cinnamaldehyde group and cinnamic acid group.The model group were treated with ox-LDL (50 mg•L⁻¹)for 24 h,other groups were separately treated with t-BHQ, cinnamyl alcohol, cinnamaldehyde and cinnamic acid of 20 μmol•L⁻¹, and exposed to ox-LDL (50 mg•L⁻¹) for 24 h at the same time.The survival rate of HBMEC was detected by MTT assay,reactive oxygen species(ROS) production of injured cells were detected using laser scanning confocal microscope (LSCM),the content of SOD, MDA, eNOS and NO in HBMEC was determined by ELISA, and the expressions of Nrf2 mRNA were detected by quantitative Real-time PCR(qRT-PCR).The results shows that oxidative stress injury of HBMEC could be induced by ox-LDL, the three phenylallyl compounds from Guizhi decoction did not affect morphology and viability of normal HBMEC.Compared with model group, the three phenylallyl compounds from Guizhi decoction could improve the above oxidative stress status and up-regulate Nrf2 mRNA expressions in injured HBMEC(P<0.05, P<0.01) .These findings suggested that the three phenylallyl compounds from Guizhi decoction have certain protective effects against ox-LDL-induced oxidative stress injury on HBMEC(cinnamaldehyde> t-BHQ> cinnamic acid>cinnamyl alcohol),the protective mechanism maybe related to regulation of antioxidant enzymes gene expression in HBMEC by Nrf2.