Inhibitory effect of flavonoids from Scutellariae Radix on human cytochrome P450 1A / 中国中药杂志

This study investigated the inhibitory effect of eight natural flavonoids in Chinese herb Scutellariae Radix on huamn cytochrome P450 1 A(CYP1 A), a key cancer chemo-preventive target. In this study, phenacetin was used as a probe substrate for CYP1 A, while human liver microsomes and recombinant human CYP1 A enzymes were used as enzyme sources. Liquid chromatography-tandem mass spectrometry was used to monitor the formation rates of acetaminophen, the O-deethylated metabolite of phenacetin. The dose-dependent inhibition curves were depicted based on the changes of the formation rates of acetaminophen, while the IC_(50) were determined. Inhibition kinetic analyses and docking simulations were used to investigate the inhibition modes and mechanism of wogonin(the most potent CYP1 A inhibitor in this herb), while the inhibition constants(K_i) of wogonin against both CYP1 A1 and CYP1 A2 were determined. Among all tested flavonoids, wogonin, 7-methoxyflavanone and oroxylin A displayed a strong inhibitory effect on CYP1 A(IC_(50)100 μmol·L~(-1)). Further investigations demonstrated that wogonin had a weak inhibitory effect on other human CYP enzymes, suggesting that it could be used as a lead compound for the development of specific inhibitors of CYP1 A. Furthermore, the inhibition kinetic analyses clearly demonstrated that wogonin could strongly inhibit phenacetin O-deethylation in both CYP1 A1 and CYP1 A2 in a competitive manner, with K_i values at 0.118 and 0.262 μmol·L~(-1), respectively. Molecular docking demonstrated that wogonin could strongly interact with CYP1 A1 and CYP1 A2 via hydrophobic and π-π interactions, as well as Ser120 and Ser116 in CYP1 A1 via hydrogen-bonding. In conclusion, this study found that some flavonoids in Scutellariae Radix displayed a strong inhibitory effect on CYP1 A, while wogonin is the most potent CYP1 A inhibitor with a relatively high selectivity towards CYP1 A over other human CYPs.

Research progress of human cytochrome P450 2J2 and its ligands / 药学学报

Cytochrome P4502J2 (CYP2J2) is widely distributed in various human tissues and takes a part in the metabolism of endogenous compounds and drugs. CYP2J2 can convert arachidonic acid (AA) to expoxyeicosatrienoic acids (EETs), which have various biological effects, implying the important role of CYP2J2 in the regulation of cardiovascular system and promotion of tumor progression and metastasis. Additionally, CYP2J2 plays an indispensable role in the intestinal metabolism of various drugs, such as astemizole, terfenadine and ebastine. In this review, the metabolic function, characteristic of catalysis and tissue distribution of CYP2J2 are discussed with the latest literatures both in China and abroad. The state-of-the-art methods for characterization of CYP2J2 and current trend of substrate discovery as well as its relationship with disease are highlighted. This review gives in-depth understanding of the function of CYP2J2 and its role in disease advance. The information of ligand (substrate and inhibitor) will provide the theoretical guidance and reference to the development of novel drugs for CYP2J2.

Mining chemodiversity from biodiversity: pharmacophylogeny of medicinal plants of Ranunculaceae / 中国天然药物

This paper reports a pharmacophylogenetic study of a medicinal plant family, Ranunculaceae, investigating the correlations between their phylogeny, chemical constituents, and pharmaceutical properties. Phytochemical, ethnopharmacological, and pharmacological data were integrated in the context of the systematics and molecular phylogeny of the Ranunculaceae. The chemical components of this family included several representative metabolic groups: benzylisoquinoline alkaloids, ranunculin, triterpenoid saponin, and diterpene alkaloids, among others. Ranunculin and magnoflorine were found to coexist in some genera. The pharmacophylogenetic analysis, integrated with therapeutic information, agreed with the taxonomy proposed previously, in which the family Ranunculaceae was divided into five sub-families: Ranunculoideae, Thalictroideae, Coptidoideae, Hydrastidoideae, and Glaucidioideae. It was plausible to organize the sub-family Ranunculoideae into ten tribes. The chemical constituents and therapeutic efficacy of each taxonomic group were reviewed, revealing the underlying connections between phylogeny, chemical diversity, and clinical use, which should facilitate the conservation and sustainable utilization of the pharmaceutical resources derived from the Ranunculaceae.

Efficacy of lamivudine and adefovir de novo combination therapy or after mono-therapy in chronic hepatitis B patients / 中华肝脏病杂志

To investigate the efficacy of 104 weeks of lamivudine (LAM) and adefovir (ADV) de novo combination therapy, as compared to optimized combination therapy administered after 48 weeks of treatment with lamivudine or adefovir mono-therapy, in chronic hepatitis B (CHB) patients. A total of 174 patients with CHB were equally divided among three treatment groups: LAM mono-therapy; ADV mono-therapy; and LAM + ADV combination therapy. The patients in the LAM + ADV group were treated with LAM plus ADV for 104 consecutive weeks. The patients in the LAM or the ADV groups were first treated for 48 weeks with LAM or ADV, respectively, after which the patient's virological response was assessed. According to the results, the patient was continued on mono-therapy or switched to combination therapy for the subsequent 56 weeks. Virological and biochemical examinations were carried out at weeks 48 and 104. The rates of undetectable HBV DNA in the LAM mono-therapy, ADV mono-therapy, and LAM-ADV combination therapy groups at week 48 were 68%, 50%, and 84%, and at week 104 were 80%, 72%, and 95%, respectively. For the same groups, the virus breakthrough rates at week 48 were 15%, 0%, and 0%, and at week 104 were 18%, 2%, and 0%, respectively. Statistical analysis showed significant differences for the rate of undetectable HBV DNA between LAM + ADV group and LAM group at week 48 (x2 = 4.473, P= 0.034) and at week 104 (x2 = 5.795, P = 0.016), LAM + ADV group and ADM group at week 48 (x2 = 14.802, P less than 0.001) and week 104 (x2 = 5.547, P = 0.001). The hepatitis B e antigen (HBeAg) seroconversion rates at week 48 were 15% (x2 = 4.543, P = 0.033), 13% (x2 = 4.035, P = 0.045) and 38%, and at week 104 were 21% (x2 = 4.438, P = 0.035), 17% (x2 = 4.223, P = 0.04) and 44%, respectively, among patients positive for HBeAg. Statistical analysis showed that the differences among the three groups for each of these parameters were statistically significant (all, P less than 0.05). When compared with LAM or ADV mono-therapy followed by LAM+ADV at week 48, the LAM plus ADV de novo combination therapy for 104 weeks provided CHB patients with better virological and serological responses and a lower drug resistance rate.

Excision repair cross complementation group 1 polymorphisms and lung cancer risk: a meta-analysis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Several studies have evaluated the association between polymorphisms of encoding excision repair cross complementation group 1 (ERCC1) enzyme and lung cancer risk in diverse populations but with conflicting results. By pooling the relatively small samples in each study, it is possible to perform a meta-analysis of the evidence by rigorous methods.</p><p><b>METHODS</b>Embase, Ovid, Medline and Chinese National Knowledge Infrastructure were searched. Additional studies were identified from references in original studies or review articles. Articles meeting the inclusion criteria were reviewed systematically, and the reported data were aggregated using the statistical techniques of meta-analysis.</p><p><b>RESULTS</b>We found 3810 cases with lung cancer and 4332 controls from seven eligible studies. T19007C polymorphism showed no significant effect on lung cancer risk (C allele vs. T allele: odds ratio (OR) = 0.91, 95% confidence interval (CI) = 0.80 - 1.04; CC vs. TT: OR = 0.76, 95%CI = 0.56 - 1.02; CC vs. (CT + TT): OR = 0.96, 95%CI = 0.84 - 1.10). Similarly, there was no significant main effects for T19007C polymorphism on lung cancer risk when stratified analyses by ethnicity (Chinese or Caucasian). No significant association was found between C8092A polymorphism (3060 patients and 2729 controls) and the risk of lung cancer (A allele vs. C allele: OR = 1.03, 95%CI = 0.95 - 1.11; AA vs. CC: OR = 1.08, 95%CI = 0.88 - 1.33; AA vs. (AC + CC): OR = 1.08, 95%CI = 0.88 - 1.31).</p><p><b>CONCLUSION</b>We found little evidence of an association between the T1900C or C8092A polymorphisms of ERCC 1 and the risk of lung cancer in Caucasian or Han Chinese people.</p>