二氢杨梅素药理作用研究进展

二氢杨梅素为藤茶中主要的黄酮类化合物,近年来其药理作用受到广泛关注。本文就10余年来二氢杨梅素抗肿瘤、抗炎、抗氧化、解酒护肝、抗病原微生物、降血糖、抗疲劳和调血脂等方面的研究进展进行综述,为二氢杨梅素的深入研究及其植物资源的进一步综合开发利用提供科学依据。     

白芍的化学成分与药理研究进展

综述近年来白芍及其他学成分的抗炎、免疫调节、抗病毒，抗氧化、抗惊厥、胃肠道疾病、护肝和心血管疾病等的药理研究。     

中药多糖对免疫功能调节的研究进展

中药多糖具有免疫调节、抗肿瘤、抗炎、抗病毒、抗氧化、抗辐射、降血糖、降血脂、保肝等多种药理作用。近年来,中药多糖对免疫功能的影响愈来愈受到国内外药理及生物学界的重视。笔者查阅了近几年资料,就中药多糖对特异性免疫与非特异性免疫的影响作一综述。     

中药多糖对免疫功能调节的研究进展△

中药多糖具有免疫调节、抗肿瘤、抗炎、抗病毒、抗氧化、抗辐射、降血糖、降血脂、保肝等多种药理作用.近年来,中药多糖对免疫功能的影响愈来愈受到国内外药理及生物学界的重视.笔者查阅了近几年资料,就中药多糖对特异性免疫与非特异性免疫的影响作一综述.     

去甲乌头碱的药理作用研究进展

近年来,植物生物碱的相关药理学研究取得了很大进展,并在临床中取得确切疗效。去甲乌头碱作为植物生物碱的代表,具有广泛的生物学效应。文章对近年来有关去甲乌头碱药理作用的研究进行总结,发现去甲乌头碱主要通过调控一系列信号转导通路发挥抗炎、抗氧化、抗细胞凋亡和免疫调节等效应,具有典型的多靶点、多通路共同发挥作用的特征,与多种疾病的治疗存在较大的相关性。因此,对去甲乌头碱的药理作用进行总结,可为去甲乌头碱的后续开发、研究及临床应用提供参考。     

海带多糖药理作用研究进展

海带多糖是海带中主要的生物活性成分，具有多方面的药理活性，如抗血栓、调血脂、降血糖、改善血流变及循环、抗肿瘤、抗辐射、免疫调节、抗氧化、抗突变、抗疲劳、抗炎及保护肝脏等作用，综述了近年来对海带多糖的药理作用研究进展。     

没食子酸抗肿瘤作用研究进展

没食子酸是多种中药中的活性成分,具有抗炎、抗突变、抗氧化等生物学效应,近年来其抗肿瘤作用引起国内外学者的关注,查阅国内外公开发表的有关研究论文,对其抗肿瘤相关研究进行了综述。研究显示其抗肿瘤作用确切,其抗肿瘤机制可能与多种分子机制相关,有待进一步深入研究。     

桦木酸的药理作用研究进展

桦木酸（betulinic acid,BA）属于羽扇豆烷型五环三萜类物质,广泛分布于多种植物中,具有抗肿瘤、抗艾滋病、免疫调节、抗氧化应激、抗菌、抗炎以及抗寄生虫等广泛的药理作用。由于BA具有优越的抗肿瘤和抗艾滋病活性,在恶性肿瘤和艾滋病等威胁人类健康的疾病防治方面具有广阔的应用前景。BA还能提高机体的抗氧化能力、增强免疫力,在机体的抗氧化损伤和免疫调节过程中发挥着重要作用。就BA的药理作用进行详细综述,为BA的研究和开发利用提供参考。     

猪苓化学成分及药理作用研究进展

综述近年来猪苓化学成分及药理作用研究进展。猪苓的化学成分主要包括多糖类、甾体类、蛋白质、氨基酸类、维生素类及微量无机元素类等,其药理作用包括利尿、抗肿瘤、抗炎、抗氧化、免疫调节、保肝、抑菌、促进头发生长等。     

槲皮素的药理作用研究概况

综述了近年来槲皮素的药理作用概况。表明了槲皮素有抗癌防癌、抗血小板聚集、镇痛、抗菌、抗病毒、抗衰老、抗炎、抗过敏、抗自由基及抗氧化等多种生物活性。     

Myricetin attenuated LPS induced cardiac injury in vivo and in vitro

Sepsis induced myocardial dysfunction (SIMD) is a common complication and leads to an increased mortality. SIMD is closely related to inflammation and oxidative stress. Myricetin exhibits strong capacities of anti‐inflammation and anti‐oxidative stress, but its pharmacological effects for lipopolysaccharide (LPS) induced cardiac injury remains undefined. This study aimed to explore whether myricetin was efficient to alleviate SIMD in mice and neonatal rat cardiomyocytes injury. Mice administrated with myricetin (100 mg/kg, po, bid) or vehicle groups were challenged with LPS (10 mg/kg, ip), and cardiac functions examined by echocardiography after 12 hr LPS exposure. LPS markedly impaired mouse cardiac functions, which were significantly attenuated by myricetin administration. Myricetin significantly reduced the production of inflammatory cytokines both in serum and cardiac tissue. Myricetin could inhibit the nuclear translocation of p65, degradation of IκBα, and cellular apoptosis in vivo and in vitro. Myricetin also prevented overexpression of iNOS and reduction of oxidoreductase (SOD and GPx) activity. Besides, Myricetin treatment could attenuate production of inflammatory cytokines of peritoneal macrophages stimulated with LPS in vitro. Thus we concluded that myricetin could attenuate the LPS induced cardiac inflammation injury in vivo and in vitro. Myricetin may be a potential therapy or adjuvant therapy for SIMD.     

Myricetin suppresses breast cancer metastasis through down‐regulating the activity of matrix metalloproteinase (MMP)‐2/9

Tumour metastasis is the major cause of breast cancer mortality. Myricetin, a natural polyphenol, is found in teas, wines, and berries. The pharmacodynamic action and molecular mechanism of myricetin on breast cancer metastasis remain unknown. Here, we investigated the effect of myricetin on MDA‐Mb‐231Br cell viability, migration, invasion, and 4T1 mouse lung metastasis mouse models. MMP‐2/9 protein expression and ST6GALNAC5 expression were analysed using western blot assays and quantitative real‐time polymerase chain reaction, respectively. Cell migration and invasion were detected by wound‐healing and Boyden transwell assays. The antimetastatic effect in vivo was evaluated by lung metastasis model. Myricetin significantly decreased the activities of MMP‐2/9 and mRNA levels of ST6GALNAC5. In addition, the migration, invasion, and adhesion were effectively inhibited in a concentration‐dependent manner. On the other hand, mice treated with myricetin exhibited smaller tumour nodules compared with the vehicle mice, with only 17.78 ± 15.41% after treatment with 50 mg/kg myricetin. In conclusion, myricetin could significantly block invasion of MDA‐Mb‐231Br cells through suppressing the protein expression of MMP‐2/9 and the expression of ST6GALNAC5, as well as lung metastasis in a mouse model, which suggests that myricetin should be developed as a potential therapeutic candidate for breast cancer.     

Activity of plant flavonoids against antibiotic-resistant bacteria

Thirty eight plant-derived flavonoids representing seven different structural groups were tested for activities against antibiotic-resistant bacteria using the disc-diffusion assay and broth dilution assay. Among the flavonoids examined, four flavonols (myricetin, datiscetin, kaempferol and quercetin) and two -flavones (flavone and luteolin) exhibited inhibitory activity against methicillin-resistant Staphylococcus aureus (MRSA). Myricetin was also found to inhibit the growth of multidrug-resistant Burkholderia -cepacia, vancomycin-resistant enterococci (VRE) and other medically important organisms such as -Klebsiella pneumoniae and Staphylococcus epidermidis. Myricetin was bactericidal to B. cepacia. The results of the radiolabel incorporation assay showed that myricetin inhibited protein synthesis by -B. cepacia. The structure-activity relationship of these flavonoids is discussed.     

Suppression of Propionibacterium acnes‐stimulated proinflammatory cytokines by Chinese bayberry extracts and its active constituent myricetin in human sebocytes in vitro

Myrica rubra Sieb. et Zucc. (Myricaceae), known as Chinese bayberry, is traditionally used as folk medicine in Asian countries. The interaction of Propionibacterium acnes signalling with sebocytes is considered important in the pathogenesis of acne. In the present study, extracts and active compounds of Chinese bayberry were used to determine chemical antioxidant activity and anti‐inflammatory effects in P. acnes‐stimulated human SZ95 sebocytes. A high‐performance liquid chromatography with electrochemical detection system was used to analyse the phenolic composition of bayberry extracts. Accordingly, the flavonols, myricitrin and myricetin, were found to be abundant in the unhydrolysed and hydrolysed extracts of Chinese bayberry fruits, respectively. The anthocyanin cyanidin‐3‐glucoside was also predominantly found in the unhydrolysed extracts. Quantification of human inflammatory cytokines indicated that cell‐free extracts of P. acnes stimulated IL‐8 and IL‐6 production, which was inhibited by myricetin, rather than its glycoside or anthocyanin. Myricetin also exhibited inhibitory effects in P. acnes‐stimulated gene expression of Toll‐like receptor (TLR) 2 and protein phosphorylation of p70 S6 kinase. In conclusion, myricetin shows a suppressive effect on P. acnes‐induced cytokine production through regulation of the TLR and mammalian target of rapamycin pathways. Myricetin goes beyond previous research findings to potentially modulate inflammatory signalling in human sebocytes. These results will be valuable in developing anti‐inflammatory agents against skin acne.     

Mediation of beta-endorphin by myricetin to lower plasma glucose in streptozotocin-induced diabetic rats

Streptozotocin-induced diabetic (STZ-diabetic) rats were employed to investigate the mechanism(s) whereby myricetin, the active principle of Abelmoschus moschatus (Malvaceae), exerts its glucose-lowering effects. Myricetin was purified from the aerial portion of the plant and administered intravenously. A dose-dependent decrease in plasma glucose concentration was observed 30 min following injection, in parallel with increased plasma beta-endorphin-like immunoreactivity (BER). Myricetin enhanced BER release similarly from isolated adrenal medulla. Plasma glucose-lowering and BER-elevating effects of myricetin were both eliminated after bilateral adrenalectomy. Myricetin failed to lower plasma glucose after treatment with opioid mu-receptor antagonists and in opioid mu-receptor knockout diabetic mice. Injection of myricetin three times daily for three consecutive days resulted in increased expression of the glucose transporter subtype 4 (GLUT 4) in soleus muscle and in reduced expression of phosphoenolpyruvate carboxykinase (PEPCK) in liver; these inductions were preventable by opioid mu-receptor blockade. Findings support the conclusion that the plasma glucose-lowering action of myricetin in insulin-deficient animals is mediated by activation of opioid mu-receptors of peripheral tissues in response to increased beta-endorphin secretion. Opioid mu-receptor activation is held responsible for the enhancement of muscle GLUT 4 gene expression and the attenuation of hepatic PEPCK gene expression observed in these myricetin-treated diabetic animals.     

杨梅素、葛根素对高尿酸血症的影响及其意义

目的：观察杨梅素、葛根素治疗前后高尿酸血症患者血清尿酸的变化.探讨杨梅素、葛根素治疗高尿酸血症的机制.方法：120例高尿酸血症患者随机分布为对照组、杨梅素组、葛根素组,分别测量治疗前后血清尿酸（UA）水平.结果：杨梅素、葛根素治疗组UA的水平明显下降（P〈0.05）.结论：杨梅素、葛根素治疗高尿酸血症有重要意义.     

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??OBJECTIVE To study the effect of myricetin and its mechanism for spermatogenesis obstruction caused by lead acetate in male mice. METHODS The spermatogenesis obstruction of male mice model was built by intraperitoneal injection with lead acetate(20 mgkg^-1) for 7 d. From the 2 d model made mice in low, medium and high doses myricetin were treated by myricetin, respectively(100, 200, 400 mgkg^-1) by intraperitoneal injection for 42 d. The mice were sacrificed on day 43 for the measurement of the sperm density and sperm aberration rate. The levels of lactate dehydrogenase(LDH), nitric oxide(NO), tumor necrosis factor ??(TNF-??) in testicular tissue homogenate, the content of malondialdehyde(MDA) in blood serum were assayed respectively. The pathological changes of testicular tissues were observed. RESULTS Compared with the model group, sperm density was increased, the sperm aberration rate mice were decreased, the activities of LDH in testicular tissue homogenate were improved and the contents of NO in testicular tissue homogenate were decreased in different doses myricetin groups. The activities of TNF-?? in testicular tissue homogenate and the content of MDA in blood serum were increased. Pathological change of testis showed there were decline of spermatogenic cells in levels and numbers and few spermiogenesis in most of seminiferous tubule in model group. Those change above could be reversed by myricetin. CONCLUSION Myricetin has certain improvement on spermatogenesis obstruction of mice caused by lead acetateits, its mechanism may be related to decreasing NO, anti-oxidation and inhibiting inflammatory mediator.     

厚藤化学成分研究Ⅲ

 目的研究药用滨海植物厚藤[Ipomea pes-caprae(Linn.)Sweet]的化学成分。方法采用硅胶柱色谱和Sephadex LH-20凝胶柱色谱从厚藤的正丁醇提取物中分离到7个化合物,经理化常数和波谱分析确定这7种化合物的结构。结果这7种化合物分别为:山柰酚(1)、槲皮素(2)、杨梅黄酮(3)、胡萝卜苷(4)、山柰苷(5)、栎皮苷(6)和槲皮素-7-O-β-D-葡萄糖苷(7)。结论其中化合物杨梅黄酮、胡萝卜苷、山柰苷、栎皮苷和槲皮素-7-O-β-D-葡萄糖苷为首次从该种植物中分离得到。     

Cardioprotective potential of myricetin in isoproterenol‐induced myocardial infarction in wistar rats

The study aimed to evaluate the protective role of myricetin obtained from Vitis vinifera (Vitaceae) on heart rate, electrocardiographic (ECG) patterns, vascular reactivity to catecholamines, cardiac marker enzymes, antioxidant enzymes together with morphological and histopathological changes in isoproterenol (ISO) induced myocardial infarction (MI) in male Wistar rats. Rats treated with isoproterenol (85 mg/kg, administered subcutaneously twice at an interval of 24 h) showed a significant increase in heart rate and ST elevation in ECG, and a significant increase in the levels of cardiac marker enzymes – lactate dehydrogenase (LDH), creatine kinase (CK) and aspartate aminotransferase (AST) in serum. Isoproterenol significantly reduced superoxide dismutase (SOD) and catalase (CAT) activity and increased vascular reactivity to various catecholamines. Pretreatment with myricetin (100 mg/kg, p.o. and 300 mg/kg, p.o.) for a period of 21 days significantly inhibited the effects of ISO on heart rate, levels of LDH, CK, AST, SOD, CAT, vascular reactivity changes and ECG patterns. Treatment with myricetin (100 mg/kg and 300 mg/kg) alone did not alter any of the parameters compared with vehicle treated Wistar rats. Myricetin treated animals showed a lesser degree of cellular infiltration in histopathological studies. Thus, myricetin (100 mg/kg and 300 mg/kg) ameliorates the cardiotoxic effects of isoproterenol and may be of value in the treatment of MI. Copyright © 2009 John Wiley & Sons, Ltd.     

杨梅树皮素诱导人肝癌HepG-2细胞凋亡机制的研究

目的:探讨杨梅树皮素(myricetin,MYR)对人肝癌HeptG-2抑制生长和诱导凋亡作用及其机制.方法:MTT法研究MYR对人肝癌HepG-2的抑制生长;荧光染色和电子透射电镜观察HepG-2细胞形态;流式细胞仪研究MYR对HepG-2细胞周期的影响及诱导凋亡作用,罗丹明123单染观察MYR对线粒体膜电位的改变;caspase 3,9试剂盒检测MYR对人肝癌HepG-2细胞内caspase3,9活性的影响.结果:MYR对人肝癌HepG-2细胞生长具有明显的抑制作用,并具有剂量依赖性,IC_(50)为58.6617 mg·L~(-1);MYR作用72 h后,HepG-2细胞呈现典型细胞凋亡特征,细胞周期阻滞于G_2/M期,凋亡率最高为64.73%.同时线粒体膜电位明显下降,caspase3,9活性增加.结论:MYR对人肝癌HepG-2细胞有明显的抑制生长和诱导凋亡作用,其机制可能与线粒体凋亡途径有关.