经典名方大秦艽汤HPLC指纹图谱及含量测定方法研究

目的制备10批大秦艽汤标准煎液,建立其HPLC指纹图谱并计算指标成分含量、转移率等数据,为建立大秦艽汤的质量控制标准提供参考。方法依据古方要求还原至现代煎煮方式制备大秦艽汤标准煎液。采用岛津Inertsil ODS-3 C_(18)色谱柱(250 mm×4.6 mm,5μm);流动相为乙腈-0.1%磷酸水溶液,梯度洗脱;体积流量为1.0 m L/min;柱温为30℃;检测波长为237 nm;进样量为10μL。建立10批大秦艽汤HPLC指纹图谱,使用中药色谱指纹图谱相似度评价系统软件(2012A版)进行相似度分析,最后对共有峰进行鉴定和药材归属,并定量测定大秦艽汤中马钱苷酸、龙胆苦苷、升麻素苷的含量。结果建立了10批大秦艽汤的指纹图谱,相似度介于0.902～0.953,确认36个共有峰,指认出7、15、18～21、23、27、31、33、35号峰分别为马钱苷酸、龙胆苦苷、芍药苷、升麻素苷、阿魏酸、甘草苷、5-O-甲基维斯阿米醇苷、黄芩苷、黄芩素、甘草酸、汉黄芩素共11个成分;其中4～8、10～12、15号峰归属于秦艽,19、23号峰归属于防风,17、18号峰归属白芍,30号峰归属于独活,21、25、33号峰归属于甘草,22、27～29、35号峰归属于黄芩,1号峰归属于当归和独活,2号峰归属于秦艽、当归和细辛,3号峰归属于川芎和白芍,13号峰归属于甘草和独活,16号峰归属于秦艽和白芍,20号峰归属于川芎、当归和羌活;以马钱苷酸、龙胆苦苷、升麻素苷3项指标建立其质量控制标准,10批次样品中马钱苷酸、龙胆苦苷、升麻素苷质量分数分别为0.158～0.103、0.475～0.373、0.029～0.012mg/g。结论所建立的汤剂制备方法稳定可行,质量控制方法简单、专属性强,结果准确,可用于大秦艽汤的质量评价。     

透皮促渗剂对黄芩总黄酮凝胶膏剂成分体外经皮渗透的影响

目的研究不同透皮促渗剂对黄芩总黄酮凝胶膏剂中总黄酮及其中6种黄酮类成分(黄芩苷、黄芩素、汉黄芩苷、汉黄芩素、千层纸素A苷及木蝴蝶素)体外经皮渗透的影响,为筛选最佳的促渗剂提供实验依据。方法选择3种常用的透皮促渗剂氮酮(azone,AZ)、薄荷醇(menthol,MT)、丙二醇(propylene glycol,PG),采用体外扩散池法考察单一促渗剂与二元复合促渗剂对体外经皮渗透参数的影响。结果采用单一促渗剂时,AZ对苷类成分的促渗效果较好,MT对苷元类成分的促渗效果较好,而PG的促渗效果相对较差,总体以3%AZ对于总黄酮及其单体的促渗能力最强;采用二元复合促渗剂时,促渗效果整体优于单一促渗剂,总体以3%AZ+5%PG渗透效果最佳。结论促渗剂可以显著影响黄芩总黄酮凝胶膏剂中总黄酮及其中6种活性黄酮类成分的经皮渗透动力学参数,3%AZ+5%PG构成的二元复合促渗剂用于黄芩总黄酮凝胶膏剂促渗效果最佳。     

Pharmacokinetic Study of Baicalein and Its Major Metabolites after iv Administration in Dogs

Objective To develop and validate a simple,rapid,sensitive,and reproducible HPLC method for simultaneous determination of baicalein and its metabolite baicalin in dog plasma and for the subsequent pharmacokinetic study after iv administration to dogs.Methods An accurate and reproducible HPLC-UV method was developed and validated for simultaneous determination of baicalein and baicalin in dog plasma,using luteolin as internal standard.The analytes were separated by an Agilent Zorbax SB-C18 column(250 mm × 4.6 mm,5 μm) and the column temperature was maintained at 40 ℃.The mobile phase was a binary mixture of acetonitrile and water(27:73) ,containing 0.05% phosphoric acid in water,with a flow rate of 1.0 mL/min.The UV detector was set at 276 nm.Results Linear relationships were validated over the range of 0.05-25 μg/mL for baicalein and 0.05-20 μg/mL for baicalin.The intra-and inter-day precision values for all samples were within 8.0%,using relative standard deviation.This method was successfully applied to the pharmacokinetic studies in dogs after iv administration of baicalein.Baicalein was converted to baicalin quickly.Cmax values were 21.13 μg/mL at 0.05 h for baicalein and 1.57 μg/mL at 0.5 h for baicalin,areas under the plasma concentration-time curve were 4.97 h·μg/mL for baicalein and 0.63 h·μg/mL for baicalin,and the elimination half-life is 0.50 h for baicalein and 0.75 h for baicalin,respectively.Conclusion The method is able and sufficient to be used in drug metabolism and pharmacokinetic studies of baicalein.     

The combination of baicalin and baicalein enhances apoptosis via the ERK/p38 MAPK pathway in human breast cancer cells

Aim:

To examine whether the cell growth inhibitory effect of the combination of baicalin and baicalein is related to apoptosis. Moreover, to determine whether the expression of some apoptosis-related proteins is regulated by the ERK/p38 MAPK pathway.

Methods:

Cell viability was measured using a 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Apoptosis was detected by acridine orange (AO) staining, DNA ladder assay and flow cytometric analysis. Apoptosis-related proteins were observed using Western blot analysis.

Results:

Compared with baicalin or baicalein alone, the combination treatment of baicalin (50 μmol/L) and baicalein (25 μmol/L) had an anti-proliferative effect in a time-dependent manner. Isobologram analysis demonstrated that the combination treatment had a synergistic effect. Moreover, apoptosis in MCF-7 cells was increased by 12% and 20% with the combination treatment at 24 h and 48 h, respectively. With the combination treatment in MCF-7 cells, cleaved caspase-3 and caspase-9 were observed, and the level of bcl-2 expression was decreased approximately 20% and 40% at 24 h and 48 h, respectively. The expression of bax and p53 were increased about 25% and 15% at 48 h, respectively. Moreover, the activation of caspase-3, -9 and the regulation of bcl-2, bax and p53 were related to ERK /p38 MAPK activation.

Conclusion:

In this study, apoptosis was enhanced by the combination treatment of baicalin and baicalein, which activated caspases-3 and caspase-9, downregulated the level of bcl-2 and upregulated the level of bax or p53 via the ERK/p38 MAPK pathway.     

黄芩素自微乳的制备及大鼠体内生物利用度研究

目的:制备黄芩素自微乳化制剂(SMEDDS),考察其大鼠体内生物利用度。方法:采用伪三元相图法筛选自微乳的油相、表面活性剂及助表面活性剂;采用HPLC法测定大鼠血浆中药物浓度,与原料比较,对黄芩素自微乳进行大鼠体内生物利用度评价。结果:通过使用混合油相、混合表面活性剂及助表面活性剂,可获得较为理想的黄芩素自微乳。大鼠体内血药浓度-时间曲线结果表明,黄芩素自微乳的AUC是原料的3.77倍,且药时曲线的形状发生一定的改变。结论:自微乳系统可显著增加黄芩素的溶解度,有利于提高口服生物利用度,且自微乳可能改变其胃肠道吸收行为。     

市售黄芩饮片的炮制质量

目的:测定黄芩药材和不同厂家的黄芩饮片中黄芩素转化率,对黄芩饮片的炮制质量进行探讨。方法:采用HPLC测定黄芩药材和不同厂家的黄芩饮片中黄芩苷与黄芩素的含量,并测定其超声自身酶解后的黄芩素含量,计算各自的黄芩素转化率。结果:黄芩药材中黄芩素的转化率为81.1%,按药典方法炮制的黄芩饮片的黄芩素转化率为5.3%,不同厂家的黄芩饮片的黄芩素转化率依次为76.3%,73.0%,54.81%,52.7%,61.3%,71.5%。结论:市售黄芩饮片的炮制质量偏低。     

黄芩素对4种肝损伤物质造成肝细胞毒性的拮抗作用

目的:观察黄芩素对4种肝毒性物质诱导的人正常肝细胞株L-02细胞损伤的拮抗作用.方法:培养的L-02细胞分别给予10 mmol· L-1对乙酰氨基酚(AP),50 μmol·L -1山岗橐吾碱( clivorine,CLI),2μmol·L-1川楝素( toosendanin,TSN)和100 mmol· L-1乙醇( EtOH)诱导肝细胞毒性.黄芩素1,10,25,50,100 μmol· L-1分别与细胞预孵15 min后,加入肝毒性物质,48 h后MTT法检测细胞存活率.结果:与对照组相比,4种肝毒性物质均能显著降低肝细胞存活率(P ＜0.001).经不同浓度黄芩素处理后,各浓度黄芩素均能显著提高AP,TSN,EtOH肝细胞损伤模型组的细胞存活率(P ＜0.01,P＜0.001);10,25,50,100μmol·L-1黄芩素能显著提高CLI肝细胞损伤模型组的细胞存活率(P ＜0.05,P＜0.001).结论:黄芩素具有拮抗对乙酰氨基酚、山岗橐吾碱、川楝素和乙醇这些肝毒性物质诱导的肝细胞毒性的作用,且具有一定的浓度依赖性.     

Anti-pruritic effect of baicalin and its metabolites, baicalein and oroxylin A, in mice Anti-tumorPharmacology

Aim:

To explore whether intestinal microflora plays a role in anti-pruritic activity of baicalin, a main constituent of the rhizome of Scutellaria baicalensis (SB).

Methods:

Baicalin was anaerobically incubated with human fecal microflora, and its metabolites, baicalein and oroxylin A, were isolated. The inhibitory effect of baicalin and its metabolites was accessed in histamine- or compound 48/80-induced scratching behavior in mice.

Results:

Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 40.2±26.2 and 1.2±1.1 nmol·h⁻¹·mg⁻¹ wet weight of human fecal microflora, respectively. Baicalin (20, 50 mg/kg) showed more potent inhibitory effect on histamine-induced scratching behavior when orally administered than intraperitoneally. In contrast, baicalein and oroxylin A had more potent inhibitory effect when the intraperitoneally administered. The anti-scratching behavior activity of oral baicalin and its metabolites was in proportion to their inhibition on histamine-induced increase of vascular permeability with oroxylin A more potent than baicalein and baicalin. In Magnus test using guinea pig ileum, oroxylin A is more potent than baicalein and baicalin in inhibition of histamine-induced contraction. The anti-scratching behavioral effect of oral baicalin was significantly reduced when oral antibiotics were simultaneously administered, whereas the effect of baicalein and oroxylin A were not affected.

Conclusion:

Oral baicalin may be metabolized by intestinal microflora into baicalein and oroxylin A, which ameliorate pruritic reactions through anti-histamine action.     

黄芩素对抗阿尔采末病及改善学习记忆能力的研究进展

阿尔采末病(Alzheimer's disease,AD)是一种以进行性认知障碍和记忆能力损害为主的中枢神经系统退行性疾病。随着人口老龄化的加剧,AD给患者及其家庭和社会带来了巨大的压力,对人类生活质量的影响乃至生存的威胁日趋明显[1,2]。对于AD这类多因素疾病,目前的治疗药物主要包括胆碱能药物、非胆碱能药物、脑细胞代谢增强剂、雌激素、抗氧化剂等。但该类药物存在问题较多,诸如作用持续时间短、毒副作用大、难于透过血脑屏障、来源困难、实际应用受限等。因此,研发理想的治疗AD的新药成为目前关注的热点。近年来,多数研究者都把目光转向天然产物,对中药、植物药逐步开展了筛选、评价及研发工作,希望从中找到治疗AD的候选药物。黄芩素作为传统中药黄芩的提取物,其表现出的抗氧化、抗炎性、抗凋亡以及改善学习记忆能力的卓越功效,使其有望成为治疗AD的潜在理想药物。     

黄芩酶解及黄芩苷元乙醇提取工艺研究

目的：优选黄芩药材的酶解工艺及黄芩苷元的乙醇提取工艺。方法：以黄芩苷元的重量为指标。采用正交实验对影响酶解的温度、醋酸溶液的体积、时间和溶液pH值进行考察;采用正交实验对影响提取的提取时间、乙醇浓度和乙醇用量进行考察。结果：最佳酶解工艺为用1．2倍的醋酸溶液（pH为4）浸润12小时。浸润温度为40℃。最佳提取工艺为用6倍量的乙醇回流提取3次,第一次乙醇浓度为90％,第二、三次乙醇浓度为80％,每次2小时。结论：该研究确定的黄芩苷元的酶解乙醇提取工艺合理、可行。