The Effect of Baicalein on Hippocampal Neuronal Damage and Metalloproteinase Activity Following Transient Global Cerebral Ischaemia

Baicalein, a flavonoid derived from Scutellaria baicalensis Georgi, is known to protect neural tissue from damage. Several studies have found that baicalein reduces brain infarction following focal brain ischaemia. However, there are few reports on the protective effects of baicalein following global brain ischaemia. Therefore, the current study was designed to address the effects of baicalein on neuronal damage and matrix metalloproteinase (MMP; gelatinase) activity in the hippocampus after transient global ischaemia. C57BL/6 mice were subjected to transient global brain ischaemia for 20 min and sacrificed 72 h after ischaemic insult. Baicalein (200 mg/kg, once daily, as a suspension in 0.5% carboxymethylcellulose) or an equal volume of vehicle was orally administered to the mice from 7 days prior to the ischaemic insult until sacrifice. After global ischaemia neuronal damage was significant in CA1 and CA2 pyramidal cell layers. In baicalein‐treated mice, neuronal damage from the ischaemic insult was significantly less than that in vehicle‐treated mice. Baicalein administration also inhibited MMP‐9 activity in the hippocampus. These data demonstrate that baicalein reduces hippocampal neuronal damage after transient global ischaemia. Besides its possible protective mechanisms, the protective role of baicalein against global ischaemia may operate, at least in part, through the inhibition of MMP‐9 activity. Copyright © 2012 John Wiley & Sons, Ltd.     

高效液相色谱法同时测定双黄消炎片中黄芩苷和黄芩素含量

目的 建立同时测定双黄消炎片中黄芩苷和黄芩素含量的反相高效液相色谱法.方法 色谱柱采用Agilent Eclipse XDB-C18柱(250 mm ×4.6 mm,5μm),以甲醇-0.1%磷酸溶液为流动相(梯度洗脱),检测波长为277 nm,流速1.0 mL/min,进样量10μL,柱温35℃.结果 黄芩苷质量浓度在5.678~141.95μg/mL范围内与峰面积有良好线性关系,r=1.000 0(n=7);黄芩素质量浓度在2.122~53.05 μg/mL范围内与峰面积有良好线性关系,r=1.000 0(n=7).黄芩苷平均回收率为99.32%,RSD为0.63%(n=6);黄芩素平均回收率为99.27%,RSD为0.48%(n=6).结论该法操作简便、快速、结果准确,可用于双黄消炎片的质量控制.     

Identification of the metabolites of baicalein in human plasma

The metabolites of baicalein in human plasma were investigated after taking baicalein, which is one of the main bioactive flavones in Scutellaria baicalensis Georgi. Five metabolites (M1–M5) together with the parent drug baicalein (P) were detected and identified by the HPLC-diode-array detector (DAD) and LC-MS/MS methods. Among them, 7-methoxybaicalein 6-O-glucuronide (M5) is a new metabolite. Based on the results, the proposed metabolic pathway of baicalein in humans was inferred.     

黄芩提取物多指标成分鉴定及指纹图谱的研究

目的：应用超高效液相串联飞行时间质谱法鉴定黄芩提取物中黄芩苷、汉黄芩苷、黄芩素、汉黄芩素4种活性成分及其指纹图谱同时检测的方法。方法：以ACQUITYTM UPLC BEH C₁₈色谱柱（2.1mm×100mm,1.7μm）,乙腈-0.1%甲酸溶液梯度洗脱,流速0.2mL?min^-1,检测波长275nm,柱温30℃。结果：4种成分色谱显示分离度良好,经质谱得到各成分离子碎片,查阅相关文献均得以证实,并在同一色谱条件下检测指纹图谱,结果显示相似度良好。结论：该方法简便、灵敏、准确,可用于黄芩提取物的质量控制研究。     

进食对健康受试者口服百可利咀嚼片药动学的影响

 目的 研究在进食和空腹状态下中国健康受试者口服百可利咀嚼片400 mg药动学的差异。方法 采用随机、双周期、自身交叉、安慰剂对照设计,12例健康受试者空腹或餐后口服百可利咀嚼片400 mg或安慰剂,HPLC-MS/MS测定血浆中百可利及其主要代谢物黄芩苷的浓度,计算其主要药动学参数并进行安全性评价。结果 受试者空腹和餐后口服单剂量百可利后,血浆中百可利的ρ_max分别为(15.752±9.328),(19.572±9.439) ng·mL^-1;AUC_0-t分别为(89.468±48.631),(122.073±28.285) ng·h·mL^-1;AUC_0-∞分别为(93.356±50.110),(126.212±28.270) ng·h·mL^-1。黄芩苷的ρ_max分别为(182.472±99.555),(154.782±100.834) ng·mL^-1;AUC_0-t分别为(1 193.230±693.408),(933.921±282.318) ng·h·mL^-1;AUC_(0-∞)分别为(1 266.425±866.664),(940.882±286.192) ng·h·mL^-1。空腹与餐后各发生4起不良事件,程度均为轻度。结论 与空腹服用400 mg百可利咀嚼片相比,进食后百可利的吸收程度增加,而黄芩苷的吸收降低。400 mg耐受性良好,空腹或进食下发生的不良事件相当。吸收程度的改变未影响药物的耐受性。     

纳豆菌液体发酵转化黄芩苷和汉黄芩苷的工艺研究

探索研究纳豆菌液体发酵黄芩药材制备黄芩素和汉黄芩素的工艺,利用纳豆菌所产生的活性酶对黄芩苷和汉黄芩苷进行生物转化,以提高黄芩中黄芩素和汉黄芩素的含量。通过考察不同碳源、氮源及无机盐的种类和浓度、培养基pH、药材粉碎度、装液量、摇床转速、液料比、发酵时间等因素对发酵工艺的影响,以黄芩素和汉黄芩素的含量为评价指标,优选得到黄芩生物转化生成黄芩素和汉黄芩素的液体发酵最佳工艺为蛋白胨质量分数为1.0%,氯化钠0.05%,pH 6.0,黄芩药材粉碎过40目,装样量33%,摇床转速200 r·min^-1,液料比5 : 1,温度37 ℃,发酵6 d,黄芩药材中黄芩苷的转化率为97.6%,汉黄芩苷转化率97.0%。验证试验表明该工艺稳定可行,为黄芩素和汉黄芩素的工业化生产提供数据参考。     

黄芩素固体脂质纳米粒冻干粉的制备及体外释药性质的研究

目的制备黄芩素固体脂质纳米粒并冻干,考察其理化性质及体外释药特性。方法采用乳化蒸发-低温固化法,以包封率为考察指标,正交试验优化其处方并考察其粒径、形态、电位、多分散系数(PDI)及体外溶出。以外观、色泽、再分散性为考察指标筛选最佳冻干保护剂,利用差示扫描量热(DSC)、X射线衍射(XRD)、傅里叶红外光谱(FT-IR)分析药物在纳米粒中的存在状态。结果黄芩素固体脂质纳米粒外观呈球状体,分布均匀,平均粒径为(82.64±6.78)nm,PDI为0.242±0.013,Zeta电位为(-25.7±0.5)m V,包封率为(81.3±1.2)%,载药量为(7.16±0.14)%(n=3),以5%甘露醇作冻干保护剂效果较好,药物以无定形状态分散在脂质载体中,体外溶出实验表明黄芩素固体脂质纳米粒与原料药相比具有明显的缓释作用。结论乳化蒸发-低温固化法制得的黄芩素固体脂质纳米粒,粒径小,包封率高,稳定性好,工艺简单。     

Baicalein Triggers Autophagy and Inhibits the Protein Kinase B/Mammalian Target of Rapamycin Pathway in Hepatocellular Carcinoma HepG2 Cells

Baicalein (BA), isolated from the Chinese medicinal herb Scutellariae radix (Huangqin in Chinese), is a flavonoid with various pharmacological effects. Herein, we found that BA only slightly reduced the cell viability on HepG2 cells after 24‐h treatment as determined by 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyl tetrazolium bromide (MTT) assay. However, BA (50 μM) effectively blocked the colony formation. Meanwhile, BA remarkably induced the formation of autophagosomes after 24‐h treatment as determined by immunofluorescence with monodansylcadaverine staining as well as transmission electron microscopy, respectively. Moreover, BA obviously up‐regulated the expression of microtubule‐associated protein 1A/1B‐light chain 3‐II in concentration‐dependent and time‐dependent manners in HepG2 cells. When combined with the autophagy inhibitor chloroquine and BA, the cell viability and colony formation were significantly decreased, indicating that BA triggered protective autophagy, which prevented cell death. Further study showed that BA concentration‐dependently and time‐dependently decreased the expression of p‐AKT (S473), p‐ULK1 (S757) and p‐4EBP1 (T37 and S65), suggesting the involvement of protein kinase B (AKT)/mammalian target of rapamycin (mTOR) in BA‐triggered autophagy. Copyright © 2015 John Wiley & Sons, Ltd.     

黄芩素对缝隙连接蛋白Cx32组成的GJIC功能的影响

目的:在转染并稳定表达Cx32的HeLa细胞上,观察黄芩素对Cx32组成的GJIC及Cx32蛋白表达水平的影响。方法:细胞接种荧光示踪法观察不同浓度黄芩素对GJIC的影响;细胞免疫荧光法观察黄芩素在影响GJIC功能浓度范围内对Cx32蛋白表达的影响。结果:黄芩素(2.5μmol/L,5μmol/L,10μmol/L)增强Cx32组成的GJIC功能的荧光渗透率为10.04%,22.5%和35.33%;黄芩素(2.5μmol/L,5μmol/L,10μmol/L)增强组成GJIC的Cx32蛋白表达的荧光强度为(27.12±0.30)%,(56.31±1.02)%和(83.47±1.85)%。结论:黄芩素可增强缝隙连接蛋白Cx32组成的GJIC功能,其机制可能与增加Cx32蛋白表达水平有关。     

黄芩素含氮衍生物的合成

目的为开发黄芩素为母体的抗肿瘤药物奠定基础。方法首先制备卤代的含氮中间体R1R2N(CH2)nCl.HCl,使之与黄芩素的6位或7位酚羟基反应,引入氮原子到黄芩素的A环。并用四甲基偶氮唑盐微量酶反应比色法[3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide,MTT]测定合成产物体外抑制人肝癌细胞HepG2和人肺腺癌细胞A549细胞的活性。结果合成了10个黄芩素含氮衍生物(4a-4f,5a-5d),并经波谱测试确证其结构,均为新化合物。初步活性测试显示4c,5d有较显著的细胞毒性提升。结论该方法提供了一类新的黄芩素衍生物,能够用来制备黄芩素衍生物有机酸盐,改善母体溶解度不佳的缺点,并在药理活性方面有开发潜力。