黄芩素包合物单层渗透泵片制备工艺研究

目的 采用包合技术提高黄芩素的溶解度及溶出速率,进而考察渗透泵片片芯及包衣处方对黄芩素包合物单层渗透泵片体外释药行为的影响,并优化最佳处方.方法 利用包合技术制备黄芩素包合物,并测定其溶解度及溶出速率.以累积释放度为评价指标,通过单因素考察NaCl用量、聚氧乙烯(PEO)用量、包衣增重及增塑剂用量对释药行为的影响,并采用正交试验得到黄芩素包合物单层渗透泵片最佳处方.结果 将黄芩素制备成包合物后,溶解度及溶出速率得到显著提高.正交试验结果显示,渗透泵片片芯处方中PEO用量和包衣膜处方中增塑剂聚乙二醇(PEG)400用量对释药行为有较大影响,得到的最佳处方为:黄芩素包合物180 mg,NaCl用量100mg,PEO用量80 mg,包衣增重4％,增塑剂用量为9％.优化后的黄芩素包合物渗透泵片在12 h内呈现良好的零级释放(r=0.997 8),药物释放比较完全(＞88％).结论 以环糊精包合物为中间体成功制备了黄芩素单层渗透泵片,其释药行为符合零级动力学方程.     

Baicalein protects against MPP+/MPTP-induced neurotoxicity by ameliorating oxidative stress in SH-SY5Y cells and mouse model of Parkinson’s disease

Baicalein, a major bioactive flavone constituent isolated from Scutellaria baicalensis Georgi, has neuroprotective properties in several neurological disorders. Many studies suggest that oxidative stress plays a central role in the pathogenesis of Parkinson’s disease (PD). Baicalein has also been shown to have antioxidant effects. Therefore, the current study was designed to investigate whether baicalein could protect against MPP⁺/MPTP-induced neurotoxicity via suppressing oxidative stress in vitro and in vivo. In vitro, our results showed that baicalein increased cell viability in MPP⁺-treated SH-SY5Y cells. Treatment with baicalein could reversed the increased MDA and ROS levels, and the decreased GSH levels in MPP⁺-treated SH-SY5Y cells. In MPTP-treated mice, baicalein ameliorated MPTP-induced motor impairment and suppressed the MPTP-induced accumulation of iron and lipid peroxides. Besides, baicalein improved the neurotoxicity induced by MPTP as seen by a significant raise of tyrosine hydroxylase (TH) and simultaneous decrease of monoamine-oxidase-B (MAO-B). The inhibitory effect of baicalein on oxidative stress probably was partially governed by inhibition of ERK activation. In conclusion, our results suggest that baicalein could prevent MPP+/MPTP-induced neurotoxicity via suppressing oxidative stress.     

HPLC法同时测定茵栀黄颗粒中4种黄酮类成分

目的 建立高效液相色谱（HPLC）法同时测定茵栀黄颗粒中4个黄酮类成分野黄芩苷、汉黄芩苷、黄芩素和汉黄芩素的含有量。方法 色谱柱：Kromasil C₁₈（4.6 mm×250 mm,5 µm）;流动相：乙腈（A）-0.1%磷酸溶液（B）梯度洗脱（0~15 min,5%~6%A;15~23 min,6%~10%A;23~42 min,10%~20%A;42~60 min,20%~25%A;60~90 min,25%~60%A）;流速：1.0 mL·min^-1;检测波长：274 nm;柱温：30 ℃。结果 野黄芩苷、汉黄芩苷、黄芩素和汉黄芩素在一定范围内线性关系良好;平均回收率在97.70%～101.2%之间,RSD均小于3.0%。结论 本文建立的高效液相色谱法经方法学验证,可用于控制茵栀黄颗粒的质量。     

Simulated gastrointestinal tract metabolism and pharmacological activities of water extract of Scutellaria baicalensis roots

Ethnopharmacological relevance

.

Scutellaria baicalensis

Georgi (Labiatae) is a well-known traditional Chinese medicine to treat inflammation, cardiovascular diseases, respiratory and gastrointestinal infections, etc. The present study was to understand the metabolism of the root of Scutellaria baicalensis (a.k.a. Huangqin in Chinese) in the gastrointestinal tract and the correlation between the metabolites and their respective pharmacological activities.

Materials and methods

The water extract of the root of Scutellaria baicalensis (WESB) was incubated with simulated gastric and intestinal juices, and human fecal microflora for 24 h at 37 °C. The HPLC–DAD analysis was used to monitor the in vitro metabolic process and identify its metabolites by comparing their absorption spectrum and retention time with those of chemical references. The in vitro anticomplementary and antimicrobial activity was evaluated with hemolysis assay, agar disc-diffusion method and MIC value, respectively.

Results

Main constituents of WESB remain unchanged during the incubation with simulated gastric juice (pH=1.5) and intestinal juice (pH=6.8), whereas four flavones, baicalin, wogonoside, oroxyloside and norwogonoside were metabolized into their respective aglycons by human intestinal bacteria. All four metabolites were demonstrated to have higher anticomplementary and antimicrobial activity than those of WESB. The anticomplementary active metabolites were identified to be baicalein, oroxylin A and norwogonin, among them, norwogonin is the most active compound.

Conclusion

The presence of intestinal bacteria is demonstrated to play an important role in the gastrointestinal metabolism of WESB, and the pharmacological effects of Scutellaria baicalensis may be dependent on the intestinal bacteria metabolism.     

Establishment of rat liver microsome-hydrogel system for in vitro phase II metabolism and its application to study pharmacological effects of UGT substrates

Studies on the efficacy evaluation of UDP-glucuronosyltransferases (UGTs) substrates often ignore the existence of active metabolites. However, the present study aims to establish an in-vitro Phase II metabolism system to predict their pharmacological effects after metabolism. Rat liver microsomes (RLMs) encapsulated in a F127′-Acr-Bis (FAB) hydrogel were placed in the incubation system. Baicalein (BA) was chosen as a model drug and the metabolic activity was investigated by quantitating the metabolite Baicalin (BG). The 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay was used to measure the cell viability in Traditional cell culture system (TCCS) and Microsome-hydrogel added to cell culture system for Phase II metabolism (MHCCS-II). Finally, MHCCS-II was applied to predict the metabolic effects of Oroxylin A (OA) and Wogonin (W). Compared to TCCS group, for HepG2 and MCF-7 cells, BA in MHCCS-II led to lower survival ratios of cells (P < 0.05), while for PC12 cells it led to higher survival ratios of cells (P < 0.01). For HepG2 cells, OA and W showed obviously enhanced tumor inhibition after metabolism with the IC₅₀ of 32.7 ± 2.9 μM and 76.1 ± 5.1 μM, respectively (P < 0.01). In conclusion, the MHCCS-II could be a useful tool for studying the pharmacokinetics and pharmacodynamics of UGTs substrates.     

黄芩素干预宫颈癌细胞凋亡机制的研究

摘要:目的　观察通过使用不同浓度黄芩素干预宫颈癌HeLa细胞后,TIMP2及凋亡相关因子Bax、Bcl2 mRNA及蛋白水平表达的变化。方法　体外培养HeLa细胞株,分为空白对照组、100 μmol/L干预组、200 μmol/L干预组,培养24 h。相差显微镜下观察细胞形态及数量的变化。流式细胞技术法检测细胞周期的变化。RT-PCR法检测TIMP2、Bax、Bcl2 mRNA水平的表达变化。Western Blot法检测TIMP2、Bax、Bcl2蛋白水平的表达变化。结果　黄芩素干预24 h后,与空白对照组相比较,各组细胞G1期均受阻滞,组织程度与黄芩素干预浓度成正向变化,Bcl2的mRNA及蛋白表达与黄芩素干预浓度浓度相关,呈逐渐降低的趋势（P＜0.05）,TIMP2、Bax的mRNA及蛋白水平表达趋势为随黄芩素浓度增加而逐渐增强（P＜0.05）。结论　黄芩素通过阻滞细胞周期中G1期,上调Bax,下调TIMP2和Bcl2的表达,促使HeLa细胞凋亡。     

12-脂氧合酶抑制剂黄芩素对2型糖尿病大鼠肾脏细胞外基质的影响及机制

目的：探讨12-脂氧合酶（12-lipoxygenase,12-LO）特异性抑制剂黄芩素（baicalein,BAI）对2型糖尿病大鼠肾脏细胞外基质（ECM）的影响及机制。方法：将链脲佐菌素（streptozotocin,STZ）诱导的2型糖尿病大鼠随机分为：对照组、模型组、黄芩素低剂量治疗组（80mg·kg^-1·d^-1）和高剂量治疗组（160mg·kg^-1·d^-1）。治疗12周后检测各组大鼠尿白蛋白排泄率（UAER）、血糖（BG）、血肌酐（Scr）、血尿素氮（BUN）、内生肌酐清除率（Ccr）等变化;应用免疫组化技术检测各组肾组织中胶原Ⅳ（ColⅣ）、纤维连接蛋白（FN）、层黏连蛋白（LN）的表达;应用RT—PCR方法检测12-LOmRNA的表达。结果：治疗组较模型组明显改善尿白蛋白、BUN水平和肾脏肥大指数等。与对照组比较,模型组大鼠肾脏ColⅣ、FN、LN的表达明显增加;治疗组可明显降低糖尿病大鼠肾脏ColⅣ、FN、LN的表达。12-LOmRNA的相对含量模型组明显高于对照组（P＜0．01）;低、高剂量治疗组较模型组显著降低（P＜0．01）。两治疗组之间各指标无统计学差异。结论：BAI对2型糖尿病大鼠肾脏具有明显的保护作用,其机制可能是通过抑制12-LOmRNA的表达,从而下调肾脏ColⅣ、FN、LN的表迭,减少ECM沉积,延缓糖尿病肾病的发生、发展。     

Baicalein exerts neuroprotective effects in 6-hydroxydopamine-induced experimental parkinsonism in vivo and in vitro

Baicalein, a flavonoid obtained from the root of Chinese medicinal herb Scutellaria baicalensis, has been shown to exert a protective effect on neurons against several neuronal insults. The aim of this study was to explore the neuroprotective effect of baicalein in 6-hydroxydopamine (6-OHDA)-induced experimental parkinsonism in vitro and in vivo. In in vitro experiments, we found that baicalein (0.5, 5 μg/mL) could significantly ameliorate the 6-OHDA-induced SH-SY5Y cell apoptosis from 31.56% in the 6-OHDA group to 18.90%, 21.61% respectively, and also promote neurite outgrowth of PC12 cell. In in vivo experiments, baicalein had no effect on apomorphine (APO)-induced rotations, but it could significantly attenuate muscle tremor of 6-OHDA-lesioned rats. The burst frequency and amplitude are 13.43%, 35.18% compared to 6-OHDA group. Moreover, baicalein treatment could also increase tyrosine hydroxylase (TH)-positive neurons to 265.52% of the 6-OHDA group. The neuroprotective action of baicalein was coincident with an attenuated astroglial response within the substantia nigra. Neuroprotective effect of baicalein as demonstrated by the increasing the number of dopaminergic neurons may have been, in part, caused by anti-apoptotic, pro-differentiation and anti-inflammatory mechanisms of baicalein. Therefore, baicalein can be a promising candidate for prevention or treatment of Parkinson's disease, owing to its anti-apoptotic, pro-differentiation and anti-inflammatory action.     

黄芩苷、黄芩素抑制铜绿假单胞菌生物膜形成的研究

目的:研究黄芩苷、黄芩素对铜绿假单胞菌生物膜形成的影响。方法:选用铜绿假单胞菌X140为研究对象,用32μg·mL-1的黄芩苷、2μg·mL-1的黄芩素干预X140生物膜的培养。以阿奇霉素为对照,采用倍比稀释法对生物膜内活菌菌落计数。扫描电子显微镜(SEM)观察不同培养条件下生物膜的变化。结果:32μg·mL-1的黄芩苷、2μg·mL-1的黄芩素可以显著抑制铜绿假单胞菌的黏附性和抑制生物膜的形成(P<0.01)。结论:黄芩苷、黄芩素可抑制细菌生物膜的形成,影响铜绿假单胞菌的黏附性。