黄芩素对喉癌Hep-2细胞增殖的抑制作用

目的：探讨黄芩素对人喉癌Hep-2细胞的增殖抑制作用。方法：Hep-2细胞在含黄芩素（10~80μmol/L）的培养基中,分别培养24 h及48 h,用MTT法检测对细胞增殖的影响;用台盼兰染色法检测对细胞活力的影响;用吖啶橙染色法（AO染色法）检测对细胞形态的影响。结果：黄芩素呈时间-剂量依赖性的抑制Hep-2细胞的增殖,并可使细胞活力明显降低;AO染色法显示,黄芩素可诱导Hep-2细胞形态发生明显变化,呈凋亡形态。结论：黄芩素可抑制喉癌Hep-2细胞增殖,降低细胞活力,诱导喉癌Hep-2细胞呈典型的凋亡形态。     

大鼠肝肠不同微粒体药物代谢酶对黄芩素葡糖醛酸酸化代谢物的影响研究

目的:探讨肝肠器官对黄芩素代谢的影响。方法:采用体外微粒体药物代谢酶孵育法,在不同孵育时间和不同浓度下,运用高效液相色谱(HPLC)法测定黄芩素及其葡糖醛酸酸化代谢物的含量。探讨大鼠肝肠不同微粒体对黄芩素葡糖醛酸酸化代谢产物生成速率的影响。结果:不同微粒体药物代谢酶对黄芩素均有代谢作用,且随孵育时间延长代谢作用增加,呈较好的时间和剂量依赖关系,其中十二指肠微粒体代谢作用最强,肝脏代谢作用最弱。结论:黄芩素在肝肠器官有较强的代谢,主要代谢部位是肠道。     

Inhibition of 12-lipoxygenase during baicalein-induced human lung nonsmall carcinoma H460 cell apoptosis.

Baicalein is known as a 12-lipoxygenase (12-LOX) inhibitor. The 12-LOX is found to be involved in the progression of human cancers and the inhibitor of 12-LOX offers a target for the prevention cancer. We demonstrated the inhibitory effect of baicalein on the gene and protein expression of 12-LOX in H460 human lung nonsmall carcinoma cell line. Treatment of baicalein inhibited the growth of H460 cells in a dose-dependent manner. Following 24h exposure to 50muM baicalein, cell cycle analysis revealed an increase in the cell population in S-phase. During the S-phase arrest, baicalein decreased the protein levels of cdk1 and cyclin B1, which are the regulating proteins of S-phase transition to G2/M-phase, in this study. Furthermore, baicalein induced the most of H460 cell apoptosis after treatment for 48h. H460 cells formed vesicles and apoptotic body, and then floated after treatment with baicalein. Baicalein-induced H460 cell apoptosis was confirmed by DNA condensation and fragmentation. Baicalein-induced apoptosis were also accompanied by decreasing in Bcl-2 and proform of caspase-3 and increasing p53 and Bax protein levels. Pretreatment with a specific caspase-3 inhibitor, Ac-DEVD-CHO, partially reduced baicalein-induced cell death, indicating baicalein induces apoptosis is partially dependent on caspase-3 pathway in H460 cells. These data suggest that baicalein, a 12-LOX inhibitor, inhibits the proliferation of H460 cells via S-phase arrest and induces apoptosis in association with the regulation of molecules in the cell cycle and apoptosis-related proteins.     

黄芩素脂质体的制备及体外释放的研究

目的:研究黄芩素脂质体的制备方法。方法:采用逆相蒸发法、薄膜-超声法制备黄芩素脂质体,利用紫外光谱测定包封率以及浆板法测定体外释放曲线。结果:逆相蒸发制备的脂质体平均粒径179nm,包封率和载药量分别为92.57%和23.24%;薄膜超声法平均粒径257nm,包封率和载药量分别为60.02%和7.70%,在PH7.4磷酸盐缓冲液中体外释药符合Higuchi方程。结论:逆相蒸发法操作简单,重现性好,制备的脂质体粒径小、包封率高,药物具有一定的缓释性。     

野黄芩甙元对糖尿病大鼠肾脏保护作用的研究

目的:探讨野黄芩甙元(EB)对糖尿病大鼠肾脏病变的保护作用及作用机制。方法:观察 EB 对糖尿病大鼠肾病理、肌酐清除率(Ccr)、尿白蛋白排泄率(UAlb)的影响,以及对肾组织局部血管紧张素Ⅱ(AngⅡ)、转化生长因子β_1(TGF-β_1)含量的影响。结果:EB 可降低糖尿病大鼠 CCr、UAlb 及系膜基质含量,降低肾内局部 AngⅡ、TGF-β_1的水平。结论:EB 可能通过降低肾组织局部 AngⅡ及 TGF-β_1的含量起到对糖尿病肾病的保护作用。     

黄芩苷对大鼠脑缺血-再灌注损伤时花生四烯酸代谢的影响及其作用机制

目的:探讨黄芩苷抑制脑缺血-再灌注损伤的作用机制。方法:线栓法制作大脑中动脉缺血-再灌注大鼠模型。应用RT-PCR、Western-blot以及酶免疫测定方法,观察黄芩苷对环氧化物酶-2(COX-2)、5-脂加氧酶(5-LOX)及其代谢产物前列腺素E2(PGE2)和半胱氨酸白三烯(cys-LT)的影响。使用聚丙烯酰胺凝胶电泳检测脑组织清蛋白含量,评价黄芩苷对脑缺血-再灌时血脑屏障的影响。结果:①黄芩苷降低脑缺血-再灌注时组织细胞质内5-LOX的含量(P<0.01),抑制cys-LT的合成(P<0.01)。②黄芩苷减轻缺血-再灌注损伤时血脑屏障破坏导致的清蛋白渗出(P<0.05)。③黄芩苷从mRNA水平抑制脑缺血-再灌注时COX-2的诱导表达(P<0.05)。结论:黄芩苷抑制脑缺血-再灌注损伤时细胞内钙超载引起的5-LOX转位表达,从而减少cys-LT的合成,减轻血脑屏障的破坏。     

HPLC法同时测定黄芩中黄芩苷、黄芩素、汉黄芩素的含量

目的:建立反相高效液相色谱法同时测定黄芩中黄芩苷、黄芩素、汉黄芩素的含量.方法:采用Agilent Eclipse XDB-C18(250 mm×4.6 mm,5μm)色谱柱,以甲醇-乙腈-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 -1;进样量10 μl;柱温35℃.结果:黄芩苷、黄芩素、汉黄芩素的线性范围分别为0.059 ～ 1.175 μg,r=1.000 0(n =7)、0.010～0.204μg,r=1.000 0(n =7)和8.210×10-3～1.642×10-1 μg,r =1.000 0(n =7);提取回收率分别为99.08％,RSD=0.5％(n=6)、98.66％,RSD =0.5％ (n =6)和98.31％,RSD =0.7％ (n =6).结论:本法操作简便、快速、结果准确,可用于黄芩的质量控制.     

The Role of Intestinal Microflora in Anti-Inflammatory Effect of Baicalin in Mice

Baicalin, a main constituent of the rhizome of Scutellaria baicalensis, is metabolized to baicalein and oroxylin A in the intestine before its absorption. To understand the role of intestinal microflora in the pharmacological activities of baicalin, we investigated its anti-inflammatory effect in mice treated with and without antibiotics. Orally administered baicalin showed the anti-inflammatory effect in mice than intraperitoneally treated one, apart from intraperitoneally administered its metabolites, baicalein and oroxylin A, which potently inhibited LPS-induced inflammation. Of these metabolites, oroxylin A showed more potent anti-inflammatory effect. However, treatment with the mixture of cefadroxil, oxytetracycline and erythromycin (COE) significantly attenuated the anti-inflammatory effect of orally administered baicalin in mice. Treatment with COE also reduced intestinal bacterial fecal β-glucuronidase activity. The metabolic activity of human stools is significantly different between individuals, but neither between ages nor between male and female. Baicalin was metabolized to baicalein and oroxylin A, with metabolic activities of 1.427 ± 0.818 and 1.025 ± 0.603 pmol/min/mg wet weight, respectively. Baicalin and its metabolites also inhibited the expression of pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in LPS-stimulated peritoneal macrophages. Of them, oroxylin A showed the most potent inhibition. Based on these findings, baicalin may be metabolized to baicalein and oroxylin A by intestinal microflora, which enhance its anti-inflammatory effect by inhibiting NF-κB activation.     

不同产地黄芩中的有效成份含量分析

目的探讨不同产地黄苓中的黄芩苷、黄芩素、汉黄芩素的含量变化。方法制备供试品、对照品溶液,采用HPLC法,测定不同产地（河北承德、内蒙古自治区乌兰浩特、山西大同、吉林长白山）黄苓中黄苓苷、黄苓素、汉黄芩素的含量。结果黄芩苷、黄芩素、汉黄苓素含量测定方法的线性关系、重复性良好。精密度稳定。河北承德黄苓中黄芩苷含量最高,其次依次由高到低为：山西大同、吉林长白山、内蒙古自治区乌兰浩特;内蒙呼兰浩特的黄芩素、汉黄芩素含量最低,表明该地区收购的黄芩野生黄芩相对较多,其他产地的黄芩的黄芩素、汉黄芩素含量由高到低为：河南承德、山西大同、吉林长白山。结论不同产地的黄芩苷、黄芩素、汉黄苓素含量不同,临床用药应根据不同病症、不同产地调整药物剂量。     

Baicalein, isolated from Scutellaria baicalensis, protects against endothelin-1-induced pulmonary artery smooth muscle cell proliferation via inhibition of TRPC1 channel expression

Ethnopharmacological relevance

We investigated the antiproliferative effects of baicalein, isolated from Scutellaria baicalensis (Huang-qin), on ET-1-mediated pulmonary artery smooth muscle cells (PASMCs) proliferation and the mechanisms underlying these effects.

Materials and methods

Intrapulmonary artery smooth muscle cells were isolated and cultured from female Sprague-Dawley rats and used during passages 3-6. The proliferation of PASMCs was quantified by cell counting and XTT assay. The protein expression of TRPC1 and PKCα were determined by western blotting. The cell cycle pattern was assayed by flow cytometry. The intracellular calcium concentrations ([Ca²⁺]_i) were measured using the fluorescent indicator fura-2-AM and flow cytometry.

Results

Baicalein (0.3-3 μM) inhibited PASMCs proliferation, promoted cell cycle progression, enhanced [Ca²⁺]_i levels, increased capacitative Ca²⁺ entry (CCE), upregulated the canonical transient receptor potential 1 (TRPC1) channel and membrane protein kinase Cα (PKCα) expression induced by ET-1 (0.1 μM). The PKC activator PMA (1 μM) reversed the inhibitory effects of baicalein on ET-1-induced upregulation of TRPC1 expression and S phase accumulation, while the PKC inhibitor chelerythrine (1 μM) potentiated baicalein-mediated G₂/M phase arrest and TRPC1 channel inhibition.

Conclusion

Our findings suggest that baicalein protects against ET-1-induced PASMCs proliferation via modulation of the PKC-mediated TRPC channel.