Baicalein attenuates the neuroinflammation in LPS-activated BV-2 microglial cells through suppression of pro-inflammatory cytokines,COX2/NF-κB expressions and regulation of metabolic abnormality

Baicalein (5,6,7-trihydroxyflavone), isolated from the root of traditional Chinese herb Scutellaria baicalensis Georgi, has anti-inflammatory and anti-oxidative activities. This study explored the protective and modulatory mechanisms of baicalein on neuroinflammation, oxidative stress and metabolic abnormality in lipopolysaccharide (LPS)-activated BV-2 cells. Our results demonstrated that treatment with baicalein remarkably restrained the production of pro-inflammatory factors including nitric oxide (NO), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in LPS-activated BV-2 cells. Moreover, baicalein significantly inhibited reactive oxygen species (ROS) production, decreased cyclooxygenase-2 (COX-2) and nuclear factor-b (NF-κB)/p65 expression. ¹H NMR metabolomics analysis revealed that 12 differential metabolites were regulated by baicalein, implicated in alanine, aspartate and glutamate metabolism, glutathione metabolism, arginine and proline metabolism, D-glutamine and D-glutamate metabolism. In conclusion, these results indicated that baicalein has protective and modulatory effects on neuroinflammation and oxidative stress in LPS-activated BV-2 cells.     

Comparative study of mucoadhesive and mucus-penetrative nanoparticles based on phospholipid complex to overcome the mucus barrier for inhaled delivery of baicalein

Efficient mucosal delivery remains a major challenge for the reason of the respiratory tract mucus act as a formidable barrier to nanocarriers by trapping and clearing foreign particulates. The surface property of nanoparticles determines their retention and penetration ability within the respiratory tract mucus. However, the interaction between nanoparticles and mucus, and how these interactions impact distribution has not been extensively investigated. In this study, polymeric nanoparticles loaded with a baicalein–phospholipid complex were modified with two kinds of polymers, mucoadhesive and mucus-penetrative polymer. Systematic investigations on the physicochemical property, mucus penetration, transepithelial transport, and tissue distribution were performed to evaluate the interaction of nanoparticles with the respiratory tract. Both nanoparticles had a similar particle size and good biocompatibility, exhibited a sustained-release profile, but showed a considerable difference in zeta potential. Interestingly, mucus-penetrative nanoparticles exhibited a higher diffusion rate in mucus, deeper penetration across the mucus layer, enhanced in vitro cellular uptake, increased drug distribution in airways, and superior local distribution and bioavailability as compared to mucoadhesive nanoparticles. These results indicate the potential of mucus-penetrative nanoparticles in design of a rational delivery system to improve the efficiency of inhaled therapy by promoting mucus penetration and increasing local distribution and bioavailability.     

黄芩素对染氟成骨细胞氧化应激水平的影响

目的探讨黄芩素在染氟成骨细胞细胞内氧化还原水平的变化中发挥的抗氧化作用。方法观察染氟成骨细胞内脂质过氧化产物(MDA)及抗氧化酶(SOD、GPX)活性在黄芩素作用前后的变化。结果低浓度氟和高浓度氟均在成骨细胞引起不同程度的氧化应激态变化,联和应用黄芩素降低了染氟成骨细胞内的氧化应激水平。结论黄芩素很可能清除了成骨细胞内由氟诱导产生的过多氧自由基,进而减弱了不同浓度氟对成骨细胞的毒性作用。     

高效液相色谱法测定复方鱼腥草颗粒中黄芩苷和黄芩素含量

目的 建立同时测定复方鱼腥草颗粒中黄芩苷和黄芩素含量的方法。方法 采用高效液相色谱法,以Thermo-C18（4.6 mm×250 mm,5 μm）为色谱柱,以乙腈-0.1%甲酸溶液为流动相,进行梯度洗脱,流速为1.0 mL/min,进样量为10 μL,检测波长为274 nm,柱温为25 ℃。结果 可在30 min内完成对黄芩苷和黄芩素的色谱分析,测得的黄芩苷的线性范围为0.069～0.34 mg/mL,r=0.999 8,平均回收率为99.5%（RSD=3.33%）;黄芩素的线性范围为0.005～0.025 mg/mL,r=0.999 4,平均回收率为102.7%（RSD=2.44%）。结论 所建立的高效液相色谱法方便快捷、准确、简便、重复性好,可用于复方鱼腥草颗粒的质量控制。     

The effects of baicalein or baicalin on the colloidal stability of ZnO nanoparticles (NPs) and toxicity of NPs to Caco-2 cells

Recent study suggested that the presence of phytochemicals in food could interact with nanoparticles (NPs) and consequently reduce the toxicity of NPs, which has been attributed to the antioxidant properties of phytochemicals. In this study, we investigated the interactions between ZnO NPs and two flavonoids baicalein (Ba) or baicalin (Bn) as well as the influence of the interactions on the toxicity of ZnO NPs to Caco-2 cells. The antioxidant properties of Ba and Bn were confirmed by 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays, with Ba being stronger. However, the presence of Ba or Bn did not significantly affect cytotoxicity, intracellular superoxide or release of inflammatory cytokines of Caco-2 cells after ZnO NP exposure. When Ba was present, the cellular viability of Caco-2 cells after exposure to ZnO NPs was slightly increased, associated with a modest decrease of intracellular Zn ions, but these effects were not statistically different. Ba was more effective than Bn at changing the hydrodynamic sizes, Zeta potential and UV–Vis spectra of ZnO NPs, which indicated that Ba might increase the colloidal stability of NPs. Taken together, the results of the present study indicated that the anti-oxidative phytochemical Ba might only modestly protected Caco-2 cells from the exposure to ZnO NPs associated with an insignificant reduction of the accumulation of intracellular Zn ions. These results also indicated that when assessing the combined effects of NPs and phytochemicals to cells lining gastrointestinal tract, it might be necessary to evaluate the changes of colloidal stability of NPs altered by phytochemicals.     

络合沉淀-紫外分光光度法测定黄芩素脂肪乳中甲氧基苯胺值

目的：建立一种专属性好适用于主药有干扰的脂肪乳中甲氧基苯胺值的测定方法。方法：以醋酸铅为络合沉淀剂,采用络合沉淀法排除主药黄芩素对甲氧基苯胺值测定的影响,并对改进后的方法进行验证分析;结果：方法中选择加入沉淀剂的量为200μL,专属性良好,干扰试验结果为99.39%,RSD为1.73%(n=3),重复性结果RSD均小于5.0%(n=5)。结论：该方法专属性好,测定结果准确可靠,能有效排除药物对脂肪乳甲氧基苯胺值测定影响,扩大了甲氧基苯胺值紫外分光光度测定法的适用性,为载药脂肪乳中甲氧基苯胺值控制提供了新的思路和方法。     

6种中药单体对人孕烷X受体介导细胞色素酶P450 3A4转录的调节作用

目的研究6种中药单体野黄芩苷、丹皮酚、芍药苷、甘草苷、黄芪甲苷以及黄芩素是否可以通过诱导孕烷X受体（PXR）介导细胞色素酶P4503A4（CYP3A4）转录表达。方法采用脂质体瞬时转染的方法,将人PXR表达质粒、CYP3A4报告质粒以及内参质粒转入LS174T细胞中,建立报告基因体系,与不同浓度及不同给药时间的中药单体共同孵育,检测细胞中荧光素酶的活性。结果黄芩素（20μmol/L、40μmol/L和80μmol/L）分别诱导PXR介导CYP3A4表达（1.49±0.23）倍（P〈0.05）、（2.45±0.56）倍（P〈0.01）和（5.27±0.40）倍（P〈0.01）,野黄芩苷、丹皮酚、芍药苷、甘草苷和黄芪甲苷在实验的浓度范围内不能明显诱导LS174T细胞中PXR介导CYP3A4表达。在不同给药时间实验中,20μmol/L、40μmol/L和80μmol/L的黄芩素在12～48h能诱导PXR介导CYP3A4表达,诱导能力随时间的延长而呈增强的趋势,各浓度的最大诱导倍数均在48h出现。结论黄芩素在LS174T细胞系中可以通过诱导PXR介导CYP3A4转录表达,而野黄芩苷、丹皮酚、芍药苷、甘草苷或黄芪甲苷无此作用。     

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.