北京延庆栽培黄芩与道地黄芩的药材鉴定研究

目的:建立北京延庆栽培黄芩与道地黄芩的鉴定方法。方法:采用TLC法测定黄芩素,HPLC法测定黄芩苷。色谱柱:Zirchrom Kromasil C8色谱柱(5μm,200 mm×4.6 mm);流动相:甲醇-水-磷酸(47∶53∶0.2);检测波长:280 nm;柱温:室温。结果:2年和3年生黄芩供试品在与对照药材、对照品相应位置显相同颜色的斑点,但2年生药材黄芩素含量较低。而野生道地黄芩的黄芩苷含量为129 mg/g,2年和3年生黄芩分别为116 mg/g、121 mg/g。加样回收率为98.43%,RSD%=0.23%。结论:不同产地黄芩的黄芩苷含量有一定区别,而3年生黄芩的黄芩苷及黄芩素比两年生的含量高。     

黄芩苷/黄芩素对耐甲氧西林金黄色葡萄球菌抗药性的逆转作用研究

目的:研究黄芩苷/黄芩素对耐甲氧西林金黄色葡萄球菌(MRSA)抗药性的逆转作用,并初步探索其逆转机制。方法:以平皿法测定黄芩苷/黄芩素与苯唑西林对MRSA的协同抗菌效力;以分光光度法测定黄芩苷/黄芩素协同苯唑西林对MRSA生长密度的抑制作用;以青霉素结合蛋白(PBP2a)胶乳凝集试剂盒检测黄芩苷/黄芩素对PBP2a生成的抑制效力。结果:黄芩苷/黄芩素联合苯唑西林对临床分离的MRSA有显著的协同抗菌作用,16μg·mL-1的黄芩素即可显著逆转MRSA对苯唑西林的高度耐药;黄芩苷/黄芩素对MRSA产生PBP2a有显著抑制作用。结论:黄芩苷/黄芩素可通过抑制MRSA产生PBP2a来逆转其对苯唑西林的高度耐药,这一现象从理论上为临床治疗MRSA感染提供了新的方法和思路。     

黄芩自生酶催化水解总黄酮苷的工艺研究

目的研究黄芩自生酶催化水解总黄酮苷的工艺条件。方法采用正交试验,考察了加水量、温度和时间等因素,采用HPLC法测定了药材中黄芩苷、黄芩素、汉黄芩素、千层纸素-A的含量。结果确定最优酶催化水解工艺条件为取药材,加4倍量水,于32℃酶催化水解12h,烘干后备用。结论黄芩自生酶催化水解总黄酮苷是一种环保、经济、可行的方法。     

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。