槲皮素抑制HSP70表达的体外研究

目的探讨不同浓度槲皮素抑制正常细胞和肿瘤细胞热休克蛋白70(HSP70)的表达规律,寻找槲皮素抑制HSP70表达的最佳浓度,为研究HSP70的功能提供一种可行的方法。方法加入槲皮素至终浓度为50,100,150,200μmol/L,继续37℃培养6 h后,置42℃水浴受热1 h,于37℃恢复培养2 h,收获细胞。设立37℃培养组(正常对照)、42℃培养组(阳性对照)和0.1%DMSO组(溶剂对照)。分别处理肿瘤细胞株A549细胞和正常细胞株2BS细胞,用Western-blot检测细胞HSP70的表达水平。结果在A549细胞和2BS细胞中,随着槲皮素浓度的增加,HSP70表达逐渐降低。与正常对照组相比,阳性对照组和溶剂对照组的HSP70水平表达增高,差异有统计学意义(P<0.01)。在A549细胞中,当槲皮素浓度达到50μmol/L时,HSP70表达开始下调,但与阳性对照组相比,差异没有统计学意义(P>0.05);当槲皮素浓度达到100μmol/L时,与阳性对照组相比,HSP70表达显著降低,差异有统计学意义(P<0.05);当槲皮素浓度达到150,200μmol/L时,与阳性对照组相比,A549细胞HSP70表达降低更加明显(P<0.01);150μmol/L组和200μmol/L组相比,HSP70水平差异无统计学意义(P>0.05)。在2BS细胞中,当槲皮素浓度达到50μmol/L时,HSP70表达开始下调,与阳性对照组相比,差异有统计学意义(P<0.05);当槲皮素浓度达到100,150,200μmol/L时,与阳性对照组相比,HSP70水平也有显著性降低(P<0.01);150μmol/L组和200μmol/L组相比,HSP70水平差异无统计学意义(P>0.05)。结论槲皮素可以抑制肿瘤细胞和正常细胞HSP70的表达,150μmol/L的槲皮素处理A549和2BS细胞,抑制HSP70表达的效果最佳。     

槲皮素对结肠癌HT-29细胞增殖及周期的影响

目的:探讨槲皮素(Qu)对结肠癌HT-29细胞增殖和凋亡影响的分子机制．方法:以40×10-6,80×10-6,160×10-6mol／L的槲皮素作用结肠癌HT-29细胞,以溶剂为对照组,采用MTT试验、流式细胞分析、免疫细胞化学和RT-PCR等方法观察槲皮素对结肠癌细胞增殖,细胞周期,细胞凋亡,及Caspase-3 蛋白表达、Caspase-3、bcl-2、bax mRNA表达的影响．结果:40×10-6mol／L Qu明显促进HT-29细胞增殖(P<0．05),80×10-6,160×10-6mol／L Qu 明显抑制细胞增殖(P<0．05或P<0．01),呈时间 (?)效应．40×10-6,80×10-6,160×10-6mol/L槲皮素作用HT-29细胞72 h,其增殖率分别为 (111．8±9．6)％,(64．6±8.3)％和(26．1±5．7)％, G0／G1期细胞分别为(32．7±5．4)％、(58．1± 18．3)％和(71．6±20．8)％,S期细胞分别为(48．6 ±17．5)％、(27．4±13．4)％和(15．4±10．1)％,细胞凋亡率分别为(7．0±1．3)％、(15．6±3．6)％和(26．4±6．2)％,80×10-6,160×10-6mol／L能明显提高G0／G1期细胞(P<0．01),明显降低S期细胞(P<0．01),细胞凋亡明显增加(P<0．01)．80 ×10-6,160×10-6mol／L的Qu增加细胞中bax mRNA,Caspase-3 mRNA及其蛋白的表达,降低 bcl-2 mRNA的表达．40×10-6mol／L的Qu增加 Caspasc-3 mRNA表达,但其蛋白表达未见明显增加,细胞增殖明显增加．结论:槲皮素能促进结肠癌HT-29细胞增殖, 也能诱导细胞凋亡,其机制可能是通过上调 Caspase-3和bax表达,降低bcl-2表达来实现的．     

槲皮黄酮对酒精性肝损伤大鼠的治疗研究

目的 探讨槲皮黄酮对酒精性肝损伤大鼠的治疗效果及其作用机制。方法 将30只大鼠随机分为正常对照组、模型组、低剂量槲皮黄酮治疗组、中剂量槲皮黄酮治疗组、高剂量槲皮黄酮治疗组,每组6只大鼠。用酒精+0.5ml鱼油灌胃诱导酒精性肝损伤模型,治疗组分别给予40、80、160mg/kg槲皮黄酮灌胃治疗,6周后处死大鼠,观察各组大鼠间肝脏病理变化,测定血清转氨酶（ALT）及血浆内毒素水平,采用ELISA试剂盒测定细胞因子TNF-α、IL-6、IL-18含量,并利用Western blot法检测大鼠肝组织CD14、LBP、TNF-α、IL-1、IL-18蛋白表达水平。结果 相对正常对照组而言,组织切片检测发现模型大鼠出现肝细胞脂肪变性、点状坏死、伴随炎性细胞浸润,血清ALT、TNF-α、IL-1、IL-18及血浆内毒素含量显著升高（P均<0.05）,并且肝组织中CD14、LBP、TNF-α、IL-1、IL-18蛋白表达水平明显上升（P均<0.05）;槲皮黄酮治疗后发现肝损伤大鼠肝细胞脂肪变性仍存在,但点状坏死和炎性细胞浸润消失,血液中TNF-α、IL-1、IL-18及内毒素含量明显降低（P均<0.05）,并且肝组织中CD14、LBP、TNF-α、IL-1、IL-18蛋白表达水平显著降低（P均<0.05）。结论 槲皮黄酮可以缓解酒精性肝损伤大鼠肝脏的炎症和坏死,其作用机制与降低内毒素水平、抑制库普弗细胞活化和下调促炎细胞因子表达有关。     

高效液相色谱法测定大瓣铁线莲中槲皮素的含量

目的:测定大瓣铁线莲中槲皮素的含量,为蒙药大瓣铁线莲中槲皮素的含量提供检测方法,制定质控标准。方法:采用高效液相色谱法,Kromasil(250mm×4.6mm,5μm)色谱柱,甲醇—0.4%磷酸(64:36)为流动相,流速为1.0mL/min;检测波长360nm。结果:槲皮素浓度在11.77～58.75μg/mL范围内呈良好的线性关系,r=0.9998,槲皮素平均回收率为101.2%,RSD=1.96%。结论:采用高效液相色谱法测定大瓣铁线莲中槲皮素的含量,具有分离效果好、简便、准确等优点。     

Cholinesterase Inhibitory Potential of Quercetin towards Alzheimer’s Disease - A Promising Natural Molecule or Fashion of the Day? - A Narrowed Review

Natural substances are known to have strong protective effects against neurodegenerative diseases. Among them, phenolic compounds, especially flavonoids, come to the fore with their neuroprotective effects. Since quercetin, which is found in many medicinal plants and foods, is also taken through diet, its physiological effects on humans are imperative. Many studies have been published up to date on the neuroprotective properties of quercetin, a flavanol derivative. However, there is no review published so far summarizing the effect of quercetin on the cholinesterase (ChE) enzymes related to the cholinergic hypothesis, which is one of the pathological mechanisms of Alzheimer''s Disease (AD). However, ChE inhibitors, regardless of natural or synthetic, play a vital role in the treatment of AD. Although the number of studies on the ChE inhibitory effect of quercetin is limited, it deserves to be discussed in a review article. With this sensitivity, the neuroprotective effect of quercetin against AD through ChE inhibition was scrutinized in the current review study. In addition, studies on the bioavailability of quercetin and its capacity to cross the blood-brain barrier and how this capacity and bioavailability can be increased were given. Generally, studies containing data published in recent years were obtained from search engines such as PubMed, Scopus, and Medline and included herein. Consequently, quercetin should not be considered as a fashionable natural compound and should be identified as a promising compound, especially with increased bioavailability, for the treatment of AD.     

槲皮素诱导人白血病细胞K562的凋亡

目的:研究槲皮素对人白血病细胞株K562增殖抑制和诱导凋亡作用. 方法:四氮甲唑蓝(MTT)观察细胞的生长状况,应用彗星分析法、TUNEL技术和流式细胞仪检测细胞凋亡. 结果:槲皮素在(1～8)×10-5 mol/L浓度范围内能明显抑制K562细胞的增殖,并具有时间和浓度依赖性,8×10-5 mol/L槲皮素作用72 h的K562细胞株A值最低;彗星分析法显示经槲皮素作用的K562细胞出现长的彗尾条带;原位细胞凋亡可见细胞变小,核固缩为一个或多个染色质团块;流式细胞仪检测细胞凋亡主要发生在G1/S期. 结论:槲皮素在体外一定浓度范围内能抑制K562细胞增殖,诱导凋亡.     

HPLC/MS analysis and anxiolytic-like effect of quercetin and kaempferol flavonoids from Tilia americana var. mexicana

Aim of the study

Around the world, Tilia species have been used in traditional medicine for their properties as tranquilizer. Furthermore, Mexican species of Tilia have been grouped as Tilia americana var. mexicana, but their specific content in flavonoids is poorly described. In this study, inflorescences of Mexican Tilia were collected in three different regions of Mexico to compare their flavonoid content and anxiolytic-like response.

Materials and methods

Flavonoid content was analyzed by using an HPLC–MS technique. For anxiolytic-like response, Tilia inflorescences extracts (from 10 to 300 mg/kg, i.p.) were tested in experimental models (open-field, hole-board and plus-maze tests, as well as sodium pentobarbital-induced hypnosis) in mice.

Results

HPLC–MS analysis revealed specific peaks of flavonoid composition demonstrating some differences in these compounds in flowers and bracts depending on the region of collection. No differences in the neuropharmacological activity among these samples of Tilia were found. Moreover, their effects were associated with quercetin and kaempferol glycosides.

Conclusions

Dissimilarities in the flavonoid composition of Mexican Tilias might imply that these species must be re-classified in more than one species, not as a unique Tilia americana var. mexicana. Since quercetin and kaempferol aglycons demonstrated anxiolytic-like response and that no difference in the pharmacological evaluation was observed between these three Mexican Tilias, we suggest that this pharmacological effect of Tilia inflorescences involves these flavonoids occurrence independently of the kind of glycosides present in the samples reinforcing their use in traditional medicine in several regions of Mexico.     

HPLC测定高良姜中槲皮素 山柰素和异鼠李素的含量

目的：建立高良姜中槲皮素、山柰素和异鼠李素的含量测定方法。方法：采用HPLC法。Kromasil C18色谱柱（5μm,4.6mm×250mm）,流动相：甲醇-0.4%磷酸溶液（52：48）,检测波长：360nm。结果：槲皮素浓度线性范围0.962-24.05μg/mL,r=0.99994;山柰素浓度线性范围1.008-25.2μg/mL,r=0.99990;异鼠李素浓度线性范围0.983-24.575μg/mL,r=0.99996,样品平均回收率为槲皮素97.97%,RSD=1.59%（n=6）;山柰素97.35%,RSD=1.86%（n=6）;异鼠李素98.11%,RSD=2.37%（n=6）。结论：该方法简便、准确、重现性好,可用于该中药的含量测定。     

HPLC法同时测定南葶苈子中槲皮素山柰素及异鼠李素的含量

目的：建立南葶苈子中槲皮素、山柰素及异鼠李素的含量测定方法。方法：色谱柱：Diamond-C18（4.6mm×250mm,5μm）;流动相：甲醇-0.4%磷酸溶液（50∶50）;检测波长：360nm;流速：1.0mL/min;柱温：30℃。结果：槲皮素在0.1184-0.8288μg范围内,r=0.9995,加样回收率99.46%,RSD=0.98%（n=6）;山柰素在0.0258-0.1806μg范围内,r=0.9994,加样回收率98.75%,RSD=1.30%（n=6）;异鼠李素在0.0444-0.3108μg范围内,r=0.9994,加样回收率98.77%,RSD=1.47%（n=6）。结论：该方法操作简便、准确,重复性好,可用于南葶苈子中槲皮素、山柰素及异鼠李素的含量测定。