白花蛇舌草中槲皮素和山柰素的含量测定

目的建立高效液相色谱法测定白花蛇舌草中槲皮素和山柰素的含量测定方法。方法色谱柱:Kromasil C18(5μm,250×4.6 mm);流动相:甲醇-0.4%磷酸溶液(60:40);检测波长:360 nm,柱温:30℃。结果槲皮素和山柰素的回收率分别为100.5%、101.2%;线性范围分别为0.032 4~0.810μg、0.039 5~0.948μg。结论结果准确,重复性好,可用于该产品的质量控制。     

Cissus quadrangularis ethanol extract upregulates superoxide dismutase, glutathione peroxidase and endothelial nitric oxide synthase expression in hydrogen peroxide-injured human ECV304 cells

Ethnopharmacological relevance

Cissus quadrangularis has been widely used in traditional medicine for the treatment of hemorrhoid. However, the detailed mechanism of antioxidant defense of C. quadrangularis in endothelial cells under oxidative stress remains unclear.

Aim of the study

The present study aims to elucidate the protective role of ethanol extract of C. quadrangularis (CQE) including its constituents, quercetin and resveratrol, on hydrogen peroxide (H₂O₂)-injured human umbilical vein endothelial ECV304 cells.

Materials and methods

Viability, genotoxicity and protein expression of ECV304 cells were analyzed by MTT, alkaline comet and Western blot, respectively. Production of intracellular reactive oxygen species (ROS) was determined using dichlorofluorescein fluorescence dye.

Results

After exposing cells to CQE containing quercetin and resveratrol, DNA damage was not observed. CQE including quercetin and resveratrol significantly attenuated ROS in H₂O₂-injured ECV304 cells in a concentration-dependent manner. The protein expression of superoxide dismutase (Cu/Zn-SOD, Mn-SOD), glutathione peroxidase (GPx) and endothelial nitric oxide synthase (eNOS) increased in the cells treated with CQE, quercetin or resveratrol prior to H₂O₂ exposure, as compared with control.

Conclusions

The results provide a molecular mechanism of C. quadrangularis, which could be partially related to quercetin and resveratrol, in restoring ROS in endothelial cells through the upregulation of Cu/Zn-SOD, Mn-SOD, GPx and eNOS.     

Potential protective effects of quercetin and curcumin on paracetamol-induced histological changes,oxidative stress,impaired liver and kidney functions and haematotoxicity in rat

The present study was carried out to evaluate the potential protective role of quercetin and curcumin against paracetamol-induced oxidative injury, liver damage and impairment of kidney function, as well as haematotoxicity in rats. Also, N-acetylcysteine was used to evaluate the potency of quercetin and curcumin. Paracetamol caused an elevation in thiobarbituric acid-reactive substances (TBARS) paralleled with significant decline in glutathione peroxidase, glutathione S-transferase, superoxide dismutase and catalase activities (in plasma, brain, lung, heart, liver, kidney and testes) and glutathione content (in lung, liver and kidney). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination, elevated plasma transmainases, alkaline phosphatase and lactate dehydrogenase. Paracetamol reduced plasma total protein, albumin and globulin, while increased bilirubin, urea and creatinine, and induced haematotoxicity. The presence of quercetin or curcumin with paracetamol successfully mitigated the rise in TBARS and restored the activities of antioxidant enzymes compared to the group treated with both paracetamol and N-acetylcysteine. They also protected liver histology, normalized liver and kidney functions, which was more pronounced with curcumin. Therefore, it can be concluded that concomitant administration of quercetin or curcumin with paracetamol may be useful in reversing the toxicity of the drug compared to N-acetylcysteine.     

Dietary quercetin exacerbates the development of estrogen-induced breast tumors in female ACI rats

Phytoestrogens are plant compounds that structurally mimic the endogenous estrogen 17β-estradiol (E₂). Despite intense investigation, the net effect of phytoestrogen exposure on the breast remains unclear. The objective of the current study was to examine the effects of quercetin on E₂-induced breast cancer in vivo. Female ACI rats were given quercetin (2.5 g/kg food) for 8 months. Animals were monitored weekly for palpable tumors, and at the end of the experiment, rats were euthanized, breast tumor and different tissues excised so that they could be examined for histopathologic changes, estrogen metabolic activity and oxidant stress. Quercetin alone did not induce mammary tumors in female ACI rats. However, in rats implanted with E₂ pellets, co-exposure to quercetin did not protect rats from E₂-induced breast tumor development with 100% of the animals developing breast tumors within 8 months of treatment. No changes in serum quercetin levels were observed in quercetin and quercetin + E₂-treated groups at the end of the experiment. Tumor latency was significantly decreased among rats from the quercetin + E₂ group relative to those in the E₂ group. Catechol-O-methyltransferase (COMT) activity was significantly downregulated in quercetin-exposed mammary tissue. Analysis of 8-isoprostane F_2α (8-iso-PGF_2α) levels as a marker of oxidant stress showed that quercetin did not decrease E₂-induced oxidant stress. These results indicate that quercetin (2.5 g/kg food) does not confer protection against breast cancer, does not inhibit E₂-induced oxidant stress and may exacerbate breast carcinogenesis in E₂-treated ACI rats. Inhibition of COMT activity by quercetin may expose breast cells chronically to E₂ and catechol estrogens. This would permit longer exposure times to the carcinogenic metabolites of E₂ and chronic exposure to oxidant stress as a result of metabolic redox cycling to estrogen metabolites, and thus quercetin may exacerbate E₂-induced breast tumors in female ACI rats.     

山奈酚和槲皮素对大鼠细胞色素P450酶活性的影响

目的:观察山奈酚和槲皮素两种银杏黄酮对细胞色素P450的影响。方法:原代培养大鼠肝细胞,接触0.1~10.0μm o l/L的山奈酚或槲皮素,作用12 h、24 h和48 h,用N ash法检测细胞色素P450同工酶-红霉素N-脱甲基酶(ENRD)和氨基比林N-脱甲基酶(ADM)的活性。分别以红霉素(10.0μm o l/L)和二甲基亚砜(DM SO)作为阳性对照和溶剂对照。结果:0.1、1.0和10.0μm o l/L山奈酚作用24 h,ENRD酶活性分别为(0.088±0.008)、(0.074±0.006)和(0.041±0.003)μm o l/(m g.m in-1);槲皮素相同浓度和作用时间处理的ENRD酶活性分别为(0.082±0.007)、(0.063±0.007)和(0.034±0.005)μm o l/(m g.m i-n 1)。其中1.0和10.0μm o l/L山奈酚和槲皮素处理的肝细胞ENRD酶活性都显著低于溶剂对照组(0.085±0.011)μm o l/(m g.m in-1),且呈剂量-效应关系(P<0.01)。10μm o l/L山奈酚处理细胞12 h和48 h后,ENRD酶活性为(0.053±0.006)和(0.037±0.007)μm o l/(m g.m i-n 1);10μm o l/L槲皮素处理细胞12 h和48 h后,ENRD酶活性为(0.067±0.005)和(0.032±0.004)μm o l/(m g.m i-n 1),都具有明显的时间-效应关系(P<0.01)。山奈酚只有在10μm o l/L浓度下作用24 h对ADM活性出现抑制,槲皮素对ADM活性没有明显影响。结论:在本实验条件下,山奈酚和槲皮素能明显抑制大鼠肝细胞ENRD活性;山奈酚在10μm o l/L浓度下能轻度抑制ADM,而槲皮素对ADM活性没有明显的抑制作用。     

邳州银杏叶黄酮类成分分析

目的：探索银杏叶黄酮类成分之间的相互关系。方法：采用HPLC法(二级管阵列检测器DAD)分别测定了银杏叶中各黄酮的含量。结果与结论：银杏叶中槲皮素和山柰素的含量随树龄的增长而下降，含量的相对关系会发生变化，二、三年树龄叶以槲皮素为主，四年以上树龄叶山柰素所占比例相对较大。     

Flavonoid Glycosides from Byrsocarpus Coccineus Leaves. Schum and Thonn (Connaraceae)

The bioactive ethyl acetate and N-butanol soluble parts of an ethanolic extract of Byrsocarpus coccineus leaves was subjected to column chromatography over silica gel G (60 – 120µ) and repeated purification of the flavonoid rich fraction over sephadex LH-20 eluted with methanol led to the isolation of three flavonoid glycosides identified as quercetin 3-O-α-arabinoside (I), quercetin(II) and quercetin 3-β-D-glucoside. Their structures were elucidated by ¹H and ¹³C-NMR data and are reported here for the first time in this plant.     

抑制HSP 70表达对体外培养的脑胶质瘤细胞生长的影响

目的 探讨抑制热休克蛋白７０（ＨＳＰ７０）表达对脑胶质瘤细胞增殖及凋亡的影响。方法 利用细胞培养、电子显微镜及流式细胞仪的方法，观察阻滞ＨＳＰ７０表达后对肿瘤细胞生长的影响。结果 体外培养脑胶质瘤细胞株、经不同浓度槲皮素作用不同时间后，碘化丙碇染色荧光显微镜观察发现细胞核固缩，致密和破裂现象；流式细胞检测发现亚二倍体峰，提示出现细胞凋亡。分析细胞周期，发现凋亡细胞主要出现在Ｇ０、Ｇ１期，随药物的浓     

槲皮素对X射线照射后大鼠免疫功能的影响

目的 探讨槲皮素(QN)对6 Gy X射线照射后大鼠免疫功能及肝脏氧化应激反应的影响。 方法40只大鼠随机分成4组,每组10只,第1组连续7 d 腹腔内注射生理盐水(0.5 ml/150 g体重)作为对照组,第2组(QN组)连续7 d 用槲皮素(40 mg/kg体重)腹腔注射,第3组用单次6 Gy X射线照射,第4组(6 Gy+QN组)连续7 d 腹腔注射槲皮素(40 mg/kg体重),在最后一次注射后1 h,给予单次6 Gy X射线照射。照射后24 h,将大鼠麻醉后断头处死,取其脾脏用四甲基偶氮唑盐(MTT)法检测淋巴细胞转化率,流式细胞术检测CD⁺₄、CD⁺₈及CD⁺₄/CD^＋₈T淋巴细胞的变化,取肝脏检测氧化应激反应并观察一般状态变化。 结果经QN预先处理组的大鼠脾脏淋巴细胞转化率显著高于6 Gy照射组,CD^＋₄、CD⁺₈及CD^＋₄/CD⁺₈ T淋巴细胞百分率亦显著高于单纯照射组(F值分别为8.455、22.644和18.911, P<0.01),尤其以增加CD^＋₄T淋巴细胞百分率为显著。同时发现QN预先处理的照射组大鼠肝脏丙二醛(MDA)含量显著低于照射组(F=10.059, P<0.01),抗氧化酶类超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性和抗氧化物质GSH含量显著高于照射组(F值分别为23.688、186.046和19.788, P<0.01)。6 Gy照射组大鼠肝脏肝小叶中心静脉扩张,肝血窦明显充血,并有炎性细胞浸润,而经QN处理后的照射组大鼠肝脏,肝小叶中心静脉轻度扩张,肝血窦充血较6 Gy照射组明显减轻。结论槲皮素对X射线照射后大鼠免疫功能具有明显增强作用,并显著改善了照射大鼠肝脏的氧化应激损伤,对6 Gy照射大鼠起到了一定程度的保护作用。     

RP-HPLC测定扯根菜中槲皮素的含量

目的测定扯根菜中槲皮素的含量。方法采用RP-HPLC法,Aichrom Bond-AQC18柱(250mm×4.6mm,5μm),以甲醇-0.2%磷酸(56∶44)为流动相,流速1.1ml·min-1,柱温35℃,检测波长370nm。结果槲皮素进样量在0.0461~0.9220μg范围内与峰面积呈很好的线性关系(r=0.9990),平均回收率为97.6%,RSD=1.86%。6批样品中槲皮素含量分别为2.16、2.25、2.21、2.26、2.08、2.05mg·g-1。结论所建方法简便、准确、重复性好,可用于扯根菜中槲皮素的含量测定。