Flavonoids and stilbenoids as a promising arsenal for the management of chronic arsenic toxicity

Rapid industrial and technological development has impacted ecosystem homeostasis strongly. Arsenic is one of the most detrimental environmental toxins and its management with chelating agents remains a matter of concern due to associated adverse effects. Thus, safer and more effective alternative therapy is required to manage arsenic toxicity. Based on existing evidence, native and indigenous plant-based active biomolecules appear as a promising strategy to mitigate arsenic-induced toxicity with an acceptable safety profile. In this regard, various phytochemicals (flavonoids and stilbenoids) are considered important classes of polyphenolic compounds with antioxidant and chelation effects, which may facilitate the removal of arsenic from the body more effectively and safely with regard to conventional approaches. This review presents an overview of conventional chelating agents and the potential role of flavonoids and stilbenoids in ameliorating arsenic toxicity. This report may provide a roadmap for identifying novel prophylactic/therapeutic strategies for managing arsenic toxicity.     

荞麦中芦丁对免疫性肝损伤小鼠肝脏超微结构的影响

目的观察荞麦中芦丁(RBFL)对卡介苗(BCG)和脂多糖(LPS)联合诱导的免疫性肝损伤小鼠肝脏的超微结构的影响。方法于尾静脉注射BCG和LPS,建立小鼠免疫性肝损伤模型。取♂昆明小鼠90只,随机均分为正常组、模型组、RBFL低、中、高剂量组及联苯双酯组。除正常组和模型组ig蒸馏水外,其余各组均ig给予对应药物干预,即40、80、160 mg·kg-1·d-1RBFL及联苯双酯200 mg·kg-1·d-1,gd,连续12 d。剖取肝脏、脾脏、胸腺,计算脏器指数,电镜下观察各组小鼠的肝脏超微结构变化。结果模型组小鼠的肝脏体积增大,肝脏指数较正常组的显著增大(P<0.01),各免疫器官脏器的指数增大,RBFL各剂量有抑制作用。结论 RBFL对BCG和LPS联合诱导的小鼠肝脏超微结构损伤具有保护作用。     

HPLC法同时测定铁包金不同药用部位中芦丁和槲皮素的含量

目的:建立同时测定铁包金不同药用部位芦丁、槲皮素含量的方法。方法:采用高效液相色谱法。色谱柱为迪马ODS C18(250 mm×4.6 mm,5μm),流动相为乙腈-甲醇-0.2%磷酸(梯度洗脱),流速为0.9 ml/min,柱温为30℃,检测波长为360 nm。结果:芦丁和槲皮素的进样量分别在0.01¹.88、0.011.88、0.01⁰.23μg范围内与各自峰面积积分值呈良好线性关系;精密度、稳定性、重复性的RSD<2%;芦丁、槲皮素的平均加样回收率分别为99.48%、102.34%,RSD分别为2.06%、2.37%(n=6)。结论:铁包金叶与藤茎部位中芦丁、槲皮素的含量均较高。该方法简单、稳定,结果准确、可靠,可用于铁包金的质量控制。     

槐米中芦丁的提取方法研究进展

槐米是一种具有广泛生物活性的传统中药,主要含有芦丁等成分。常用的方法有碱提酸沉法,醇提法,超声波辅助法,微波辅助法等。本文对近年来槐米中芦丁的提取工艺进行了综述和研究,为更好地开发和利用槐米提供了借鉴和理论依据。     

芸香苷水解液中糖的纸色谱检测条件优化

槐米中芸香苷的提取、精制及对其水解液中糖的纸色谱鉴别是我校中药制药技术及药品质量检测技术等专业的学生必做的化学实验。但多年来,采用径向纸层析方法,以传统的BAW上层展开系统即正丁醇-醋酸-水（4∶1∶5,上层）进行展开,易出现鼠李糖条带严重扩散等问题,效果不理想。本文对纸色谱展开条件进行了改进,确定乙酸乙酯-吡啶-水（10∶4∶0.5）为最佳展开剂,葡萄糖及鼠李糖条带清晰,显色明显,分离度良好,方法简单,重现性良好,可用此法快速鉴别葡萄糖和鼠李糖。     

抗高原缺氧药雪莲黄酮胶囊的质量控制标准

目的：建立抗高原缺氧药雪莲黄酮胶囊的质量控制标准。方法采用薄层色谱法定性鉴别雪莲的主要有效成分芦丁和绿原酸;采用紫外分光光度法测定制剂中总黄酮的含量,并采用高效液相色谱法测定其中芦丁的含量,色谱柱为Hypersil ODS2 C18柱(150 mm ×4.6 mm,5μm),流动相为甲醇-水(40：60),流速：1 ml/min;柱温为室温,检测波长为340 nm。结果薄层定性鉴别的斑点清晰,分离效果良好;总黄酮含量在9.84~59.04μg/ml浓度范围内具有良好的线性关系(r=0．9997),平均回收率为99.32%,RSD为1.47%(n=6);芦丁含量在4~120μg/ml浓度范围内具有良好的线性关系(r=0．9999),平均加样回收率为97.98%,RSD为1.35%(n=6)。结论本实验简便易行,结果准确可靠,重复性好,可作为该制剂的质量控制方法。     

高效液相色谱法测定吉如心片中芦丁的含量

目的:建立HPLC法测定吉如心片中芦丁含量的方法。方法:色谱柱为HypersilC₁₈柱（250mm×4.6mm,5μm）;以乙腈-0.1%磷酸溶液（15:85）为流动相,流速为1.0ml·min^-1,检测波长257nm,柱温:35℃。结果:芦丁在18.64～93.18ng范围内线性关系良好。平均回收率为99.81%,RSD=0.62%。结论:该方法准确、可靠,可用于吉如心片的质量控制。     

HPLC波长切换法同时测定杜仲双降袋泡剂中7种成分的含量

目的建立高效液相(HPLC)波长切换法同时测定杜仲双降袋泡剂中桃叶珊瑚苷、京尼平苷酸、绿原酸、京尼平苷、松脂醇二葡萄糖苷、芦丁及槲皮素7种成分含量的方法。方法以80%甲醇为溶剂,加热回流提取;色谱柱:Hydrosphere C18(4.6 mm×200 mm,5μm);柱温:30℃;流动相:乙腈-0.1%磷酸溶液,梯度洗脱;检测波长:208 nm(桃叶珊瑚苷)、235 nm(京尼平苷酸、绿原酸、京尼平苷、松脂醇二葡萄糖苷)、270 nm(芦丁、槲皮素);流速:0.9 ml/min。结果桃叶珊瑚苷、京尼平苷酸、绿原酸、京尼平苷、松脂醇二葡萄糖苷、芦丁、槲皮素的质量浓度分别在10.97~274.25μg/ml(r=0.999 7)、9.78~244.50μg/ml(r=0.999 8)、6.86~171.50μg/ml(r=0.999 6)、2.47~61.75μg/ml(r=0.999 7)、8.11~202.75μg/ml(r=0.999 1)、4.59~114.75μg/ml(r=0.999 9)、1.85~46.25μg/ml(r=0.999 5)范围内线性关系良好;平均加样回收率分别为99.85%、98.92%、97.52%、97.08%、98.51%、97.10%、96.91%,RSD分别为0.93%、0.74%、1.26%、1.37%、0.88%、1.05%、1.33%。结论所建立的HPLC波长切换法可以同时测定杜仲双降袋泡剂中桃叶珊瑚苷、京尼平苷酸、绿原酸、京尼平苷、松脂醇二葡萄糖苷、芦丁和槲皮素的含量,方法简便准确、灵敏度高,可用于杜仲双降袋泡剂的质量控制。     

Attachment of rhamnosyl glucoside on quercetin confers potent iron-chelating ability on its antioxidant properties

The pharmacological essence of the natural addition of rhamnosyl glucoside on quercetin that is commonly found in nature in medicinal plants is rather obscure. The present study therefore sought to compare the antioxidant activities of both compounds by comparing their ability to decolourise DPPH radicals, reduce Fe³⁺, chelate Fe²⁺, prevent deoxyribose degradation and inhibit hepatic thiobarbituric acid reactive substances induced by both Fe²⁺ and sodium nitroprusside. The results show that quercetin is generally a more potent antioxidant than its rhamnosyl glucoside derivative (rutin). However, rutin exerted a more potent iron-chelating ability than quercetin which diminishes in a time dependent fashion suggesting why it exhibited a reduced inhibitory effect on lipid peroxidation and deoxyribose degradation under harsh prooxidant assault than quercetin. Taken together, we speculate that rutin may have been produced initially in plants as a possible defense mechanism for protection and survival under oxidative assaults and where both flavonoids are found to co-exist in nature, there is a possible synergy in their antioxidant actions.     

Protective effect of flavonoids against red blood cell hemolysis by free radicals

BACKGROUND:

Flavonoids are polyphenolic substances with antioxidant properties, and they are found in different vegetables and fruits. Epidemiological studies have shown that the consumption of flavonoids reduces the prevalence of cardiovascular diseases. The use of synthetic antioxidants, however, has been limited because of their toxicity. Therefore, medical researchers have intensified their quest to find natural antioxidants.

OBJECTIVES:

To investigate the effect of several pure flavonoids, such as kaempferol, quercetin, morin and rutin, on red blood cell hemolysis and evaluate their -SH capacity as an indicator of membrane protection.

METHODS:

The rate of hemolysis and cell membrane -SH capacity were determined by spectrophotometry. Red blood cell peroxidation was induced using 2,2′-azo-bis-(2-amidinopropane) dihydrochloride. The effect of each flavonoid on hemolysis was examined at three concentrations (0.5 μg/mL, 5 μg/mL and 10 μg/mL), however, only the greatest concentration (10 μg/mL) of each flavonoid was used to study the effect on -SH groups.

RESULTS:

In all cases, the antioxidant activity was dose-dependent. Rutin showed the highest inhibitory effect on hemolysis among flavonoids (42.5%). The protective effect of kaempferol, rutin and morin against -SH group oxidation measured 7.7%, 23.3% and 26.4%, respectively.

CONCLUSIONS:

Results showed that flavonoids and flavonoid-containing plants can be used as natural antioxidants for the treatment and prevention of disease conditions, the pathogenesis of which is mediated by lipid peroxidation.