Investigation on the spectrum-effect relationships of EtOAc extract from Radix Isatidis based on HPLC fingerprints and microcalorimetry

This work investigated the spectrum-effect relationships between HPLC fingerprints and the anti-bacterial activities of EtOAc extracts from Radix Isatidis. Fingerprints of EtOAc extracts of Radix Isatidis from various sources were established by a High-Performance Liquid Chromatography. The process of Escherichia coli (E. coli) growth affected by EtOAc extracts was monitored using a Thermal Activity Monitor (TAM) Air Isothermal Calorimeter by microcalorimetry. By analyzing the power-time curves, quantitative parameters, such as growth rate constant k, maximum heat-production rate P(m), appearance time t and total heat-production Q were obtained to characterize the interactions of E. coli and the EtOAc extracts from Radix Isatidis. The HPLC fingerprints were investigated using hierarchical clustering analysis. The main thermo-kinetic parameters from the power-time curves were analyzed using principal component analysis. The spectrum-effect relationships between the HPLC fingerprints and anti-bacterial activities were analyzed with multivariant correlation analysis. Close correlation existed between the spectrum-effect relationships of the EtOAc extracts. Salicylic acid in the HPLC fingerprints might be one of the anti-bacterial components. This work provides a general model of the combination of HPLC and microcalorimetry to study the spectrum-effect relationships of EtOAc extracts from Radix Isatidis, which can be used to search for principal components of Radix Isatidis on bioactivity.     

Hypoglycemic effect of Belamcanda chinensis leaf extract in normal and STZ-induced diabetic rats and its potential active faction

Belamcanda chinensis (Iridaceae) belongs to the family of iridaceae and its rhizoma has been widely used for the treatment of throat ailment. Here we report a new pharmacological activity of B. chinensis leaf extract (BCL), that is, the hypoglycemic effect in normal and STZ-induced diabetic rats. Animals either healthy or STZ-induced diabetic show significantly lowered fasting blood glucose levels after treatment with BCL. The serum insulin concentration in normal rats is also enhanced. Additionally, the increase in blood glucose levels after administration of various carbohydrates in normal rats is significantly decreased and the oral glucose tolerance (OGTT) of STZ-induced diabetic rats is largely improved by BCL treatment. However, co-administration of BCL with Nifedipine, a Ca²⁺ ion channel blocker, or Nicorandil, an ATP-sensitive K⁺ ion channel opener thoroughly abolishes the hypoglycemic effect of BCL. HPLC analysis and compound identification showed that several isoflavone glycosides with antidiabetic activities were contained in BCL while pharmacological experiment showed that the polysaccharide fraction of BCL had no significant hypoglycemic effect on normal rats. Therefore, the isoflavone glycosides but not polysaccharides might be the active fraction of BCL in diabetes treatment.     

The hypoglycemic effect of Phyllanthus sellowianus fractions in streptozotocin-induced diabetic mice.

Phyllanthus sellowianus Müller Arg. (Euphorbiaceae) is a plant used in folk medicine as a hypoglycemic and diuretic agent. The present study describes the hypoglycemic effect of fractions obtained from the stem barks of P. sellowianus using a bioassay-guided fractionation protocol and streptozotocin-induced hyperglycemic mice. The aqueous extract was partitioned between dichloromethane and butanol to yield the dichloromethane (D), butanol (B) and the remaining aqueous (A) fractions. Fractions B and A, administered at the dose of 200 mg/kg p.o., caused a significant reduction in blood glucose concentration at 6 and 9 h, while the same dose of fraction D was ineffective. The reduction in blood glucose levels obtained with the B and A fractions was similar to that observed with glibenclamide (10 mg/kg) which was used as a reference for the hypoglycemic activity. Phytochemical analysis of fractions B and A revealed the presence of flavonoid compounds, of which rutin and isoquercitrin were the major constituents, respectively. The possible involvement of these flavonoids in the hypoglycemic effect of the active fractions is discussed.     

固液态发酵条件对桑叶发酵提取物中降糖活性物质的影响

目的:探讨不同发酵条件对桑叶总黄酮、总多酚含量及体外降糖活性的影响。方法:本研究主要利用比色法考察固态、液态两种发酵条件对桑叶发酵物中总黄酮、总多酚含量的影响,同时建立α-葡萄糖苷酶和α-淀粉酶为体外降糖活性筛选模型,以期筛选最佳发酵条件。结果:液体发酵7 d桑叶70%乙醇提取物对α-葡萄糖苷酶抑制率最高(92.79%);未发酵水提取物对α-淀粉酶抑制率最高(63.68%),其次为液体发酵7 d桑叶70%乙醇提取物(54.81%)。且在生药浓度为10 mg·m L-1时,都高于阳性对照阿卡波糖。结论:利用冠突散囊菌发酵,可以改变桑叶提取物的体外降糖活性,为开发糖尿病药物提供可行思路。     

Identification and determination of major flavonoids in rat serum by HPLC-UV and HPLC-MS methods following oral administration of Dalbergiaodorifera extract

The major flavonoids in rat serum after oral administration of Dalbergia odorifera extract were analyzed qualitatively and quantitatively by high performance liquid chromatography (HPLC) and its coupling to mass spectrometry (HPLC-MS). Utilizing HPLC-MS technique, 18 flavonoids including five isoflavones, four isoflavanones, four neoflavones, two flavanones, two chalcones, one isoflavanonol were identified in free form in serum sample based on comparison with the authentic standards. Furthermore, the amounts of the four prominent flavonoids, (3R)-4'-methoxy-2',3,7-trihydroxyisoflavanone, vestitone, formononetin and sativanone were determined in serum by HPLC-UV with internal standard method. The method was validated and utilized in pharmacokinetic studies of these four analytes. This is the first report on identification and determination of the major flavonoids in rat serum after oral administration of D. odorifera extract and the results provided a firm basis for clarifying the pharmacological effect of D. odorifera and evaluating the clinical applications of this medicinal herb.     

Effects of Ballota nigra on glucose and insulin in alloxan-diabetic albino rats

The hypoglycemic effect of Ballota nigra extract on albino rats was investigated. Alloxan-induced diabetes mellitus was accompanied by several fold increases in plasma glucose. Administration of aqueous extract of B. nigra extract significantly reduced glucose in both healthy and diabetic rats. These results suggest that B. nigra possess hypoglycemic effects in rats and therefore, can be useful for the treatment of diabetes mellitus.     

超声提取枸杞叶总黄酮的工艺研究

目的：优选超声辅助提取枸杞叶总黄酮的提取工艺并探讨枸杞叶的合理采收时期。方法：分别研究乙醇浓度、乙醇用量、超声提取时间、超声时温度四个单因素对提取效果的影响,设计正交试验,所得结果采用方差分析。利用优选出的最佳超声提取工艺测定比较不同采收时期枸杞叶中的总黄酮含量。结果：确定了最佳单因素水平,通过正交试验法优选出超声辅助提取枸杞叶总黄酮的最佳工艺条件为乙醇浓度75％、乙醇用量1：40、超声提取时间30min、超声时温度50℃。结论：通过比较不同采收时期枸杞叶总黄酮的含量,发现总黄酮的含量随枸杞叶生长而下降,结合枸杞果园生产探讨得出枸杞叶合理采摘时期为4月上旬和11月中旬。     

油菜蜂花粉抗氧化活性研究

采用回流提取、大孔吸附树脂分离,得到8个油菜蜂花粉提取部位;利用H2O2诱导PC12细胞氧化损伤模型,评价各提取部位对PC12细胞氧化损伤的保护作用。在此基础上,采用HPLC法初步分析最佳抗氧化部位活性物质基础。结果表明,8个油菜蜂花粉提取部位中,部位B处理组细胞存活率最高,为90.0%,显著高于模型组53.6%(P<0.001),且高于VE阳性对照组85.0%(P<0.05)。通过对乙酸乙酯各提取部位进行HPLC分析,并用对照品标定色谱图中色谱峰,表明部位B含有3种主要黄酮:山奈酚-3,4’-双-O-β-D-葡萄糖苷(KMG)、山奈酚-3-O-β-D-(2-O-β-D-葡萄糖基)吡喃葡萄糖苷(KMP)和山奈酚-3-O-β-D-葡萄糖苷(KMC)。     

Anti-ultraviolet radiation effects of Coptis chinensis and Phellodendron amurense glycans by immunomodulating and inhibiting oxidative injury

HPLC analysis proved that Coptis chinensis glycan contained Ara, Man, and Gal. The monosaccharide constituents of Phellodendron amurense glycan were determined by HPLC analysis. HPLC analysis proved that P. amurense glycan contained Ara, Xyl, Glu, and Gal. FT-IR spectrum of C. chinensis glycan and P. amurense glycan showed the characteristic absorption peaks of carbohydrate polymers. Exposure of the human skin to ultraviolet radiation (UVR) leads to depletion of cutaneous antioxidants, regulation of gene expression and ultimately to the development of skin diseases. In the present study, free radical scavenging activity of C. chinensis and P. amurense glycan were evaluated. The photoprotective effect of C. chinensis and P. amurense glycan against UV-induced oxidative damage was also investigated in skin. At the concentration range employed, the two glycans showed strong free radical scavenging activity. Ultraviolet radiation reduced skin antioxidant enzyme and immunity activities in animals. Administration of C. chinensis and P. amurense glycans dose-dependently significantly increased skin antioxidant enzyme and immunity activities in animals. In conclusion, C. chinensis and P. amurense glycans present photoprotective properties, which can be attributed to molecules, such as flavonoids and carotenoids, which act as UV-absorbing molecules and as antioxidants, as well as stimulate immunity activities in animals.     

High-performance liquid chromatography-based multivariate analysis to predict the estrogenic activity of an Epimedium koreanum extract

This study characterizes the correlation between the chemical fingerprint and estrogenic activity of an Epimedium koreanum extract. The estrogenic activity of 31 E. koreanum extract samples was evaluated by a luciferase reporter gene assay, and the samples were classified into 3 groups based on their bioactivity. A chemical fingerprint analysis was performed on each sample by high-performance liquid chromatography (HPLC), and 44 common peaks were selected from the chromatogram and used as a dataset for a pattern recognition analysis. A canonical discriminant analysis performed on this dataset determined a distinct distribution of the samples according to their estrogenic activity on the scoring plot. The classification results showed that 90.3% of the original grouped cases had been correctly classified. The total content of the 4 major extract compounds, epimedin A, epimedin B, epimedin C, and icariin, exhibited good correlation (r=0.784) with the estrogenic activities of the respective extracts. This chromatographic fingerprint-chemometric analysis system could be useful for predicting the E. koreanum pharmacological activity and consequent biological activity-relevant quality control assessment.     

红花降糖活性成分谱效关系研究

红花为菊科植物红花(Carthamus tinctorius L.)的干燥花,具有活血通经,散瘀止痛等功能。为研究其降糖活性成分及谱效关系,本文确定了红花降糖活性部位;建立了HPLC指纹图谱,通过对照品指认其中7个主要成分后,用灰色关联度法和正交偏最小二乘法分析,揭示了这7个共有峰协同发挥蛋白酪氨酸磷酸酯酶1B抑制作用,其中羟基红花黄色素A(HSYA,6号峰)和6-羟基山柰酚-3,6-二-O-葡萄糖基-7-O-葡萄糖苷(3号峰)是贡献最大的成分。含量测定显示10批红花中羟基红花黄色素A及山柰素的含量均在1.67%~1.94%和0.09%~0.12%之间,该研究为红花在糖尿病药物开发领域的应用提供了依据。     

Chemical standardization of the aqueous extract of Cecropia glaziovii Sneth endowed with antihypertensive, bronchodilator, antiacid secretion and antidepressant-like activities

This study reports the extraction process and standardization of the aqueous extract (AE) of a Cecropia species aiming its pharmacological characterization as a phytomedicine to be used in primary health care. The plant was originally collected in its environment, and was thereafter specially cultivated for the present work. To standardize the plant AE, several 2.0% tea of the dried leaves were prepared under controlled conditions and freeze dried. The AE (20% yield) was partitioned with n-butanol yielding the butanolic fraction (BuF; 1% yield). The activity of AE on vital organ functions (cardiovascular, respiratory, gastrointestinal and central nervous system) was determined in vivo. The effects of AE were compared to those of BuF in the same models and the relative potency determined. BuF was further evaluated in representative in vitro models to assess possible mechanisms of action. Chemical constituents of BuF were isolated in preparative HPLC columns yielding 10 highly purified compounds chemically identified as catechins (2), procyanidins (4), flavonoids (2), mixed sugars (1) and chlorogenic acid. All the compounds were identified by chemical analytic instrumentation (13C-NMR, 1H-NMR, LC-MS). Their relative concentrations in AE were ca 12% catechins, 19% procyanidins and 19% flavonoids. The pharmacological activity of the standardized AE is reported in accompanying papers.     

Chemical composition and vasodilatation induced by Cuphea carthagenensis preparations

The aerial parts of Cuphea carthagenensis (Jacq.) J.F. Macbride (Lythraceae) are traditionally employed in Brazil to treat cardiovascular diseases. The aim of this study was to compare preparations of C. carthagenensis aerial parts (aqueous and ethanol extracts, together with derived fractions) with regard to their total phenolic contents and in vitro vasodilating activity. The main flavonoids found in the extracts were isolated and identified as quercetin derivatives. The extracts and fractions showed similar HPLC profiles with the presence of quercetin-5-O-β-glucopyranoside, quercetin-3-O-α-arabinofuranoside and quercetin-3-sulfate in all of them, but marked differences in the contents of flavonoids, proanthocyanidins, tannis and total phenolics. Excepting the aqueous extract, all assayed preparations elicited vasodilatation on pre-contracted rat aortic rings in the range of pIC(50) 4.53±0.03 to 4.98±0.06. Polynomial regression analysis demonstrated the relationship between vasodilating activity and the contents of flavonoids (r(2)=0.5190), proanthocyanidins (r(2)=0.8016), tannins (r(2)=0.8041) and total phenolics (r(2)=0.6226), suggesting the participation of these compounds in the pharmacological effect and their potential use as chemical markers for the species.     

Effect of Costus spiralis (Jacq.) Roscoe Leaves,Methanolic Extract and Guaijaverin on Blood Glucose and Lipid Levels in a Type II Diabetic Rat Model

This study aimed to isolate and identify flavonoids with hypoglycemic activity in Costus spiralis leaves. The methanolic extract (ME) was rich in flavonoids, while the powdered leaves (PL) contained considerable amounts of macro‐ and microelements. Oral acute treatment of streptozotocin (STZ)‐induced diabetic rats for 18 h with the C. spiralis PL, ME and isolated guaijaverin (GUA) lowered glycemia, improved oral glucose tolerance and inhibited liver lipid peroxidation. GUA and ME lowered plasma levels of low‐density and non‐high density lipoproteins; GUA also lowered total cholesterol levels. PL, ME and GUA did not significantly alter the plasma levels of triglycerides, high‐density lipoproteins, very low‐density lipoproteins, creatinine and aspartate transaminase, and the total protein levels in the kidney and liver tissues. Therefore, C. spiralis leaves are promising raw materials and rich sources of bioactive flavonoids for the development of novel antidiabetic drugs due to their hypoglycemic, antidyslipidemic and antioxidant actions.     

香露兜叶的抗氧化活性(英文)

本文评价了香露兜叶的乙醇提取物以及石油醚、乙酸乙酯、正丁醇和水相组分的抗氧化活性。在体外测定了提取物和组分的总抗氧化活性,二苯代苦味肼基(DPPH)自由基清除活性,超氧阴离子自由基清除活性和铁离子还原能力,并利用分光光度法测定了其总酚和总黄酮的含量。结果表明,所有的提取物和组分均表现出抗氧化和自由基清除活性。抗氧化活性的大小如下:正丁醇部分>乙酸乙酯部分>乙醇提取物>水部分>石油醚部分。总酚含量的顺序和其相似,说明提取物和组分中的酚类化合物使其具有抗氧化活性。香露兜叶提取物可能会成为有价值的天然抗氧化资源,并将在保健品和食品中得到应用。     

Antimicrobial activity and mechanism of action of Nu-3, a protonated modified nucleotide

For centuries, plants have been used in traditional medicines and there has been recent interest in the chemopreventive properties of compounds derived from plants. In the present study, we investigated the antibutyrylcholinestrasic (anti-BuChE) and antioxidant (against some free radicals) activities of extracts from Rhus pentaphyllum. Aqueous extracts were prepared from powdered R. pentaphyllum roots, leaves and seeds and characterized for the presence of tannins, flavonoids and coumarins. Seeds aqueous extract contained the highest quantities of both flavonoids and tannins (21.12% and 17.45% respectively). In the same way, seeds extracts displayed remarkable inhibition against BuChE over 95%, at 100 μg/ml and with IC₅₀ 0.74 μg/ml. In addition, compared to leaves and roots extracts, seeds aqueous extract revealed relatively strong antiradical activity towards the ABTS ^.+ (IC₅₀ = 0.25 μg/ml) and DPPH (IC₅₀ = 2.71 μg/ml) free radicals and decreased significantly the reactive oxygen species such O₂ ^.- (IC₅₀ = 2.9 μg/ml) formation evaluated by the non-enzymatic generating O₂ ^.- system (Nitroblue tetrazolium/riboflavine). These data suggest that the anti-BuChE activities mechanism of these extracts occurs through a free radical scavenging capacities. The present study indicates that extracts of Rhus pentaphyllum leaves, seeds and roots are a significant source of compounds, such as tannins, flavonoids and coumarins, with anti-BuChE and antioxidant activities, and thus may be useful for chemoprevention.     

The antioxidant activity of aqueous spinach extract: chemical identification of active fractions

In previous studies we have elucidated the presence of powerful, natural antioxidants (NAO) in water extracts of spinach leaves and demonstrated their biological activity in both in vitro and in vivo systems. In the present study, the chemical identity of several of these antioxidant components is presented. Spinach leaves were extracted with water and the 20,000 g supernatant which contained the antioxidant activity was extracted with a water:acetone (1:9) solution. The 20,000 g supernatant obtained was further purified on reverse phase HPLC using C-8 semi-preparative column. Elution with 0.1% TFA resulted in five hydrophilic peaks. Elution with acetonitrile in TFA resulted in seven additional hydrophobic peaks. All the peaks were detected at 250 nm. All the fractions obtained showed antioxidant activity when tested using three different assays. Based on 1H and 13C NMR spectroscopy four of the hydrophobic fractions were identified as glucuronic acid derivatives of flavonoids and three additional fractions as trans and cis isomers of p-coumaric acid and others as meso-tartarate derivatives of p-coumaric acid. The present study demonstrates for the first time the presence of both flavonoids and p-coumaric acid derivatives as antioxidant components of the aqueous extract of spinach leaves.     

Oxygen radical absorbance capacity of the phenolic compounds in plant extracts fractionated by high-performance liquid chromatography

The oxygen radical absorbance capacity (ORAC) assay has been used to quantify the antioxidative properties of phytonutrients in fruit and vegetable extracts. Using aqueous methanol extracts of tea and spinach as a model systems, separation of the components in the extracts by HPLC followed by semiautomatic ORAC analysis of the column fractions permitted the determination of peroxyl-radical-scavenging profiles, demonstrating the relative abilities of the individual extract components to scavenge peroxyl radicals. ORAC values for up to 80 HPLC fractions were measured, confirming the major contribution of epigallocatechin gallate in the peroxyl radical scavenging of green tea extracts. Although the flavonoids in spinach extracts provided resistance to peroxyl radicals, components that did not bind to the HPLC column and simple phenolic compounds may also be important contributors to the total ORAC activity of spinach leaf extracts. Application of these procedures to plants believed to provide certain human health benefits by reducing free radicals may allow the identification and characterization of the specific components responsible for the free-radical-scavenging activities.     

High-performance liquid chromatographic profile and 1H quantitative nuclear magnetic resonance analyses for quality control of a Xinjiang licorice extract

ABSTRACT

Various pharmacological properties of Xinjiang licorice flavonoids have been reported recently. We have investigated constituents corresponding to distinct peaks on the high-performance liquid chromatography (HPLC) profile of a flavonoid-rich extract from licorice, and identified 13 flavonoids, including licochalcone A (1), licochalcone B (3), glabrone (4), and echinatin (5), by isolating them and then performing high-resolution electrospray ionization mass spectrometry and ¹H nuclear magnetic resonance (NMR) spectral analyses. We then applied the ¹H quantitative NMR (qNMR) method for analysis of major flavonoids, 1 and 3–5 in the extract. The ¹H qNMR results were supported by ¹³C NMR analysis. The results demonstrated the utility of the combination of HPLC profiling and qNMR analyses for quality control of Xinjiang licorice. Additionally, we observed a moderate inhibitory effect of the most abundant constituent, licochalcone A (1), on acetylcholine esterase activity, suggesting utility as a seed for drug development.     

Inhibition of endogenous glucose production accounts for hypoglycemic effect of Spergularia purpurea in streptozotocin mice.

The purpose of this study was to determine the underlying mechanism of the hypoglycemic activity of the aqueous extract perfusion of Spergularia purpurea (SP) in diabetic mice and streptozotocin-induced diabetic rats. The aqueous extract was administered intravenously and the blood glucose levels were determined within 4 hours after starting the treatment. Plasma insulin concentrations and endogenous glucose production were also determined. The aqueous extract at a dose of 10 mg/kg produced a significant decrease in blood glucose levels in normal rats (P < 0.05), and even more in diabetic rats (P < 0.001). This hypoglycemic effect might be due to an extra-pancreatic action of the aqueous extract of SP, since the basal plasma insulin concentrations were unchanged after SP treatment. In diabetic mice, a similar effect was observed and the results showed that aqueous extract of SP caused a potent inhibitor effect on basal endogenous glucose production (p < 0.001). We conclude that aqueous extract perfusion of SP inhibits endogenous glucose production in mice. This inhibition is at least one mechanism explaining the observed hypoglycemic activity of this plant in diabetic animals.