Oligomeric proanthocyanidins from Rumex acetosa L. inhibit the attachment of herpes simplex virus type-1

The polyphenole-enriched acetone-water extract R2 from the aerial parts of Rumex acetosa L. containing high amounts of oligomeric and polymeric proanthocyanidins and flavonoids was tested for antiviral activity. R2 exhibited strong antiviral activity against herpes simplex virus type-1 (HSV-1) while the replication of adenovirus 3 was not affected. By plaque reduction test and MTT assay on Vero cells, the HSV-1-specific inhibitory concentration (IC(50)) and cytotoxic concentration (CC(50)) were determined. R2 exibited an IC(50) of 0.8 μg/mL and a selectivity index (SI) (ratio of IC(50) to CC(50)) of approximately 100 when added to the virus inoculum for 1h at 37°C prior to infection. The antiviral activity was due to the presence of flavan-3-ols and oligomeric proanthocyanidins in the extract. Structure-activity analyses indicated that flavan-3-ols and proanthocyanidins with galloylation at position O-3 are highly potent compounds (SI>40), while ungalloylated compounds did not exhibit antiviral effects (SI<1). R2 and a major proanthocyanidin from R2, epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate abolished virus entry into the host cell by blocking attachment to the cell surface. When added after attachment at a concentration of ≥ 12.5 μg/mL, R2 inhibited also penetration of HSV-1 into the host cell. R2 and epicatechin-3-O-gallate-(4β→8)-epicatechin-3-O-gallate were shown to directly interact with viral particles leading to the oligomerisation of envelope proteins as demonstrated for the essential viral glycoprotein gD. Using raft cultures with three-dimensional organotypic human skin equivalents it was shown that treatment of cultures with R2 after infection with HSV-1 resulted in a reduced viral spread.     

Phenolic compounds on the leaves ofBetula platyphylla var.latifolia

Chemical examination ofBetula platyphylla var. latifolia afforded a novel diarylheptanoid named betulatetraol, together with a phenylpropanoid (3,4′-dihydroxypropiophenone), flavan-3-ol [(+)-catechin] and its glycosides [(+)-catechin 5-O-β-D-glucopyranoside, (+)-catechin 7-O-β-D-glucopyranoside] and two proanthocyanidins (procyanidins B-1 and B-3).     

Resveratrol/phloroglucinol glycosides from the roots of Lysidice rhodostegia

Two new phloroglucinol glycosides, lysidisides C (1) and D (2), together with two new resveratrol glycosides, lysidisides E (3) and F (4), were isolated from the n-BuOH extract of the roots of Lysidice rhodostegia. The structures were elucidated on the basis of spectroscopic and chemical evidence. The antioxidant activity of the isolates was also investigated     

Phytochemical Screening,Proximate Analysis and Antioxidant Activity of Dracaena reflexa Lam. Leaves

In the present study, the antioxidant activity of successive leaf extracts of Dracaena reflexa was investigated using the scavenging activity on 1,1-diphenyl-2-picrylhydrazyl and reducing power by ferric reducing antioxidant power assay. Methanol extract was found potent in both the assays. IC50 values of 1,1-diphenyl-2-picrylhydrazyl assay for methanol extract was 0.97 mg/ml and ferric reducing antioxidant power value for the same is 1.19. Phytochemical screening, proximate analysis and total phenolic content were also determined. Qualitative screening for phytochemical showed the presence of alkaloids, flavonoids, terpenoids, glycosides and saponins. Highest phenolic content was shown by methanol extract (49.69 mg gallic acid equivalent/g dry weight). Proximate analysis showed moisture content (3.31%), ash content (8.02%), crude fibre (1.31%), crude fat (0.97%), total protein (3.70%), total carbohydrate (86.01) and nutritive value (367.56 kcal/100 g), which would make it a potential nutraceutical. This study suggested that Dracaena reflexa, a potential natural free radical scavenger, which could find use as an antioxidative.     

Isolation of two new bioactive proanthocyanidins from Cistus salvifolius herb extract

Two new proanthocyanidins, epigallocatechin-3-O-p-hydroxybenzoate-(4beta-->8)-epigallocatechin (1) and epigallocatechin-3-O-p-hydroxybenzoate-(4beta-->8)-epigallocatechin-3-O-gallate (2) in addition to the known compound epigallocatechin-(4beta-->6)-epigallocatechin-3-O-gallate (3), were isolated from the air-dried herb of Cistus salvifolius. The chemical structures were determined on the basis of 1D-and 2D-NMR-spectra (HSQC, HMBC) of their peracetylated derivatives, MALDI-TOF-mass spectra, and by acid-catalysed degradation with phloroglucinol. The isolated compounds 1-3 and the water extract of C. salvifolius herb were tested for their inhibitory activities against COX-1 and COX-2. Compound 2 showed the strongest inhibitory effect on COX-2 followed by compound 3, compound 1 and the water extract, while compounds 1-3 exhibited moderate in vitro inhibition against COX-1.     

In vitro inhibition of [3H]-angiotensin II binding on the human AT1 receptor by proanthocyanidins from Guazuma ulmifolia bark

A bioassay-guided fractionation of the 70% acetone extract of the bark of Guazuma ulmifolia Lam. on the inhibition of angiotensin II binding to the AT 1 receptor led to the isolation and identification of bioactive oligomeric and polymeric proanthocyanidins consisting mainly of (-)-epicatechin units. The displacement of [3H]-angiotensin II binding was dose-dependent and correlated with the degree of polymerization of the different fractions containing proanthocyanidins. A strong displacement was seen for the residual fraction suggesting that the most active substances corresponding to the highly polymerized proanthocyanidins. Angiotensin II AT 1 receptor binding might be considered as a potentially interesting biological activity of proanthocyanidins contributing to the very broad spectrum of biological activities of the condensed tannins.     

Pharmacokinetics and disposition of monoterpene glycosides derived from Paeonia lactiflora roots (Chishao) after intravenous dosing of antiseptic XueBiJing injection in human subjects and rats

Aim:

Monoterpene glycosides derived from Paeonia lactiflora roots (Chishao) are believed to be pharmacologically important for the antiseptic herbal injection XueBiJing. This study was designed to characterize the pharmacokinetics and disposition of monoterpene glycosides.

Methods:

Systemic exposure to Chishao monoterpene glycosides was assessed in human subjects receiving an intravenous infusion and multiple infusions of XueBiJing injection, followed by assessment of the pharmacokinetics of the major circulating compounds. Supportive rat studies were also performed. Membrane permeability and plasma-protein binding were assessed in vitro.

Results:

A total of 18 monoterpene glycosides were detected in XueBiJing injection (content levels, 0.001–2.47 mmol/L), and paeoniflorin accounted for 85.5% of the total dose of monoterpene glycosides detected. In human subjects, unchanged paeoniflorin exhibited considerable levels of systemic exposure with elimination half-lives of 1.2–1.3 h; no significant metabolite was detected. Oxypaeoniflorin and albiflorin exhibited low exposure levels, and the remaining minor monoterpene glycosides were negligible or undetected. Glomerular-filtration-based renal excretion was the major elimination pathway of paeoniflorin, which was poorly bound to plasma protein. In rats, the systemic exposure level of paeoniflorin increased proportionally as the dose was increased. Rat lung, heart, and liver exposure levels of paeoniflorin were lower than the plasma level, with the exception of the kidney level, which was 4.3-fold greater than the plasma level; brain penetration was limited by the poor membrane permeability.

Conclusion:

Due to its significant systemic exposure and appropriate pharmacokinetic profile, as well as previously reported antiseptic properties, paeoniflorin is a promising XueBiJing constituent of therapeutic importance.     

Separations of flavan-3-ols and dimeric proanthocyanidins by capillary electrophoresis

Micellar electrokinetic capillary chromatography (MECC), using a phosphate buffer pH 7.0 and sodium dodecyl sulfate as the surfactant, was found suitable for the separation of structurally similar flavan-3-ols and related dimeric proanthocyanidins. A total of 20 substances has been tested, 17 of which were successfully separated simultaneously in less than 7 minutes. Retention of the investigated compounds by the SDS micelles is affected by (i) the stereochemistry of the heterocycle of the flavan-3-ol skeleton, (ii) the molecular size, the number and position of free phenolic hydroxy groups, and (iii) the type of acyl residues attached at the C-3 hydroxy function. The method was successfully applied to the phytochemical analysis of tannin enriched extracts of Cistus incanus L. ssp. incanus and C. salvifolius L. (Cistaceae), two traditionally used medicinal plants.     

Characterization of Constituents and Anthelmintic Properties of Hagenia abyssinica

The dried female flowers of Hagenia abyssinica (Bruce) J. F. Gmel. (Rosaceae) are traditionally used as an anthelmintic remedy in Ethiopia and formerly were incorporated into the European Pharmacopoeia. One-, two- and tricyclic phloroglucinol derivatives (kosins) were suggested to be the active principles. However, polar constituents may also contribute to the activity. Therefore, we investigated for the first time the polar constituents. We isolated typical Rosaceae constituents such as quercetin 3-O-β-glucuronide, quercetin 3-O-β-glucoside and rutin. Polar kosin glycosides or derivatives could not be detected.The anthelmintic activity of fractions of different polarity were tested against the blood fluke Schistosoma mansoni, the liver flukes Clonorchis sinensis and Fasciola hepatica and the intestinal fluke Echinostoma caproni. The anthelmintic activity decreased with increasing polarity of the tested fractions. ESI-MS investigations indicated the predominant occurrence of kosins in the active fractions.Using the anthelmintic active extracts of Hagenia abyssinica we developed a simple, inexpensive bioassay against the non-parasitic nematode Caenorhabditis elegans, which can be used as an initial screening procedure for anthelmintic properties of crude extracts of plants or fungi. The anthelmintic activity of test extracts against the model organism was determined in a microtiter plate assay by enumeration of living and dead nematodes under a microscope.     

葡萄籽原花青素降血脂药效部位筛选

目的：研究不同组分葡萄籽原花青素降血脂药效。方法：采用不同浓度乙醇渗漉提取、大孔树脂分离纯化,制得10%、30%、50%、70%乙醇部位葡萄籽原花青素提取物,建立大鼠高血脂模型,分别测定各组血清甘油三酯（TG）、总胆固醇（TC）、谷丙转氨酶（ALT）、谷草转氨酶（AST）的含量,以及Lee’S指数和脏器指数,对各提取物进行药效学研究,确定葡萄籽原花青素降血脂有效部位。结果：葡萄籽原花青素提取物10%、30%、50%乙醇部位具有明显降低高血脂大鼠模型的TG的含量（P<0.01）;同时50%乙醇部位还可以明显降低高血脂大鼠模型的ALT和AST含量（P<0.01）;10%、30%、50%、70%乙醇部位能抑制Lee’S指数的升高（P<0.01或P<0.05）;10%乙醇组显著升高肾脏指数;10%、30%、50%、70%乙醇组能显著升高脾脏指数（P<0.01）;10%、50%、70%乙醇组能显著降低总脂指数（P<0.01）。结论：50%乙醇部位葡萄籽原花青素提取物为葡萄籽降血脂有效部位。     

In vitro and in vivo antioxidant activities of the aqueous extract of Celosia argentea leaves

Objective:

The aqueous extract of Celosia argentea var. cristata L. leaves at 100, 200, and 400 mg/kg body weight (b.w.) was investigated against cadmium (Cd)-induced oxidative stress in Wistar rats. The in vitro antioxidant of the extract was evaluated using ammonium thiocyanate, reducing power, and membrane stabilizing models.

Materials and Methods:

For the in vivo study, 30 male rats (Rattus norvegicus) weighing 138.02 ± 7.02 g were completely randomized into 6 groups (A–F) of 5 animals each. Animals in groups A and B received 0.5 ml of distilled water and the same volume containing 8 mg/kg b.w. of Cd, respectively, for 7 days orally. Animals in groups C, D, E, and F were treated like those in group B except that they received 100 mg/kg b.w. of ascorbic acid, and 100, 200, and 400 mg/kg b.w. of the extract, respectively, in addition to Cd.

Results:

Phytochemical screening revealed the presence of alkaloids (0.61%), saponins (2.93%), cardiac glycosides (0.21%), cardenolides (0.20%), phenolics (3.26%), and flavonoids (2.38%). A total of 10 mg/ml of the extract inhibited linoleic acid oxidation by 67.57%. The highest reducing power was 100 mg/ml as against 10 mg/ml for ascorbic acid. In addition, 2 mg/ml of the extract produced a membrane stabilizing activity of 63.49% as against 77.46% for indomethacin. Compared with the distilled water control group, the administration of Cd alone significantly (P < 0.05) decreased the alkaline phosphatase activity of the rat liver and brain. This decrease was accompanied by a corresponding increase in the serum enzyme. The simultaneous administration of the extract and Cd produced an enzyme activity that compared favorably (P > 0.05) with the animals that received Cd and ascorbic acid. In addition, the reduction in the superoxide dismutase and catalase activity of the liver and brain of the animals, serum uric acid, albumin and bilirubin, and also the increase in the serum malondialdehyde content in animals treated with Cd alone was attenuated by the extract; the values compared well (P > 0.05) with those simultaneously administered with Cd and ascorbic acid.

Conclusion:

Overall, the results indicated that the aqueous extract of C. argentea leaves attenuated Cd-induced oxidative stress in the animals, with the best result at 400 mg/kg b.w. The antioxidant activity of the extract may be attributed to the phenolic and flavonoid components of the extract. The induction of antioxidant enzymes and scavenging of free radicals may account for the mechanism of action of the extract as an antioxidant.     

独一味总环烯醚萜苷分离纯化工艺的优化

目的 优化独一味总环烯醚萜苷的制备工艺,获取纯度相对较高的总环烯醚萜苷。方法 以甲醇-水为流动相,梯度洗脱方式建立分离分析独一味总环烯醚萜苷的高效液相色谱方法,实现各组分的最佳分离,统计、记录其三维吸收图谱,并结合紫外全波长扫描,对前期制备的独一味总环烯醚萜苷中影响纯度的杂质特征进行分析,根据杂质特性优化大孔树脂结合聚酰胺柱制备过程,紫外实时监测,剔除杂质,产品溶液经冷冻干燥获得冻干粉,并以HPLC对比前后制备工艺产品成分差异。结果 工艺优化前产品中环烯醚萜苷含量为69.06%,优化后含量为90.60%,含量提升21.54%;本次制备总产率为16.70%（以水提取物的质量为参照）,总环烯醚萜苷转移率为74.72%（相对于水提取物中总环烯醚萜苷的质量）。结论 优化过程简单,操作步骤可控,易于实现,纯化效果显著。     

Qualitative Determination of Proanthocyanidin Cleavage Products After Acid-Catalyzed Degradation in the Presence of Excess Phloroglucinol by Cyclodextrin-Modified Micellar Electrokinetic Chromatography

Abstract

A micellar electrokinetic chromatographic (MEKC) method has been established for the identification and determination of acid-catalyzed proanthocyanidin cleavage products in the presence of phloroglucinol. Using fused-silica capillaries (50/57 cm, 22 kV) with phosphate buffer containing sodium dodecyl sulfate as the surfactant and β-cyclodextrin as modifier, structurally similar phloroglucinol adducts and flavan-3-ols were fully separated.     

Vasodilator constituents from the roots of Lysidice rhodostega

Two new phloroglucinol glycosides, lysidisides A and B, and two new flavanol ramifycations, lysidicichin and mopanolside, together with (+)-mopanol, polydatin and E-resveratrol 3-O-beta-D-xylopyranoside were isolated from the EtOAc extract of the roots of Lysidice rhodostega. The structures of the new compounds were elucidated on the basis of chemical and spectral evidence. Lysidisides A and B, (+)-mopanol and polydatin inhibited phenylepherine (Phe)-induced vasoconstriction in the rat aortic rings in the presences of indomethacin (Indo) and Nomega-L-nitroarginine (L-NA).     

莲房原花青素提取纯化工艺研究与抗氧化活性评价

目的 优化莲房原花青素提取纯化工艺并评价抗氧化活性。方法 以正交设计L₉(3⁴)优化莲房原花青素提取工艺参数,用大孔吸附树脂进行纯化,而后通过1,1-二苯基-2-苦肼基(DPPH)和羟基自由基(·OH)清除率评价其体外抗氧化活性。结果 在最佳提取工艺条件下(8倍量50%乙醇回流提取2次,每次3 h),提取率达91.3%,进一步通过大孔树脂AB-8纯化,最终提取物中原花青素纯度为80.7%。莲房原花青素抗氧化活性与葡萄籽原花青素无显著性差异,均明显优于维生素C。结论 该提取纯化方法简单、高效,可用于莲房原花青素提取物的制备。莲房原花青素具有较强的抗氧化活性,值得进一步开发利用。     

Phytochemical Screening and Evaluation of Analgesic Activity of Oroxylum indicum

We aimed to study phytochemical screening and analgesic activity of ethanol extract of Oroxylum indicum. The dried powder of the barks of the plant was extracted with 95% ethanol and was subjected to various phytochemical tests to ascertain the principle constituents contained in the extract. The result revealed the presence of alkaloids, flavonoids, tannins, glycosides in the ethanol extract of Oroxylum indicum. The extract was screened for analgesic activity by using hot plate, acetic acid-induced writhing and formalin test. The ethanol extract of the plant at two different doses (250 and 500 mg/kg) showed significant (P<0.05) analgesic effect in all test methods (hot plate, acetic acid-induced writhing and formalin). The analgesic activity was compared with a standard drug (ketorolac at 10 mg/kg). Based on the present findings and previous literature review it can be concluded that flavonoids and tannins might be responsible for the analgesic activity. We suggest that ethanol extract of Oroxylum indicum might have potential chemical constituents that could be used in the future for the development of novel analgesic agent.     

Phloroglucinol: Antioxidant properties and effects on cellular oxidative markers in human HepG2 cell line

Phloroglucinol is an ubiquitous secondary metabolite encountered in a free state or polymerised as phlorotannins in brown macroalgae, and present in higher plants. FRAP and TEAC assays measured the antioxidant properties of phloroglucinol in non-biological conditions. Additionally, the biological effects of phloroglucinol (4–400 μM) were scrutinised using cellular oxidative stress markers, such as the generation of ROS, antioxidant defences (concentration of GSH and activities of GPx, GR and GST), and levels of MDA as a marker for lipid peroxidation. The direct effect was assessed immediately after an incubation period, whereas for the protective effect, the incubation period was followed by 3-h treatment with the pro-oxidant t-BOOH. The results indicated that despite having a higher radical scavenging capacity than Trolox after 30 min, phloroglucinol was not a suitable antioxidant standard for phlorotannins. Regarding the biological effects, phloroglucinol had no impact on cell viability, reduced levels of ROS and increased antioxidant defences in the direct treatment for most concentrations. The results of the protective effect were mitigated as phloroglucinol failed to protect from ROS generation but evoked a significant recovery of the stress-altered cellular antioxidant defences to restful conditions. Additionally, MDA levels were greatly reduced, preventing a radical chain oxidation.     

Prodelphinidin trimers and characterization of a proanthocyanidin oligomer from Cistus albidus

Two new natural prodelphinidin trimers have been isolated from the air-dried herb of Cistus albidus, epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-catechin and epigallocatechin-(4beta --> 8)-gallocatechin-(4alpha --> 8)-gallocatechin in addition to catechin, gallocatechin and thirteen known proanthocyanidins. The structures were determined on the basis of 1D- and reverse 2D-NMR (HSQC, HMBC) experiments of their peracetylated derivatives, MALDI-TOF-MS and by acid-catalysed degradation with phloroglucinol. A more abundant higher oligomeric proanthocyanidins fraction was also isolated and its chemical constitution studied by 13C-NMR. The mean molecular weight of the higher oligomeric fraction was estimated to be 6-7 flavan-3-ol-units.     

Phenolic constituents from Rhopalocnemis phalloides with DPPH radical scavenging activity

The 80% aqueous acetone extract of the whole plant of Rhopalocnemis phalloides Jungh. (Balanophoraceae) showed obvious radical scavenging activity (SC₅₀?=?32.1 μg/mL) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical assay. Further chemical investigation of the extract led to the isolation of 12 phenolic compounds (1–12). Among these, bis-6,8’-catechinylmethane (2), a flavan-3-ol dimer, was first isolated as a natural product from Rhopalocnemis phalloides. The full NMR assignments of bis-catechinylmethanes (1 and 2) are reported for the first time, on the basis of detailed spectroscopic analysis. The DPPH assay showed that flavan-3-ol dimers (1–3) had remarkable free radical scavenging activity, while flavonoid aglycones (4 and 9) presented stronger activities than those of their glycosides (5–8 and 10).     

Antidiabetic Activity of Clerodendron phlomoidis Leaf Extract in Alloxan-Induced Diabetic Rats

Ethanol extract of leaves of Clerodendron phlomoidis L. subjected to preliminary qualitative phytochemical investigations showed the presence of alkaloids, phytosterols, glycosides, saponins, phenolic compounds, proteins and flavonoids. The extract was screened for hypoglycemic activity in alloxan-induced diabetic rats (120 mg/kg, i.p.) at two dose levels, viz., 100 and 200 mg/kg. The ethanol extract at 200 mg/kg dose level exhibited significant (p<0.05) hypoglycemic activity and also correction of altered biochemical parameters viz., cholesterol and triglycerides (p<0.05).