白藜芦醇生物学活性研究进展

白藜芦醇是一种植物抗毒素,主要存在于虎杖、葡萄及花生等有限的植物中,它具有对人体有益的生物学活性,如具有拮抗肿瘤作用、心血管保护作用、抗炎作用、抗病毒作用、神经保护作用、植物雌激素作用和对骨钙的影响等。     

白藜芦醇心血管保护作用研究进展

白藜芦醇(resveratrol)是广泛存在于水果、中药和葡萄酒中的一种植物抗毒素,具有多种生物学作用。本文主要从白藜芦醇减少心肌缺血-再灌注损伤、舒张血管、抗动脉粥样硬化等方面对其心血管保护作用及其机制作一综述。     

白藜芦醇的生物活性及作用机制

白藜芦醇(RSV)是一种广泛存在的非黄酮类多酚化合物,具有抗氧化、抗炎、抗菌、抗病毒以及调节细胞代谢等多种生物学功能,目前在人体健康领域和动物生产中具有广泛的应用。本文简要综述了RSV的来源及理化性质、生物利用率、生物活性及其作用机制,为RSV的深入研究和进一步开发应用提供参考依据。     

白藜芦醇和白藜芦醇苷的测定方法研究进展

白藜芦醇和白藜芦醇苷具有抗肿瘤、保护心血管系统等多种显著的生物活性,国内外已经开始以其为指标性成分评定葡萄酒及相关中药的质量。本文综述了白藜芦醇和白藜芦醇苷等二苯乙烯类化合物的测定方法。     

拮抗人和动物病毒的细菌及其作用机制研究进展

目前病毒性疾病对人类、动物健康的危害以及对国民经济各领域的影响,突出了研发有效、安全防控病毒性疾病新产品的重要意义.某些细菌如益生乳酸菌和芽胞杆菌、放线菌等具有良好的抗病毒作用,可作为病毒性疾病防控新产品研制基料.本文综述了细菌抗人和动物病毒作用及机制方面的国内外研究现状,以期为细菌尤其是益生菌在病毒性疾病防控上的应用提供科学参考.     

益生菌抗真菌作用机制研究进展

真菌感染性疾病是普遍的全球性问题,随着感染人数的增多,已成为威胁人类健康的主要传染疾病之一。其对治疗药物出现的耐药性及药物本身的副作用,迫切需要开发新的安全、有效的替代品。益生菌作为对人体健康有益的微生物,已被实验证明对断发毛癣菌、须癣毛癣菌、酵母菌和霉菌等有明显的抑制作用。研究表明益生菌在繁殖过程中产生的有机酸以及产生的酸性物质使周围环境pH降低能有效地抑制真菌的生长。益生菌培养液的无细胞上清液及其自身具备的粘附性、疏水性等对浅部真菌和深部真菌都具有抑制作用。本研究对益生菌抗真菌作用的机制作一综述。     

白藜芦醇合酶的研究进展

白藜芦醇是一种重要的植物抗毒素,具有多种医疗保健作用,因此其应用前景 非常广泛,已引起多方关注。白藜芦醇合酶是白藜芦醇生物合成途径中的关键酶之一,它催化1分子4-香豆酰辅酶A和3分子丙二酰辅酶A反应合成白藜芦醇,它是白藜芦醇生物合成中惟一必需的酶,关于它的研究已广泛开展起来。本文综述了白藜芦醇的药理活性、白藜芦醇合 酶的酶学性质、诱导途径和机制以及分子生物学方面的研究进展。     

白藜芦醇在糖尿病治疗中的作用

白藜芦醇(resveratrol)是一种从植物中提取的多酚类化合物,它广泛存在于葡萄等植物中。白藜芦醇具有广泛的生物学活性,抗氧化、抗癌和调节代谢等作用。白藜芦醇在治疗糖尿病(diabetes mellitus, DM)中可有效改善胰岛β细胞功能及刺激胰岛素的分泌。白藜芦醇的作用机制较为复杂,现就白藜芦醇在DM治疗中的作用及机制作一概述。     

三株长蠕孢属真菌对毛脉酸模幼苗中白藜芦醇、白藜芦醇苷含量和产量的影响

以幼苗期毛脉酸模（Rumex gmelinii Turcz．）为实验材料,研究经长蠕孢属真菌（Helminthosporium carbonum）侵染后毛脉酸模中白藜芦醇和白藜芦醇苷的含量和产量的变化。实验结果表明：幼苗期毛脉酸模中的白藜芦醇在受到外界真菌诱导时对真菌具有一定的选择性。而且同一真菌的不同菌株诱导强度也有一定的差异,主要表现在起效时间上。但白藜芦醇苷含量受外界真菌诱导的专属性不强,且影响强度与诱导浓度有关。对幼苗期毛脉酸模各种诱导处理都没有使其生物量受到明显的抑制。通过试验筛选出大斑病长蠕孢001使幼苗期毛脉酸模中白藜芦醇苷和白藜芦醇产量影响较大,与对照相比分别使其提高1．54和3．99倍。     

白皮杉醇抗肿瘤作用研究进展

白皮杉醇是一种化学结构类似于白藜芦醇的天然小分子化合物,具有抗氧化、清除自由基、抗菌、抗炎、抗白血病、抗细胞增殖、提高免疫调节能力、抗癌、防癌等生物活性。白皮杉醇的抗氧化、抗侵袭等生物活性强于白藜芦醇,而其抗肿瘤作用机制尚未明确。近年,白皮杉醇在抑制肿瘤细胞增殖、诱导肿瘤细胞凋亡及抑制肿瘤细胞侵袭和迁移方面的作用越来越受到广泛关注,本文通过文献查阅后对白皮杉醇抗肿瘤作用的最新研究进展进行归纳总结,旨在为白皮杉醇进一步开发成抗肿瘤药物奠定理论基础和实验依据。     

ٍSome biologically active microorganisms have the potential to suppress mosquito larvae (Culex pipiens,Diptera: Culicidae)

Malaria is a disease caused by protozoan species of the genus Plasmodium. It is widespread and becoming a challenge in several African countries in the tropical and subtropical regions. In 2010, a report was published showing that over 1.2 million death cases were occurred globally due to malaria in just one year. The transmission of the disease from one person to another occurs via the bite of the Anopheles female. It is known that Plasmodium ovale, P. vivax, P. malariae, P. falciparum, and P. knowlesi are the highly infective malaria species. The problem of this disease is the absence of any effective medical treatment or vaccine, making the mosquito control is the only feasible way for disease prevention. Pesticides are currently the most widely used method for mosquito control, despite its well-known negative effects, including health hazards on human, the increasing insecticidal resistance, and the negative impact on the environment and beneficial organisms. Biological control (also called: biocontrol) of insects has been a promising method to overcome the negative effects of using chemical insecticides, as it depends on just using the natural enemies of pests to either minimize their populations or eradicate them. This article provides an overview of the recent and effective biological means to control malaria, such as bacteria, fungi, viruses, larvivorous fish, toxorhynchites larva and nematodes. In addition, the importance, advantages, and disadvantages of the biocontrol methods will be discussed in comparison with the traditionally used chemical methods of malaria control with special reference to nanotechnology as a novel method for insects’ control.     

ٍSome biologically active microorganisms have the potential to suppress mosquito larvae (Culex pipiens,Diptera: Culicidae)

Malaria is a disease caused by protozoan species of the genus Plasmodium. It is widespread and becoming a challenge in several African countries in the tropical and subtropical regions. In 2010, a report was published showing that over 1.2 million death cases were occurred globally due to malaria in just one year. The transmission of the disease from one person to another occurs via the bite of the Anopheles female. It is known that Plasmodium ovale, P. vivax, P. malariae, P. falciparum, and P. knowlesi are the highly infective malaria species. The problem of this disease is the absence of any effective medical treatment or vaccine, making the mosquito control is the only feasible way for disease prevention. Pesticides are currently the most widely used method for mosquito control, despite its well-known negative effects, including health hazards on human, the increasing insecticidal resistance, and the negative impact on the environment and beneficial organisms. Biological control (also called: biocontrol) of insects has been a promising method to overcome the negative effects of using chemical insecticides, as it depends on just using the natural enemies of pests to either minimize their populations or eradicate them. This article provides an overview of the recent and effective biological means to control malaria, such as bacteria, fungi, viruses, larvivorous fish, toxorhynchites larva and nematodes. In addition, the importance, advantages, and disadvantages of the biocontrol methods will be discussed in comparison with the traditionally used chemical methods of malaria control with special reference to nanotechnology as a novel method for insects’ control.     

Protective and therapeutic effects of resveratrol on acetic acid-induced gastric ulcer

Sprague Dawley rats of both sexes were injected with either saline or RVT (10 mg/kg) either before or after acetic acid ulcer induction and decapitated 3, 5 or 10 days after ulcer. In the saline-treated ulcer groups, macroscopically evident ulcers were observed, while RVT-pretreated or RVT-treated groups had lower macroscopic ulcer scores. Likewise, the microscopic damage scores were lower for the RVT-administered groups. Gastric myeloperoxidase activity, malondialdehyde, collagen and tumour necrosis factor-alpha levels, as well as luminol- and lucigenin-enhanced chemiluminescence levels that were elevated in the saline-administered ulcer groups, were depressed with both RVT-pretreatment and RVT-treatment. Moreover, depleted glutathione levels in the ulcer groups were increased back to control levels by both pre- and post-treatments of RVT. Results demonstrate that resveratrol has both protective and therapeutic effects on oxidative gastric damage by suppressing pro-inflammatory cascades, including the activation of pro-inflammatory cytokines, accumulation of neutrophils and release of oxygen-derived free radicals.     

白藜芦醇的药理作用机理和合成途径

白藜芦醇具有多种药理作用,其合成的化学途径与生物途径研究有新的进展。     

Protectants used in the cryopreservation of microorganisms

The cryoprotective additives (CPAs) used in the frozen storage of microorganisms (viruses, bacteria, fungi, algae, and protozoa) include a variety of simple and more complex chemical compounds, but only a few of them have been used widely and with satisfactory results: these include dimethylsulfoxide (Me2SO), glycerol, blood serum or serum albumin, skimmed milk, peptone, yeast extract, saccharose, glucose, methanol, polyvinylpyrrolidone (PVP), sorbitol, and malt extract. Pairwise comparisons of the cryoprotective activity of the more common CPAs used in cryomicrobiology, based on published experimental reports, indicate that the most successful CPAs have been Me2SO, methanol, ethylene glycol, propylene glycol, and serum or serum albumin, while glycerol, polyethylene glycol, PVP, and sucrose are less successful, and other sugars, dextran, hydroxyethyl starch, sorbitol, and milk are the least effective. However, diols (as well as some other CPAs) are toxic for many microbes. Me2SO might be regarded as the most universally useful CPA, although certain other CPAs can sometimes yield better recoveries with particular organisms. The best CPA, or combination of CPAs, and the optimum concentration for a particular cryosensitive microorganism has to be determined empirically. This review aims to provide a summary of the main experimental findings with a wide range of additives and organisms. A brief discussion of mechanisms of CPA action is also included.     

Identification and purification of resveratrol targeting proteins using immobilized resveratrol affinity chromatography

The phytochemical resveratrol (trans-3,4′,5-trihydroxystilbene) is a naturally occurring polyphenol with a plethora of health-beneficial properties, including a preventive role in cancer. We surmise that resveratrol may exert its diverse biological effects by interacting with specific target proteins, denoted RTPs. To test this possibility, resveratrol was immobilized on epoxy-activated agarose forming a resveratrol affinity column (RAC), which was used to detect and isolate RTPs. Distinct RTPs can be resolved on RAC by fractionation with increasing NaCl, followed by 1 mM ATP, and finally, with 1-2 mM resveratrol. A 22-kDa polypeptide, RTP-22, eluted with resveratrol was identified by MALDI-TOF MS and cloning/expression in Escherichia coli, as dihydronicotinamide riboside quinone reductase 2 (NQO2). The utility of RAC was additionally explored with extracts derived from different staging prostate cancer cells. NQO2 was most abundant in CWR22Rv1, a model for prostate cancer transition from androgen-dependent to the hormone-refractory state, but was marginally expressed in JCA-1 cells as representing more advanced stage prostate cancer. These results provide evidence for the existence of distinctive RTPs in mammalian cells and that RAC is a facile approach to identify and purify RTPs.     

Antioxidant properties of resveratrol and piceid on lipid peroxidation in micelles and monolamellar liposomes

The antioxidant activities of trans-resveratrol (trans-3,5,4′-trihydroxystilbene) and trans-piceid (trans-5,4′-dihydroxystilbene-3-O-β-d-glucopyranoside), its more widespread glycosilate derivative, have been compared measuring their inhibitory action on peroxidation of linoleic acid (LA) and the radical scavenging ability towards different free radicals (such as DPPH) and radical initiators. It has been found that the two stilbenes have similar antioxidant capacity, while the comparison with BHT (2,6-di-tert-butyl-4-methylphenol) and -tocopherol (vitamin E, vit. E), taken as reference, points out a slower but prolonged protective action against lipid peroxidation. Furthermore, piceid appears more efficacious than resveratrol as a consequence of the reaction of the latter with its radical form.

The DSC profiles of phosphatidylcholine liposomes of various chain lengths, and EPR measurements of spin labelled liposomes demonstrated that the susceptible hydroxyl group of these compounds are located in the lipid region of the bilayer close to the double bonds of polyunsatured fatty acids, making these stilbenes particularly suitable for the prevention and control of the lipid peroxidation of the membranes.     

The functional genomic studies of resveratrol in respect to its anti-cancer effects

Resveratrol has anti-cancer effects in vitro, and hypothetical chemopreventive effects in vivo. Effects are pleiotropic, mediated by changes in expression of many genes and epigenetic reprogramming. Thus, they are well suited for functional genomic studies. We carried out systematic review of such studies (reflecting also on technological progress). Differentially expressed genes commonly linked to resveratrol treatment were linked to cell cycle, proliferation, and apoptosis. However, it is unclear if these are primary and specific targets of resveratrol. We conclude by discussing areas where additional functional genomic studies are desirable, including experiments that better model in vivo effects of dietary intake.     

Pro-apoptotic versus anti-apoptotic properties of dietary resveratrol on tumoral and normal cardiac cells

Resveratrol is a natural dietary polyphenol found in grape skin, red wine, and various other food products. Resveratrol has proved to be an effective chemopreventive agent for different malignant tumors. It has also been shown to prevent vascular alterations such as atherosclerosis and inflammatory-associated events. In view of these observations, we investigated the anti-proliferative and pro-apoptotic activities of resveratrol on a tumoral cardiac cell line (HL-1 NB) derived from mouse tumoral atrial cardiac myocytes. These effects were compared with those found on normal neonatal mouse cardiomyocytes. HL-1 NB cells and neonatal cardiomyocytes were treated with resveratrol (5, 30, and/or 100 μM) for different times of culture (24, 48, and/or 72 h). Resveratrol effects were determined by various microscopical and flow cytometric methods. After resveratrol treatment, a strong inhibition of tumoral cardiac HL1-NB cell growth associated with a loss of cell adhesion was observed. This cell proliferation arrest was associated with an apoptotic process revealed by an increased percentage of cells with fragmented and/or condensed nuclei (characteristic of apoptotic cells) identified after staining with Hoechst 33342 and by the presence of cells in subG1. At the opposite, on normal cardiomyocytes, no cytotoxic effects of resveratrol were observed, and a protective effect of resveratrol against norepinephrine-induced apoptosis was found on normal cardiomyocytes. Altogether, the present data demonstrate that resveratrol (1) induces apoptosis of tumoral cardiac HL1-NB cells, (2) does not induce cell death on normal cardiomyocytes, and (3) prevents norepinephrine-induced apoptosis on normal cardiomyocytes.     

Effect of resveratrol on proliferation and differentiation of embryonic cardiomyoblasts

Resveratrol (trans-3,5,4′-trihydroxystilbene), a polyphenolic compound found largely in the skins of red grapes, has been used as a nutritional supplement or an investigational new drug for prevention of cardiovascular diseases. Previous reports showed that resveratrol had a protective effect against oxidative agent-induced cell injury. Our studies indicate that resveratrol plays a role in the differentiation of cardiomyoblasts. The cardiomyoblast cell line, H9c2, was exposed to 30-120 μM resveratrol for up to 5 days. Resveratrol inhibits cardiomyoblast proliferation without causing cells injury. Moreover, resveratrol treatment modulated the differentiation of morphological characteristics including elongation and cell fusion in cardiomyoblasts. Proliferation and differentiation of H9c2 cells were further revealed by measurement of the mRNA expression of a cell cycle marker (CDK2), a differentiation marker (myogenin), and a contractile apparatus protein (MLC-2). Gene expression analysis revealed that resveratrol promoted entry into cell cycle arrest but extended the myogenic differentiation progress. These results have implications for the role of resveratrol in modulating cell cycle control and differentiation in cardiomyoblasts.