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1.
Cancer is a leading cause of death worldwide. There are a lot of cancer causing agents which are divided as physical carcinogens, chemical carcinogens and biological carcinogens. But most of the carcinogens or causes of cancer are related to our lifestyle like diet, habit, occupation, radiation and some infection, etc. Chemoprevention is highly necessary to prevent cancer related preterm death. For this besides avoiding the causes of cancer we should concentrate ourselves on our diet. Because, numerous phytochemicals derived from edible plants have been reported to interfere with a specific stage of the carcinogenic process. Many mechanisms have been shown to account for the anticarcinogenic actions of dietary constituents and recently attention has been focused on intracellular-signalling cascades as common molecular targets for various chemopreventive phytochemicals. In this study, we tried to describe lifestyle related causes of cancer and the molecular basis of cancer prevention through the phytochemicals.  相似文献   

2.
Diabetes mellitus is one of the most wide spread endocrine disorders and an important developing health problem in the world. Cardiovascular disease is a common complication of type 2 diabetes. Several risk factors for coronary heart disease cosegregate in type 2 diabetes, including hyperglycemia, hyperlipaemia, increases production of free radical and decrease in antioxidant defense system. In this study we evaluated the effect of vitamin C supplementation on fasting and postprandial oxidative stress and lipid profile in type 2 diabetic patients. 30 patients with type 2 diabetes from Nader Kazemi Clinic, Shiraz, Iran were randomly divided into 2 groups; vitamin C treatment group (1000 mg d(-1)) and placebo group from May to September 2010. Fasting and postprandial lipid profile and Malondialdehyde (MDA) level were measured at the beginning of the study and after six weeks of supplementation. Data analysis was carried out using Mann-Whitney U test with p < 0.05 being significant by SPSS software version 16.The result of the study showed a significantly decrease in fasting (p = 0.006) and postprandial MDA (p < 0.001) in vitamin C group compare to placebo group but not in lipid profile. This study suggests that vitamin C supplementation can decrease fasting and postprandial oxidative stress and may prevent diabetes complication.  相似文献   

3.
Metabolic syndrome-related diseases affect millions of people worldwide. It is well established that changes in nutritional habits and lifestyle can improve or prevent metabolic-related pathologies such as type-2 diabetes and obesity. Previous reports have shown that nutritional supplements have the capacity to limit glucose intolerance and suppress diabetes development. In this study, we investigated the effect of dietary supplementation with fish-derived extracts on obesity and type 2 diabetes and their impact on gut microbial composition. We showed that nutritional supplements containing Fish Complex (FC), Fish Complex combined with Cod Powder (FC + CP), or Cod Powder combined with Collagen (CP + C) improved glucose intolerance, independent of abdominal fat accumulation, in a mouse model of diet-induced obesity and type 2 diabetes. In addition, collagen-containing supplements distinctly modulate the gut microbiome in high-fat induced obesity in mice. Our results suggest that fish-derived supplements suppress diet-induced type 2 diabetes, which may be partly mediated through changes in the gut microbiome. Thus, fish-derived supplements and particularly the ones containing fish collagen have potential beneficial properties as dietary supplements in managing type 2 diabetes and metabolic syndrome via modulation of the gut microbiome.  相似文献   

4.
陈浩  徐平  张志会  王岳飞 《茶叶》2012,(3):136-141
随着人们生活水平的提高和饮食结构的变化,糖尿病的患病呈流行趋势,发病率逐年上升,预防和治疗糖尿病成为热门话题。现代科学证明茶叶作为健康饮品的同时对人体健康具有多方面的保健功效。本文回顾了茶叶在糖尿病预防方面已取得研究进展,综述了茶叶与糖尿病预防的相关流行病学和人体临床研究结果,并对茶叶预防糖尿病的机制进行了梳理。  相似文献   

5.
Cancer has always been a threat to human health with its high morbidity and mortality rates. Traditional therapy, including surgery, chemotherapy and radiotherapy, plays a key role in cancer treatment. However, it is not able to prevent tumor recurrence, drug resistance and treatment side effects, which makes it a very attractive challenge to search for new effective and specific anticancer drugs. Nature is a valuable source of multiple pharmaceuticals, and most of the anticancer drugs are natural products or derived from them. Marine-derived compounds, such as nucleotides, proteins, peptides and amides, have also shed light on cancer therapy, and they are receiving a fast-growing interest due to their bioactive properties. Their mechanisms contain anti-angiogenic, anti-proliferative and anti-metastasis activities; cell cycle arrest; and induction of apoptosis. This review provides an overview on the development of marine-derived compounds with anticancer properties, both their applications and mechanisms, and discovered technologies.  相似文献   

6.
Crop losses caused by viruses   总被引:1,自引:0,他引:1  
L. Bos 《Crop Protection》1982,1(3):263-282
Several plant viruses are highly contagious and their effects on plants are often drastic. Many seriously reduce crop yield and quality. Numerous disorders are caused or triggered by viruses and a great deal of money is spent on preventing virus diseases from becoming disastrous. Losses caused by any disease cannot be measured directly because potential yield and damage are so variable. Experimental assessment of the losses attributable to virus diseases is particularly difficult because it is extremely hard to prevent contamination of healthy control plants and inoculation under vector-proof conditions may not reflect accurately what happens under natural conditions. The prevalence of the causal viruses or the extent of attack are not reliable guides to the amount of damage caused; this contrasts with the situation with invertebrate pests where losses are usually related to the population densities of the pests. In a few virus diseases, attempts have been made to establish the relationships between final yield loss and certain indicators such as incidence, severity and duration of disease, or between combinations of these, but the relationships seem to be valid only under strictly defined conditions. The main aims of this work have been to estimate actual losses inflicted on a farmer's crop or upon a larger area, to predict the magnitude of losses that may develop and to decide what control measures are justified. In practice, assessment of loss has been extrapolated from trials in which various infection severities and infection times have been used to simulate natural situations. Yield improvements with virus-free propagation material have sometimes been used for loss assessment. Losses caused by virus diseases depend on the cultivar involved: evaluation of the resistance of different cultivars may be further improved by assessing the effects of viruses on yield rather than by assessing the severity of symptoms. Losses is strictly financial terms are influenced by fluctuating prices for crop products and are even more difficult to asses, let alone to predict, than are losses of yield. Nevertheless, a better understanding of the way in which virus disease epidemics develop, and of the resulting biological and economic losses, is essential for effective crop protection, whether on individual farms or on a national scale.  相似文献   

7.
根据第4次全国中药资源普查的技术规范与要求,采用样地与样线调查法,对珠海市凤凰山野生药用植物资源的科属组成、区系特征、生活型、药用部位、药性、药味、药效等方面进行研究.结果显示:该地区野生药用维管植物共有106科276属385种;药用植物属的分布区类型以热带性质为主;根及根茎类药物是该地药用植物的主要组成部分,占总种数...  相似文献   

8.
通过查阅大量文献和实地调查,整理出海南省有禾本科(Poaceae)药用植物资源48属,87种(包括变种)。其中簕竹属(Bambusa Schreber)药用植物最多,有9种。海南省禾本科药用植物按药用部位分,全草类最多;按药用功效分,清热类最多。同时还分析了海南省禾本科药用植物资源现状,并提出合理开发利用和保护的建议。  相似文献   

9.
《Field Crops Research》1999,60(1-2):1-10
Micronutrient malnutrition (`Hidden Hunger') now afflicts over two billion people worldwide, resulting in poor health, low worker productivity, high rates of mortality and morbidity, increased rates of chronic diseases (coronary heart disease, cancer, stroke, and diabetes), and permanent impairment of cognitive abilities of infants born to micronutrient-deficient mothers. The consequences of food system failures include lethargic national development efforts, continued high population growth rates, and a vicious cycle of poverty for massive numbers of underprivileged people in all nations. Our food systems are failing us globally by not providing enough balanced nutrient output to meet all the nutritional needs of every person, especially resource-poor women, infants and children in developing countries. Agriculture is partly responsible because it has never held nutrient output as an explicit goal of its production systems. Indeed, many agricultural policies have fostered a decline in nutrition and diet diversity for the poor in many countries. Nutrition and health communities are also partly responsible because they have never considered using agriculture as a primary tool in their programs directed at alleviating poor nutrition and ill health globally. Now is the time for a new paradigm for agriculture and nutrition. We must consider ways in which agriculture can contribute to finding sustainable solutions to food system failures through holistic food-based system approaches, thereby closely linking agricultural production to improving human health, livelihood and well being. Such action will stimulate support for agricultural research in many developed countries because it addresses consumer issues as well as agricultural production issues and is, therefore, politically supportable.  相似文献   

10.
After earlier debates on the role of fat, high fructose corn syrup, and added sugar in the aetiology of obesity, it has recently been suggested that wheat consumption is involved. Suggestions have been made that wheat consumption has adverse effects on health by mechanisms related to addiction and overeating. We discuss these arguments and conclude that they cannot be substantiated. Moreover, we conclude that assigning the cause of obesity to one specific type of food or food component, rather than overconsumption and inactive lifestyle in general, is not correct. In fact, foods containing whole-wheat, which have been prepared in customary ways (such as baked or extruded), and eaten in recommended amounts, have been associated with significant reductions in risks for type 2 diabetes, heart disease, and a more favourable long term weight management. Nevertheless, individuals that have a genetic predisposition for developing celiac disease, or who are sensitive or allergic to wheat proteins, will benefit from avoiding wheat and other cereals that contain proteins related to gluten, including primitive wheat species (einkorn, emmer, spelt) and varieties, rye and barley. It is therefore important for these individuals that the food industry should develop a much wider spectrum of foods, based on crops that do not contain proteins related to gluten, such as teff, amaranth, oat, quinoa, and chia. Based on the available evidence, we conclude that whole-wheat consumption cannot be linked to increased prevalence of obesity in the general population.  相似文献   

11.
In the traditional system ofmedicine, Ayurveda, several spices and herbsare thought to possess medicinal properties. Amongthe spices, turmeric rhizomes (Curcumalonga. Linn.) are used as flavoring and coloringagents in the Indian diet everyday. In this research,we studied the effect of turmeric and itsactive principle, curcumin, on diabetes mellitus in arat model. Alloxan was used to induce diabetes.Administration of turmeric or curcumin to diabeticrats reduced the blood sugar, Hb and glycosylatedhemoglobin levels significantly. Turmeric andcurcumin supplementation also reduced the oxidativestress encountered by the diabetic rats. This wasdemonstrated by the lower levels of TBARS (thiobarbituric acid reactive substances), which mayhave been due to the decreased influx of glucose intothe polyol pathway leading to an increased NADPH/NADPratio and elevated activity of the potent antioxdiantenzyme GPx. Moreover, the activity of SDH (soorbitol dehydrogenase), whichcatalyzes the conversion of sorbitol to fructose, waslowered significantly on treatment with turmeric orcurcumin. These results also appeared to reveal thatcurcumin was more effective in attenuating diabetesmellitus related changes than turmeric.  相似文献   

12.
在第四次全国中药资源普查工作中,采用查阅文献、样线和样方相结合的调查方法,对阳朔县药用植物资源的种类、分布及蕴藏量等进行调查和统计分析。结果表明:(1)本次调查和鉴定,阳朔县共有野生和栽培药用植物919种(包括种下单位),隶属于160科527属;其中野生重点调查药用植物70种,栽培重点调查药用植物6种,国家Ⅰ级保护植物1种,国家II级保护植物7种,广西重点保护植物8种。(2)对样方调查中发现的57种野生重点药用植物的出现频率和蕴藏量进行统计,其中60.00%的物种蕴藏量小于100 t,野生重点中药材总蕴藏量11 610.18 t;66.67%的物种出现频率低。可见,阳朔县药用植物资源丰富,珍稀濒危保护植物种类多,生态环境保护较好;但各物种的出现频率和蕴藏量差异大,很多物种野生资源稀缺,对部分药用植物的保护已刻不容缓;建议把旅游业与中药种植业相结合,保护自然景观与生态环境,确保经济与生态协调发展。  相似文献   

13.
Abstract The objective of this work was to study the insecticidal effect of labramin, a protein that shows lectin-like properties. Labramin was isolated from seeds of the Beach Apricot tree, Labramia bojeri A. DC ex Dubard (Ericales: Sapotaceae), and assessed against the development of the Mediterranean flour moth Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), an important pest of stored products such as corn, wheat, rice, and flour. Results showed that labramin caused 90% larval mortality when incorporated in an artificial diet at a level of 1% (w/w). The presence of 0.25% labramin in the diet affected the larval and pupal developmental periods and the percentage of emerging adults. Treatments resulted in elevated levels of trypsin activity in midgut and fecal materials, indicating that labramin may have affected enzyme-regulatory mechanisms by perturbing peritrophic membranes in the midgut of is. kuehniella larvae. The results of dietary experiments with E. kuehniella larvae showed a reduced efficiency for the conversion of ingested and digested food, and an increase in approximate digestibility and metabolic cost. These findings suggest that labramin may hold promise as a control agent to engineer crop plants for insect resistance.  相似文献   

14.
《Journal of Crop Improvement》2013,27(1-2):155-210
Abstract

Viral, bacterial, and fungal diseases of ornamental plants cause major losses in productivity and quality. Chemical methods are available for control of fungal diseases, and to a lesser extent for bacterial diseases, but there are no economically effective chemical controls for viral diseases except to control vector species. Host plant resistance is an effective means of controlling plant diseases, and minimizing the necessity for the application of pesticides; however, there are many ornamentals in which no natural disease resistance is available. It is possible to introduce resistance derived from other species, or even from the pathogen itself, by genetic engineering. This allows the introduction of specific, or in some instances broad spectrum, disease resistance into plant genotypes that have been selected for desirable horticultural characters; in contrast, introduction of natural resistance by traditional breeding may take many cycles of breeding to combine disease resistance with desirable ornamental quality. This article briefly reviews existing work on transformation systems for ornamentals, and discusses the various approaches to introducing resistance to viral, bacterial, and fungal diseases, and to nematode infestations. These include pathogen-related proteins, R genes, and general pathogen resistance; anti-microbial peptides; expression of anti-pathogen antibodies; viral sequences; ribozymes; antiviral peptides; ribonucleases; and ribosome-inactivating proteins. Examples are given of application of these approaches to disease resistance in other types of crop and model plant systems, and actual or potential application to disease resistance in ornamentals. Future prospects for obtaining plants with multiple pest and disease resistances are discussed.  相似文献   

15.
闽楠(Phoebe bournei),我国Ⅱ级保护濒危植物,是亚热带常绿阔叶林重要组成树种,而闽楠溃疡病的发生严重危害其开发利用。为明确闽楠溃疡病的致病菌,以便后续科学的指导病害防治,本文从福建省闽楠病枝中分离纯化菌株,通过致病性测定、形态学观测以及 rDNA-ITS、GAPDH、β-tubulin、Histone3 序列分析鉴定病原菌,并分析其生物学特性。结果显示:从闽楠病枝中分离出 4 种菌株,分别编号为 SS-01、SS-02、SS-03 和 SS-04,其中菌株 SS-03 致病菌为粉红粘帚霉(Clonostachys rosea Schroers, et al.=Gliocladium roseum Bainier);该菌菌丝在 PDA+PBL 培养基(pH 6.0)上 25 ℃黑暗条件下生长最好;最适菌丝生长碳源为麦芽糖,可溶性淀粉有利于产孢;最适氮源为牛肉浸膏;产孢量在 PDA 培养基(pH 7.0)上 25 ℃全黑暗条件最高。空气相对湿度≥90%(pH 8.0)时孢子萌发率最高。高温高湿以及高郁闭度易于闽楠溃疡病发生,故在营林造林以及苗圃抚育时应注意通风透气,控制温湿度,防止病害发生。该研究结果为科学有效地指导闽楠溃疡病防治提供技术支持。  相似文献   

16.
水稻白叶枯病是浙江稻区常发流行性病害,调查研究其为害与损失,科学制订防治指标,对于有效预测和综合防控病害,确保水稻丰产和农民增收具有重要意义。通过对浙江桐庐、余杭等地几年来水稻白叶枯病发生为害损失调查测定,探明了病害发生为害与损失的关系,分别建立了水稻分蘖、圆秆拔节和孕穗破口期株、叶发病率与产量损失率关系的6个模型,考查了侵染发病对主要经济性状的影响,受害稻株株高下降、实粒数减少、空秕率增加是导致减产的主要原因。调查分析了田间用药和防治成本,测定了经济允许水平,首次提出了该病防治指标为水稻株发病率5%、叶发病率3%。该指标经浙江桐庐、温岭、温州等地大田验证与示范应用,与实际发生为害情况相符,药治面积压缩1/3,省药、节本、增效,取得了显著的经济、社会和生态效益。  相似文献   

17.
Buddleja globosa is a medicinal shrub native to Chile. Its leaves have been traditionally used for wound and ulcer healing. Different medicinal properties, such as outstanding antioxidant, anti-inflammatory, wound healing and analgesic activities have been shown. Today, all raw materials for pharmaceutical process are coming from wild collection or recently established crops but not from selected plants. Studies of the genetic or environmental variability of the species would permit the optimization of yield and quality factors through the selection of genetic material or suitable production sites and management techniques.To assess which traits are determined genetically some yield related plant and leaf characteristics were studied in three wild populations and the cultivated accessions from the same provenances. The cultivated accessions also included three clones coming from individuals found in rural home gardens. For the cultivation studies individuals were arranged in a randomised block design, and those for the irrigation studies in split plots watered at 20% and 65% field capacity.Plant characteristics such as height and width of the plant, the ratio of both, stem diameter and leaf density differed significantly among natural populations. In leaf characteristics only the presence of stipules showed significant differences. The cultivated progenies or clones may give an idea if these differences among populations are due to environmental or to genetic effects. Compared with other provenances, plants from the coastal provenance Los Ruiles are tallest in both natural populations and cultivated clones and also showed superior leaf yields in spite of their lower leaf density.The hairy leaves may cause allergic reactions at the moment of harvest. This characteristic is not influenced by different irrigation treatments and shows no significant differences between cultivated and wild plants.Because of the significant higher leaf yields per plant in home garden clones we assume that formerly individuals with a higher leaf production were selected for cultivation.  相似文献   

18.
The building-up of plant components is controlled by the action of enzymes. The activity of these enzymes is influenced as well by endogenous as by exogenous factors. Therefore the building-up of plant substances gives the picture of a continuous evolution only if an interpolation over larger timecourses is done. By detailed observations it may be seen that really the components of the growing plant are intensively metabolized whereby anabolic and catabolic reactions are tightly connected. Environmental impulses may influence the concerned enzyme systems in one or the other direction followed by short-time changes in the content of certain compounds. Out of the manifold of plant enzyme systems nitrate reductase and proteases will be discussed in detail. Nitrate reductase catalyzes the first step from inorganic to organic nitrogen. The action of this enzyme can be altered e.g. by light. With different model plants the connection between light intensity on one side and enzyme activity and content of nitrate on the other is studied. The results of first tests show that significant diurnal changes in the nitrate content take place. Further studies with the green parts of plants after interruption of nutrient supply by harvesting show that this step either gives way to activation or de novo synthesis of proteases or simply block the anabolic way of protein synthesis. Thereupon the content of amino compounds of low molecular weight rises, which is undesirable in view of nutritional quality. At this point knowledge of the dependence of protease activity from exogenous factors would greatly help conservation of post harvest quality of sensitive vegetables. Owing to the difficult analytic procedure, work in this field is just at the beginning. Conclusions for practical work drawn from the existing results are discussed.  相似文献   

19.
Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). It is an ocular manifestation of systemic disease, which affects up to 80% of all patients who have had diabetes for 10 years or more. The genetically diabetic db/db mouse, as a model of type-2 diabetes, shows diabetic retinopathy induced by apoptosis of RGCs. Astaxanthin is a carotenoid with powerful antioxidant properties that exists naturally in various plants, algae and seafood. Here, astaxanthin was shown to reduce the apoptosis of RGCs and improve the levels of oxidative stress markers, including superoxide anion, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity in the retinal tissue of db/db mouse. In addition, astaxanthin attenuated hydrogen peroxide(H2O2)-induced apoptosis in the transformed rat retinal ganglion cell line RGC-5. Therefore, astaxanthin may be developed as an antioxidant drug to treat diabetic retinopathy.  相似文献   

20.
The bacterial ring rot disease of potato (Corynebacterium sepedonicum) can be detected in seed potato lots by serological tests with greater accuracy than by visual field inspections. Indexing tests can make use of highly specific immunofiuorescence probes, enzyme-linked immunosorbent assays, and perhaps other procedures. Sensitivity and specificity of these procedures need to be determined in order to estimate the confidence with which ring rot can be detected in a seed lot. In addition to the laboratory tests, the sampling strategy determines the efficacy and sensitivity of the indexing procedure. Samples might consist of stems, leaf petioles, or tubers in single or composite units. Disease incidence and number of plants sampled also determine the confidence level with which ring rot can be detected in a potato seed lot. Although research has been conducted on many aspects of ring rot testing procedures, further work needs to be done. Nevertheless, it is anticipated that indexing potato seed lots for the presence of ring rot will be a significant factor in control and eradication of the disease.  相似文献   

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