043 转基因作物食用潜在致敏性的安全评价

转基因作物食用潜在致敏性是转基因作物食用安全性评价的焦点问题,目前国内外对其致敏性检测和评价尚无统一的方法和标准.本文借鉴FAO/WHO转基因食品致敏安全性评价的有关策略和评价程序,结合药品、生物制品以及化妆品的相关致敏安全性评价方法,采用危险评价、实质等同性分析、个案处理和逐步完善的评价原则,从转基因作物的转入基因、转基因作物和非预期效应等3方面进行评价,并对目前国内外采用的序列相似性比较、特异血清筛选、靶向血清筛选、模拟胃肠液消化试验和动物模型等不同方法进行综述,旨在为转基因作物食用潜在致敏安全性评价提供科学合理的方案.     

转基因作物食用潜在致敏性的安全评价

转基因作物食用潜在致敏性是转基因作物食用安全性评价的焦点问题，目前国内外对其致敏性检测和评价尚无统一的方法和标准。本文借鉴FAO／WHO转基因食品致敏安全性评价的有关策略和评价程序，结合药品、生物制品以及化妆品的相关致敏安全性评价方法，采用危险评价、实质等同性分析、个案处理和逐步完善的评价原则，从转基因作物的转入基因、转基因作物和非预期效应等3方面进行评价，并对目前国内外采用的序列相似性比较、特异血清筛选、靶向血清筛选、模拟胃肠液消化试验和动物模型等不同方法进行综述，旨在为转基因作物食用潜在致敏安全性评价提供科学合理的方案。     

转基因抗虫棉籽油的营养质量评价指标研究设想

转基因食品(Genetically Modified Food,GMF)是利用基因工程技术改造基因组构成的食品,包括转基因植物、转基因动物和转基因微生物食品[1].目前在联合国粮农组织(FAO)、世界卫生组织(WHO)等的倡议下,美国等发达国家在评价食品安全性问题时均采用"实质等同性"的概念和原则,其中营养成分评价是必不可少的环节,也是转基因食品的安全性评价的重要组成部分.     

转基因食品致敏性检验和评价技术

转基因食品的致敏性是转基因食品安全性评价中受到普遍关注的问题．与其特有的生产工艺、原料来源及产品成分有着密切的关系．与现有的食品品种比较有着显著的特征。转基因食品致敏性的检验和评价尚无统一的模式和方法。本文通过危险性评价、实质等同性分析、个案处理的原则和遗传稳定性分析、表达忠实性分析、致敏原特性及含量测定、血清学试验、动物试验等技术和方法．对转基因食品致敏性及其危害性的评价进行综述。     

转基因大米营养评价试验

目的: 探讨转基因大米和传统非转基因大米在营养学方面是否具有实质等同性,为转基因大米的安全性评价提供科学方法。方法: 以转豇豆胰蛋白酶抑制剂(cowpea trypsin inhibitor, CpTI)基因大米和蛋白含量与之相近的非转基因大米分别配成含蛋白10%(以其所含的大米蛋白为主,添加少量的酪蛋白)、其它营养成分同AIN-93G的饲料喂养断乳Wistar大鼠28 d,比较两组大鼠各营养指标、血液生化指标、体重身长、脏体比、蛋白质功效比(PER)、骨密度。结果: 饲喂转基因大米和非转基因大米的大鼠各项营养学指标无差异。结论: 转基因大米和非转基因大米的蛋白质的营养价值具有实质等同性,并且转基因大米中的CpTI并未明显干扰饲料中其它营养素的吸收,因此,从营养学角度看,转CpTI基因大米基本是安全的。     

WK蛋白在转基因抗旱小麦和大肠杆菌中的等同性验证

目的作为转基因抗旱小麦安全性风险评价的重要前提,对转基因抗旱小麦中表达的蛋白和大肠杆菌外源表达蛋白进行等同性验证。方法本研究首先在大肠杆菌中表达了His-WK融合蛋白,然后提取了对照小麦种子和转基因抗旱小麦种子的总蛋白,最后通过SDS-PAGE凝胶电泳、蛋白免疫印迹、糖基化修饰检测和液相色谱-串联质谱(LC-MS-MS)技术分析WK蛋白在转基因抗旱小麦和大肠杆菌中的等同性。结果本研究在大肠杆菌中表达了His-WK融合蛋白,并成功进行了纯化;大肠杆菌中表达的His-WK融合蛋白和转基因抗旱小麦的WK蛋白的表观分子量和免疫原性具有一致性;大肠杆菌中表达的His-WK融合蛋白和转基因抗旱小麦的WK蛋白都没有翻译后糖基化修饰;大肠杆菌中表达的His-WK融合蛋白和转基因抗旱小麦的WK蛋白的一级结构具有一致性。结论本研究验证了WK蛋白在转基因抗旱小麦和大肠杆菌中的等同性,为后续转基因抗旱小麦在营养学、毒理学、致敏性、免疫性等安全性评价研究中提供了可靠的参考依据。     

引起争议的转基因作物食用安全性动物实验研究和全食品喂养实验方法的适用性及敏感性评述

<正>转基因作物的安全性一直以来是学术界和公众关注的焦点。任何以转基因作物作为受试物的科学实验结果均会引起社会上的广泛关注,自从开始进行安全性评价以来,转基因作物食用安全性评价的原则和方法就在发展、变化。     

转基因大米的免疫毒理学评价

目的　评价转基因大米和非转基因大米对小鼠免疫功能的异同。方法　以转豇豆胰蛋白酶抑制剂 (cowpeatrypsininhibitor ,CpTI)基因大米和母系非转基因大米喂养BALB C小鼠 30天 (均配成AIN 93G的全价营养饲料 ,并且含有最大量的转基因大米或非转基因大米 ) ,比较各组小鼠的各项免疫毒理指标 :体重、脏器指数、血常规、淋巴细胞分类、血清抗体滴度、空斑试验 (PFC)、迟发型皮肤过敏反应 (DTH)、腹腔巨噬细胞吞噬鸡红细胞试验。结果　发现转基因大米和非转基因大米喂养的小鼠各项免疫毒理指标无差异。结论　转基因大米对小鼠的免疫功能的影响与非转基因大米基本相同 ,转基因大米与非转基因大米在免疫毒理学方面的评价具有“实质等同性”。     

抗草甘膦大豆及豆粕营养成分和抗营养因子研究

目的研究和评价转基因大豆与豆粕营养学安全性。方法采用浸提法将大豆加工成豆粕,再采用AOAC等分析方法测定RR(Roundup Ready)抗草甘膦转基因大豆和普通大豆与豆粕营养成分和抗营养因子含量。结果抗草甘膦大豆、豆粕中8种普通营养成分、17种氨基酸、14种脂肪酸、4种微量元素营养指标与未经基因修饰的普通品种相比基本一致,具有营养学的实质等同性;植酸磷、胰蛋白酶抑制因子、脲酶活性和蛋白溶解度4种抗营养因子含量也未发生显著变化。结论抗草甘膦大豆加工成豆粕,各种营养成分和抗营养因子含量的变化与普通品种相似,抗草甘膦基因的植入并没有影响大豆在加工过程中的营养学特性的变化。     

转基因食品致敏性评价细胞模型研究进展

随着转基因作物的快速发展,转基因食品的安全性,尤其是引起食物过敏的可能性成为广大民众关心的主要问题之一。目前,国际上转基因作物致敏性评价的研究和开发的热点之一是使用细胞模型进行致敏性评价,本文简单介绍了转基因食品致敏性评价的现状,重点对细胞模型方面的研究进展进行了综述。     

Risk assessment of genetically modified organisms

Since the commercial approve in 1996, the global area of transgenic crops has raised more than 50 times. In the last two decades, governments have been planning strategies and protocols for safety assessment of food and feed genetically modified (GM). Evaluation of food safety should be taken on a case-by-case analysis depending on the specific traits of the modified crops and the changes introduced by the genetic modification, using for this the concept of substantial equivalence. This work presents approaches for the risk assessment of GM food, as well as some problems related with the genetic construction or even with the expression of the inserted gene.     

Constantly evolving safety assessment protocols for GM foods

he introduction of GM foods has led to the evolution of a food safety assessment paradigm that establishes safety of the GM food relative to its conventional counterpart. The GM foods currently approved and marketed in several countries have undergone extensive safety testing under a structured safety assessment framework evolved by international organizations like FAO, WHO, Codex and OECD. The major elements of safety assessment include molecular characterization of inserted genes and stability of the trait, toxicity and allergenicity potential of the expressed substances, compositional analysis, potential for gene transfer to gut microflora and unintentional effects of the genetic modification. As more number and type of food crops are being brought under the genetic modification regime, the adequacy of existing safety assessment protocols for establishing safety of these foods has been questioned. Such crops comprise GM crops with higher agronomic vigour, nutritional or health benefit/ by modification of plant metabolic pathways and those expressing bioactive substances and pharmaceuticals. The safety assessment challenges of these foods are the potential of the methods to detect unintentional effects with higher sensitivity and rigor. Development of databases on food compositions, toxicants and allergens is currently seen as an important aid to development of safety protocols. With the changing global trends in genetic modification technology future challenge would be to develop GM crops with minimum amount of inserted foreign DNA so as to reduce the burden of complex safety assessments while ensuring safety and utility of the technology.     

Genetically modified food (food derived from biotechnology): current and future trends in public acceptance and safety assessment

Current and future trends regarding genetically modified (GM) crops and food stuffs were reviewed, with a particular focus on public acceptance and safety assessment. While GM foods, foods derived from biotechnology, are popular with growers and producers, they are still a matter of some concern among consumers. In fact, our recent surveys showed that Japanese consumers had become uneasy about the potential health risks of genetically modified foods. Many Japanese consumers have only vague ideas about the actual health risks, and they appear to be making decisions simply by rejecting GM food because of non-informed doubts. Although the debate about GM foods has increased in the mass media and scientific journals, few articles concerning direct studies on the potential toxicity or adverse health effects of GM foods have appeared. The roles of relevant international regulatory bodies in ensuring that GM crops and food are safe are therefore have summarized. Finally, the current debate on use of GM crops in agriculture and future trends for development of GM foods with enriched nutrients, better functionality, and medicinal ingredients, which will be of direct benefit to the consumer, are covered.     

An Asian perspective on GMO and biotechnology issues

Of the 102 million hectares that made up the global area of biotech crops in 2006, less than 8% (7.6 million ha) were in Asia. Three biotech crops are currently planted in significant areas in four Asian countries with government regulatory approval; namely, cotton, corn (maize), and canola. However, the amount of GM crop material imported into the Asian region for processing into food and animal feed is very substantial, and almost every country imports GM food. The issues which concern Asian scientists, regulators, and the lay public resemble those of other regions - biosafety, food safety, ethics and social justice, competitiveness, and the "EU" trade question. Most Asian countries now have regulatory systems for approving the commercialization of GM crops, and for approving food safety of GM crops. In Asia, because of the varied cultures, issues concerning the use of genes derived from animals arouse much emotion for religious and diet choice reasons. Because many Asian producers and farmers are small-scale, there is also concern about technology dependency and to whom the benefits accrue. All consumers surveyed have expressed concern about potential allergenic and long-term toxic effects, neither of which is grounded on scientific facts. Because of Asia's growing demand for high volumes of quality food, it is likely that GM crops will become an increasing feature of our diet.     

Nutritional and safety assessment of foods and feeds nutritionally improved through biotechnology--case studies by the International Food Biotechnology Committee of ILSI

During the last two decades, the public and private sectors have made substantial research progress internationally toward improving the nutritional value of a wide range of food and feed crops. Nevertheless, significant numbers of people still suffer from the effects of undernutrition. As newly developed crops with nutritionally improved traits come closer to being available to producers and consumers, scientifically sound and efficient processes are needed to assess the safety and nutritional quality of these crops. In 2004, a Task Force of international scientific experts, convened by the International Food Biotechnology Committee (IFBiC) of ILSI, published recommendations for the safety and nutritional assessment of foods and feeds nutritionally improved through modern biotechnology (J. Food Science, 2004, 69:CRH62-CRH68). The comparative safety assessment process is a basic principle in this publication and is the starting point, not the conclusion, of the analysis. Significant differences in composition are expected to be observed in the case of nutritionally enhanced crops and must be assessed on a case-by-case basis. The Golden Rice 2 case study will be presented as an example of a food crop nutritionally enhanced through the application of modern biotechnology (i.e., recombinant DNA techniques) to illustrate how the 2004 recommendations provide a robust paradigm for the safety assessment of "real world" examples of improved nutrition crops.     

Nutrition and health--genetically modified food

The genetically modified (GM) crops cultivated at present have new properties of benefit to agriculture. It is expected that in the future GM crops will also be cultivated with more complex genetic modifications that are aimed at improving the nutritional and health value to the consumer. The safety assessment of GM foods before market approval is based on a comparison of the characteristics of the GM food with those of the conventional counterpart. Identified differences are thoroughly tested for their toxicological and nutritional consequences. Supplementary modern analytical techniques are being developed for the assessment of future complex GM foods. No cases of adverse health or nutritional effects in consumers have been reported for the existing generation of GM foods. The feasibility of post-market surveillance of (GM) foods, in order to identify small or chronic effects that have not been noticed in the pre-market phase, is being investigated, yet its value should not be overestimated. Surveillance can be informative in case of specific questions concerning certain products as long as the consumer intake is well documented. To this end traceability and labelling systems must be set up.     

Risk assessment of genetically modified crops for nutrition and health

The risk assessment of genetically modified (GM) crops for human nutrition and health has not been systematic. Evaluations for each GM crop or trait have been conducted using different feeding periods, animal models, and parameters. The most common result is that GM and conventional sources induce similar nutritional performance and growth in animals. However, adverse microscopic and molecular effects of some GM foods in different organs or tissues have been reported. Diversity among the methods and results of the risk assessments reflects the complexity of the subject. While there are currently no standardized methods to evaluate the safety of GM foods, attempts towards harmonization are on the way. More scientific effort is necessary in order to build confidence in the evaluation and acceptance of GM foods.     

Attitudes, perceptions, and trust. Insights from a consumer survey regarding genetically modified banana in Uganda

Genetically modified (GM) crops and food are still controversial. This paper analyzes consumers’ perceptions and institutional awareness and trust toward GM banana regulation in Uganda. Results are based on a study conducted among 421 banana-consuming households between July and August 2007. Results show a high willingness to purchase GM banana among consumers. An explanatory factor analysis is conducted to identify the perceptions toward genetic modification. The identified factors are used in a cluster analysis that grouped consumers into segments of GM skepticism, government trust, health safety concern, and food and environmental safety concern. Socioeconomic characteristics differed significantly across segments. Consumer characteristics and perception factors influence consumers’ willingness to purchase GM banana. The institutional awareness and trust varied significantly across segments as well. The findings would be essential to policy makers when designing risk-communication strategies targeting different consumer segments to ensure proper discussion and addressing potential concerns about GM technology.     

Genetically modified foods,science, consumers and the media

In contrast to the situation in the USA, where a wide range of genetically modified (GM) foods is available, in Europe very few GM products have been approved for marketing as foods, and there is widespread public concern about their safety and environmental impact. The marketing of a GM crop for food use in Europe falls under the EC novel foods regulations, and applications require the submission of an extensive dossier of information. The safety evaluation of GM foods presents considerable problems both in the conduct and interpretation of experimental studies, because conventional toxicity tests used in the evaluation of simple chemicals may not be appropriate for whole foods. To rationalise the safety evaluation process and to circumvent the difficulties in toxicological assessment of food materials, the concept of substantial equivalence has been developed. The concept is that if it can be demonstrated that the novel food is essentially similar to its conventional counterpart in terms of critical nutritional or anutritional components, then it is likely to be no more or less toxic than the latter. The possible introduction of unintended effects by the genetic modification process is particularly problematic for the safety evaluation process. The new genomic and post-genomic techniques are potentially valuable in the safety evaluation of GM foods, although they are as yet in their infancy.     

Genetic engineering in agriculture and corporate engineering in public debate: risk, public relations, and public debate over genetically modified crops

Corporations have long influenced environmental and occupational health in agriculture, doing a great deal of damage, making substantial profits, and shaping public debate to make it appear that environmental misfortunes are accidents of an otherwise well-functioning system, rather than systemic. The debate over the genetically modified (GM) crops is an example. The largest producer of commercial GM seeds, Monsanto, exemplifies the industry's strategies: the invocation of poor people as beneficiaries, characterization of opposition as technophobic or anti-progress, and portrayal of their products as environmentally beneficial in the absence of or despite the evidence. This strategy is endemic to contemporary market capitalism, with its incentives to companies to externalize health and environmental costs to increase profits.