Fumonisins as a possible contributory risk factor for primary liver cancer: A 3-year study of corn harvested in Haimen, China, by HPLC and ELISA

Employing HPLC fluorometry, gas-liquid chromatography (GLC) and a novel enzymelinked immunosorbent assay (ELISA) based on a monoclonal antibody, 40 corn samples, each collected in 1993 from agricultural stocks for human consumption in Haimen (Jiangsu County) and Penlai (Shandong Province), high- and low-risk areas for primary liver cancer (PLC) in China, respectively, were analysed for fumonisins (FBs), aflatoxins (AFs) and trichothecenes. Levels and positive rates of FBs and deoxynivalenol (DON) were significantly higher in Haimen than in Penlai. ELISA of the 40 corn samples harvested in the two areas in 1994 revealed that FB contamination levels and rates in these areas were comparable to those observed in 1993 in Haimen. ELISA analysis of 1993 and 1994 products revealed a wide occurrence of AFB₁ but the positive rates as well as levels were not significantly different between these areas. ELISA of the same sample number of corn harvested in 1995 revealed that FB contamination in Haimen was significantly higher than in Penlai. These 3-yearly surveys of corn samples (240 in total) demonstrated that corn harvested in Haimen was highly contaminated with FBs and that the contamination level, as well as positive rate in 1993 and 1995, were 10–50-fold higher than those in Penlai, suggesting FBs as a risk factor for promotion of PLC in endemic areas, along with the trichothecene DON. Co-contamination with AFs, potent hepatocarcinogens, was assumed to play an important role in the initiation of hepatocarcinogenesis.     

镰刀菌对太子参品质影响及DON毒素在其煎煮过程中迁移规律研究

目的:探究镰刀菌对太子参品质的影响和太子参中脱氧雪腐镰刀菌烯醇(DON)毒素在其煎煮过程中的迁移规律。方法:采用反式培养法,探讨镰刀菌侵染太子参后DON毒素积累变化及对太子参质量的影响,计算水煎煮后汤液DON毒素的迁移率。结果:受镰刀菌侵染后,太子参表面会形成1层白色菌丝和黑色沉积物,DON毒素在太子参中随时间推移显著增加;受镰刀菌侵染的太子参中总皂苷和多糖含量分别为对照组的1.5、2.0倍,而太子参环肽B含量显著降低。镰刀菌侵染太子参20 d后,DON毒素质量分数达到45.40μg·kg–1,DON毒素煎煮后转移率为12.50%~27.90%。结论:研究结果为制定中药材DON毒素限量标准及临床安全用药提供了参考。     

Toxicology of 3-epi-deoxynivalenol,a deoxynivalenol-transformation product by Devosia mutans 17-2-E-8

Microbial detoxification of deoxynivalenol (DON) represents a new approach to treating DON-contaminated grains. A bacterium Devosia mutans 17-2-E-8 was capable of completely transforming DON into a major product 3-epi-DON and a minor product 3-keto-DON. Evaluation of toxicities of these DON-transformation products is an important part of hazard characterization prior to commercialization of the biotransformation application. Cytotoxicities of the products were demonstrated by two assays: a MTT bioassay assessing cell viability and a BrdU assay assessing DNA synthesis. Compared with DON, the IC₅₀ values of 3-epi-DON and 3-keto-DON were respectively 357 and 3.03 times higher in the MTT bioassay, and were respectively 1181 and 4.54 times higher in the BrdU bioassay. Toxicological effects of 14-day oral exposure of the B6C3F₁ mouse to DON and 3-epi-DON were also investigated. Overall, there were no differences between the control (free of toxin) and the 25 mg/kg bw/day or 100 mg/kg bw/day 3-epi-DON treatments in body and organ weights, hematology and organ histopathology. However, in mice exposed to DON (2 mg/kg bw/day), white blood cell numbers and serum immunoglobulin levels were altered relative to controls, and lesions were observed in adrenals, thymus, stomach, spleen and colon. Taken together, in vitro and in vivo studies indicate that 3-epi-DON is substantially less toxic than DON.     

Risk analysis of main mycotoxins occurring in food for children: An overview

Mycotoxins are secondary metabolites produced by fungi contaminating the food chain that are toxic to animals and humans. Children up to 12 years old are recognized as a potentially vulnerable subgroup with respect to consumption of these contaminants. Apart from having a higher exposure per kg body weight, they have a different physiology from that of adults. Therefore they may be more sensitive to neurotoxic, endocrine and immunological effects. For these reasons, a specific and up-to-date risk analysis for this category is of great interest.In this review, an accurate analysis of the main mycotoxins occurring in food intended for children (deoxynivalenol, aflatoxins, ochratoxins, patulin and fumonisins) is presented. In particular, known mechanisms of toxicity and levels of exposure and bioaccessibility in children are shown. In addition, recent discoveries about the strategies of mycotoxins managing are discussed.     

Deoxynivalenol: Toxicology,Degradation by Bacteria,and Phylogenetic Analysis

Deoxynivalenol (DON) is a toxic secondary metabolite produced by fungi that contaminates many crops, mainly wheat, maize, and barley. It affects animal health, causing intestinal barrier impairment and immunostimulatory effect in low doses and emesis, reduction in feed conversion rate, and immunosuppression in high doses. As it is very hard to completely avoid DON’s production in the field, mitigatory methods have been developed. Biodegradation has become a promising method as new microorganisms are studied and new enzymatic routes are described. Understanding the common root of bacteria with DON degradation capability and the relationship with their place of isolation may bring insights for more effective ways to find DON-degrading microorganisms. The purpose of this review is to bring an overview of the occurrence, regulation, metabolism, and toxicology of DON as addressed in recent publications focusing on animal production, as well as to explore the enzymatic routes described for DON’s degradation by microorganisms and the phylogenetic relationship among them.     

The benchmark dose approach in food risk assessment: Is it applicable and worthwhile?

The benchmark dose (BMD) approach is being increasingly used in the area of food risk assessment because it offers several advantages compared to the conventional no-observed-adverse-effect-level approach. The aim of this work was to check the applicability of the BMD approach on toxicity data available from pesticides, mycotoxins and natural toxins.     

Early awareness of emerging risks associated with food and feed production: Synopsis of pertinent work carried out within the SAFE FOODS project

This introduction to the journal’s supplement on emerging food and feed safety issues summarizes the objectives and activities of the EU-funded SAFE FOODS project in general and its work package focusing on the early identification of emerging food safety risks, in particular. Within this work package, a number of studies have been carried out on methods enabling the early awareness, identification, and prevention of emerging issues before they can become real risks. The various reviews in this supplement explore the background of the emergence of known food safety risks, both of microbial and chemical/biochemical nature, as well the methods that can be used to identify such risks. Another review identifies a number of chemical and microbiological hazards that are likely to be affected by a changing climate. A major conclusion from these explorative reviews is that monitoring and information exchange systems or procedures are in place to detect, in an early phase, the emergence of potential food safety risks linked to known hazards. Additional systems are needed to predict the development of new potential food safety risks, which are linked to either new hazards or known hazards to which exposure has been altered.     

Assessment of deoxynivalenol metabolite profiles in UK adults

Deoxynivalenol (DON) requires no activation for toxicity, though susceptibility may reflect individual variations in detoxification. This study reports the measurement of un-metabolised urinary DON (free DON) and DOM-1 in samples previously analysed for the combined measure of free DON + DON-glucuronide (fD + DG), with a concentration >5 ng/ml, for 34 UK adults. Four consecutive daily urine samples were analysed from twenty-two individuals, whilst from 12 individuals only a single sample was analysed. The mean (median) concentration of urinary fD + DG in this sub-set was 17.8 ng/ml (13.8 ng/ml), range 5.0-78.2 ng/ml. In 23/34 (68%) individuals, free DON was detected, mean 2.4 ng/ml; range 0.5-9.3 ng/ml. Urinary DOM-1 was detected in 1/34 (3%) of individuals; present at ∼1% of urinary fD + DG concentration for that individual. The concentration of fD + DG combined was significantly correlated with urinary free DON (p < 0.001, R² = 0.65), but not with the percentage of free DON to fD + DG (p = 0.615, R² = 0.01), suggesting that the level of DON exposure did not affect the metabolism to DG within the range observed. In this survey most individuals had no detectable urinary DOM-1 and 68% did not detoxify all of the ingested DON to DON-glucuronide. This study needs to be extended to understand whether the fD / DG ratio provides a phenotypic measure of DON susceptibility.     

小麦中DON的薄层色谱测定

作者对小麦中脱氧雪腐镰刀菌烯醇(DON)的薄层色谱的测定，主要改变了柱净化条件的薄层板展开方式以适合本地实验条件。用本法测定小麦中的DON在100ppb、500ppb两个水平，回收范围在75～90%、方法灵敏度为100ppb，本实验该项测定灵敏度可提高到40ppb．     

脱氧雪腐镰刀菌烯醇致家兔多脏器损伤的实验观察

目的观察脱氧雪腐镰刀菌烯醇（DON）对家兔器官的毒性及损伤作用。方法将成年雄性家兔随机分为高剂量组、低剂量组和对照组，高、低剂量组分别用0．1mg·kg^-1BW，0．05mg·kg^-1 BW剂量的脱氧雪腐镰刀菌烯醇，经耳缘静脉注射染毒，每48h染毒一次，染毒10次后处死家兔，取心、肝、肾、脾等器官进行常规病理检查。结果染毒家兔的心、肝、肾、脾均有病理变化，可见组织细胞肿胀、空泡变性、炎性细胞浸润及细胞坏死。结论DON具有明显的细胞毒性，对多脏器具有损伤作用。