NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis. I. Study design and clinical outcomes

A 3-month double-blind and placebo-controlled, phase IIa clinical trial was conducted in Ghana to investigate the safety, tolerance and aflatoxin-sorption efficacy of dietary NovaSil (NS). Volunteers (507 subjects) were clinically screened to evaluate their general health, pregnancy status and blood AFB₁-albumin adduct levels. Of these subjects, 177 were randomly assigned to three groups: high-dose (HD), low-dose (LD) and placebo-control (PL) groups receiving 3.0, 1.5 and 0 g NS day^-1 in capsules. Trained study-monitors supervised NS capsule administration to participants and recorded side-effects daily. Physical examinations were performed monthly. Blood and urine samples were collected for laboratory analysis. Approximately 92% of the participants (162 of 177) completed the study and compliance rate was over 97%. Overall, 99.5% of person × time reported no side-effects throughout the study. Mild to moderate health events (∼0.5% of person × time) were recorded in some participants. Symptoms included nausea, diarrhea, heartburn and dizziness. These side-effects were statistically similar among all three groups. No significant differences were shown in hematology, liver and kidney function or electrolytes in the three groups. These findings demonstrate that NS clay is apparently safe and practical for the protection of humans against aflatoxins in populations at high risk for aflatoxicosis.     

NovaSil clay intervention in Ghanaians at high risk for aflatoxicosis. I. Study design and clinical outcomes

A 3-month double-blind and placebo-controlled, phase IIa clinical trial was conducted in Ghana to investigate the safety, tolerance and aflatoxin-sorption efficacy of dietary NovaSil (NS). Volunteers (507 subjects) were clinically screened to evaluate their general health, pregnancy status and blood AFB₁–albumin adduct levels. Of these subjects, 177 were randomly assigned to three groups: high-dose (HD), low-dose (LD) and placebo-control (PL) groups receiving 3.0, 1.5 and 0 g NS day^?1 in capsules. Trained study-monitors supervised NS capsule administration to participants and recorded side-effects daily. Physical examinations were performed monthly. Blood and urine samples were collected for laboratory analysis. Approximately 92% of the participants (162 of 177) completed the study and compliance rate was over 97%. Overall, 99.5% of person?×?time reported no side-effects throughout the study. Mild to moderate health events (～0.5% of person?×?time) were recorded in some participants. Symptoms included nausea, diarrhea, heartburn and dizziness. These side-effects were statistically similar among all three groups. No significant differences were shown in hematology, liver and kidney function or electrolytes in the three groups. These findings demonstrate that NS clay is apparently safe and practical for the protection of humans against aflatoxins in populations at high risk for aflatoxicosis.     

富含共轭亚油酸的食用油安全性毒理学试验研究

目的日本已经有富含共轭亚油酸的食用油商品。为了使共轭亚油酸在我国得到广泛的应用,进行富含纯度共轭亚油酸食用油的食品安全性毒理试验研究。方法依据GB15193—94《食品安全性毒理学评价程序和方法》进行急性毒性试验、三项遗传毒性试验和30天喂养试验。结果共轭亚油酸对两种性别的SPF级昆明种小鼠经口毒性,一次灌胃量达20g／kg·bw两周内动物未见明显中毒症状,无动物死亡,按急性毒性分级标准规定,该受试物属无毒级。三项遗传毒性试验（Ames、小鼠骨髓嗜多染红细胞微核试验、小鼠精子畸形试验）结果均为阴性。30天喂养试验结果表明：该受试物O．87、2．20、4.30g／kg.bw剂量（分别相对于推荐人群日摄影入量3．6g/kg.bw的20、50、100倍）对wistar大鼠的临床检查,血液学,生化学,脏器重量和系数以及病理组织多样指标无明显影响,未发现该受试物有明显的毒性作用。结论富含共轭亚油酸的食用油既无毒也无任何副作用。     

Determination of the aflatoxin AFB1 from corn by direct analysis in real time-mass spectrometry (DART-MS)

Direct analysis in real time (DART) ionisation coupled to a high-resolution mass spectrometer (MS) was used for screening of aflatoxins from a variety of surfaces and the rapid quantitative analysis of a common form of aflatoxin, AFB1, extracted from corn. Sample preparation procedure and instrument parameter settings were optimised to obtain sensitive and accurate determination of aflatoxin AFB1. 84:16 acetonitrile water extracts of corn were analysed by DART-MS. The lowest calibration level (LCL) for aflatoxin AFB1 was 4 μg kg^–1. Quantitative analysis was performed with the use of matrix-matched standards employing the ¹³C-labelled internal standard for AFB1. DART-MS of spiked corn extracts gave linear response in the range 4–1000 μg kg^–1. Good recoveries (94–110%) and repeatabilities (RSD = 0.7–6.9%) were obtained at spiking levels of 20 and 100 μg kg^–1 with the use of an isotope dilution technique. Trueness of data obtained for AFB1 in maize by DART-MS was demonstrated by analysis of corn certified reference materials.     

Fate of aflatoxin M1 in cheese whey processing

Aflatoxin M₁ (AFM₁) is an important mycotoxin frequently found in milk and in dairy products. It is a minor metabolic product of Aspergillus flavus and A parasiticus. However, it occurs in dairy products as a metabolite formed in cows from aflatoxin B₁ contained in animal feeds. In cheese production, AFM₁ distributes between curd and whey, being present in products derived from cheese whey processing. In this study, cheese whey from dairy processing was artificially contaminated with the mycotoxin at about 0.1 µg l⁻¹. Ultra‐filtration experiments of whey were carried out in order to determinate AFM₁ distribution between retentate (protein‐rich fraction) and permeate (lactose‐rich fraction). Recoveries of AFM₁ in retentate were 72.6–86.4% while, in permeate, recoveries were in the range 2.4–14.7%. Partition coefficients of AFM₁, lactose and protein were calculated to determine whether there was an interaction between AFM₁ and protein. In all experiments, AFM₁ partition coefficient was lower than 1, whilst for lactose coefficients close to 1 were determined, showing an affinity of aflatoxin M₁ to the protein‐rich fraction (retentate). Copyright © 2005 Society of Chemical Industry     

茶叶中黄曲霉毒素的安全性风险研究进展

茶叶是世界上最流行的饮品之一,因其独特的风味和对人体有益的健康功能为人们所喜爱。茶叶在生长、采摘、加工、运输及储存过程中可能存在潜在的黄曲霉毒素污染,黄曲霉毒素是世界上已知毒性最大的真菌毒素,对人类健康存在极大威胁。黄曲霉毒素主要有四种常见的亚型,包括黄曲霉毒素B1,B2,G1,G2。其中黄曲霉毒素B1是毒性最大的黄曲霉毒素,被国际癌症研究机构列为Ⅰ类致癌物。因此评估茶叶中是否存在黄曲霉毒素及其安全性具有重要意义。本文系统地综述了黄曲霉毒素的理化性质、致病机理,以及茶叶中可能产黄曲霉毒素的微生物和黄曲霉毒素在茶叶中的检出情况等,并探讨茶叶中黄曲霉毒素的潜在风险,为茶叶中黄曲霉毒素的风险评估与防控提供支持。     

莓茶乙醇提取物的急性毒性研究

对莓荼乙醇提取物的急性毒性进行研究.取Wistar大鼠40只,清洁级,随机分为2组,每组20只,雌雄各半,以最大耐受量法灌胃给予受试样品组大鼠最大使用浓度和最大灌胃容量的莓茶乙醇提取物,1天2次(相隔4h),连续观察14d.结果表明,受试样品组大鼠毛色,皮肤,粘膜,眼睛,呼吸,循环,自主活动及中枢神经系统、行为表现等均与阴性对照组大鼠无明显差别,整个试验期内无大鼠死亡,莓茶乙醇提取物大鼠口服灌胃的最大耐受量为10.0g/kg大鼠体重;对所有试验大鼠进行大体解剖,组织器官未见有颜色、体积、质地等改变,说明莓荼乙醇提取物的毒性很小,具有较好的食用安全性.     

Toxic Compounds Formed on Prolonged Heating of Citrinin under Watery Conditions

Citrinin was partially decomposed by heating under aqueous conditions at 90°C for > 10 min and a group of degraded compounds (Group I) was detected by TLC. At 100°C and 110°C, citrinin disappeared rapidly, and the cytotoxicity of the samples increased with prolonged heating. At 120°C, citrinin disappeared more rapidly while TLC spots of Group I compounds also diminished upon >20 min heating and a new group of compounds (Group II) appeared. Cytotoxicity decreased rapidly at > 120°C and was eliminated after 10 min at 130°C. Group I appeared to contain toxic compound(s) but Group II did not. Heating citrinin under conditions similar to cooking may cause formation of additional cytotoxic compounds.     

食品污染物3-氯-1,2-丙二醇毒理作用的研究进展

氯丙醇类化合物3-氯-1,2-丙二醇（3-MCPD）是目前国际上广为关注的食品污染物,最初发现在酸水解植物蛋白加工而成的食品中。近年来,许多食品特别是精制油中发现大量3-MCPD脂类,其能够在体内通过代谢途径产生3-MCPD。研究发现3-MCPD在啮齿类动物中存在明显的毒性作用,且具有种属和位点特异性。结合国内外毒理学研究成果,概述3-MCPD体内代谢途径,详细综述其急性毒理、致癌性以及遗传、生殖、免疫、神经毒性机制的研究进展,并展望了3-MCPD毒理学评价进一步研究的方向。      

动力源胶囊的安全性评价研究

目的对抗运动疲劳功能食品动力源胶囊进行安全性评价研究。方法采用限量法测定急性毒性试验,给予KM小鼠受试物最大剂量1 0 g/kg·BW后,观察14天内有无动物死亡,计算半数致死量(LD50)。应用30 d喂养试验观察可能的亚慢性毒性,分别设2670 mg/kg·BW、1330 mg/kg·BW、670 mg/kg·BW)剂量组和蒸馏水空白对照组,灌胃给予SD大鼠受试物30 d,观察和记录SD大鼠的生长发育情况、摄食量、食物利用率、血液学指标、血液生化指标和脏器病理检查。结果急性毒性试验观察期内受试动物未出现任何异常表现及死亡,表明样品无毒;在30 d喂养试验中各组大鼠给予不同剂量的动力源胶囊30 d后,其血液生化学检查、脏器称量结果表明,各检验项目的实验组与对照组比较均差异不显著。病理组织学检查结果表明对照组和各剂量组雄、雌性大鼠的肝、脾、肾、胃、肠、睾丸(卵巢)均未见与实验因素有关的病理组织学变化,表明30 d喂养试验未见其对受试动物有毒性损害作用。结论动力源胶囊使用安全。     

免疫亲和层析及其在真菌毒素检测中应用

该文简介免疫亲和层析工作原理,载体要求与选择,免疫亲和柱制备与使用,重点综述免疫亲和层析在黄曲霉毒素,赭曲霉毒素,玉米赤霉烯酮,脱氧雪腐镰刀菌烯醇,伏马毒素,T-2毒素等真菌毒素检测中应用最新进展。     

Lifetime,low-dose ochratoxin A dietary study on renal carcinogenesis in male Fischer rats

Carcinoma arising from male rat renal parenchyma is an aspect of the nephrotoxicity of ochratoxin A (OTA) and is a factor in considering application of animal data to human health risk assessment. We present experimental data to complement already published and to complete dose–response findings for dietary OTA. From 34 rats, only four unilateral renal carcinomas (12%) developed during a 2-year exposure to dietary OTA, contaminated to give the same weekly overall dosage as in the 50 µg kg^?1 gavage-dosing regimen of an NTP study (30%). Statistical analysis included adjustment for premature leukaemia deaths, resulting in the carcinoma incidence of 35% (10–81%), and showed no significant difference from NTP (incidence of 43% (23–49%)) due to the smaller number of animals. However, absence of microscopic neoplastic renal lesions in premature decedents argues for minimal effect of the 47% leukaemia on carcinoma expression in the present experiment. This would fit with previously published findings showing significantly less carcinoma expression from a regimen administering an OTA dose in feed than was achieved by a lower dose by gavage as in the NTP study. It is concluded that chronic gavage administration of OTA to male rats may optimise carcinoma incidence for toxicological purposes, but that the dietary mode gives data more applicable to assessing putative health risk for humans.     

沙棘果皮渣黄酮毒理学初步评价

以沙棘果皮渣黄酮为受试物,经口染毒针对ICR小鼠做急性毒性实验、小鼠骨髓细胞染色体畸变实验、小鼠骨髓细胞微核实验、小鼠精子畸变实验,对受试物进行急性毒性实验及初步遗传毒性评价。实验结果表明:小鼠经口染毒最大耐受量(MTD)为24g/kg(>15g/kg),受试物的急性毒性分级为无毒级;在MTD以下分设高(8g/kg)、中(4g/kg)、低(2g/kg)三个剂量组考察受试物的遗传毒性,实验结果为小鼠骨髓染色体畸变率、小鼠骨髓细胞微核率以及小鼠精子畸变率均未发现增高,表明受试物不能导致小鼠骨髓细胞染色体畸变,不会诱发小鼠嗜多染红细胞微核产生,对小鼠精子无致畸作用。     

Evaluation of atoxigenic isolates of Aspergillus flavus as potential biocontrol agents for aflatoxin in maize

Aflatoxin contamination resulting from maize infection by Aspergillus flavus is both an economic and a public health concern. Therefore, strategies for controlling aflatoxin contamination in maize are being investigated. The abilities of eleven naturally occurring atoxigenic isolates in Nigeria to reduce aflatoxin contamination in maize were evaluated in grain competition experiments and in field studies during the 2005 and 2006 growing seasons. Treatments consisted of inoculation of either grains in vials or ears at mid-silking stage in field plots, with the toxigenic isolate (La3228) or atoxigenic isolate alone and co-inoculation of each atoxigenic isolate and La3328. Aflatoxin B₁?+?B₂ concentrations were significantly (p?<?0.05) lower in the co-inoculation treatments compared with the treatment in which the aflatoxin-producing isolate La3228 was inoculated alone. Relative levels of aflatoxin B₁?+?B₂ reduction ranged from 70.1% to 99.9%. Among the atoxigenics, two isolates from Lafia, La3279 and La3303, were most effective at reducing aflatoxin B₁?+?B₂ concentrations in both laboratory and field trials. These two isolates have potential value as agents for the biocontrol of aflatoxin contamination in maize. Because these isolates are endemic to West Africa, they are both more likely than introduced isolates to be well adapted to West African environments and to meet regulatory concerns over their use throughout that region.     

Determination of aflatoxins in by-products of industrial processing of cocoa beans

This study has examined the occurrence of aflatoxins in 168 samples of different fractions obtained during the processing of cocoa in manufacturing plants (shell, nibs, mass, butter, cake and powder) using an optimised methodology for cocoa by-products. The method validation was based on selectivity, linearity, limit of detection and recovery. The method was shown to be adequate for use in quantifying the contamination of cocoa by aflatoxins B₁, B₂, G₁ and G₂. Furthermore, the method was easier to use than other methods available in the literature. For aflatoxin extraction from cocoa samples, a methanol–water solution was used, and then immunoaffinity columns were employed for clean-up before the determination by high-performance liquid chromatography. A survey demonstrated a widespread occurrence of aflatoxins in cocoa by-products, although in general the levels of aflatoxins present in the fractions from industrial processing of cocoa were low. A maximum aflatoxin contamination of 13.3?ng?g^?1 was found in a nib sample. The lowest contamination levels were found in cocoa butter. Continued monitoring of aflatoxins in cocoa by-products is nevertheless necessary because these toxins have a high toxicity to humans and cocoa is widely consumed by children through cocoa-containing products, like candies.     

CAC、欧盟、美国与中国粮食中真菌毒素限量标准的差异分析

真菌毒素是真菌产生的毒性次级代谢产物,危害较大的有黄曲霉毒素、赭曲霉毒素A、单端孢霉烯族毒素、玉米赤霉烯酮、伏马毒素和麦角类生物碱等。制定真菌毒素的限量标准是真菌毒素一级预防的主要措施。通过对CAC、欧盟、美国和中国粮食中真菌毒素限量标准的对比分析,找出我国现行食品安全国家标准中有关粮食真菌毒素污染控制指标存在的差异,对修订我国粮食中真菌毒素含量的限量标准提供参考和借鉴。     

汉莲牌红曲灵芝丹参胶囊的动物毒理学 安全性评价研究

目的对汉莲牌红曲灵芝丹参胶囊的服用安全性开展毒理学研究。方法按照国家标准要求和相关规定,首先进行小鼠急性毒性试验,采用最大给药量实验法(maximum tolerated dose,MTD),然后进行遗传性毒性试验,包括Ames试验、小鼠骨髓细胞微核试验和小鼠精子畸形试验,最后进行大鼠30 d喂养实验来评价其毒理学安全性,以2670.0、2002.5、1335.0 mg/kg·bw三个剂量,观察大鼠体重、增重量、进食量、食物利用率、血常规等指标的变化。结果给最大给药量(30000 mg/kg)的样品灌胃后,未见中毒症状,无动物死亡;Ames试验、小鼠骨髓细胞微核试验和小鼠精子畸形试验3项遗传毒性试验结果均为阴性;30 d喂养试验发现,与对照组相比,各剂量组大鼠的各项指标差异无统计学意义(P0.05)。结论本品在本实验范围内无毒,无遗传性产品,可以作为降血脂保健食品用于人体。     

膳食反式脂肪酸的风险评估研究进展

反式脂肪酸是一类包含一个或多个反式构型双键的不饱和脂类分子。膳食中的反式脂肪酸有2类:微量的天然反式脂肪酸和可观的人造反式脂肪酸。过去的研究认为反式脂肪酸的摄入仅仅是一个营养问题,但越来越多的毒理学和暴露评估的研究结果表明反式脂肪酸对人体健康有诸多不良影响。因此,反式脂肪酸的摄入已成为一个食品安全问题。目前,许多国家已经对反式脂肪酸的摄入量做了规定。本文主要围绕膳食反式脂肪酸的来源、对人体产生的生理效应和病理影响、产生这些效应的细胞或分子机制,以及如何有效控制反式脂肪酸的摄入等进行综述,并讨论了反式脂肪酸的风险评估现状和未来展望。