Natural Plant Toxins Research Articles

Insight into the Impact of Food Processing and Culinary Preparations on the Stability and Content of Plant Alkaloids Considered as Natural Food Contaminants

Pyrrolizidine alkaloids, tropane alkaloids and opium alkaloids are natural plant toxins that have recently gained special interest in food safety due to their concerning occurrence in many foods and feeds. Although a legislation for these alkaloids has recently been established, the concentration levels of these toxins in food exceed in many cases the maximum limit established by the competent authorities. Moreover, these regulations only establish maximum limits of these compounds for certain raw materials, but processed products are generally not considered. However, it is important to correctly assess the potential health risk of these alkaloids through the diet. Accordingly, this review aims to provide insight into these alkaloids and give an overview on how food processing and culinary preparation can influence their content and stability. For this purpose, the most relevant works that address the effect of heat treatment, fermentation, infusion preparation (transfer rate) and other treatments (milling, washing and soaking) on these natural toxins are reviewed. To date, this research field has been scarcely studied and many of the results published are contradictory, so it is not always possible to establish conclusive findings. In many cases, this is due to a lack of experimental design and exhaustive control of the different variables that may affect these treatments and preparations. Likewise, considering the transformation of these alkaloids into toxic degradation products it is also of high interest. Therefore, further studies are needed to delve deeper into the stability of these toxins and to understand how their content may be affected by the transformation of contaminated raw materials into processed products, so that the risk exposure of the population to these alkaloids through diet can be determined more precisely. Hence, this topic constitutes a research line of great interest for future works with many challenges to be resolved.

Potential toxicity of wild Ipomoea ingested by schoolchildren in remote Northeastern Thailand

Background: Natural plant toxins can cause food poisoning upon intentional or unintentional consumption of wild plants. Some toxic wild plants can be mistaken for edible species because of their morphological resemblance. This study examined a poisoning case report of schoolchildren who consumed a steamed tuberous root of wild Ipomoea, misidentified as I. mauritiana, and experienced gastrointestinal toxicity. Objectives: This study aimed to identify the tuberous root of wild Ipomoea using the internal transcribed spacer (ITS) region as a DNA barcode and characterize compounds obtained using gas chromatography-mass spectrometry (GC-MS). Materials and methods: DNA was extracted from fresh and cooked samples of the storage root. PCR amplification and DNA sequencing of the entire ITS region were performed. FastTree and maximum likelihood analyses were used to obtain phylogenetic trees of the Ipomoea species. Root extracts were prepared for GC-MS analysis, and potentially harmful phytochemicals responsible for poisonous plant exposure were predicted based on a well-established plant toxin database. Results: ITS phylogeny showed a close relationship between wild toxic Ipomoea and edible I. mauritiana. The chemometric profile obtained from GC-MS analysis of the root extracts revealed the presence of 31 phytochemicals. Among them, two putatively toxic compounds identified were β-amyrin and coumarin. Conclusion: Misidentification of the wild poisonous plant reported herein resulted in toxic plant ingestion. Although most poisonous plant exposures are not life threatening, measures should be taken to ensure the safety of the general public.

Эффективность применения спиртовых и СО2-экстрактов из ядовитых растений для контроля численности проволочников в посевах подсолнечника

The mostly cultivated crop in the Krasnodar region is sunflower, which seedlings are damaged a lot by larvae of bugs from a family Elateridae. Wireworm is quite spread soil pest, so seed treatment with pesticides is an obligatory action for plant protection. However, there are some alternatives to the pesticides; one of them is usage of natural plant toxins containing different types of chemical combinations, such as alkaloids, terpenes, essential oils, etc. Many plants contain toxins characterized with repellent qualities or highly toxic matters – phytotoxins that serve as a natural protection of the pests. The pur-pose of the research is to study the effectiveness of extracts from noxious plants that are used for treatment of sunflower seeds as an alternative method to decrease wireworm damages of the crop sowings. The researches were conducted in the central agricultural and climatic zone of the Krasnodar region in the V.S. Pustovoit All-Russian Research Institute of Oil Crops (Krasnodar) in 2014–2016. In a vegetative experiment, the plants damage on a plot sown with seed treated with the plant extracts was equal to 10–20%, and in control one – 40%. Application of the СО2-extract of tobacco dust proved 100% protection of sunflower plants against damage and death. In variants with seed treatment with ethanolic extracts of leafy spurge (Euphorbia virgata Waldst. et Kit.) and greater celandine (Chelidonium majus L.), number of died wireworms was the biggest and reached up 75%. The results of field experiments showed the sunflower seed treatment with the ethanolic and СО2-extracts of plants provided sunflower plant population of 73.1–85.4% of a norm at an average wireworm number of 8.5 pcs/m2. The biological effeciency of the extracts was 52.2–74.0%, it was highest at the variant with seed treatment with the ethanolic extract of greater celandine. The sunflower seed treatment with the ethanolic extract of greater celandine, and the СО2-extract of tobacco dust allowed obtaining a maximal saved yield – 0.11–0.17 t/hа.

Development, optimization, validation and application of ultra high performance liquid chromatography tandem mass spectrometry for the analysis of pyrrolizidine alkaloids and pyrrolizidine alkaloid N-oxides in teas and weeds

Pyrrolizidine alkaloids (PAs) and their corresponding N-oxides (PANOs) are natural plant toxins, which are widely distributed in various types of teas. The source of PAs contamination in tea is probably related to weeds in tea gardens. The method of simultaneously detecting PAs/PANOs in teas and weeds has not been reported. A sensitive method was developed for detecting 14 PAs/PANOs simultaneously in teas and weeds using ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS). Sample preparation was optimized step by step. Sulfuric acid at 0.1 M was used to extract the target compounds. Large capacity PCX column was used to enrich target compounds and remove complex matrices effectively, following by the elution solvent with methanol containing 0.5% NH 4 OH. The method showed good linearity for all 14 analytes with regression coefficients (R 2 ) > 0.99. Satisfactory recoveries of target compounds spiked at three concentrations (10, 50, 100 μg/kg) ranged from 68.6% to 110.2%, while intra-day and inter-day precision were below 18.5%. Limits of detection (LODs) and limits of quantification (LOQs) of 14 PAs/PANOs in different matrices were in the range of 0.001–0.4 μg/kg and 1–5 μg/kg, respectively. This method was firstly applied to monitor the occurrence of PAs/PANOs in different kinds of teas from China and weed samples collected in the local tea gardens. Seven PAs/PANOs (>LOQs) were detected in 15.32% of tea samples and maximum total PAs/PANOs content was 151.33 μg/kg. Pollution levels and patterns of PAs/PANOs were different significantly in various types of teas. Based on the occurrence of PAs/PANOs in teas and weeds, weeds in tea garden were likely to be the source of PAs/PANOs in teas and the most relevant contaminating species of tea samples could be Crassocephalum crepidioides (Benth.) S. Moore. • 14 PAs/PANOs were determined in teas and weeds using UHPLC-MS/MS. • Targets were extracted using 0.1M H 2 SO 4 and complex matrices were purified by SPE. • Weeds in tea garden were likely to be source of PAs in teas. • The most relevant contaminating species of teas was found.

Suspect and Target Screening of Natural Toxins in the Ter River Catchment Area in NE Spain and Prioritisation by Their Toxicity.

This study presents the application of a suspect screening approach to screen a wide range of natural toxins, including mycotoxins, bacterial toxins, and plant toxins, in surface waters. The method is based on a generic solid-phase extraction procedure, using three sorbent phases in two cartridges that are connected in series, hence covering a wide range of polarities, followed by liquid chromatography coupled to high-resolution mass spectrometry. The acquisition was performed in the full-scan and data-dependent modes while working under positive and negative ionisation conditions. This method was applied in order to assess the natural toxins in the Ter River water reservoirs, which are used to produce drinking water for Barcelona city (Spain). The study was carried out during a period of seven months, covering the expected prior, during, and post-peak blooming periods of the natural toxins. Fifty-three (53) compounds were tentatively identified, and nine of these were confirmed and quantified. Phytotoxins were identified as the most frequent group of natural toxins in the water, particularly the alkaloids group. Finally, the toxins identified to levels 2 and 1 were prioritised according to their bioaccumulation factor, biodegradability, frequency of detection, and toxicity. This screening and prioritisation approach resulted in different natural toxins that should be further assessed for their ecotoxicological effects and considered in future studies.

Detection of cyanogenic glycosides in ethnomedicinal plants of Euphorbiaceae used by Tribes in Mizoram, India

Cyanogenic glycosides are natural plant toxins found in various plants, the majority of which are consumed by humans. Cyanide is formed after cyanogenic glycoside hydrolysis that occurs during the crushing of the edible plant material, either during consumption or during the processing of the plant. In this paper, we tested for cyanogenic glycosides using picrate impregnated filter paper in a number of ethnomedicinally important plants. We evaluate 19 species of euphorbiaceae, out of which 7 are cyanogenic. In Mizoram, people living in the urban region still relies heavily on ethnomedicinal plant, most of the times these plants are eaten boiled, cooked or raw, so it is important that we know the content of these plants. From the research we found several plants to contain cyanogenic glycosides which are eaten as a form of medication for various ailments.

Current Problems Associated with Overseas Health Products

In recent years, consumer interest in health and health foods (e.g., dietary supplements) has increased, and the types of and market for health foods have also expanded rapidly. The safety of health foods is a significant concern in many countries. Numerous adverse events associated with the consumption of health foods have been reported. There are cases that have resulted in serious liver failure, renal failure, and death in other countries. These products may contain undeclared medical ingredients and toxic chemical compounds that are illegally and intentionally added or contain natural plant toxins. Products containing high levels of heavy metals have also been reported to cause such adverse events. Some products remain on the market, even after regulatory agencies alert consumers and issue warnings to their sellers. Moreover, because people can buy health foods from sources overseas via the Internet, adverse effects associated with the use of such products remain a concern. Two cases of adverse events were reported in Japanese individuals who purchased "OxyElite Pro" products imported privately. They are advertised as weight-loss and muscle-building products and have been associated with many cases of liver failure and hepatitis in the USA. In this paper, regulatory systems and adverse events associated with the use of health foods in other countries are discussed.

Pyrrolizidine alkaloids in honey: Quantification with and without standards

Quantification of a large number of compounds in the absence of authentic standards is always a challenge. More than 600 pyrrolizidine alkaloids (PAs) have been found in plants however only limited number of PAs standards are commercially available. As PAs are the most widely distributed natural plant toxins with threat to human health, risk assessment calls for quantitative analytical methods with a wide scope including PAs without available standards. In this study, a method was developed that allows simultaneous quantification of 12 PAs in the honey samples by using HPLC-HRMS with authentic standards. This method was further extended to screen for other potential PAs in the honey using multi-target screening combined with a quantitative prediction model in the cases that authentic PAs were not available. The prediction model was subsequently validated by cross-validation and additional PAs standards which were not included in the model. The maximum concentration prediction error was 50.8%.

Toxalbumin exposures: 12 years' experience of U.S. poison centers

Toxalbumins are natural plant toxins purported to be highly toxic. The purpose was to evaluate toxalbumin exposures reported to U.S. poison centers to determine plants involved and their toxicities. A retrospective review of National Poison Data System data on acute toxalbumin exposures with known outcomes from 2000 through 2011 was performed. There were 1164 exposures. The majority involved one route (1135; 97.5%), mostly ingestions (904; 79.7%) or dermal (166; 14.3%). Most patients developed no effects (694; 59.6%) or minor effects (374; 32.1%). Moderate or major effects occurred in 8.3% with 66.6% ingestions and 23.9% dermal. There were no deaths. Exposures to the plants Ricinus communis and Robinia pseudoacacia were most common (33.8% and 32.9%, respectively), with gastrointestinal effects from R.communis (vomiting 19.6%, diarrhea 8.9%, nausea 7.9%) and dermal effects from R.pseudoacacia (puncture 28.7%, dermal irritation/pain 27.9%, and edema 13.3%). While toxalbumin plant exposures were generally well-tolerated, continued evaluation of risk is warranted since plants were primarily identified by the public. Major effects occurred in under 1% of cases overall, and not at all following unintentional ingestions. These findings should help allay concerns that unintentional ingestions of toxalbumin plants by young children will cause serious toxicity and possibly death.

Toxic Trojans: can feral cat predation be mitigated by making their prey poisonous?

Predation, along with competition and disease transmission from feral domestic cats (Felis catus), poses the key threat to many in situ and reintroduced populations of threatened species globally. Feral cats are more challenging to control than pest canids because cats seldom consume poison baits or enter baited traps when live prey are readily available. Novel strategies for sustainably protecting threatened wildlife from feral cats are urgently required. Emerging evidence suggests that once they have successfully killed a challenging species, individual feral cats can systematically eradicate threatened prey populations. Here we propose to exploit this selective predation through three targeted strategies to improve the efficacy of feral cat control. Toxic collars and toxic implants, fitted or inserted during monitoring or reintroduction programs for threatened species, could poison the offending cat before it can effect multiple kills of the target species. A third strategy is informed by evidence that consumption of prey species that are relatively tolerant to natural plant toxins, can be lethal to more sensitive cats. Within key habitats of wildlife species susceptible to cat predation, we advocate increasing the accessibility of these toxins in the food chain, provided negative risks can be mediated. Deliberate poisoning using live and unaffected ‘toxic Trojan prey’ enables ethical feral cat management that takes advantage of cats’ physiological and behavioural predilection for hunting live prey while minimising risks to many non-targets, compared with conventional baiting.

Gramine-induced growth inhibition, oxidative damage and antioxidant responses in freshwater cyanobacterium Microcystis aeruginosa

In recent years, the exploration and development of the effective methods of treatment and prevention to algal blooms, especially Microcystis aeruginosa blooms has been an important issue in the field of water environment protection. Allelochemicals (natural plant toxins) are considered promising sources of algicides to control algal blooms. The objective of this study is to determine the inhibitory effects and potential mechanisms of a well-known allelochemical gramine (N,N-dimethyl-3-amino-methylindole) on bloom-forming cyanobacterium M. aeruginosa. The results showed that this indole alkaloid effectively inhibited the growth of M. aeruginosa. The effective concentration causing a 50% inhibition at 3 d (EC 50, 3 d) increased with the initial algal density (IAD) increasing. When IAD increased from 5 × 10 4 to 5 × 10 5 cells mL −1, the values of EC 50, 3 d increased from 0.5 to 2.1 mg L −1. In the cells of M. aeruginosa, gramine caused an obvious increase in the level of reactive oxygen species (ROS). The lipid-peroxidation product malondialdehyde (MDA) increased significantly in gramine-treated cells. The effects of gramine on enzymatic and non-enzymatic antioxidants were in different manners. The activity of superoxide dismutase (SOD) was decreased after gramine exposure. The catalase (CAT) activity was increased after 4 h but decreased from 60 h. Both the contents and the regeneration rates of ascorbic acid (AsA) and reduced glutathione (GSH) were increased after 4 h of exposure to gramine. However, only GSH content was still increased after 40 h of exposure. These results suggested that the activation of antioxidants in M. aeruginosa played an important role to resist the stress from gramine at initial time, the inactivation of SOD is crucial to the growth inhibition of M. aeruginosa by gramine, and the phytotoxicity of gramine on M. aeruginosa may be due to oxidative damage via oxidation of ROS.

Plant biocommunicators: their phytotoxicity, degradation studies and potential use as herbicide models

The development of new bioactive molecules with potential application in pharmacology and agriculture by using natural products as templates has been a widely used approach in the recent years. Focusing our attention in phytochemicals with potential application in agriculture, allelochemicals (natural plant toxins) have been deeply researched with the main purpose of finding phytotoxic substances to use as new herbicidal templates. The development of new analytical methodologies, improved bioassay techniques and a complete understanding of the allelopathic phenomenon will provide new tools for natural herbicide models development, in the context of the new approaches to integrated pest management. A deeper knowledge of the release and assimilation of allelochemicals, and the degradation phenomena associated to them will aid to discover new chemical structures with potential utility, in addition to a better understanding on the ecological interactions mediated by phytochemicals. The research on these topics, made with promising allelochemicals such as benzoxazinones and their degradation derivatives, the improvements on analytical design, the degradation mechanisms elucidation and the novel bioassay techniques recently developed, are revised herein.

First European interlaboratory study of the analysis of benzoxazinone derivatives in plants by liquid chromatography

Six laboratories from four different countries participated in the first European interlaboratory comparison exercise within the framework of the “Fate and toxicity of allelochemicals (natural plant toxins) in relation to environment and consumer” (FATEALLCHEM) European Union Project. The study, organized between November 2002 and March 2003, involved the analyses of seven benzoxazinone derivatives in two standard solutions and one purified extract of root material. Results are reported from the first phase of the study that examined the variability associated with different detection methods and different laboratories. The analytical strategies were based on liquid chromatography (LC) with diode array detection, LC coupled to mass spectrometry (MS) and LC coupled to tandem MS. When data from all laboratories were pooled, the relative standard deviation values ranged from 2 to 14% for the determination of target compounds in standard solutions, and between 19 and 47% for the analysis in root material. Comparison of the three detection techniques leads to the conclusion that MS approaches are the most accurate and precise techniques for the determination of benzoxazinone derivatives at ng/μL level in plant material.

Do plant toxins impose constraints on herbivores? An investigation using compartmental analysis

Plant secondary metabolites are often acutely toxic to animals, but the influence of this property on interactions with herbivores has been debated vigorously. In this paper we apply a compartmental model, developed to investigate the movement of insecticides through the bodies of animals, to quantify the effect of natural plant toxins. A simulation based on the model is also used to examine the degree of tolerance necessary for a herbivore to avoid illness. Comparison with studies from insecticide science suggests that the required level of tolerance is high enough to impose major ecological limitations on herbivory at naturally occurring concentrations. Various adaptive mechanisms could be employed to overcome this inhibitory effect, and the model allows a precise analysis of their relative importance in a given species. More generally, elasticity analysis shows that these mechanisms differ considerably in efficiency, with desensitisation at the molecular site of action cited as particularly cost effective. However, such efficient mechanisms are often toxin‐specific, and more likely to evolve in herbivores which display a high degree of host‐plant constancy. It should therefore be less costly to achieve tolerance in oligophagous herbivores than polyphagous ones. Reduced concentrations of secondary metabolites in cultivated species could curtail their effectiveness dramatically and universally.

The molecular perspective: microtubules and the taxanes.

interlocking protein filaments. A beautiful star of microtubules, the largest of these filaments, radiates outward from the center of the cell to the cell surface. This “aster” of microtubules is the railway system of the cell. Many types of cargo are carried along these rails. The endoplasmic reticulum is pulled by molecular motor proteins along microtubules, spreading it evenly throughout the cell. Vesicles are delivered to their destinations along microtubules. And, when cells divide, the most valuable cargo of the cell is carried by microtubules. Paired copies of each of the chromosomes are attached to the ends of a doubled microtubule aster and carefully separated into the two daughter cells. The cytoskeleton, in contrast to our articulated skeleton of bones, is a dynamic structure. It is continually constructed and demolished according to the shifting needs of the cell. A typical microtubule lasts for only 10 minutes before it is disassembled and the parts used to build a new one. Microtubules are nucleated in the “microtubule-organizing center,” at the center of the cell, and then extended one piece at a time into the cytoplasm. Growth proceeds in fits and starts in a process known as “dynamic instability.” Tubules grow slowly and steadily, but are punctuated by periods of rapid disassembly, when large regions peel away from the ends. A small portion of the microtubule may break up, or the fragmentation may extend all the way back to the start, completely destroying the tubule. In special cases, such as the microtubules that support the long axons and dendrites of nerve cells, auxiliary proteins stabilize the microtubule for longer periods of time. But the dynamic structure of microtubules is essential for their everyday function in transport and cell division. Essential functions make excellent targets for toxins and for cancer chemotherapy. The central role of microtubules in cell division makes them particularly attractive. Many organisms have developed toxins that block the dynamic instability of microtubules, thus blocking the ability of the cell to divide. Two types of natural plant toxins are widely used in medicine. They have the identical result of blocking division, but achieve it in exactly opposite ways. The vinca alkaloids, such as vinblastine, vincristine, and vinorelbine, bind to the end of growing microtubules, blocking the addition of more tubulin dimers. The tubule cannot grow, but it can still disassemble, so the microtubules ultimately break down into nothing. Alternatively, the taxanes, The Molecular Perspective: Microtubules and the Taxanes

The molecular perspective: microtubules and the taxanes.

interlocking protein filaments. A beautiful star of microtubules, the largest of these filaments, radiates outward from the center of the cell to the cell surface. This “aster” of microtubules is the railway system of the cell. Many types of cargo are carried along these rails. The endoplasmic reticulum is pulled by molecular motor proteins along microtubules, spreading it evenly throughout the cell. Vesicles are delivered to their destinations along microtubules. And, when cells divide, the most valuable cargo of the cell is carried by microtubules. Paired copies of each of the chromosomes are attached to the ends of a doubled microtubule aster and carefully separated into the two daughter cells. The cytoskeleton, in contrast to our articulated skeleton of bones, is a dynamic structure. It is continually constructed and demolished according to the shifting needs of the cell. A typical microtubule lasts for only 10 minutes before it is disassembled and the parts used to build a new one. Microtubules are nucleated in the “microtubule-organizing center,” at the center of the cell, and then extended one piece at a time into the cytoplasm. Growth proceeds in fits and starts in a process known as “dynamic instability.” Tubules grow slowly and steadily, but are punctuated by periods of rapid disassembly, when large regions peel away from the ends. A small portion of the microtubule may break up, or the fragmentation may extend all the way back to the start, completely destroying the tubule. In special cases, such as the microtubules that support the long axons and dendrites of nerve cells, auxiliary proteins stabilize the microtubule for longer periods of time. But the dynamic structure of microtubules is essential for their everyday function in transport and cell division. Essential functions make excellent targets for toxins and for cancer chemotherapy. The central role of microtubules in cell division makes them particularly attractive. Many organisms have developed toxins that block the dynamic instability of microtubules, thus blocking the ability of the cell to divide. Two types of natural plant toxins are widely used in medicine. They have the identical result of blocking division, but achieve it in exactly opposite ways. The vinca alkaloids, such as vinblastine, vincristine, and vinorelbine, bind to the end of growing microtubules, blocking the addition of more tubulin dimers. The tubule cannot grow, but it can still disassemble, so the microtubules ultimately break down into nothing. Alternatively, the taxanes, The Molecular Perspective: Microtubules and the Taxanes

Public perceptions of risk and acceptability of forest vegetation management alternatives in Ontario

We examined public perceptions of risk and acceptability for 9 alternatives to controlling forest vegetation in Ontario (N = 2,301) in the fall of 1994. The proportion of respondents indicating whether an alternative was 1) difficult to control, 2) potentially catastrophic, 3) a problem for future generations, and 4) a personal worry determined perceptions of risk for each vegetation management alternative. Ranking of alternatives from highest to lowest perceived risk was: aerially-applied herbicides > biological control > ground-applied herbicides > mulches > prescribed fire > heavy equipment > cover cropping > manual cutting > grazing animals. Public acceptance was lowest for aerially-applied herbicides (18%) followed by ground-applied herbicides (37%), biological control (57%), prescribed fire (57%), mulches (65%), heavy equipment (72%), cover cropping (80%), grazing animals (82%), and manual cutting (89%). Public acceptability of various agents for biological control differed depending on the proposed agent. Natural plant toxins were viewed as most acceptable (73%) followed by microorganims (42%), genetically-engineered organisms (39%), and viruses (21%). We found a strong correlation between a risk perception index and acceptability of the alternatives for the general public (r2 = 0.84) and those in timber-dependent communities (r2 = 0.89). Our results suggest that stronger public support can probably be achieved for forest vegetation management programs that include non-herbicide alternatives. Key words: forest vegetation management, public opposition, risk perception, herbicides, biological control, prescribed fire, mulches, heavy equipment, cover cropping, grazing animals, manual cutting

Cytochrome P450-Mediated Resistance to Isoquinoline Alkaloids and Susceptibility to Synthetic Insecticides inDrosophila

It is well documented that cytochrome P450 enzymes play a central role in metabolic resistance to natural plant toxins and synthetic pesticides. Using insecticide-susceptible and -resistant strains ofDrosophila melanogasterand monophagous Sonoran Desert drosophilids, the current study looked for a correlation between resistance to toxic cactus alkaloids and resistance to pesticides (DDT and propoxur) or a toxic, noncactus alkaloid (nicotine). Resistance to cactus alkaloids in cactophilicDrosophilawas not associated with resistance to DDT or propoxur. Conversely, a DDT-resistant strain ofD. melanogaster(Hikone R) was no more tolerant of cactus alkaloids than a susceptible strain (Canton S). Cactus alkaloid-metabolizingDrosophilawere, however, less susceptible to nicotine than a noncactophilic species (D. melanogasterstrain Canton S). These data suggest that resistance to cactus alkaloids in monophagous desertDrosophilainvolves the activity of cytochrome P450 isoforms with substrate specificities sufficiently narrow to preclude detectablein vivoactivity on compounds other than those that are chemically similar. These results are in contrast to what has generally been reported for more highly polyphagous insect species.

State Programs for Pesticide Residues in Foods

Two U.S. data collection and dissemination programs, FEEDCON and FOODCONTAM, are described. FEEDCON provides information on contamination levels in animal feeds of toxic chemical residues (pesticides, industrial chemicals, heavy metals, mycotoxins, natural plant toxins, salmonella, and therapeutic drug cross-contaminations). FEEDCON data are collected from approximately 40 state feed regulatory agencies, feed manufacturers, and related groups who subscribe ($100-$200 per year) to the program, which is sponsored by the Association of American Feed Control Officials. FOODCONTAM provides similar information, but is limited to pesticides, heavy metals and industrial chemicals (polychlorinated and polybrominated biphenyls, etc.) in human foods. Both programs have been developed and initiated under U.S. Food and Drug Administration contracts with the Mississippi State Chemical Laboratory. Program structures of both are outlined conceptually, and FOODCONTAM is described in detail. FOODCONTAM data-sharing program development is essentially complete, but expansion by incorporating FDA data with State Laboratory data is nearing reality.

Cancer and Cuisine

Cancer and Cuisine