Effects of isolated or combined exposure to sibutramine and rosuvastatin on reproductive parameters of adult male rats.

Many obese patients are exposed to hypolipidemic and serotonin-norepinephrine reuptake inhibitor (SNRI) drugs. Statins are one of the most marketed drugs in the world to treat dyslipidemia, while sibutramine, a SNRI drug, is prescribed in some countries to treat obesity and is detected as an additive in many adulterated weight loss supplements marketed worldwide. Previous studies reported adverse effects of isolated exposure to these drugs on male rat reproductive parameters. In the present work, we further investigated male reproductive toxicity of these drugs, administered in isolation or combination in adult rats for a longer period of treatment. Adult male rats (90 days) were treated (gavage) for 70 days with saline and dimethyl sulfoxide (control), sibutramine (10 mg/kg), rosuvastatin (5 mg/kg), or rosuvastatin combined with sibutramine. Sibutramine alone or with rosuvastatin, promoted a reduction in food intake and body weight gain, weight of the epididymis, ventral prostate and seminal vesicle; as well as decreased sperm reserves and transit time through the epididymis; androgen depletion; and increased index of cytoplasmic droplet. The rosuvastatin-treated group showed reduced frequency of ejaculation. Exposure to this drug alone or combined with sibutramine impaired epididymal morphology. Co-exposed rats had altered epididymal morphometry, and seminal vesicle and testis weights. The rats also showed decreased fertility after natural mating and a trend toward a delay in ejaculation, suggesting a small synergistic effect of these drugs. Given the greater reproductive efficiency of rodents, the results obtained in the present study raise concern regarding possible fertility impairment in men taking statins and SNRI drugs.

Synthesis and biological evaluation of new long-chain squaramides as anti-chagasic agents in the BALB/c mouse model.

Chagas Disease is caused by infection with the insect-transmitted protozoan Trypanosoma cruzi and affects more than 10 million people. It is a paradigmatic example of a chronic disease without an effective treatment in Latin America where the current therapies, based on Benznidazole and Nifurtimox, are characterised by limited efficacy, toxic side-effects and frequent failures in the treatment. We present a series of new long-chain squaramides, identified based on their 1H and 13C NMR spectra, and their trypanocidal activity and cytotoxicity were tested in vitro through the determination of IC50 values. Compounds 4 and 7 were more active and less toxic than the reference drug Benznidazole, and these results were the basis of promoting in vivo assays, where parasitaemia levels, assignment of cure, reactivation of parasitaemia and others parameters were determined in mice treated in both the acute and chronic phases. Finally, the mechanisms of action were elucidated at metabolic and mitochondrial levels and superoxide dismutase inhibition. The experiments allowed us to select compound 7 as a promising candidate for treating Chagas Disease, where the activity, stability and low cost make long-chain squaramides appropriate molecules for the development of an affordable anti-chagasic agent versus current treatments.

Quantitative analysis of UV photolesions suggests that cyclobutane pyrimidine dimers produced in mouse skin by UVB are more mutagenic than those produced by UVC.

The amount of photolesions produced in DNA after exposure to physiological doses of ultraviolet radiation (UVR) can be estimated with high sensitivity and at low cost through an immunological assay, ELISA, which, however, provides only a relative estimate that cannot be used for comparisons between different photolesions such as cyclobutane pyrimidine dimer (CPD) and pyrimidine(6-4)pyrimidone photoproduct (64PP) or for analysis of the genotoxicity of photolesions on a molecular basis. To solve this drawback of ELISA, we introduced a set of UVR-exposed, calibration DNA whose photolesion amounts were predetermined and estimated the absolute molecular amounts of CPDs and 64PPs produced in mouse skin exposed to UVC and UVB. We confirmed previously reported observations that UVC induced more photolesions in the skin than UVB at the same dose, and that both types of UVR produced more CPDs than 64PPs. The UVR protection abilities of the cornified and epidermal layers for the lower tissues were also evaluated quantitatively. We noticed that the values of absorbance obtained in ELISA were not always proportional to the molecular amounts of the lesion, especially for CPD, cautioning against the direct use of ELISA absorbance data for estimation of the photolesion amounts. We further estimated the mutagenicity of a CPD produced by UVC and UVB in the epidermis and dermis using the mutation data from our previous studies with mouse skin and found that CPDs produced in the epidermis by UVB were more than two-fold mutagenic than those by UVC, which suggests that the properties of CPDs produced by UVC and UVB might be different. The difference may originate from the wavelength-dependent methyl CpG preference of CPD formation. In addition, the mutagenicity of CPDs in the dermis was lower than that in the epidermis irrespective of the UVR source, suggesting a higher efficiency in the dermis to reduce the genotoxicity of CPDs produced within it. We also estimated the minimum amount of photolesions required to induce the mutation induction suppression (MIS) response in the epidermis to be around 15 64PPs or 100 CPDs per million bases in DNA as the mean estimate from UVC and UVB-induced MIS.

Synthesis, spectroscopic characterization and biological evaluation of unsymmetrical aminosquarylium cyanine dyes.

New unsymmetrical aminosquarylium cyanine dyes were synthesized and their potential as photosensitizers evaluated. New dyes, derived from benzothiazole and quinoline, were prepared by nucleophilic substitution of the corresponding O-methylated, the key intermediate that was obtained by methylation with CF3SO3CH3 of the related zwitterionic unsymmetrical dye, with ammonia and methylamine, respectively. All three news dyes herein described displayed intense and narrow bands in the Vis/NIR region (693-714nm) and their singlet oxygen formation quantum yields ranged from 0.03 to 0.05. In vitro toxicity, in Caco-2 and HepG2 cells, indicated that dark toxicity was absent for concentrations up to 5µM (for the less active dye) or up to 1µM (for the two more active dyes). The three dyes present potential as photosensitizers, differing in irradiation conditions and period of incubation in the presence of irradiated dye. The less active dye needs a longer irradiation period to exhibit phototoxicity which is only evident after longer period of contact with cells (24h). However, the remaining two more active dyes produce higher phototoxicity, even at shorter incubation periods (1h), with shorter irradiation time (7min). Although in different extents, these dyes show promising in vitro results as photosensitizers.

Allergic Contact Dermatitis: A Model of Inflammatory Itch and Pain in Human and Mouse.

This chapter is an overview of published observations from our laboratory on the psychophysics and neurobiology of the persistent itch and pain of allergic contact dermatitis (ACD). ACD is a clinically significant problem with many features characteristic of other pruritic disorders. Our approach was to produce ACD experimentally in humans and in the mouse. The goal was to use the mouse as an animal model for investigating the peripheral neural mechanisms of itch and pain of ACD in humans. Humans and mice were each sensitized by cutaneous topical application of squaric acid dibutyl ester, a hapten not encountered in the environment. Subsequent challenge at another cutaneous site produced local inflammation ("ACD") with humans reporting persistent itch (lasting up to a week) and mice exhibiting persistent itch- and pain-like behaviors directed toward the ACD site. Enhanced mechanically evoked itch and pain in surrounding skin in humans were reversibly blocked by numbing the ACD site with cold, suggesting dependence on ongoing activity from the site. In mice, in vivo recordings revealed spontaneous activity in a subset of pruriceptive, mechanoheat-sensitive nociceptors with unmyelinated axons innervating the ACD site. These and a larger subpopulation of acutely dissociated small-diameter neurons innervating the ACD site exhibited an upregulation of the receptor CXCR3 and excitatory responses to one of its ligands, the chemokine CXCL10 (IP-10) that contributes to the pathogenesis of ACD. Preliminary findings point to possible therapeutic targets that could be investigated in inflammatory itch disorders in humans.

Can Spirulina maxima reduce the mutagenic potential of sibutramine?

The worldwide obesity pandemic requires the use of anti-obesity drugs. Sibutramine is an anti-obesity drug that has been used worldwide but is indiscriminately consumed in Brazil. Several studies have demonstrated that sibutramine promotes weight loss and weight maintenance, but several side effects have been associated with its systematic consumption. For this reason, sibutramine was withdrawn from the European and American markets, but still remains legal for use in Brazil. Studies have shown that a 5-10% reduction in body weight results in outstanding health benefits for obese patients. However, in order to promote significant weight loss, it is necessary to use sibutramine for at least 2 years. This long-term exposure has carcinogenic potential, as sibutramine causes DNA damage. Thus, this study evaluated the in vivo mutagenic potential of sibutramine alone (5, 7, 10, 15, and 20 mg/kg) and in association with Spirulina maxima (150 and 300 mg/kg), a cyanobacterium with antioxidant potential, using the polychromatic erythrocyte micronucleus test. Our results reinforced the mutagenic potential of sibutramine alone, which showed a time-dependent action. Combinatory treatments with S. maxima were not able to reduce the genotoxicity of sibutramine. These results were confirmed in vitro with the cytokinesis-blocked micronucleus test. In conclusion, our data showed that new alternative anti-obesity treatments are needed since the consumption of sibutramine can increase the risk of cancer in overweight patients.

Fusarial toxins: secondary metabolites of Fusarium fungi.

Exposure to mycotoxins occurs worldwide, even though there are geographic and climatic differences in the amounts produced and occurrence of these substances.Mycotoxins are secondary chemical metabolites of different fungi. They are natural contaminants of cereals, so their presence is often inevitable. Among many genera that produce mycotoxins, Fusarium fungi are the most widespread in cereal-growing areas of the planet. Fusarium fungi produce a diversity of mycotoxin types, whose distributions are also diverse. What is produced and where it is produced is influenced primarily by environmental conditions, and crop production and storage methods. The amount of toxin produced depends on physical (viz., moisture, relative humidity, temperature, and mechanical damage), chemical (viz., carbon dioxide,oxygen, composition of substrate, insecticides and fungicides), and biological factors (viz., plant variety, stress, insects, spore load, etc.). Moisture and temperature have a major influence on mold growth rate and mycotoxin production.Among the most toxic and prevalent fusaria) toxins are the following: zearalenone,fumonisins, moniliformin and trichothecenes (T-2/HT-2 toxin, deoxynivalenol,diacetoxyscirpenol, nivalenol). Zearalenone (ZEA; ZON, F-2 toxin) isaphy to estrogenic compound, primarily a field contaminant, which exhibits estrogenic activity and has been implicated in numerous mycotoxicoses of farm animals,especially pigs. Recently, evidence suggests that ZEA has potential to stimulate the growth of human breast cancer cells. Fumonisins are also cancer-promoting metabolites,of which Fumonisin 8 I (FBI) is the most important. Moniliformin (MON) isalso highly toxic to both animals and humans. Trichothecenes are classified as gastrointestinal toxins, dermatotoxins, immunotoxins, hematotoxins, and gene toxins.T-2 and HT-2 toxin, and diacetoxyscirpenol (DAS, anguidine) are the most toxic mycotoxins among the trichothecene group. Deoxynivalenol (DON, vomitoxin) and nivalenol although less toxic are important because they frequently occur at levels high enough to cause adverse effects.The presence of mycotoxins in the animal diet can produce significant production losses. Any considerable presence of mycotoxins, in major dietary components,confirms the need to adopt a continuous prevention and control program. Such programs are usually based on several common approaches to minimize mycotoxin contamination in the food chain. Major strategies include preventing fungal growth and therefore mycotoxin formation, reducing or eliminating mycotoxins from contaminated feedstuffs, or diverting contaminated products to low risk uses. Because of the complexity of their chemical structures, mycotoxins also present a major analytical challenge. They are also found in a vast array of feed matrices. Analysis is essential for determining the extent of mycotoxin contamination, for risk analysis, confirming the diagnosis of a mycotoxicosis and for monitoring mycotoxin mitigation strategies.For the future, adequately controlling the mycotoxin problem in the livestock economy will depend on implementing appropriate agricultural management policies,as well as augmenting production and storage systems and analysis methods.Only such policies offer the opportunity to bring solid and long-lasting economical results to the livestock industry that is afflicted with the mycotoxin problem.

The effect of sibutramine, a serotonin-norepinephrine reuptake inhibitor, on platelets and fibrin networks of male Sprague-Dawley rats: a descriptive study.

Sibutramine is used in the treatment of obesity due to its ability to influence feelings of hunger and satiety by inhibiting the re-uptake of serotonin and noradrenalin in the central nervous system (CNS). Sibutramine use has been associated with numerous adverse events in particular cardiovascular complications possibly due to the formation of thrombi. This ultrastructural descriptive study investigated the effect of sibutramine on blood coagulation, specifically the effect on morphology of platelets and fibrin networks using scanning electron microscopy. Male Sprague-Dawley rats treated with either a recommended therapeutic dose [low dosage 1.32 mg/kg] or a toxicological higher dose [high dosage 13.2 mg/kg] of sibutramine for 28 days were used and compared to control animals. Blood samples were collected and plasma smears were prepared for platelet evaluation. Following the addition of thrombin to the plasma samples, the morphology of the fibrin clots was evaluated. Platelet evaluation by scanning electron microscopy revealed morphology typical of a prothrombotic state with a characteristic excessive platelet activation in both low-dose (LD) and high-dose (HD) rats. The fibrin clots of sibutramine-treated rats, LD and HD revealed fused thick fibers with thin fibers forming a net-like structure over the thick fibers which differ considerably from the organized structure of the control animals. It can be concluded that sibutramine alters the ultrastructure of platelets and fibrin networks creating a prothrombotic state.

Rats on a high-energy diet showing no weight gain present with ultrastructural changes associated with liver fibrosis.

Sibutramine is widely used as a weight-loss substance in the treatment of obesity and is a selective inhibitor of the neuronal reuptake of serotonin and noradrenaline. Although banned, it is often a hidden ingredient in herbal and dietary supplements that are widely used by the general public. Various weight loss products, including sibutramine, have successfully been tested in animal models of diet-induced obesity. In the female Sprague-Dawley rat model, fed a high-energy diet that did not produce a significant increase in BMI, the cellular structure of the liver was evaluated using transmission electron microscopy. Compared to controls showing no damage, the livers of rats fed a high-energy diet were found to have increased fibrosis without steatosis, while for rats fed high-energy diet with sibutramine, fibrosis was increased and steatosis had developed. In conclusion, in female rats fed a high-energy diet that does not result in weight gain hepatic fibrosis occurs without steatosis. In these rats the co-administration of sibutramine increases the degree of fibrosis and steatosis develops. Although it has been widely believed that sibutramine is not hepatotoxic, this study clearly shows that at an ultrastructural level, rats fed a high-energy diet treated with sibutramine show signs of hepatotoxicity.

Molecular mechanisms of apoptosis induction by 2-dodecylcyclobutanone, a radiolytic product of palmitic acid, in human lymphoma U937 cells.

The irradiation of fat-containing food forms 2-dodecylcyclobutanone (2-DCB) from palmitic acid (PA). In this study, we investigated whether 2-DCB and PA induce apoptosis in human lymphoma U937 cells. We found that cell viability decreased by 2-DCB and apoptosis was induced by 2-DCB and PA. 2-DCB and PA significantly enhanced the formation of intracellular reactive oxygen species (ROS). Apoptosis induced by 2-DCB and PA was strongly prevented by an antioxidant, N-acetyl-L: -cysteine. The treatment with 2-DCB and PA resulted in the loss of mitochondrial membrane potential, and Fas, caspase-8 and caspase-3 activation. Pretreatment with a pan-caspase inhibitor (z-VAD) significantly inhibited apoptosis induced by 2-DCB and PA. Moreover, 2-DCB and PA also induced Bax up-regulation, the reduction in Bcl-2 expression level, Bid cleavage and the release of cytochrome c from the mitochondria to the cytosol. In addition, an increase in intracellular Ca(2+) concentration ([Ca(2+)](i)) was observed after the treatment with 2-DCB and PA. Our results indicated that intracellular ROS generation, the modulation of the Fas-mitochondrion-caspase-dependent pathway and the increase in [Ca(2+)](i) involved in apoptosis are induced by 2-DCB and PA in U937 cells.

Toxic interaction between fumonisin B1 and moniliformin for cardiac lesions in Japanese quail.

This study examined the effects of fumonisin B1 (FB1) and moniliformin (M) on the heart of Japanese quail (Coturnix coturnix japonica). Three hundred and ninety day-old Japanese quail were randomly divided into four groups: 1) FB1 alone (FX), 2) M alone (MX), 3) FB1 and M (FM), and 4) chick mash alone (CX). We used three pen replicates of 35 quail per pen in groups FX, MX, and FM and three pen replicates of 25 quail per pen in group CX. Gross and microscopic changes in the heart were studied in nine birds (three birds per replicate) from each group at weekly intervals up to 28 days postfeeding (DPF). Ultrastructural changes were studied in the heart of three birds (one bird per replicate) from each group at 21 DPF. Thinning of the heart was the only significant gross lesion in group FX. In contrast, mild-to-severe cardiomegaly was a significant finding in groups MX and FM throughout the study. Microscopically, thinning of cardiomyocytes was evident at 7 DPF in group FX. In addition to the hypertrophy of cardiomyocytes evident as early as 7 DPF, myocardial karyomegaly, nuclear hyperchromasia, and myofibril disarray exhibiting a wavy pattern were more pronounced at 28 DPF in group MX. Similar but more severe lesions were observed in the FM combination group that included myocardial hemorrhages, vacuolar changes, hypertrophy of cardiomyocytes, focal myocarditis, and loss of myofibrils cross-striations. Via transmission electron microscopy, the maximum effect of FB1 toxicity was observed on mitochondria. In addition to an increase in the number of mitochondria, the mitochondria seemed invariably swollen and pleomorphic, although the outer membrane was intact, and the membrane cristae were usually distinct. Myofibrils seemed thinner, without much disruption in their architecture. Large numbers of vacuolar bodies of irregular size, both in the sarcoplasm and in between the myofibrils, were conspicuous in group FX. In contrast to group FX, the increase in number of mitochondria resulted in widespread separation of muscle fibers in group MX. In addition, the mitochondria were swollen and varied from round to oval to slightly elongated and occasionally forked, and vacuolation was rarely noticed in group MX. In the FM combination group, a significant increase in the number of mitochondria caused muscle fibers to look much thinner and assume a wavy pattern. We conclude that the effect of M on the heart is exaggerated in the presence of FB1. Although the overall interactive effect of FB1 and M was less than additive, the interactive effects between the two toxins for cardiac lesions were greater than additive to synergistic up to the second week, raising serious concerns on early age exposure to a combination of these two mycotoxins.

Evaluation of mutagenic effect of two antiobesity drugs on mice's genetic materials.

Obesity is a complex, multifactorial disease that, similarly to high blood pressure and diabetes, frequently requires pharmacological treatment with long-term use, suggesting that pattern of use could increase the rates of genetic damage. Among antiobesity drugs, meridia and orlistat act with completely different mechanisms of action. This study aimed to evaluate the mutagenic effect of meridia and orlistat on genetic material of mice by cytogenetic analysis, which included the micronucleus test and chromosomal aberration assay at two doses comparable to propose human therapeutic and double therapeutic doses. Results revealed that the total number of structural chromosomal aberrations in bone marrow cells, with gap, was significantly increased for the two drugs at therapeutic doses. The structural chromosomal aberrations involved breaks, gaps, deletions and fragments, and centric fusion. Chromosomal deletions and fragments were the most frequently increased types of structural chromosomal aberrations. At double therapeutic doses, the treated animals showed a high significant increase of total structural chromosomal aberrations with and without gaps for the two drugs. The frequency of micronucleus in mice treated with therapeutic doses was significantly increased for both drugs. The treated animals at double therapeutic doses showed a positive response for both drugs. In conclusion, treatment with these two drugs at therapeutic doses should be taken under precaution and contraindicated at double therapeutic doses, because the cytogenetic analysis of meridia and orlistat showed an adverse effect on genetic materials at therapeutic doses and a mutagenic effect at double therapeutic doses.

Interrelated In Vitro Mechanisms of Sibutramine-Induced Cardiotoxicity.

Consumption of illicit pharmaceutical products containing sibutramine has been reported to cause cardiovascular toxicity problems. This study aimed to demonstrate the toxicity profile of sibutramine, and thereby provide important implications for the development of more effective strategies in both clinical approaches and drug design studies. Action potentials (APs) were determined from freshly isolated ventricular cardiomyocytes with whole-cell configuration of current clamp as online. The maximum amplitude of APs (MAPs), the resting membrane potential (RMP), and AP duration from the repolarization phases were calculated from original records. The voltage-dependent K+-channel currents (IK) were recorded in the presence of external Cd2+ and both inward and outward parts of the current were calculated, while their expression levels were determined with qPCR. The levels of intracellular free Ca2+ and H+ (pHi) as well as reactive oxygen species (ROS) were measured using either a ratiometric micro-spectrofluorometer or confocal microscope. The mechanical activity of isolated hearts was observed with Langendorff-perfusion system. Acute sibutramine applications (10-8-10-5 M) induced significant alterations in both MAPs and RMP as well as the repolarization phases of APs and IK in a concentration-dependent manner. Sibutramine (10 µM) induced Ca2+-release from the sarcoplasmic reticulum under either electrical or caffeine stimulation, whereas it depressed left ventricular developed pressure with a marked decrease in the end-diastolic pressure. pHi inhibition by sibutramine supports the observed negative alterations in contractility. Changes in mRNA levels of different IK subunits are consistent with the acute inhibition of the repolarizing IK, affecting AP parameters, and provoke the cardiotoxicity.

Impact of timing of the anorexigen sibutramine administration on reproductive end-points of male rats.

Sibutramine is a non-selective serotonin-norepinephrine reuptake inhibitor orally administered for weight loss. In a previous study, we showed pharmacological mechanisms involved in the reduction of sperm quality and fertility of rats exposed for 30 days to this anorexigen in the light phase of the light-dark (l/d) cycle. It is already known that rodents are nightlife animals, with higher metabolic activity during the dark phase than in the light phase of the light-dark (l/d) cycle. Thus, the present study aimed to investigate whether the deleterious effects on reproductive parameters after sibutramine administration would be enhanced after a shorter period of exposure during the dark phase of the l/d cycle. For this, adult male Wistar rats were treated with sibutramine (10 mg/kg/d) or vehicle for 15 days during the dark phase of the l/d cycle. Sibutramine treatment decreased final body and reproductive organ weights, as well as serum testosterone levels. Sperm transit time through the epididymis was accelerated, and sperm concentration and motility were diminished in the sibutramine-exposed rats. The decrease in sperm concentration was also verified in the epididymal histological sections. In conclusion, the deleterious effects of sibutramine on reproductive parameters of male rats were enhanced when the exposure occurred in the dark phase of the l/d cycle, even after a short exposure duration. Our results reinforce the impact of timing on drug therapeutic action.

Isolation, structure elucidation and cytotoxic evaluation of endiandrin B from the Australian rainforest plant Endiandra anthropophagorum.

Chemical investigations of the DCM extract from the roots of Endiandra anthropophagorum resulted in the isolation of a new cyclobutane lignan endiandrin B (1), together with the known natural products, endiandrin A (2), and (-)-dihydroguaiaretic acid (3). The structure of 1 was determined by extensive spectroscopic analyses, and confirmed by single crystal X-ray crystallography. Methylation of 1 using diazomethane afforded the previously reported natural product, cinbalansan (4). All compounds were evaluated for their cytotoxicity towards human lung carcinoma cells (A549) using high-content screening. (-)-Dihydroguaiaretic acid (3) was found to be the most potent cytotoxin against the A549 lung carcinoma cell line, with an IC(50) value of 7.49 microM.

Electrophysiological safety of sibutramine HCl.

Sibutramine is known to induce cardiovascular side effects such as tachycardia, vasodilation, and hypertension. The present study was aimed to examine the effects of sibutramine on action potential of guinea pig papillary muscle, recombinant hERG currents (IhERG), and inward currents (INa and ICa) of rat ventricular myocytes. Sibutramine at 30 mug/mL induced a shortening of action potential duration (APD) of guinea pig papillary muscle; on average, APD30 and APD90 were shortened by 23% and 17% at a stimulation rate of 1 Hz, respectively. Sibutramine suppressed the following currents: IhERG (IC50:2.408 +/- 0.5117 microg/mL), L-type Ca current (IC50:2.709 +/- 0.4701 microg/mL), and Na current (IC50:7.718 +/- 1.7368 microg/mL). Sibutramine blocked IhERG, ICa, and INa in a concentration-dependent manner. In conclusion, sibutramine exerted a shortening effect on APD in guinea pig papillary muscle through its more powerful blocking effects on ICa and INa rather than IhERG.

Individual and combined effects of fumonisin b1 and moniliformin on clinicopathological and cell-mediated immune response in Japanese quail.

A total of 390 one-day-old quail chicks (Coturnix coturnix japonica) were divided into 4 groups (3 replicates per treatment), viz. CX, FX, MX, and FM, containing 75, 105, 105, and 105 birds, respectively. Birds in the control group (CX) were fed quail mash alone, whereas birds in group FX were fed 200 ppm of fumonisin B(1) (FB(1)) from Fusarium verticillioides culture material; group MX was fed 100 ppm of moniliformin (M) from Fusarium fujikuroi culture material; and group FM was fed a combination of 200 ppm of FB(1) and 100 ppm of M. Diets were fed from d 1 to 35 to study clinical signs, growth response, serum biochemical changes, and cell-mediated immune response. Birds fed FB(1) (FX) showed ruffled feathers and poor growth. Birds in group MX appeared more stunted than those in group FX and exhibited signs of poor feathering and decreased feed and water intake. Clinical signs observed in group FM were more or less similar to those observed in groups FX and MX. Total mortality was 12.38, 7.62, and 20.95% for groups FX, MX, and FM, respectively. Mean BW in groups FX, MX, and FM were significantly lower than those in the control group (CX) at almost all intervals. Total serum proteins, albumin, cholesterol, aspartate transaminase, lactate dehydrogenase, and creatine kinase values were higher in all treatment groups compared with the control group. Cell-mediated immune response was more or less comparable in groups CX and MX, whereas the presence of FB(1) in the diet of groups FX and FM was found to be associated with a gradual increase in skin thickness, and the mononuclear inflammatory cell response was poor as compared with groups CX and MX throughout the study. Except for mortality (additive effect) and serum aspartate transaminase values (less than an additive effect up to 14 DPF), no additive or synergistic effects were observed for any of the other response variables measured in the current study, where all statistical differences were attributed to either one mycotoxin or the other.

Toxicological evaluation of 2-dodecylcyclobutanone, a unique radiolytic compound of palmitic acid.

This study was conducted to evaluate the toxic effects and potency of 2-dodecylcyclobutanone (2-dDCB), a unique compound derived from palmitic acid via irradiation. In a series of assays of bacterial reverse-mutation, in vitro chromosomal aberration, and in vivo micronucleus, negative responses were found by the treatment of 2-dDCB comparing vehicle control, dimethyl sulfoxide or corn oil. In the acute oral toxicity test, all of the mice administrated 2-dDCB survived, and there were no clinical and necropsy signs observed at any doses (0, 300, and 2000 mg/kg body weight) during the experimental period of 14 days. These results suggested that 2-dDCB is a relatively non-toxic substance with median lethality dose higher than 2000 mg/kg body weight. Moreover, there were no adverse effects noted in rats orally administrated 2-dDCB everyday via gavage for 28 days, even at the highest dose (2.0 mg/kg body weight/day) tested, which is 1000-times higher than the human daily intake of 2-dDCB estimated through an extreme exposure scenario. Overall, these results indicate that 2-dDCB is not likely to raise any human health concerns and irradiated foods containing palmitic acid can be recognized as safe for human consumption under the current international regulation systems for food irradiation.

Fusarium avenaceum -- the North European situation.

The Fusarium species complex found on small-grain cereals in Northern Europe is largely dominated by F. avenaceum, while other important species include F. tricinctum, F. poae, F. culmorum and F. graminearum. The dominance of F. avenaceum has in recent years initiated extensive analytical activity in Norway and Finland in order to gain insight into the contamination of grain with secondary metabolites related to the fungus. Of these, moniliformin is the most studied compound with regard to toxicity. However, the data from analytical surveys indicate that field conditions in Northern Europe do not favour production of the metabolite. Instead, enniatins are regularly found in ppm-concentrations in grain, especially wheat and barley, while the bio-production of a range of other F. avenaceum related metabolites has so far barely been investigated. This paper summarises the results from mycological and chemical analyses of grain samples from Norway and Finland for major Fusarium species and F. avenaceum-related secondary metabolites.

Toxicological potential of 2-alkylcyclobutanones--specific radiolytic products in irradiated fat-containing food--in bacteria and human cell lines.

Food irradiation has been considered as a safe processing technology to improve food safety and preservation, eliminating efficiently bacterial pathogens, parasites and insects. This study aims to characterize the toxicological potential of 2-alkylcyclobutanones (2-ACBs), radiolytic derivatives of triglycerides, formed uniquely upon irradiation of fat-containing food. In irradiated food they are generated proportionally to fat content and absorbed radiation dose. The cyto- and genotoxic potentials of various highly pure synthetic 2-ACBs were studied in bacteria and human cell lines. While pronounced cytotoxicity was evident in bacteria, no mutagenic activity has been revealed by the Ames test in Salmonella strains TA 97, TA 98 and TA 100. In mammalian cells genotoxicity was demonstrated mainly by the induction of DNA base lesions recognized by the Fpg protein as determined by both the Comet Assay and the Alkaline Unwinding procedure. Formation of DNA strand breaks was observed by the Alkaline Unwinding procedure but not by the Comet Assay. The extent of cytotoxicity and genotoxicity were dependent on chain length and degree of unsaturation of the fatty acid chain. Further studies will have to clarify mechanisms of action and potential relevance for human exposure situation.