Sex differences in zonulin in affective disorders and associations with current mood symptoms.

INTRODUCTION: The bidirectional connection between the brain and the gut within psychiatric entities has gained increasing scientific attention over the last years. As a regulator of intestinal permeability, zonulin acts as a key player on the interface of this interplay. Like several psychiatric disorders, intestinal permeability was associated with inflammation in previous findings. METHODS: In this study we explored differences in zonulin serum levels in currently depressed (n = 55) versus currently euthymic (n = 37) individuals with an affective disorder. Further, we explored sex differences and possible influences on zonulin and affective symptoms like medication, age, body mass index, and smoking status. RESULTS: Serum zonulin was significantly higher in females than in men independent from affective status (z = -2.412, p = .016). More specifically, females in the euthymic subgroup had higher zonulin levels than euthymic men (z = -2.114, p = .035). There was no difference in zonulin serum levels in individuals taking or not taking a specific psychopharmacotherapy. We found no correlation between zonulin serum levels and depression severity. DISCUSSION: Increased serum zonulin levels as a proxy for increased intestinal permeability in women may indicate a state of elevated susceptibility for depression-inducing stimuli.

One-year chronic oral toxicity with combined reproduction toxicity study of a novel probiotic, Bacillus coagulans, as a food ingredient.

Some strains of Bacillus coagulans can survive extremes of heat, stomach acid and bile acids, to which commonly consumed probiotics are susceptible. A toxicological safety assessment was published in 2009 on a proprietary preparation of B. coagulans - GanedenBC(30)™ - a novel probiotic. It was concluded that GanedenBC(30)™ is safe for chronic human consumption based upon scientific procedures, supported by a safe history of use (Endres et al., 2009). A one-year chronic oral toxicity study combined with a one-generation reproduction study was conducted to further investigate safety of long-term consumption. The one-year study of GanedenBC(30)™ administered to male and female HsdBrlHan: Wistar rats in their diet showed no signs of toxicity at the highest dose tested. The conclusion from the reproduction toxicity study is that administration of GanedenBC(30)™ in the diet caused no signs of toxicity in the parental generation (male or female) nor the F1 offspring. Using the lowest NOEL of 1948 mg/kg concluded at the end of the 1-year feeding study, a 100-fold safety factor, a test article concentration of 6.88×10(10) CFU (colony forming units) per gram, and an average 70 kg human, it is determined that GanedenBC(30)™ is safe for chronic consumption at up to 9.38×10(10) CFUs per day.

Safety assessment of a novel ingredient for removable chewing gum.

Rev7 is an indigestible gum polymer used for the manufacturing of chewing gum. It allows for the formulation of chewing gum with low adhesion; thus can be readily removed from surfaces such as sidewalks, clothing, carpets and furniture. In a toxicological safety assessment, Rev7 was found to be non-mutagenic in the AMES assay. The highest concentration tested in a mouse lymphoma thymidine kinase locus gene mutation assay induced a slight but biologically relevant increase in mutations under non-metabolic activation conditions after 24h. Because of this finding, a mouse micronucleus assay was performed, and the test article was found to be negative for inducing chromosomal damage. A 28-day repeated oral toxicity study resulted in a NOAEL of 80,000 ppm; the highest concentration tested. Rev7 was found to be free from contaminants such as heavy metals, monomers, and solvents. Lastly, Rev7 did not demonstrate skin-sensitizing properties in the murine local lymph node assay.

Safety assessment of a proprietary preparation of a novel Probiotic, Bacillus coagulans, as a food ingredient.

It has been demonstrated that some strains of Bacillus coagulans can survive extremes of heat, acidity of the stomach, and bile acids, to which commonly consumed probiotics are susceptible. A toxicological safety assessment was performed on a proprietary preparation of B. coagulans - GanedenBC(30) - a novel probiotic. Seven toxicologic studies were conducted and included: in vitro bacterial reverse mutation assay; in vitro chromosomal aberration assay; micronucleus assay in mice; acute and 90 day subchronic repeated oral toxicity studies were conducted in Wistar Crl:(WI) BR rats; acute eye and skin irritation studies were conducted in rabbits. The results of this toxicological safety assessment indicate that GanedenBC(30)B. coagulans does not demonstrate mutagenic, clastogenic, or genotoxic effects. Furthermore, the results of the acute and 90-day subchronic oral toxicity studies in rats resulted in the conclusion of a NOAEL greater than 1000 mg/kg per day. Since the concentration of the cell mass used in the 90-day study was 1.36 x 10(11) CFUs/g, this corresponds to 95.2 x 10(11) CFUs for a 70 kg human and since the suggested human dose is in the range of 100 x 10(6) to 3 x 10(9) CFUs, this gives a safety factor ranging from 3173 to 95,200 times. Based upon scientific procedures and supported by history of use, GanedenBC(30) is considered safe for chronic human consumption.

Anabolics: the approach taken in the USA.

In the United States, the Food and Drug Administration has developed a scientifically sound and rational approach to assure human safety from both naturally occurring and synthetically-derived hormones used in animal production. On this basis, estradiol, progesterone, androsterone, zeranol and trenbolone have been registered. For trenbolone a maximal residue limit of 50 ppb for meat has been accepted.

Evaluation of the carcinogenic potential of pesticides. 1. Acifluorfen.

The Health Effects Division of the Office of Pesticide Programs evaluates the carcinogenic properties of pesticides by a consensus peer review process in which all available biological information on a compound is evaluated according to EPA's guidelines for cancer risk assessment. In many cases, pesticides are also evaluated by an external group of accomplished scientists who comprise the Agency's Scientific Advisory Panel. The herbicide acifluorfen was evaluated by these processes and was classified as a Category B2 (probable human) carcinogen based upon evidence of an increased incidence of malignant, or combined benign and malignant, tumors in multiple experiments involving two different strains of mice. The compound produced benign and malignant liver tumors in male and female B6C3F1 mice and in female CD1 mice. Stomach papillomas were also observed in male and female B6C3F1 mice. Acifluorfen was mutagenic in bacteria and yeast, but not in mammalian cell systems. In addition, acifluorfen is structurally related to eight other diphenyl ether pesticides, all of which evoke liver tumours in mice or rats. The data were found to be sufficient to quantify human risk to acifluorfen.

Extrapolation of animal toxicity data to man.

Laboratory animals are used as models for humans in toxicity studies. This use is based on the assumption that extrapolation of biological data from animals to humans is valid. Three methods of extrapolation are considered: the use of body mass equivalence, caloric scaling across species, and the use of the surface area equivalence. Allometry, defined as the study of size and its consequences, is considered. There is still controversy whether there is an allometric relationship for energy metabolism. Allometry offers, among others, the concept that not all of the mass of the animal is equally involved in metabolism. In recent years the principles of pharmacokinetics have been applied to interspecies scaling; pharmacokinetic short-term studies can be used to determine whether allometric scaling is justified. Considerations, however, should be given to (pharmacokinetic) differences in the same species and to species variability. It would be useful to develop a set of criteria for deciding when the pharmacokinetic model is needed and when simpler models will suffice.

A strategy for the assessment of the carcinogenic potency of veterinary drug residues: recommendations of the FDA.

The United States Food and Drug Administration's assessment strategy for the determination of the carcinogenic potential of drug residues in food-producing animals is embodied in its Human Food Safety Policy. This policy calls for the utilization of a threshold-assessment procedure to determine whether a veterinary drug possesses carcinogenic potential. Chronic lifetime studies in rodents must be performed if it is deemed that the agent may possess carcinogenic properties. A virtually safe level (VSL) of exposure for man is established by applying a modified statistical linear-extrapolation model to the carcinogenic dose-response relationship seen in the test-animal studies. Identification of the major metabolites in the total drug residue in the target animals is required, and the same process applied to the parent drug may be applied to the metabolites. If a carcinogenic metabolite is found in the edible tissue which is significantly more potent and/or more persistent than the parent drug, the VSL is established for the metabolite rather than for the parent compound. A rigorous identification of metabolites is required, which is followed by the development of analytical methodology to ensure that carcinogenic residues in tissue are below the VSL.

Effect of cefazolin on aminotransferase activity in the rat.

Cefazolin given sc to male rats in daily doses of 0.5-2 g per kilogram of body weight significantly decreased alanine aminotranferase activity in serum, liver, kidney, heart, and brain 2-4 wk from the beginning of the treatment. Serum aspartate aminotransferase was also reduced, but serum alkaline phosphatase and tissue pyruvate decarboxylase activities remained unaltered. In female rats, daily sc administration of cefazolin at 0.1-1 g/kg also brought about a dose-related reduction of alanine and aspartate aminotransferase activities, which reached statistical significance at high dose levels. The effect of cefazolin at low concentrations was partly reversed by administration of pyridoxal in vivo. Paradoxically, at higher dose levels pyridoxal potentiated the action of cefazolin on serum aminotranferases. The low enzyme activities were elevated by subsequent addition of pyridoxal 5'-phosphate in vitro. Similar results were obtained when rats were treated with isoniazid at daily oral doses of 200 mg/kg; administration of pyridoxal completely restored alanine aminotransferase activity to the normal level within 2 wk. Cefazolin was metabolized in vivo, resulting in some metabolites that probably possessed a hydrazine group, since positive reactions were obtained with p-dimethylaminobenzaldehyde and Fast Blue B salt. The potentiation of decreased aminotransferase activity by pyridoxal indicated, however, some dissimilarity in the effect between isoniazid and cefazolin.

Problems in the safety evaluation of tissue residues.

Toxicologists must contend with many uncertainties in the establishment of safe conditions for use of a particular agent when that level of use is based on the interpretation of toxicologic studies. Some of these traditional difficulties are discussed this paper. The regulatory review scientist who is involved in the determination of the safe level of use of an agent administered to food producing animals is faced with some additional problems. Accurately determining the exposure of the population to a residue in edible tissue is somewhat difficult because of the limited nature of the data available on the national eating pattern. Judgment must be made on the safety of edible tissue after the administration of substances which may be complex mixtures of a known or unknown nature. In situations where known agents are administered the toxicologist must have information regarding te qualitative and quantitative nature of the residue that would be ingested by humans. Additionally, the regulatory toxicologist is faced with making a safety extrapolation from th test animal to humans when the test animal may not have been exposed to the same metabolites present in the edible tissue that may be ingested by humans.

Testicular atrophy and impaired spermatogenesis in rats fed high levels of the methylxanthines caffeine, theobromine, or theophylline.

Experiments were designed to determine the effects of feeding the methylxanthines caffeine, theobromine, or theophylline to 4- to 6-week-old males rats at a dietary level of 0.5 percent for periods ranging from 14 to 75 weeks. In the first two experiments, Osborne-Mendel rats were fed the test substances alone or in combination with sodium nitrite to test the hypothesis that these amines might nitrosate in vivo to produce toxic nitrosamine compounds. The compounds failed to produce neoplastic or preneoplastic lesions, but a significant positive finding was the occurrence of severe bilateral testicular atrophy with aspermatogenesis or oligospermatogenesis in 85-100 percent of the rats fed caffeine or theobromine. In a third experiment the methylxanthines were fed to Holtzman rats for 19 weeks to determine whether testicular atrophy would be induced in a second strain of rat. The testicular effects were similar to those in Experiments I and II but were more pronounced. Caffeine and theobromine induced testicular injury in nearly all rats. Theophylline induced severe testicular atrophy in 14 percent of the rats, mild to moderate atrophy in 71 percent, and had no effect in 15 percent. The relative testicular toxicity of the methylxanthines was caffeine, most potent; theobromine, slightly less potent; and theophylline, considerably less potent. Somewhat variable atrophic changes of the accessory sexual organs (epididymis, prostate, and seminal vesicles) accompanied the testicular changes. Cytogenetic analysis of testes from caffeine- or theophylline-treated rats revealed a significantly reduced number of mitotic cells in the caffeine-treated group. Plasma testosterone concentrations were significantly elevated in the theobromine group and somewhat elevated in the caffeine-treated group; this correlated morphologically with an apparent hyperplasia of interstitial cells in severely atrophied testes in these groups. Plasma cholesterol concentrations were significantly increased in the caffeine and theobromine groups. Possible sites and mechanisms of action of the methylxanthines in the induction of testicular atrophy and impaired spermatogenesis are discussed.

Testicular atrophy and impaired spermatogenesis in rats fed high levels of the methylxanthines caffeine, theobromine, or theophylline.

Experiments were designed to determine the effects of feeding the methylxanthines caffeine, theobromine, or theophylline to 4- to 6-week-old male rats at a dietary level of 0.5 percent for periods ranging from 14 to 75 weeks. In the first two experiments, Osborne-Mendel rats were fed the test substances alone or in combination with sodium nitrite to test the hypothesis that these amines might nitrosate in vivo to produce toxic nitrosamine compounds. The compounds failed to produce neoplastic or preneoplastic lesions, but a significant positive finding was the occurrence of severe bilateral testicular atrophy with aspermatogenesis or oligospermatogenesis in 85-100 percent of the rats fed caffeine or theobromine. In a third experiment the methylxanthines were fed to Holtzman rats for 19 weeks to determine whether testicular atrophy would be induced in a second strain of rat. The testicular effects were similar to those in Experiments I and II but were more pronounced. Caffeine and theobromine induced testicular injury in nearly all rats. Theophylline induced severe testicular atrophy in 14 percent of the rats, mild to moderate atrophy in 71 percent, and had no effect in 15 percent. The relative testicular toxicity of the methylxanthines was caffeine, most potent; theobromine, slightly less potent; and theophylline, considerably less potent. Somewhat variable atrophic changes of the accessory sexual organs (epididymis, prostate, and seminal vesicles) accompanied the testicular changes. Cytogenetic analysis of testes from caffeine- or theophylline-treated rats revealed a significantly reduced number of mitotic cells in the caffeine-treated group. Plasma testosterone concentrations were significantly elevated in the theobromine group and somewhat elevated in the caffeine-treated group; this correlated morphologically with an apparent hyperplasia of interstitial cells in severely atrophied testes in these groups. Plasma cholesterol concentrations were significantly increased in the caffeine and theobromine groups. Possible sites and mechanisms of actions of the methylxanthines in the induction of testicular atrophy and impaired spermatogenesis are discussed.