Determination toxic effects of Hystrix Brachyura Bezoar extracts using cancer cell lines and embryo zebrafish (Danio rerio) models and identification of active principles through GC-MS analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Porcupine bezoar (PB) is used as folk medicine for various medical conditions including cancer treatment in Malaysia. However, its toxicity profile has never been thoroughly ascertained to confirm its safe nature as an efficacious traditional medicine in the treatment of cancer as well as other ailments.

AIM OF THE STUDY

This study was aimed to reveal three different PBs' aqueous extracts(viz. PB-A, PB-B, PB-C) chemical constituent's profile using GC-MS analysis, anticancer property on A375, HeLa and MCF7 cancer cells, toxicity profile on zebrafish embryo morphology, EC₅₀, LC₅₀ and teratogenicity index.

MATERIALS AND METHODS

PBs' extracts characterization was performed through GC-MS analysis, in vitro anticancer effect was carried out on A375, HeLa and MCF7 cancer cell lines and finally and toxicity properties on three different PBs aqueous extracts (viz. PB-A, PB-B, PB-C) were determined using zebrafish embryo model.

RESULTS

The GC-MS analysis revealed 10 similar compounds in all PBs' extracts. Dilauryl thiodipropionate was found to be a major compound in all PBs' extracts followed by tetradecanoic acid. An in vitro anticancer study revealed PB extracts exerted median inhibition concentration (IC₅₀) <50 μg/mL, on cancer cells viz. A375, HeLa and MCF7 with no significant toxicity on normal cells viz. NHDF cells. In vivo toxicity of PBs extracts found affecting tail detachment, hatching, craniofacial, brain morphology, soft tissues, edema, spinal, somites, notochord and cardiovascular system (brachycardia, disruption of blood circulation) deformities. The LC₅₀ and EC₅₀ demonstrated PB extracts effect as dose and time dependent with median concentration <150.0 μg/mL. Additionally, teratogenicity index (TI) viz. >1.0 revealed teratogenic property for PB extracts.

CONCLUSIONS

The findings revealed that all three PBs aqueous extracts possessed anticancer activity and exhibited significant toxicological effects on zebrafish embryos with high teratogenicity index. Hence, its use as an anticancer agent requires further investigation and medical attentions to determine its safe dose.

Tritrophic metabolism of plant chemical defenses and its effects on herbivore and predator performance

Insect herbivores are frequently reported to metabolize plant defense compounds, but the physiological and ecological consequences are not fully understood. It has rarely been studied whether such metabolism is genuinely beneficial to the insect, and whether there are any effects on higher trophic levels. Here, we manipulated the detoxification of plant defenses in the herbivorous pest diamondback moth (Plutella xylostella) to evaluate changes in fitness, and additionally examined the effects on a predatory lacewing (Chrysoperla carnea). Silencing glucosinolate sulfatase genes resulted in the systemic accumulation of toxic isothiocyanates in P. xylostella larvae, impairing larval development and adult reproduction. The predatory lacewing C. carnea, however, efficiently degraded ingested isothiocyanates via a general conjugation pathway, with no negative effects on survival, reproduction, or even prey preference. These results illustrate how plant defenses and their detoxification strongly influence herbivore fitness but might only subtly affect a third trophic level.

Haematological, biochemical and histopathological aspects of Hericium erinaceus ingestion in a rodent model: A sub-chronic toxicological assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Hericium erinaceus is a culinary-medicinal mushroom and has a long history of usage in traditional Chinese medicine as a tonic for stomach disorders, ulcers and gastrointestinal ailments.

AIM OF THE STUDY

The present investigation was aimed to evaluate the potential toxic effects of the aqueous extract from the fruiting bodies of H. erinaceus in rats by a sub-chronic oral toxicity study.

MATERIALS AND METHODS

In this sub-chronic toxicity study, rats were orally administered with the aqueous extract of H. erinaceus (HEAE) at doses of 250, 500 and 1000mg/kg body weight (b.w.) for 90 days. Body weights were recorded on a weekly basis and general behavioural changes were observed. The blood samples were subjected to haematological, biochemical, serum electrolyte, and antioxidant enzyme estimations. The rats were sacrificed and organs were processed and examined for histopathological changes.

RESULTS

No mortality or morbidity was observed in all the treated and control rats. The results showed that the oral administration of HEAE daily at three different doses for 90 days had no adverse effect on the general behaviour, body weight, haematology, clinical biochemistry, and relative organ weights. Histopathological examination at the end of the study showed normal architecture except for few non-treatment related histopathological changes observed in liver, heart and spleen.

CONCLUSION

The results of this sub-chronic toxicity study provides evidence that oral administration of HEAE is safe up to 1000mg/kg and H. erinaceus consumption is relatively non-toxic.

Endocidal Regulation of Secondary Metabolites in the Producing Organisms

Secondary metabolites are defined as organic compounds that are not directly involved in the normal growth, development, and reproduction of an organism. They are widely believed to be responsible for interactions between the producing organism and its environment, with the producer avoiding their toxicities. In our experiments, however, none of the randomly selected 44 species representing different groups of plants and insects can avoid autotoxicity by its endogenous metabolites once made available. We coined the term endocides (endogenous biocides) to describe such metabolites that can poison or inhibit the parent via induced biosynthesis or external applications. Dosage-dependent endocides can selectively induce morphological mutations in the parent organism (e.g., shrubbiness/dwarfism, pleiocotyly, abnormal leaf morphogenesis, disturbed phyllotaxis, fasciated stems, and variegation in plants), inhibit its growth, development, and reproduction and cause death than non-closely related species. The propagule, as well as the organism itself contains or produces adequate endocides to kill itself.

Scavenger deterrent factor (SDF) from symbiotic bacteria of entomopathogenic nematodes

Entomopathogenic nematodes (EPNs) in the genera Steinernema and Heterorhabditis are symbiotically associated with bacteria in the genera Xenorhabdus and Photorhabdus, respectively. The symbiotic bacteria produce a chemical compound(s) that deterred ants from feeding on nematode-killed insects (i.e., cadavers) and has been previously referred to as an Ant Deterrent Factor (ADF). We studied the response of different arthropod scavenger species which included the ant Lepisiota frauenfeldi, cricket Gryllus bimaculatus, wasps Vespa orientalis and Paravespula sp., and calliphorid fly Chrysomya albiceps, to ADF. These scavengers (ants, crickets, and wasps) were exposed to cadavers with and without the nematode/bacterium complex or to Photorhabdus luminescens cultures of different ages on different substrates. The ant, cricket, and wasp species did not feed on nematode-killed insects containing the nematode/bacterium complex that were 2 days old and older but fed on 1-day-old nematode-killed and freeze -killed insects. Crickets consumed 2- to 7-day-old axenic nematode-killed insects, 1-, 4-, and 5-day-old insects killed by the bacterium, Serratia marcescens, and freeze-killed, putrid insects that were up to 10 days old. The crickets only partially consumed 2- and 3-day-old insects killed by S. marcescens which differed significantly from the 1-, 4-, and 5-day-old killed insects by this bacterium. Ants fed only on 5% sucrose solution (control) and 1- to 3- day old cultures of P. luminescens containing 5% sucrose but not on older cultures of P. luminescens. Wasps did not feed on meat treated with P. luminescens supernatant, whereas they fed on meat treated with Escherichia coli supernatant and control meat. Calliphorid flies did not oviposit on meat treated with P. luminescens supernatant but did oviposit on untreated meat. Based on the response of these scavengers, the chemical compound(s) responsible for this deterrent activity should be called "scavenger deterrent factor" (SDF).

Microparticles from preeclamptic women induce vascular hyporeactivity in vessels from pregnant mice through an overproduction of NO

Preeclampsia is associated with an increase of circulating levels of microparticles (MPs), but their role in vascular dysfunction during the course of preeclampsia is not understood. Inasmuch as preeclampsia is a gestational disease, we tested the effect of MPs from preeclamptic women (PrMPs) and MPs from normal pregnant women (CMPs) on vessels from pregnant mice. We exposed aortic rings from pregnant mice to circulating levels of PrMPs or CMPs for 24 h and evaluated their response to serotonin (5-HT). PrMPs, but not CMPs, were able to induce hyporeactivity in response to 5-HT in aortas from pregnant mice. The nitric oxide (NO) synthase inhibitor NG-nitro-l-arginine strongly enhanced the response to 5-HT in PrMP-treated vessels but had no significant effect on CMP-treated vessels. The 5-HT-induced contraction in PrMP-treated vessels was completely abolished by the selective cyclooxygenase-2 (COX-2) inhibitor NS-398 but was only reduced in CMP-treated vessels, suggesting an increased participation of COX-2 vasoconstrictor products in the effect of PrMPs. Consistent with this hypothesis, PrMPs enhanced levels of 8-isoprostane and PGE2in vessels, despite reduction of thromboxane B2. These results strengthen the main concept that MPs in preeclampsia could act as vectors to stimulate intracellular cascades in vascular cells, leading to an enhanced NO production to counteract increased COX-2 vasoconstrictor metabolites by taking into account pregnancy.

Natural products that have been used commercially as crop protection agents

Many compounds derived from living organisms have found a use in crop protection. These compounds have formed the basis of chemical synthesis programmes to derive new chemical products; they have been used to identify new biochemical modes of action that can be exploited by industry-led discovery programmes; some have been used as starting materials for semi-synthetic derivatives; and many have been used or continue to be used directly as crop protection agents. This review examines only those compounds derived from living organisms that are currently used as pesticides. Plant growth regulators and semiochemicals have been excluded from the review, as have living organisms that exert their effects by the production of biologically active secondary metabolites.

Altered in-vitro and in-vivo expression of glial glutamate transporter-1 following exposure to cerebrospinal fluid of amyotrophic lateral sclerosis patients

Our earlier studies have shown that cerebrospinal fluid (CSF) of amyotrophic lateral sclerosis (ALS) patients causes death of motor neurons, both in in-vitro as well as in-vivo. There was an aberrant phosphorylation of neurofilaments in cultured spinal cord neurons of chick and rats following exposure to CSF of ALS patients (ALS-CSF). Other features of neurodegeneration, such as swollen neuronal soma and beading of neurites were also observed. In neonatal rat pups exposed to ALS-CSF, we observed phosphorylated neurofilaments in the soma of spinal motor neurons in addition to the increased lactate dehydrogenase activity and reactive astrogliosis. The present study examines the effect of ALS-CSF on the expression of glial glutamate transporter (GLT-1) in embryonic rat spinal cord cultures as well as in spinal astrocytes of neonatal rats. Immunostaining suggested a decrease in the expression of GLT-1 by astrocytes both in culture and in-vivo following exposure to ALS-CSF. Quantification of Western blots confirmed the decreased expression of GLT-1. Our results provide evidence that toxic factor(s) present in ALS-CSF depletes GLT-1 expression. This could lead to an increased level of glutamate in the synaptic pool causing excitotoxicity to motor neurons, possibly by triggering the 'glutamate-mediated toxicity-pathway'.

Bioregulators as prototypic nontraditional threat agents

Bioregulators are naturally occurring organic compounds that regulate a multitude of biologic processes. Under natural circumstances, bioregulators are synthesized in minute quantities in a variety of living organisms and are essential for physiologic homeostasis. In the wrong hands, these compounds have the capability to be used as nontraditional threat agents that are covered by the prohibitions of the Chemical Weapons Convention and the Biological and Toxin Weapons Convention. Unlike traditional biowarfare/bioterrorism agents that have a latency period of hours to days,the onset of action of bioregulators may occur within minutes after host exposure. Concerns regarding the potential misuse of bioregulators for nefarious purposes relate to the ability of these nontraditional agents to induce profound physiologic effects.

Epithelial and inflammatory responses in the airways of laboratory rats coexposed to ozone and biogenic substances: enhancement of toxicant-induced airway injury

People are often concurrently exposed to more than one air pollutant whether they are in outdoor or indoor environments. Therefore, inhalation studies that are designed to examine the toxicity of coexposures to two or more airborne toxicants may be more relevant for assessing human health risks than those studies that investigate the toxic effects of only one airborne toxicant at a time. Furthermore, airborne biogenic substances such as pollens, bacteria, fungi, and microbial toxins often coexist with common air pollutants in the ambient air, and when inhaled may also cause specific adverse effects on the respiratory tract. One such biogenic substance, bacterial endotoxin, is a potent stimulus of airway inflammation and is commonly found in domestic, agricultural, and industrial settings. Little is known about the interaction of exposures to biogenic substances and common air pollutants, such as ozone or airborne particulate matter. In the last few years, we have performed a series of in vivo studies using laboratory rodents that examined how airway surface epithelial cells are altered by coexposure to ozone and a biogenic substance, either bacterial endotoxin or a commonly used experimental aeroallergen (ovalbumin). Results from these studies indicate that the ozone-induced epithelial and inflammatory responses in laboratory rodents may be markedly enhanced by coexposure to an inhaled biogenic substance. Conversely, the adverse airway alterations caused by exposure to biogenic substances may be enhanced by coexposure to ozone. The results from these initial studies have also suggested some of the cellular and molecular mechanisms underlying the phenotypic epithelial alterations induced by these coexposures. Many more studies are needed to fully elucidate the potential risk to human health from coexposure to air pollutants and airborne biogenic substances.

Screening study for potential lead compounds for natural product-based fungicides: I. Synthesis and in vitro evaluation of coumarins against Botrytis cinerea

An efficient, one-pot synthesis of angular and linear dihydropyranocoumarins, along with C-6 and C-8 prenylated coumarins is reported. These compounds, together with single- and furanocoumarins, were tested for their potential antifungal activity against the phytopathogen Botrytis cinerea Pers ex Fr. The results show that furanocoumarins may be able to control the fungus B cinerea.

Mechanisms of cell death associated with death-inducing factors from genomically unstable cell lines

We recently described a unique non-targeted effect of ionizing radiation whereby growth medium from two clones of GM10115 cells exhibiting radiation-induced chromosomal instability was cytotoxic to parental GM10115 cells. We termed this the death-inducing effect (DIE). The goal of the present study was to determine how DIE killed cells. Our hypothesis was that DIE medium contained either a secreted factor(s) from unstable clones or products from dead/dying cells that were cytotoxic to parental cells. First, we investigated the apoptotic characteristics of our unstable clones by Annexin V binding and TUNEL assays. Both the parental GM10115 cells and cells from the unstable clone LS12 had a low background (approximately 2%) level of apoptosis. The unstable Fe-10-3 clone showed a high spontaneous level of apoptosis, indicating major differences in the spontaneously occurring levels of apoptosis. We then analyzed how medium from these unstable clones killed cells by investigating the induction of DNA breaks, micronucleus formation and apoptosis induction in cells exposed to medium from unstable clones. Medium from unstable clones was capable of eliciting DNA double-strand breaks and increased apoptosis. Increased micronucleus frequencies were also observed in cells exposed to medium from either unstable clone, indicating a role of mitotis-linked cell death in DIE. These data suggest that DIE most likely results from cytotoxic factors secreted into the culture medium that can cause DNA double-strand breaks in recipient cells. These breaks can then lead to mitotis-linked cell death, as measured by micronuclei, or apoptosis, which accounts for the DIE.

[Extracellular factors of bacterial adaptation to unfavorable environmental conditions]

Data on extracellular compounds of bacteria involved in their adaptation to unfavorable environmental conditions are reviewed, including high or low temperatures, growth-inhibiting or bactericidal concentrations of toxic substances (oxidants, phenols, and heavy metals) and antibiotics, deviation of pH values from optimum levels, and salinity of the medium. Chemically, the compounds identified belong to diverse types (proteins, hydrocarbons, organic acids, nucleotides, amino acids, lipopeptides, volatile substances, etc.). Most of them remain unidentified, and their properties are studied using biological testing. It is proposed to view extracellular adaptation factors (EAFs) as a new group of biologically active substances. EAFs may be divided into several subgroups by the mechanism of action. These subgroups include protectors (stabilizers), signaling molecules inducing defense responses, regulators (e.g., adhesion regulators) not acting as inducers, and antidotes (neutralizers). The fields of EAF study include screening (search for new compounds, using biological tests), identification, and research into mechanisms of action. EAFs may find utility in biotechnology, medicine, agriculture, and environmental protection.

Safety evaluation of natural flavour complexes

Natural flavour complexes (NFCs) are chemical mixtures obtained by applying physical separation methods to botanical sources. Many NFCs are derived from foods. In the present paper, a 12-step procedure for the safety evaluation of NFCs, 'the naturals paradigm', is discussed. This procedure, which is not intended to be viewed as a rigid check list, begins with a description of the chemical composition of the commercial product, followed by a review of the data on the history of dietary use. Next, each constituent of an NFC is assigned to one of 33 congeneric groups of structurally related substances and to one of three classes of toxic potential, each with its own exposure threshold of toxicological concern. The group of substances of unknown structure is placed in the class of greatest toxic potential. In subsequent steps, for each congeneric group the procedure determines the per capita intake, considers metabolic pathways and explores the need and availability of toxicological data. Additional toxicological and analytical data may be required for a comprehensive safety evaluation. The procedure concludes with an evaluation of the NFC in its entirety, also considering combined exposure to congeneric groups. The first experiences with the use of this procedure are very promising. Future safety evaluations of larger numbers of NFCs will indicate the usefulness of the system, either in its present form or in a form modified on the basis of experience.

Nocardia asteroides culture filtrates cause dopamine depletion and cytotoxicity in PC12 cells

Experimental infection of BALB/c mice with the gram-positive bacterium Nocardia asteroides produces marked loss of nigrostriatal dopamine neurons, resulting in striatal dopamine depletion. To investigate the mechanism(s) responsible for this neuronal loss, we evaluated the influence of N. asteroides cell-free culture filtrates on rat pheochromocytoma PC12 cells, an in vitro model for dopamine neurons. Changes in cell viability and cell numbers were minimal after 24 h, but increased with longer incubation. In contrast, dopamine depletion occurred after 30 min incubation, and was greater with GUH-2 filtrate than with filtrate from the less virulent strain 10905. Incubation with the culture filtrate decreased viability in neuroblastoma and glioma cell lines, indicating that cytotoxic effects were not limited to dopaminergic cells. These findings suggest that the loss of nigrostriatal dopamine neurons and concomitant striatal dopamine depletion in Nocardia-infected mice may be due, at least in part, to the neurotoxicity of nocardial secretory products.

Mode of action and pesticidal activity of the natural product dunnione and of some analogues

This paper reports the investigation of the insecticidal and fungicidal activity of dunnione, a natural product obtained inadvertently as a by-product of a synthesis programme. Dunnione exhibits no insecticidal activity but has an unusually broad spectrum of antifungal activity. In vitro and in vivo (preventative) activities were comparable to those of several long-established fungicides (eg carbendazim). However, in whole-plant assays, its eradicant activity was unexpectedly low, probably due to poor dose-transfer from leaf surface to fungus. The level of residual activity appears to be influenced by the formulation. Finally, its potential as a lead structure was assessed, and several analogues synthesised which exhibited high activity in the in vitro assays. Mode-of-action studies revealed that dunnione exerts its action primarily through initiation of redox cycling. This contrasts to the activity of BTG 505, the biochemical/chemical precursor, which does not initiate redox cycling but instead exhibits both insecticidal and fungicidal activity by inhibiting mitochondrial Complex III.

Characterization of a novel epigenetic effect of ionizing radiation: the death-inducing effect

The detrimental effects associated with exposure to ionizing radiation have long been thought to result from the direct targeting of the nucleus leading to DNA damage; however, the emergence of concepts such as radiation-induced genomic instability and bystander effects have challenged this dogma. After cellular exposure to ionizing radiation, we have isolated a number of clones of Chinese hamster-human hybrid GM10115 cells that demonstrate genomic instability as measured by chromosomal destabilization. These clones show dynamic and persistent generation of chromosomal rearrangements multiple generations after the original insult. We hypothesize that these unstable clones maintain this delayed instability phenotype by secreting factors into the culture medium. To test this hypothesis we transferred filtered medium from unstable cells to unirradiated GM10115 cells. No GM10115 cells were able to survive this medium. This phenomenon by which GM10115 cells die when cultured in medium from chromosomally unstable GM10115 clones is the death-inducing effect. Medium transfer experiments indicate that a factor or factors is/are secreted by unstable cells within 8 h of growth in fresh medium and result in cell killing within 24 h. These factors are stable at ambient temperature but do not survive heating or freezing, and are biologically active when diluted with fresh medium. We present the initial description and characterization of the death-inducing effect. This novel epigenetic effect of radiation has implications for radiation risk assessment and for health risks associated with radiation exposure.

Marine pharmacology in 1999: compounds with antibacterial, anticoagulant, antifungal, anthelmintic, anti-inflammatory, antiplatelet, antiprotozoal and antiviral activities affecting the cardiovascular, endocrine, immune and nervous systems, and other miscellaneous mechanisms of action

This review, a sequel to the 1998 review, classifies 63 peer-reviewed articles on the basis of the reported preclinical pharmacological properties of marine chemicals derived from a diverse group of marine animals, algae, fungi and bacteria. In all, 21 marine chemicals demonstrated anthelmintic, antibacterial, anticoagulant, antifungal, antimalarial, antiplatelet, antituberculosis or antiviral activities. An additional 23 compounds had significant effects on the cardiovascular, sympathomimetic or the nervous system, as well as possessed anti-inflammatory, immunosuppressant or fibrinolytic effects. Finally, 22 marine compounds were reported to act on a variety of molecular targets, and thus could potentially contribute to several pharmacological classes. Thus, during 1999 pharmacological research with marine chemicals continued to contribute potentially novel chemical leads in the ongoing global search for therapeutic agents for the treatment of multiple disease categories.

Human health effects of exposure to Pfiesteria piscicida: a review

Since its identification, the dinoflagellate Pfiesteria piscicida has been implicated in fish kills and fish disease in the southeastern United States. Adverse health effects have been reported in researchers working with the organism and in watermen following exposure to a fish kill in Maryland. A bioactive secretion is postulated as the cause of these effects but has not yet been isolated and chemically characterized. The biology and toxicology of this organism remain the topic of debate and research.

Development of a bioassay for phytochemicals using Daphnia pulex

The freshwater cladoceran Daphnia pulex was explored as an alternative to Artemia salina for the biological screening of phytochemicals. This paper reports on the results of screening 27 compounds, and comparisons are made with screens using Artemia salina. The effect of miniaturisation of the assay system was investigated. Petri-dish based tests were performed for the 27 compounds using 10 daphnids at each of 5 concentrations (1 - 1000 mg l(-1)). Potassium dichromate was used as a control and the number immobile after 24 hours were counted. Results were expressed as EC(50) values. The active compounds (EC(50) < 25 mg l(-1)) comprised mainly adrenoceptor agonist alkaloids, while the cytotoxins vincristine and colchicine, and several antibiotics were relatively non-toxic towards Daphnia. The method was validated by comparative bioassay of A. belladonna fractions. Overall, this screen compared favourably with those based on Artemia. Daphnia were sensitive to a wide range of biologically active molecules including CNS-stimulants, anti-malarials, narcotics and anti-spasmodics, and the sensitivity was broader than previously seen with Artemia. The screen is perhaps limited by the lack of sensitivity to cytotoxins, but this might be overcome by altering the test criteria.

Morphological transformation of C3H/M2 mouse fibroblasts by, and genotoxicity of, extracts of human milk

Breast cancer may be initiated by environmental/dietary agents and human milk may act as an ex vivo indicator of in vivo exposure of mammary epithelial cells to genotoxins. Extracts of human milk from UK-resident women (n=7) were tested for their abilities to morphologically transform C3H/M2 mouse fibroblasts. Genotoxicities were assessed in the Salmonella typhimurium reverse-mutation assay in the presence of S9 using strains TA1538 and YG1019, and in metabolically-competent human MCL-5 cells with the micronucleus and with the alkaline single cell gel electrophoresis (comet) assays. Two of the seven extracts were inactive in the transformation assay both in the presence or absence of S9, two appeared to be equally transforming either in the presence or absence of S9, and two other extracts induced increased transformation frequencies in the presence of S9. A seventh extract, tested only in the absence of S9, was inactive. Extracts were either active or inactive in at least three of the four tests applied. Four extracts were active or inactive in all four tests. The results suggest that human milk could be used as a resource for investigations of the as-yet-unidentified transforming agents previously detected in mammary lipid.

Micronucleus formation in human lymphocytes and in the metabolically competent human hepatoma cell line Hep-G2: results with 15 naturally occurring substances

To examine the concordance of two metabolizing systems for use in genotoxocity testing with the micronucleus test, 15 naturally occurring substances (arecoline, the plant extract aristolochic acid, beta-asarone, benzyl acetate, coumarin, emodine, isatidine dihydrate, monocrotaline, psoralen, reserpine, retrorsine, safrole, sanguinarine chloride, tannin and thiourea) were tested for their genotoxicity in the cytokinesis-block micronucleus test in vitro with human lymphocytes and in the presence and the absence of an exogenous metabolizing system from rat liver S9-mix and the metabolically competent human hepatoma cell line Hep-G2. Arecoline, the plant extract aristolochic acid, psoralen and tannin caused a significant increase in the number of micronuclei in human lymphocytes in the presence and the absence of an exogenous metabolising system from rat liver S9-mix and the metabolically competent human hepatoma cell line Hep-G2. A significant increase in the number of micronuclei with beta-asarone, coumarin, monocrotaline and retrorsine could be detected in the presence of S9-mix and the cell line Hep-G2. Benzyl acetate, emodine, isatidine dihydrate, reserpine, safrole, sanguinarine chloride and thiourea did not reveal any micronucleus inducing activity in either human lymphocytes or in Hep-G2. In addition to the other Hep-G2 results in the literature, this human hepatoma cell line could have a useful potential in the in vitro micronucleus test.

[A toxicological hygiene assessment of microorganisms likely for the creation of agents for agricultural intensification]

Pathogenic properties of new technological bacterial and fungal strains have been studied in rats, mice and guinea pigs. Products of these strains were planned to be implemented in agriculture (pesticides, growth regulators, etc.) Various protocols of toxicological studies of strains and microbial preparations have been used including sensibilization, immunomodulation and disbiotic testing. The objects studied, were classified as nontoxic and non-infecting for mammals. They may be implemented in the agriculture and microbiological industry with the application of routine sanitary standards.

[A comparative study of the biological properties of Biosporin and other commercial Bacillus-based preparations]

A new probiotic Biosporin and other commercial biopreparations based on aerobic sporulating bacteria of the Bacillus genus have been comparatively studied for their specific activity and safety. It has been established that only Biosporin is characterized by expressed antagonistic activity in respect to a wide range of pathogenic and conditionally pathogenic microorganisms including those with multiple resistance to antibiotics. Biosporin is also characterized by the absence of any negative action on the organism of animals even in the doses considerably exceeding those recommended for use.

Toxicity and properties of the extract from Sarcocystis cruzi cysts

The extract from Sarcocystis cruzi cysts in bovine muscle was subcutaneously injected to mice, guinea pigs, chickens, and rabbits to detect its toxicity. Only rabbits showed reactions after administration of the extract at a dose of 25 micrograms. The main clinical signs of the rabbits were depression, reduction in body temperature and intermittent diarrhea and the hematological findings observed were elevation in WBC, RBC, PCV, TP, BUN, AST, AUT and creatinine values and reduction in glucose, K+ and pH of blood. The extract, crude toxin, was a water soluble, acid-alkali stable and thermolabile protein and estimated to be a molecular mass of 15-16 kd.

The pancreatic cancer cell line MIA PaCa2 produces one or more factors able to induce hyperglycemia in SCID mice

A reduced glucose tolerance or frank diabetes mellitus is a frequent finding in patients with pancreatic cancer. The aim of this study was to verify whether the pancreatic cancer cell line MIA PaCa2 was able to produce any factor which could induce hyperglycemia in SCID (severe complete immunodeficient) mice. MIA PaCa2 cells were cultured in Dulbecco's modified Eagle's medium (DMEM) for 7 days. Twenty-five female SCID mice were used. They were daily i.p. injected with 300 ul of cell culture supernatants (Group T, n = 13) or with 300 ul of DMEM (Group C, n = 12) and followed up for 82 days. Blood glucose levels were significantly higher in Group T than in Group C on days 10 and 25. Intravenous glucose tolerance test, success-fully performed in 9 animals (4 controls and 5 treated), demonstrated a significantly reduced glucose tolerance in Group T compared to Group C mice. At sacrifice, plasma and pancreatic insulin and glucagon levels did not vary between groups. The ratio between pancreatic and plasma insulin was significantly lower in Group T than in Group C. We conclude that: 1. The pancreatic cancer cell line MIA PaCa2 produces one or more soluble factors able to cause hyperglycemia in vivo; 2. this effect is not immunologically mediated, and 3. this/these factor/s could both interfere with the pancreatic beta cells and/or with insulin peripheral action.

Features of the Guillain-Barré syndrome in mice following intraperitoneal injection of patient serum

Intraperitoneal injection of serum from a patient with the Guillain-Barré syndrome (GBS) produced GBS-like signs in mice: inadequate respiration and weakness in the legs. We studied the clinical, electrophysiological and pathological features of these mice. Three groups of three mice were injected with patient serum from days 6, 10 and 15 after onset of neurological symptoms. GBS-like signs in mice were observed only with serum from day 6 and improved within 48 h. When serum was frozen and thawed more than once no signs were seen. Electrophysiological measurements of the sciatic nerves of injected and control mice were done before and after serum injection. Five days after injection of patient serum of day 6, the mice showed a significant decrease in the ratio between CMAP amplitude from proximal and distal stimulation and increase in H-M interval from proximal stimulation. These electrophysiological changes returned to normal within 12 days. The sciatic nerve showed no morphological abnormalities. Our results indicate that the observed GBS-like signs in mice are caused by peripheral nerve dysfunction.

[Microbial saprotrophic pharmacotherapy: the possible indications, the conditions for its realization and the overall strategy]

Potential indications for bacterial strains-producers of biologically active substances to be utilized for microbial saprotrophic pharmacotherapy are presented. These indications include some infectious diseases and tumors, a number of noninfectious diseases, transplantation and contraception. The cardinal problem of microbial pharmacotherapy, the capacity of strains-producers of getting acclimatized to the patient organism, is discussed. For its solution, a "microbiological passportization of a patient" ("saprotrophic mapping"), that is drawing up a map of patient microbiological status, is proposed. This "saprotrophic secretory passportization (mapping)" of strains-producers is first submitted for consideration. A strategy of future microbial pharmacotherapy is stated. The necessity of careful approbation of this kind of therapy is emphasized.

[New biologically active substances from protozoa and an evaluation of their action]

Novel biologically active substances were obtained from nonpathogenic for humans and free-living protozoa: Crithidia oncopelti, Trypanosoma lewisi, and Astasia longa. There were studied conditions of biosynthesis, composition and biological activity of the total lipid fraction from the protozoa species, sucrose ethers and fatty acids, the latter were isolated from A. longa--(astazilide preparation), reserve beta-1,3 glucan from A. longa (astazian preparation), and fraction of surface glycophospholipids and peptides from Crithidia oncopelti (GLP preparation). Two of three preparations studied (astazilide and GLP) are the complexes of natural substances with certain composition. Conditions of the protozoa cultivation were developed to provide standardization of the complex composition. Division of the complexes into separate components decreased or abolished the biological activity. It was established that the substances studied modify biological reactions, that is exert a systemic effect. They may be used for inhibiting the growth of experimental tumors and preventing the metastatic spreading in tumor-carrier animals. The substances obtained belong to the group of nonspecific stimulators for cellular immunity which can be used in medicine, veterinary medicine, food industry, pharmacologic industry and cosmetology.

[Negative effects of anti-nutritional factors in animal feed on nitrogen burden of the environment and possibilities of its reduction. Nutritional physiology effects]

Antinutritional factors (ANFs) protect the seed against attacks of moulds, bacteria, insects and birds. The defensive effect of ANFs is apparently related to disturbances in digestive processes in insects and microorganisms. When animals consume seeds containing ANFs, the digestive processes and growth may be disturbed in a similar manner. In the present paper, the fact is discussed that all proteins passing undigested through the small intestine will be fermentatively digested in the large intestine. The final products of the protein digested in the large intestine are excreted in the faeces or urine. For investigations into the digestion of protein in pigs and the amounts of N excreted into the environment, it is of importance to measure the ileal digestibility of protein. Studies showed that ANFs such as trypsin inhibitors, lectins and tannins present in legume seeds reduce the ileal digestibility of protein. In the case of Phaseolus beans it was found that more protein passed through the terminal ileum than was ingested with the feed. With peas was shown that ANFs reduce the ileal digestibility of protein. The carbohydrates of peas did not affect the ileal digestibility of protein, although the ileal chyme was more loose. In the case of faba beans, negative correlation of tannins with ileal digestibility of protein was observed. Calculations showed that, when ANFs were removed from peas and faba beans a considerable reduction in excretion of N into the environment can be achieved. These calculations also showed important possibilities of reducing the secretion of N into the environment by elimination of ANFs.

[Comparative pathomorphologic study of the toxic properties of a corpuscular pertussis vaccine and of a cell-free pertussis preparation]

The comparative study of morphological changes in the body of outbred mice under the action of corpuscular pertussis vaccine and acellular pertussis preparation has been made. The corpuscular vaccine has been shown to produce a pronounced, dynamically increasing toxic effect, thus causing the damage of lymphoid thymic and spleen cells, prolonged interstitial reaction in the lungs, destructive inflammatory process at the site of injection. The acellular pertussis preparation is less toxic, induces less pronounced changes in these organs at the early period of the experiment, stimulates the proliferation of lymphoid cells and lymphoblast transformation. As noted in this study, the damaging action of pertussis vaccine is mainly indicated by pathological phenomena appearing in the organs of the immune system, pulmonary parenchyma and muscular tissue (in the inoculation zone).

Effects of human diabetic serum on the in vitro development of mouse preimplantation embryos

The effects of sera from different types of human diabetes (type I with and without ketoacidosis; type II treated with insulin or Daonil or untreated) on the in vitro development of early preimplantation mouse embryos were studied. In controls, 20% of blastocysts failed to develop successfully when grown for 72 h in RPMI medium supplemented with 10% fetal bovine serum and 50% nondiabetic human serum. In experiments using 50% diabetic serum, the highest embryotoxic effect was found in type-I diabetes with and without ketoacidosis: The percents of undeveloped embryos were 66 and 58, respectively. In type-II diabetes, embryotoxic effects were found among all studied types: The percent of undeveloped blastocysts varied from 36% in insulin-treated type-II diabetes to 44% in untreated type-II diabetes. A high correlation was found between the number of undeveloped embryos and the blood concentrations of metabolic diabetic factors: glucose (r = .53-.64 in type-I diabetes), B-HOB (r = .7-.77 in type-II diabetes untreated or treated with Daonil), acetoacetate (r = .66 in insulin-treated type-II diabetes), and HbA1c (r = .89 in insulin-treated type-II diabetes or .99 in Daonil-treated type-II diabetes). A concentration of 80% serum was embryo-toxic when obtained from nondiabetic or from diabetic human. The possible role of diabetic metabolic factors in causing increased risk of spontaneous abortions and infertility among diabetic women is discussed.

Monokine-induced lung injury in rats: similarities to monocrotaline-induced pneumotoxicity

Previous studies have shown that abnormal alveolar macrophages and biological activity resembling the macrophage-derived mediator interleukin-1 (IL-1) can be detected in bronchoalveolar lavage fluid from rats with monocrotaline-induced lung injury and pulmonary hypertension. To determine if monokines might play a pathogenic role in this model, the present study evaluated the effects of a murine monokine preparation enriched in IL-1 bioactivity on selected events characterizing the early pneumotoxic response to monocrotaline, including pulmonary edema and protein extravasation, pulmonary vascular hyperreactivity, and enhanced lung tissue activity of the rate-limiting enzyme in polyamine biosynthesis, ornithine decarboxylase (ODC). Intravenous injection of the monokine preparation containing 200 units/kg IL-1 (quantified by lymphocyte activating factor assay) into intact rats produced pulmonary edema within 3 hr manifested by increases in the lung wet-to-dry weight ratio and in the extent of pulmonary albumin extravasation. The edema had resolved within 24 hr of monokine administration as indicated by a return to control levels of the wet-to-dry weight ratio and albumin extravasation index. The monokine preparation also increased the transfer of albumin across monolayers of cultured porcine pulmonary vascular endothelial cells. While salt solution-perfused rat lungs isolated from animals treated 3 hr previously with the monokine preparation were hyporesponsive to angiotensin II, preparations derived from animals treated 24 hr previously were markedly hyperresponsive to the vasoconstrictor actions of the peptide. Pressor responses to potassium chloride and prostaglandin F2a were unaffected by exposure to the monokine preparation. Lung ODC activity in monokine-exposed animals did not differ from control at 3, 6, or 24 hr after treatment. In contrast, a 24-hr exposure of cultured pulmonary vascular endothelial cells to the monokine preparation increased ODC activity approximately 100-fold. These observations indicate that a monokine preparation containing IL-1 bioactivity causes transient pulmonary edema and pulmonary vascular hyperreactivity and increases ODC activity in pulmonary vascular endothelial cells. Because the monokine preparation mimics certain aspects of monocrotaline-induced pneumotoxicity in the rat, it is reasonable to postulate that monokines could play a pathogenic role in this and similar animal models of lung injury and pulmonary hypertension.

Species specificity and involvement of other cytokines in endotoxic shock action of recombinant tumour necrosis factor in mice

We compared the effects of human rTNF and murine rTNF in murine models of toxicity, esp. the induction of endotoxic shock. As was the case for the antitumour activity, we found a marked difference in activity between these two TNFs. Only murine rTNF was able to cause lethality, while human rTNF needed the synergistic action of sensitizing agents to become lethal. Further experiments, such as the study of IL-6 induction by TNF in mice, allowed us to distinguish two types of TNF effects: those that can equally well be exerted by human rTNF and by murine rTNF (type I effects) and those that can only be exerted by murine rTNF (type II effects). Both types of effects, the "toxic" (a type I effect) and the sensitizing (a type II effect) are needed to produce a lethal outcome. Other cytokines such as IL-1 and IFN-gamma, however, can also exert such a sensitizing effect and consequently lead to a fatal outcome when co-administered with human rTNF.