Sphaeranthus senegalensis DC: Evaluation of chemical constituents, oral safety, gastroprotective activity, and mechanism of action of its hydroethanolic extract

ETHNOPHARMACOLOGICAL RELEVANCE

Sphaeranthus senegalensis DC is a seasonal herb with a spicy smell that grows wild in wet grounds of tropical Africa and Asia. The plant is used in folk medicine for the treatment of various diseases; that includes its use to treat gastric ulcers.

AIM OF THE STUDY

This study aimed to investigate the chemical constituents of the hydroethanolic extract of Sphaeranthus senegalensis DC and evaluate its oral safety, gastroprotective activity, and mechanisms of action using laboratory models in rats and mice.

MATERIALS AND METHODS

Hydroethanolic extract (70%) of the powdered whole dried material was prepared, and chemical constituents of the resultant extract (denoted HESs) standardized using the high-performance liquid chromatography (HPLC) method. The safety profile of HESs was assessed using 2000 mg/kg, oral (p.o.) for Hippocratic screening in mice, and 800 mg/kg, p.o. for 28 days subchronic toxicity assay in rats. The gastroprotective effect of HESs (25, 100, and 400 mg/kg, p.o.) was investigated using acidified ethanol, piroxicam, water immobilization stress, and acetic acid-induced ulcer models. The gastroprotective mechanisms of HESs were evaluated using its effect on gastric mucus protection, nitric oxide modulation, gastric juice secretory parameters, catalase and myeloperoxidase activities. Histological analysis of the stomach tissues was also carried out.

RESULTS

The HPLC analysis indicated the presence of 25.94% phenolics (gallic acid, caffeic acid, and ferulic acid) and 14.53% flavonoids (rutin, morin, luteolin, quercetin, and apigenin). Hippocratic screening and the 28 days subchronic study indicated that HESs is generally safe. Result shows that oral administration of HESs (25, 100 and 400 mg/kg) alleviated the severity of the gastric ulcers induced by acidified ethanol by 35.65% (p < 0.05), 48.70% (p < 0.05) and 78.02% (p < 0.001) respectively; exhibited gastroprotective effect against the gastric lesions induced by piroxicam by 37.97% (p < 0.05), 53.27% (p < 0.05) and 76.23% (p < 0.001) respectively; and decreased the severity of the water immobilization stress-induced gastric ulcers by 32.43% (p < 0.05), 55.26% (p < 0.01) and 74.05% (p < 0.001) respectively, when compared to the vehicle control group. The mechanisms of action assays indicated that the gastroprotective activity was mediated mainly through gastroprotection, antisecretory, and antioxidant activities. Histological analysis showed it inhibited epithelial cell loss, vascular damage, and leucocyte infiltration.

CONCLUSION

HESs contains useful phytochemicals, is safe, and exhibited significant gastroprotective action. The results provided justification for its claim in the treatment of gastric ulcers and its evaluation for potential application as a gastroprotective agent.

Lung Surfactant Decreases Biochemical Alterations and Oxidative Stress Induced by a Sub-Toxic Concentration of Carbon Nanoparticles in Alveolar Epithelial and Microglial Cells

Carbon-based nanomaterials are nowadays attracting lots of attention, in particular in the biomedical field, where they find a wide spectrum of applications, including, just to name a few, the drug delivery to specific tumor cells and the improvement of non-invasive imaging methods. Nanoparticles inhaled during breathing accumulate in the lung alveoli, where they interact and are covered with lung surfactants. We recently demonstrated that an apparently non-toxic concentration of engineered carbon nanodiamonds (ECNs) is able to induce oxidative/nitrosative stress, imbalance of energy metabolism, and mitochondrial dysfunction in microglial and alveolar basal epithelial cells. Therefore, the complete understanding of their "real" biosafety, along with their possible combination with other molecules mimicking the in vivo milieu, possibly allowing the modulation of their side effects becomes of utmost importance. Based on the above, the focus of the present work was to investigate whether the cellular alterations induced by an apparently non-toxic concentration of ECNs could be counteracted by their incorporation into a synthetic lung surfactant (DPPC:POPG in 7:3 molar ratio). By using two different cell lines (alveolar (A549) and microglial (BV-2)), we were able to show that the presence of lung surfactant decreased the production of ECNs-induced nitric oxide, total reactive oxygen species, and malondialdehyde, as well as counteracted reduced glutathione depletion (A549 cells only), ameliorated cell energy status (ATP and total pool of nicotinic coenzymes), and improved mitochondrial phosphorylating capacity. Overall, our results on alveolar basal epithelial and microglial cell lines clearly depict the benefits coming from the incorporation of carbon nanoparticles into a lung surfactant (mimicking its in vivo lipid composition), creating the basis for the investigation of this combination in vivo.

Study on evaluation of toxicology and quality control of Yimusake tablet

ETHNOPHARMACOLOGICAL RELEVANCE

The Yimusake tablet (YMSK-T) is a type of Xinjiang Uygur Medicine, which affects curing diseases of impotence and premature ejaculation. It has remarkable pharmacological effects that mainly involve improving the number and shape of smooth muscle cells in the corpus cavernosum and enhancing the relaxation and contraction function of corpus cavernosum smooth muscle.

AIM OF THE STUDY

The YMSK-T prescription, which consists of 11 traditional herbs, has significant pharmacological effects, however the evaluation of toxicology and quality control of the preparation has not yet been reported. Therefore, in this study, we evaluated the toxicology and quality control of YMSK-T to ensure its safety and effectiveness in clinical applications.

MATERIALS AND METHODS

Male rats were divided into three groups and were given continuous gavage administration of high, medium and low concentrations of YMSK-T. To determine hematopoietic parameters, orbital blood was collected at regular intervals. At termination of the experiment, rats were dissected for histopathological examination. According to the function of the prescription medicinal materials, seven active components were selected for content determination under the same chromatographic condition of using 0.2% aqueous phosphoric acid (solvent A) and acetonitrile (solvent B) with a 40 min post time: 0-13 min, 20% →30% B; 13-26 min, 30% →72% B; 26-38 min, 72% →92% B; 38-40 min, 92% →96% B. The column was maintained at 25 °C and the total sample injection was 10 μL.

RESULTS

Our data showed that using a large dose (400X the dosage used in humans) of YMSK-T resulted in myocardium and liver damage, and eventually death of the rats. At sub-chronic toxicity, no significant differences were observed among indexes about relative organ weight, hematology, serum biochemistry and histopathological examination, and rats behaved normally. Our results also demonstrated that the YMSK-T dosage used was not toxic in the normal range. The linearity of each component was sufficient (correlation coefficients>0.9997). Moreover, the relative standard deviations of precision, repeatability, stability, and recovery were less than 2.0%, which showed that the method for determination of content was stable and reliable.

CONCLUSIONS

YMSK-T has been found to be relatively safe in a rat model, and the method of content determination can be used for quality control of YMSK-T. Toxicology and quality control studies indicated that, the drug is safe and effective for clinical application.

Cadmium-Induced Testicular Toxicity in Mice: Subacute and Subchronic Route-Dependent Effects

This study aimed to compare Cd exposure by intraperitoneal (i.p.) and oral routes, evaluating the testicular subacute and subchronic effects. Adult male mice were separated into three groups subdivided according to the experimental period (7 and 42 days after Cd exposure: subacute and subchronic effects, respectively): one group received water and two groups received CdCl₂ (1.2 mg/kg i.p. and 24 mg/kg oral). The testicular concentration of essential minerals and Cd, activity of antioxidant enzymes and markers of oxidative stress, histology, and testicular histomorphometry were evaluated. The subacute effect of oral Cd showed reduced Fe concentration, while Ca and Cu increased in this route. The subchronic effect promoted decreasing in Mg in i.p. and oral routes, whereas Zn decreased only in the oral, and the Fe concentration did not change. SOD activity decreased in the oral subacute evaluation and in both pathways, i.p. and oral routes, in the subchronic evaluation, while GST activity increased, and MDA concentration decreased. Labeling of apoptotic cells was increased in the subacute and subchronic evaluation. Seminiferous epithelium degeneration, death of germ cells, and Leydig cell damages occurred in i.p. and oral routes. However, these damages were more intense in the oral route, mainly evaluating the subchronic effects. The results confirm that the severity of Cd-induced testicular injury depends on the pathway, as well as the duration of exposure.

Pulmonary toxicity in rats following inhalation exposure to poorly soluble particles: The issue of impaired clearance and the relevance for human health hazard and risk assessment

Intensive discussions are ongoing about the interpretation of pulmonary effects observed in rats exposed to poorly soluble particles. Alveolar clearance differs between rats and humans and becomes impaired in rats at higher exposure concentrations. Some have doubted the human relevance of toxic effects observed in rats under impaired clearance conditions and have suggested that experimental exposures should stay below concentrations inducing impaired clearance. However, for regulatory purposes, insight in potential health effects at relatively high concentrations is needed to fully understand the hazard. Many aspects of impaired particle clearance remain unclear, hampering human health hazard and risk assessment. For an adequate evaluation of the impact of impaired clearance on pulmonary toxicity, a clear definition of alveolar clearance is needed that enables to quantitatively relate the level of impairment to the induction of adverse pulmonary health effects. Also, information is needed on the mechanism of action and the appropriate dose metric for the pulmonary effects observed. In absence of these data, human hazard and risk assessment can only be performed in a pragmatic way. Unless available data clearly point out otherwise, rat pulmonary toxicity including lung inflammation and tumour formation, needs to be considered relevant for human hazard and risk assessment.

Multibiomarker Responses of Juvenile Stages of Zebrafish (Danio rerio) to Subchronic Exposure to Polycyclic Musk Tonalide

Synthetic polycyclic musks, widely used as additives in personal care products, are present in both biotic and abiotic matrices of the aquatic environment at concentrations of ng/l to µg/l. Although they are determined at comparatively low concentrations, these levels are biologically relevant and pose a significant growing risk as stressors to aquatic organisms. The purpose of our study was to evaluate the effects of 28-day-long exposure to polycyclic musk tonalide in zebrafish juvenile stages (Danio rerio) using selected biomarkers. Environmentally relevant concentrations of tonalide caused significant changes in selected enzyme activities in the experimental groups exposed to the highest concentrations. The activity of glutathione S-transferase and lipid peroxidation increased significantly (p < 0.05) after exposure to the highest concentration (50,000 ng/l) compared with the control. A similar trend was observed in catalase activity; there was a significant increase (p < 0.05) after exposure to two highest concentrations of tonalide (5000 and 50,000 ng/l). In addition, a statistically significant decrease (p < 0.05) in glutathione reductase activity was found in the lowest test concentration of tonalide (50 ng/l). None of the tested concentrations resulted in histopathological changes in liver, kidney, skin, or gill. Furthermore, no effects on body weight, body length, specific growth rate, and behavior were observed. Our results showed that tonalide exposure induced profound changes in the activities of antioxidant and detoxifying enzymes, such changes representing an adaptive response of the fish organism to tonalide toxicity.

[Acute oral toxicity and 90 days feeding test of recombinant human lactoferrin]

OBJECTIVE

To study the edible safety of recombinant human lactoferrin( rh LF) expressed from transgenic cow mammary gland bioreactor.

METHODS

According to the food additive safety toxicology evaluation procedures and method, acute oral toxicity in rats and 90 day subchronic toxicity test in mice were done to evaluate the edible safety of rh LF.

RESULTS

Acute oral toxicity test indicated that rh LF was no toxic effect during the observation period, mouse acute oral LD50 of recombinant human lactoferrin was greater than 20 000 mg/kg. 90 days feeding test indicated that there was no-observedadverse-effect-level after givening 300 times rh LF recommended dose of animals body, toxicological parameters NOAEL was 10. 00 g/( kg·d).

CONCLUSION

According to the acute toxic dose graduation standard, rh LF was nonpoisonous. Rh LF was no-observedadverse-effect-level and no subchronic toxicity after givening 300 times rh LF recommended dose of animals body. According to the result, rh LF was no potential food safety risk.

Enzymatic extract from Ecklonia cava: Acute and subchronic oral toxicity and genotoxicity studies

Ecklonia cava (EC) is known to have antioxidant, anti-inflammatory, antidiabetic, and anticancer properties. Despite its wide use and beneficial properties, comprehensive toxicological information regarding EC extract is currently limited. Therefore, the purpose of this study was to investigate acute toxicity, subchronic toxicity, and genotoxicity of enzymatic EC extract according to test guidelines published by Organization for Economic Cooperation and Development. The acute oral LD50 values of this EC extract administered to rats and dogs were estimated to be more than 3000 mg/kg BW. In an oral 13-week toxicity study, changes in body weights of rats exposed to the EC extract up to 3000 mg/kg BW were found to be normal. In addition, repeated doses of EC extract failed to influence any systematic parameters of treatment-related toxic symptoms such as food/water consumption, mortality, urinalysis, hematology, serum biochemistry, organ weight, or histopathology. These results indicated that the no-observed-adverse-effect level for the EC extract was 3000 mg/kg/day for male and female rats. Data obtained from Ames test, chromosome aberration assay, and micronucleus assay indicated that EC extract was not mutagenic or clastogenic. Taken together, these results support the safety of enzymatic EC extract as a potential therapeutic for human consumption against various diseases.

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.

A subchronic feeding study of dicamba-tolerant soybean with the dmo gene in Sprague-Dawley rats

The dicamba-tolerant soybean MON87708 expresses the dicamba mono-oxygenase (DMO) enzyme that is encoded by the dmo gene. In order to evaluate the safety of this soybean, a 90-day subchronic feeding toxicity study (13 weeks) was conducted on Sprague-Dawley rats. A total of 140 rats were divided into 7 groups (10/sex/group), including a standard commercial diet control group. The genetically modified (GM) soybean MON87708 and the near isogenic non-GM soybean A3525 were respectively processed to unhulled, full-fat, and heat-treated powder, then mixed into the diet at levels of 7.5%, 15%, and 30% (wt/wt) with the main nutrients of the various diets balanced and then fed to 6 groups. The remaining group of rats fed with a commercial rat diet served as blank control. Some isolated parameters indicated statistically significant differences in body weight, feed consumption/utilization, hematology, serum biochemistry, and relative organ weights. These differences were not consistent across gender or test-diet dose, which were attributed to incidental and biological variability. In conclusion, the results demonstrated that the transgenic soybean MON87708 containing DMO was as safe as non-transgenic isogenic counterpart with historical safe use.

Comparison of integrated genotoxicity endpoints in rats after acute and subchronic oral doses of 4-nitroquinoline-1-oxide

During interlaboratory validation trials for the Pig-a gene mutation assay we assessed the genotoxicity of 4-nitroquinoline-1-oxide (4NQO) across endpoints in multiple tissues: induction of Pig-a mutant red blood cells (RBCs) and reticulocytes (RETs); micronucleated RETs (MN RETs); and DNA damage in blood and liver via the alkaline Comet assay (%tail intensity [TI]). In a previous subchronic toxicity study with 28 daily doses, biologically meaningful increases were observed only for Pig-a mutant RBCs/RETs while marginal increases in the frequency of MN RET were observed, and other clastogenic endpoints were negative. Follow up acute studies were performed using the same cumulative doses (0, 35, 70, 105, and 140 mg/kg) administered in a bolus, or split over three equal daily doses, with samples collected up to 1 month after the last dose. Both of the acute dosing regimens produced similar results, in that endpoints were either positive or negative, regardless of 1 or 3 daily doses, but the three consecutive daily dose regimen yielded more potent responses in TI (in liver and blood) and Pig-a mutant frequencies. In these acute studies the same cumulative doses of 4NQO induced positive responses in clastogenic endpoints that were negative or inconclusive using a subchronic study design. Additionally, a positive control group using combination doses of cyclophosphamide and ethyl methanesulfonate was employed to assess assay validity and potentially identify a future positive control treatment for integrated genetic toxicity studies.

Safety assessment of saponins extract in Dolichos falcatus Klein: Subchronic study in Sprague-Dawley rats

ETHNOPHARMACOLOGICAL RELEVANCE

Dolichos falcatus Klein (DF), a Chinese Dai ethnic medicine popularly known as "Tuoyeteng" in Yunnan province of China, has been widely used in China to treat fracture, rheumatoid arthritis and soft tissue injuries for a long time. Our previous study showed that saponins in DF (DFS) ameliorated the gouty arthritis induced by MSU crystals in vivo and in vitro. The present study was carried out to evaluate the no-observed-adverse-effect level (NOAEL) of DFS.

MATERIALS AND METHODS

Sprague-Dawley rats (10/sex/group) were gavaged with DFS at dose level of 0, 50, 100 and 200 mg/kg body weight /day for 90-days.

RESULTS

DFS administration did not result in mortality or show treatment-related changes in clinical signs of toxicity, body weights gain or feed consumption. Similarly, in addition to slightly hemolytic anemia and gastrointestinal tract lesion in males of high-dose treatment group, no toxicologically significant treatment-related changes in hematological, clinical chemistry, urine analysis parameters, organ weights, and macroscopic and microscopic abnormalities were noted during the testing period.

CONCLUSION

The results of subchronic toxicity study support the NOAEL for DFS as 200 mg/kg/d in females and as 100mg/kg/d in males. These results provide an important reference for further DFS-related clinical trials or new drug exploration.

Inhibition of Voltage-Gated Calcium Channels After Subchronic and Repeated Exposure of PC12 Cells to Different Classes of Insecticides

We previously demonstrated that acute inhibition of voltage-gated calcium channels (VGCCs) is a common mode of action for (sub)micromolar concentrations of chemicals, including insecticides. However, because human exposure to chemicals is usually chronic and repeated, we investigated if selected insecticides from different chemical classes (organochlorines, organophosphates, pyrethroids, carbamates, and neonicotinoids) also disturb calcium homeostasis after subchronic (24 h) exposure and after a subsequent (repeated) acute exposure. Effects on calcium homeostasis were investigated with single-cell fluorescence (Fura-2) imaging of PC12 cells. Cells were depolarized with high-K(+) saline to study effects of subchronic or repeated exposure on VGCC-mediated Ca(2+) influx. The results demonstrate that except for carbaryl and imidacloprid, all selected insecticides inhibited depolarization (K(+))-evoked Ca(2+) influx after subchronic exposure (IC50's: approximately 1-10 µM) in PC12 cells. These inhibitory effects were not or only slowly reversible. Moreover, repeated exposure augmented the inhibition of the K(+)-evoked increase in intracellular calcium concentration induced by subchronic exposure to cypermethrin, chlorpyrifos, chlorpyrifos-oxon, and endosulfan (IC50's: approximately 0.1-4 µM). In rat primary cortical cultures, acute and repeated chlorpyrifos exposure also augmented inhibition of VGCCs compared with subchronic exposure. In conclusion, compared with subchronic exposure, repeated exposure increases the potency of insecticides to inhibit VGCCs. However, the potency of insecticides to inhibit VGCCs upon repeated exposure was comparable with the inhibition previously observed following acute exposure, with the exception of chlorpyrifos. The data suggest that an acute exposure paradigm is sufficient for screening chemicals for effects on VGCCs and that PC12 cells are a sensitive model for detection of effects on VGCCs.

Sublinear response in lacZ mutant frequency of Muta™ Mouse spermatogonial stem cells after low dose subchronic exposure to N-ethyl-N-nitrosourea

The transgenic rodent mutation assay was used to compare the dose-response relationship of lacZ mutant frequency (MF) in spermatogonial stem cells exposed acutely or subchronically to N-ethyl-N-nitrosourea (ENU). Muta(™) Mouse males were exposed orally to 0, 25, 50, or 100 mg/kg ENU for acute exposures and 0, 1, 2, or 5 mg/(kg day) for 28-day subchronic exposures. LacZ MF was measured in sperm collected 70 days post-exposure to target spermatogonial stem cells. Dose-response data were fit to linear, quadratic, exponential, or power models. Acute exposure resulted in a dose-dependent increase in MF that was significant (P < 0.05) at all doses tested and was best described by a quadratic dose-response model that was linear in the low dose range. In contrast, similar total doses fragmented over a 28-day subchronic exposure only resulted in a significant increase in lacZ MF at the highest dose tested. Therefore, the subchronic no observable genotoxic effect level (NOGEL) was 2 mg/(kg day) (or 56 mg/kg total dose). The subchronic dose-response was best described by the exponential and power models, which were sublinear in the low dose range. Benchmark dose lower confidence limits (BMDLs) for acute and subchronic exposure were 3.0 and 1.0 mg/(kg day) (or 27.4 mg/kg total dose), respectively. These findings are supportive of a saturable DNA repair mechanism as the mutagenic mode of action for ENU in spermatogonia and imply that sufficiently low exposures would not cause appreciable genotoxic effects over background. This may have important implications for the quantitative risk assessment of germ cell mutagens.

Subacute and subchronic toxicity of Avalon(®) mixture (bentazone+dicamba) to rats

Subacute and subchronic toxicity of the herbicide Avalon(®), a mixture of bentazone and dicamba, were tested on rats. Avalon(®) was administered at dose levels of 250, 500 and 1000mg/kg body weight/day for 28 and 90 days. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP) activities were monitored together with biochemistry parameters. The results showed that the mixture caused increases in the activities of ALT, AST and ALP, elevated concentrations of sodium, albumin and albumin/globulin ratio in males. In females, ALT activity, cholesterol and phosphate levels were increased. The changes generally were dose related and, in most cases, females exhibited lower susceptibility than males. The effects of a mixture are, in the most cases, different from the effects of the individual substances. The effects of bentazone were not prevalent which would be expected taking the composition of the mixture into account.

Anticoagulant activity of isolated coumarins (suberosin and suberenol) and toxicity evaluation of Ferulago carduchorum in rats

CONTEXT

Ferulago carduchorum Boiss. & Hausskn. (Apiaceae) is known as Chavil in Persian which grows in west of Iran. Local people add Chavil to dairy and oil ghee as a natural preservative to extend the expiration date.

OBJECTIVE

The goal of this survey is the safety evaluation of the total extract of F. carduchorum in rats by determining both oral acute and subchronic toxicities; furthermore, the anticoagulant activity of isolated coumarins was evaluated.

MATERIALS AND METHODS

The aerial parts of F. carduchorum were extracted by the percolation method. The anticoagulant activity of isolated coumarins was evaluated and the total extract was used to investigate acute and subchronic toxicity in rats. In the subchronic toxicity model, doses of 250, 500, and 1000 mg/kg of the extract were administered to treated groups for 30 consecutive days by gavage.

RESULTS

According to the results of acute toxicity, the LD50 of Chavil extract was more than 2000 mg/kg. The subchronic study showed no significant difference (p > 0.05) between the groups treated with extract and control groups in hematological (erythrocyte, total and differential leukocyte, hematocrit, hemoglobin, platelet count) and biochemical parameter (glucose, albumin, cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) evaluations. The isolated coumarins (suberosin and suberenol) prolonged the prothrombin time (PT) at doses of 3 and 6 mg/kg compared with control (p < 0.05). The longest PT was for suberosin at 6 mg/kg (17.4 s).

CONCLUSION

In conclusion, oral administration of the Chavil extract did not cause either acute or subchronic toxicities although the coumarins showed anticoagulant effect in rats.

The sub-chronic toxicity of regular White Spirit in rats

Hydrocarbon solvents are mostly complex substances (UVCB) with carbon numbers in the range of approximately C5-C20. One of the most common types is a C9-C14 aliphatic solvent containing approximately 20% aromatics and commonly known as White Spirit in Europe and mineral spirits in the US. In previous repeated inhalation toxicity studies, White Spirit was reported to cause minimal systemic effects in most animal species with few effects other than male rat-specific kidney changes at levels up to approximately 2000mg/m(3). In the present study male and female rats were exposed to White Spirit vapors, 6h/day, 5days/week for 13weeks at levels of approximately 2000, 4000, or 8000mg/m(3) to assess the potential for effects at higher exposure levels. All of the rats survived the treatment period. In life observations were largely restricted to acute central nervous system (CNS) effects in the high exposure group. Terminal body weights of high exposure groups animals were significantly below control values. Statistically significant differences in the clinical and hematological observations were small and within normal physiological limits. Weights of some organs including liver, spleen and kidneys were elevated, but microscopic examination indicated that the only pathological effects were changes in the kidneys of the male rats, consistent with an α2u-globulin-mediated process, which is gender and species-specific and not relevant to humans. The overall no observed adverse effect level (NOAEC) was 4000mg/m(3).

A subchronic in situ exposure method for evaluating effects in small-bodied fish at contaminated sites

In situ fish-caging studies at contaminated sites can provide information that is more realistic compared to traditional laboratory-based studies. However, few methods have been developed for exposing sentinel fish species for subchronic durations, and fewer still are optimized for exposing small-bodied fish while maintaining fish health and growth throughout the caging trial. Those methods typically lack a feeding regimen during the fish caging trial. While that may be acceptable or even appropriate for typical short-term toxicity testing, it does limit the duration of the exposure, and may not be suitable when post-caging trials or observations are necessary. Returning healthy fish to the lab following the in situ exposure would be important, for example, in studies designed to examine long-term or multigenerational effects following an in situ exposure. In this article we describe a subchronic method for caging small fish at contaminated sites while maintaining growth and reproductive development. Fathead minnow (Pimephales promelas) were caged in situ for 6 weeks, after which time they were returned to the lab where they were evaluated for health and reproductive performance. Growth and reproductive endpoints revealed no adverse effect on fish due to fish caging and related handling, demonstrating the suitability of our caging and feeding method for long-term caging studies.

Subchronic toxicity study of ulvan from Ulva pertusa (Chlorophyta) in Wistar rats

Ulvan extracted from Ulva pertusa (Chlorophyta) is a group of sulfated heteropolysaccharide, for simplicity, the sulfated polysaccharide is referred to as ulvan in this paper. To our knowledge, there is no detailed report investigating the toxicity of ulvan. In this study, the subchronic (6 months) toxicity of varying levels of ulvan extracted from U. pertusa was investigated in Wistar rats after oral administration. ALT, ALB, ALP, WBC, PLT, and liver relative organ weigh of female rats showed significantly difference at 3000 mg/kg body weight per day, compared with control group. On the other hand, TG, T-CHO concentrations of female rats (6 months) were significantly decreased at 600, 1200 and 3000 mg/kg body weight per day. This result proved that ulvan had antihyperlipidemic activity. Beside, ulvan showed anticoagulant activity in this study. Overall, our findings indicated that ulvan had affected specific hematology, serum biochemistry parameters and liver, and had great differences between males and females rats.

A battery of bioassays for the evaluation of phenanthrene biotoxicity in soil

A battery of bioassays was used to assess the ecotoxicological risk of soil spiked with a range of phenanthrene levels (0.95, 6.29, 38.5, 58.7, 122, and 303 μg g(-1) dry soil) and aged for 69 days. Multiple species (viz. Brassica rapa, Eisenia feotida, Vibrio fischeri), representing different trophic levels, were used as bioindicator organisms. Among acute toxicity assays tested, the V. fischeri luminescence inhibition assay was the most sensitive indicator of phenanthrene biotoxicity. More than 15 % light inhibition was found at the lowest phenanthrene level (0.95 μg g(-1)). Furthermore, comet assay using E. fetida was applied to assess genotoxicity of phenanthrene. The strong correlation (r (2) ≥ 0.94) between phenanthrene concentration and DNA damage indicated that comet assay is appropriate for testing the genotoxic effects of phenanthrene-contaminated soil. In the light of these results, we conclude that the Microtox test and comet assay are robust and sensitive bioassays to be employed for the risk evaluation of polycyclic aromatic hydrocarbon-contaminated soil.

Sub-chronic exposure to chlorpyrifos induces hematological, metabolic disorders and oxidative stress in rat: attenuation by glutathione

The current work aimed to investigate the different toxic effects of chlorpyrifos (CPF) in subchronic exposure. Two groups of Sprague-Dawley male rats were exposed to CPF alone in a dose of 30 mg/kg body weight, or CPF dose as previous plus glutathione (GSH) in a dose of 100 mg/kg body weight, for 90 days, twice weekly, orally. Another two groups of rat were given corn oil (control) or GSH. There is a significant decrease in hemoglobin concentration, haematocrit percentage, thrombocytic indices, total protein and albumin levels in CPF-exposed group. CPF induced hyperglycemia and significant increase in total cholesterol, but a significant decrease in triglyceride levels was obtained. A significant increase in the levels of lipid peroxidation was obtained while a significant decrease of the total antioxidant was recorded. The decrease in glycogen content and some histopathological changes were observed in liver after CPF exposure. Furthermore, co-administration of GSH can restore some of these alterations.

Subchronic toxicity study of GH transgenic carp

A subchronic toxicity study of GH (growth hormone) transgenic carp was carried out with 60 SD rats aged 4 weeks, weight 115∼125 g. Ten male and 10 female rats were allotted into each group. Animals of the three groups (transgenic carp group (GH-TC), parental carp group (PC) and control group) were fed soy- and alfalfa-free diet (SAFD) with 10% GH transgenic carp powder, 10% parental carp powder or 10% common carp powder for 90 consecutive days, respectively. In the end of study, animals were killed by exsanguination via the carotid artery under diethyl ether anesthesia, then weights of heart, liver, kidneys, spleen, thymus, brain, ovaries and uterus/testis were measured. Pathological examination of organs was determined. Endocrine hormones of triiodothyronine (T3), thyroid hormone (T4), follicle-stimulating hormone (FSH), 17β-estradiol (E2), progesterone (P) and testosterone (T) levels were detected by specific ELISA kit. Parameters of blood routine and blood biochemical were measured. The weights of the body and organs of the rats, food intake, blood routine, blood biochemical test and serum hormones showed no significant differences among the GH transgenic carp-treated, parental carp-treated and control groups (P>0.05). Thus, it was concluded that at the dose level of this study, GH transgenic carp showed no subchronic toxicity and endocrine disruption to SD rats.

Toxicological evaluation of ammonium perfluorobutyrate in rats: twenty-eight-day and ninety-day oral gavage studies

Sequential 28-day and 90-day oral toxicity studies were performed in male and female rats with ammonium perfluorobutyrate (NH(4)(+)PFBA) at doses up to 150 and 30mg/kg-d, respectively. Ammonium perfluorooctanoate was used as a comparator at a dose of 30mg/kg-d in the 28-day study. Female rats were unaffected by NH(4)(+)PFBA. Effects in males included: increased liver weight, slight to minimal hepatocellular hypertrophy; decreased serum total cholesterol; and reduced serum thyroxin with no change in serum thyrotropin. During recovery, liver weight, histological, and cholesterol effects were resolved. Results of RT-qPCR were consistent with increased transcriptional expression of the xenosensor nuclear receptors PPARα and CAR as well as the thyroid receptor, and decreased expression of Cyp1A1 (Ah receptor-regulated). No observable adverse effect levels (NOAELs) were 6 and >150mg/kg-d for male and female rats in the 28-day study and 6 and >30mg/kg-d in the 90-dat study, respectively.