Bioactive Compounds from Pale Ale Beer Powder Attenuate Experimental Colitis in BALB/c Mice.

Phenolic compounds (PCs) present in foods are associated with a decreased risk of developing inflammatory diseases. The aim of this study was to extract and characterize PCs from craft beer powder and evaluate their potential benefits in an experimental model of inflammatory bowel disease (IBD). PCs were extracted and quantified from pure beer samples. BALB/c mice received either the beer phenolic extract (BPE) or beer powder fortified with phenolic extract (BPFPE) of PCs daily for 20 days by gavage. Colon samples were collected for histopathological and immunohistochemical analyses. Dextran sodium sulfate (DSS)-induced mice lost more weight, had reduced colon length, and developed more inflammatory changes compared with DSS-induced mice treated with either BPE or BPFPE. In addition, in DSS-induced mice, the densities of CD4- and CD11b-positive cells, apoptotic rates, and activation of NF-κB and p-ERK1/2 MAPK intracellular signaling pathways were higher in those treated with BPE and BPFPE than in those not treated. Pretreatment with the phenolic extract and BPFPE remarkably attenuated DSS-induced colitis. The protective effect of PCs supports further investigation and development of therapies for human IBD.

Toxicity of topically applied drugs beyond skin irritation: Static skin model vs. Two organs-on-a-chip.

Skin model cultivation under static conditions limits the observation of the toxicity to this single organ. Biology-inspired microphysiological systems associating skin with a liver in the same circulating medium provide a more comprehensive insight into systemic substance toxicity; however, its advantages or limitations for topical substance toxicity remain unknown. Herein, we performed topical (OECD test guideline no. 439) and systemic administration of terbinafine in reconstructed human skin (RHS) vs. a RHS plus liver model cultured in TissUse' HUMIMIC Chip2 (Chip2). Aiming for a more detailed insight into the cutaneous substance irritancy/toxicity, we assessed more than the MTT cell viability: lactate dehydrogenase (LDH), lactate and glucose levels, as well as inherent gene expressions. Sodium dodecyl sulfate (SDS) was the topical irritant positive control. We confirmed SDS irritancy in both static RHS and Chip2 culture by the damage in the morphology, reduction in the lactate production and lower glucose consumption. In the static RHS, the SDS-treated tissues also released significantly high LDH (82%; p < 0.05) and significantly lower IL-6 release (p < 0.05), corroborating with the other metabolic levels. In both static RHS and Chip2 conditions, we confirmed absence of irritancy or systemic toxicity by LDH, glucose or lactate levels for topical 1% and 5% terbinafine and systemic 0.1% terbinafine treatment. However, topical 5% terbinafine treatment in the Chip2 upregulated IL-1α in the RHS, unbalanced apoptotic and proliferative cell ratios in the liver and significantly increased its expression of CYP1A2 and 3A4 enzymes (p < 0.05), proving that it has passed the RHS barrier promoting a liver impact. Systemic 0.1% terbinafine treatment in the Chip2 increased RHS expression of EGFR, increased apoptotic cells in the liver, downregulated liver albumin expression and upregulated CYP2C9 significantly (p < 0.05), acting as an effective hepatotoxic terbinafine control. The combination of the RHS and liver model in the Chip2 allowed a more sensitive assessment of skin and hepatic effects caused by chemicals able to pass the skin (5% terbinafine and SDS) and after systemic 0.1% terbinafine application. The present study opens up a more complex approach based on the microphysiological system to assess more than a skin irritation process.

Colorimetric method for determining viability of sea urchin sperm applied in toxicity tests.

The aim of this study was to improve the methodological procedure for the evaluation of sea urchin (Lytechinus variegatus) sperm sensitivity in MTT (3-(4,5-dimethylthiazol-2yl)-2,5 diphenyltetrazolium bromide) enzyme reduction assays with the formation of formazan (purple color) in the interior of viable cells. Assays were carried out with the reference toxicants sodium dodecyl sulfate (SDS), copper, zinc, cadmium and ammonium, using a sperm solution previously activated in sea water and a sperm solution prepared in sea water containing 400 µg L-1 verapamil, which enabled activation of the sperm to occur only when exposed to the toxicants. The assays performed with sperm in verapamil presented similar sensitivity to that shown in the fertilization tests with copper, zinc and SDS, while the assays carried out with the pre-activated sperm solution presented greater resistance to the action of the toxicants. It appears that the action of verapamil involves an intracellular effect on the distribution of Ca2+ ions and that the toxicants used prevent the metabolic reactivation of the sperm.

Set-up of an infrared fast behavioral assay using zebrafish (Danio rerio) larvae, and its application in compound biotoxicity screening.

Zebrafish (Danio rerio) is increasingly employed for evaluating toxicity and drug discovery assays. Commonly experimental approaches for biotoxicity assessment are based on visual inspection or video recording. However, these techniques are limited for large-scale assays, as they demand either a time-consuming detailed inspection of the animals or intensive computing resources in order to analyze a considerable amount of screenshots. Recently, we have developed a simple methodology for tracking the locomotor activity of small animals cultured in microtiter plates. In this work, we implemented this automatic methodology, based on infrared (IR) microbeam scattering, for measuring behavioral activity in zebrafish larvae. We determined the appropriate culture conditions, number of animals and stage of development to get robust results. Furthermore, we validated this methodology as a rapid test for evaluating toxicity. By measuring the effects of reference compounds on larvae activity, we were able to estimate the concentration that could cause a 50% decrease in activity events values (AEC50), showing a strong linear correlation (R² = 0.91) with the LC50 values obtained with the standard DarT test. The toxicity order of the measured compounds was CuSO4 > 2,4-dinitrophenol > 3,4-dichloroaniline > SDS > sodium benzoate > EDTA > K2CrO4 ; regarding solvents, EtOH ≈ DMSO. In this study, we demonstrate that global swimming behavior could be a simple readout for toxicity, easy to scale-up in automated experiments. This approach is potentially applicable for fast ecotoxicity assays and whole-organism high-throughput compound screening, reducing the time and money required to evaluate unknown samples and to identify leading pharmaceutical compounds.

Acute and chronic effects of atrazine and sodium dodecyl sulfate on the tropical freshwater cladoceran Pseudosida ramosa.

Toxicities of atrazine and sodium dodecyl sulfate (SDS) to the tropical freshwater cladoceran Pseudosida ramosa were studied in the laboratory. Acute tests showed that the 48-h LC50 of atrazine was 20.9 mg l⁻¹, while that of SDS was 11.1 mg l⁻¹. P. ramosa showed to be slightly more sensitive than the other species of temperate cladocerans, in the assay conditions specified for each one. Long-term exposure of P. ramosa individuals to atrazine decreased the 21-day fecundity, the 21-day fertility and r(m), at concentrations ranging from 0.8 to 3.2 mg l⁻¹. Furthermore, fecundity and fertility at each brood decreased from the first to the fifth, at concentrations ranging from 0.8 to 3.2 mg l⁻¹ and for the first three broods at the concentration of 0.4 mg l⁻¹. Long-term exposure of female P. ramosa to SDS decreased the 21-day fecundity, the 21-day fertility and r(m), at concentrations of 2 and 4 mg l⁻¹. Fecundity and fertility of each brood were reduced from the first to the fifth, at concentrations of 2-4 mg l⁻¹, and for the first three at concentrations of 0.5 and 1 mg l⁻¹. The survival and moulting of the adult females were not affected by either chemical at the concentrations tested. Many water quality criteria in tropical regions are based on ecotoxicological tests with non-native species and this may lead to errors in setting the maximum permissible levels of chemicals in water bodies. Therefore, we reiterate here the idea of using native species in ecotoxicological assessments.

Acute toxicity tests with the tropical cladoceran Pseudosida ramosa: The importance of using native species as test organisms.

Cladocerans have long been used for toxicological assessments of a diverse range of substances. The use of cladocerans in toxicity tests has many advantages, such as their short life cycle, parthenogenetic reproduction (clones), and high sensitivity to toxicants, as well as the easy laboratory maintenance of cultures. The most commonly used cladoceran in ecotoxicological studies of aquatic environments is undoubtedly Daphnia magna. Standard methods using cladocerans as test organisms have been documented and adopted by major international organizations and regulatory agencies of many countries. However, today there is a growing need for improving test organisms and protocols to better reflect local species sensitivity or site-specific conditions. The present study aimed to assess the tropical species Pseudosida ramosa as a potential test organism for ecotoxicological purposes, by carrying out standard acute tests with six reference compounds. Based on the results obtained in the present study and in comparison with other cladocerans, it was found that P. ramosa was more sensitive than Daphnia magna, had a sensitivity similar to that of Daphnia similis, and was less sensitive compared to Ceriodaphnia dubia and C. silvestrii (Neotropical species), except for the salts, sodium chloride and potassium chloride. Also, when P. ramosa was compared with test organisms of other taxonomic groups, we observed that it was more sensitive than most of the others, from simple coelenterates to complex fish. Considering these results and the wide distribution of the cladoceran P. ramosa in tropical and subtropical regions, we suggest that this species can be adopted as a test organism, being a good substitute for the exotic daphnid D. magna, for monitoring of toxicants in freshwaters.

Influence of the albumin concentration and temperature on the lysis of human erythrocytes by sodium dodecyl sulfate.

The stability of human erythrocytes to sodium dodecyl sulfate (SDS) was assessed spectrophotometrically in the presence of different concentrations of bovine serum albumin (BSA) and at different temperatures (27-45 °C). The absorbance at 540 nm (A540) was correlated with the SDS concentration by sigmoidal regression based on the Boltzmann equation. Erythrocyte stability was characterized on the basis of the SDS concentration that induces hemolysis in 50% of the cells (D50). Progressive increases in the albumin concentration led to increases in the D50 value. The protective effect of BSA against SDS-induced hemolysis was attributed to the binding of the surfactant to the hydrophobic binding sites of this protein. The D50 values decreased sigmoidally with an increase in the temperature. This trend, which could not be explained by changes in the spectral properties of hemoglobin, maybe due to heterogeneity in the erythrocyte population.

Validation test with embryonic and larval stages of Chordodes nobilii (Gordiida, Nematomorpha): sensitivity to three reference toxicants.

Chordodes nobilii is a parasite whose pre- and postparasitic stages are found in different types of freshwater bodies. Due to the peculiarities of its life cycle, it acts as a link between freshwater bodies and terrestrial ecosystems. There is little toxicological information on the group Gordiida. It is only known that embryos and larvae of C. nobilii are sensitive to glyphosate and malathion at relevant concentrations in the environment. On this basis, the aims of this study were to characterize the sensitivity of the pre-parasitic stages of C. nobilii to three reference toxicants: sodium dodecyl sulfate (SDS), cadmium chloride and potassium dichromate (Cr(6+)), and to validate a previous experimental protocol for ecotoxicological risk assessment. The protocol involved acute exposure of early embryonic stages and larvae to the three toxicants for 96 h and 48 h, respectively. Embryo development was inhibited only by Cr(6+) which presented a IC(50) of 0.71 mg Cr(6+)L(-1). The development of the eggs exposed to SDS and those exposed to cadmium chloride showed no differences as compared to that of controls. However, the infective capacity of larvae derived from the eggs exposed to the three toxicants was lower than that of controls. Larval survival was affected even at the lowest concentration of the three toxicants assayed. In relation to other freshwater organisms, C. nobilii can be characterized as an organism medium to highly sensitive to the toxicants tested.

Cytotoxicity of endodontic irrigants containing calcium hydroxide and sodium lauryl sulphate on fibroblasts derived from mouse L929 cell line.

The aim of this study was to evaluate the cytotoxicity of root canal irrigating solutions containing calcium hydroxide and sodium lauryl sulphate on fibroblasts derived from L929 cell line. Saturated calcium hydroxide aqueous solution (CH), sodium lauryl sulphate (SLS) and SLS associated with calcium hydroxide (HCT20) were diluted with sterile distilled water at 50%, 20%, 10% and 5% concentrations. Minimum essential medium (MEM) served as the control group. The cytotoxicity of the solutions was evaluated on L929 mouse fibroblast cell line, at 4 and 24 h of contact time by the 51Cr radiotracer method. Data were compared and statistical inferences were made with the chi-square test. In all analysis, significance level was set at 5%. CH and HCT20 showed toxicity at 50% concentration, while at concentrations lower than 50% these solutions showed cell tolerance. SLS was cytotoxic at all concentrations. In conclusion, the association of calcium hydroxide and SLS (HCT20) combines the beneficial properties of these solutions and was not harmful to the fibroblast cell line, seeming to be a suitable endodontic irrigating solution.

Cytotoxicity of endodontic irrigants containing calcium hydroxide and sodium lauryl sulphate on fibroblasts derived from mouse L929 cell line

The aim of this study was to evaluate the cytotoxicity of root canal irrigating solutions containing calcium hydroxide and sodium lauryl sulphate on fibroblasts derived from L929 cell line. Saturated calcium hydroxide aqueous solution (CH), sodium lauryl sulphate (SLS) and SLS associated with calcium hydroxide (HCT20) were diluted with sterile distilled water at 50 percent, 20 percent, 10 percent and 5 percent concentrations. Minimum essential medium (MEM) served as the control group. The cytotoxicity of the solutions was evaluated on L929 mouse fibroblast cell line, at 4 and 24 h of contact time by the 51Cr radiotracer method. Data were compared and statistical inferences were made with the chi-square test. In all analysis, significance level was set at 5 percent. CH and HCT20 showed toxicity at 50 percent concentration, while at concentrations lower than 50 percent these solutions showed cell tolerance. SLS was cytotoxic at all concentrations. In conclusion, the association of calcium hydroxide and SLS (HCT20) combines the beneficial properties of these solutions and was not harmful to the fibroblast cell line, seeming to be a suitable endodontic irrigating solution.

O objetivo desta pesquisa foi avaliar a citotoxicidade de soluções irrigadoras de canais radiculares contendo hidróxido de cálcio e lauril sulfato de sódio em linhagem de fibroblastos L929. Solução aquosa saturada de hidróxido de cálcio, lauril sulfato de sódio e HCT20 (lauril sulfato de sódio e hidróxido de cálcio) foram diluídos em água destilada em concentrações de 50 por cento, 20 por cento, 10 por cento e 5 por cento. O grupo controle foi representado por meio de cultura de células (MEM - minimum essential medium). A citotoxicidade das soluções sobre os fibroblastos foi avaliada em 4 e 24 h de contato, pelo método do cromo radioativo. Os resultados foram analisados estatisticamente pelo teste do qui-quadrado. Em todas as análises, o intervalo de confiança referente às médias entre os grupos foi estabelecido em 95 por cento. As soluções saturadas de hidróxido de cálcio e o HCT20 apresentaram toxicidade nas concentrações de 50 por cento. O lauril sulfato de sódio foi tóxico em todas as concentrações. As soluções de hidróxido de cálcio em concentrações menores que 50 por cento apresentaram tolerância celular, assim como combinadas ao lauril sulfato de sódio. Tal comportamento não foi observado na solução pura de lauril sulfato de sódio em todas as concentrações.

Evaluation of the sensitivity of three cladoceran species widely distributed in Mexico to three reference toxicants.

Acute toxicity effects of sodium dodecyl sulfate (SDS), sodium pentachlorophenate (SPCP), and hexavalent chromium (Cr(VI)) were determined in Ceriodaphnia dubia, Daphnia pulex, and Simocephalus mixtus. Neonates were obtained from parthenogenetic females of different ages to establish the relative sensitivity of these species, in order to propose them as test organisms in the Mexican environmental standards. For C. dubia the average LC(50) (48 h) values were 8.59 +/- 1.08, 0.92 +/- 0.16, and 0.23 +/- 0.04; for D. pulex, 5.34 +/- 0.90, 1.49 +/- 0.29, and 0.28 +/- 0.06; whereas for S. mixtus, they were 4.50 +/- 0.41, 1.31 +/- 0.16, and 0.12 +/- 0.03 mg/L for SDS, SPCP, and Cr(VI), respectively. SDS and SPCP acute toxicity results depicted coefficients of variation of

Effects of anionic surfactant and salinity on the bioenergetics of juveniles of Centropomus parallelus (Poey).

The acute and sublethal chronic effects of sodium dodecyl sulphate (SDS) on the survival, metabolism, and growth of juveniles of Centropomus parallelus were investigated at three different salinities. Results of 96 h LC50 test showed that juveniles of C. parallelus were very sensitive to SDS in comparison to other species investigated. For each group of exposure to nominal concentrations of SDS (0.10 and 0.25 mg/L) and the control group (0.0 mg/L), at the different salinities (5, 20, and 30) there were significant differences in the specific growth rate, oxygen consumption, and ammonia excretion rates, O:N atomic ratio at the different exposure periods (15 and 30 days). There were also interactions between factors for the parameters investigated. The present results show a pronounced effect of SDS, mainly at the highest concentration and salinity, as well as after a long time of exposure.

Histologic evaluation of periradicular tissues in dogs treated with calcium hydroxide in combination with HCT20 and camphorated P-chlorophenol.

OBJECTIVE: The aim of this study was to evaluate the biocompatibility of calcium hydroxide suspended in HTC20 or calcium hydroxide plus CMCP and their effects on the healing of periapical lesions in dogs. STUDY DESIGN: Experimental apical periodontitis was induced by opening the pulp chamber of 36 mandibular premolars in 6 3-year old dogs. The teeth were left opened for 1 week and then closed with IRM for 60 days in order to induce periapical lesions. The teeth were divided into 1 control and 2 experimental groups. Both experimental groups received intracanal dressings with a calcium hydroxide slurry. In the first experimental group calcium hydroxide was mixed with a detergent vehicle and in the second group with camphorated parachlorophenol. The medications were kept in the root canal for 2 periods of 30 days each. Afterwards, the dogs were killed and the periapical areas were studied histologically. RESULTS: Based on biocompatibility and tissue remodeling in the periapical area, the best results were observed when calcium hydroxide was mixed with the detergent. The difference was statistically significant (P < .05). CONCLUSION: Calcium hydroxide plus CMCP intracanal dressing was the most irritating to the periapical region, and the group of calcium hydroxide plus HCT 20 showed the best results whenever biocompatibility and the capacity of new bone formation was considered.

Use of sodium dodecyl sulfate and zinc sulfate as reference substances for toxicity tests with the mussel Perna perna (Linnaeus, 1758) (Mollusca: Bivalvia).

Effects of anthropogenic pollution have been observed at different trophic levels in the oceans, and toxicity tests constitute one way of monitoring these alterations. The present assay proposes the use of two reference substances, sodium dodecyl sulfate (SDS) and zinc sulfate, for Perna perna larvae. This common mussel on the Brazilian coast is used as a bioindicator and is of economic interest. The chronic static embryo-larval test of short duration (48 h) was employed to determine the NOEC, LOEC, and IC50 for SDS and zinc sulfate, as well as the coefficient of variation. Salinity, pH and un-ionized ammonia (NH3) and dissolved oxygen (DO) concentrations were measured to monitor water quality. The results demonstrated that the main alterations in veliger larvae are the development of only one shell, protruded mantle, malformed shell, formation of only part of a valve, clipped edges, uneven sizes and presence of a concave or convex hinge. NOEC values were lower than 0.25 mg L(-1) for zinc sulfate and 0.68 mg L(-1) for SDS. The coefficient of variation was 17.63% and 2.50% for zinc sulfate and SDS, respectively.

Assessment of the freshwater annual fish Cynopoecilus melanotaenia as a toxicity test organism using three reference substances.

This study presents a preliminary evaluation of the use of the Brazilian fish Cynopoecilus melanotaenia as a test organism in toxicity tests. The cryptobiotic stage presented by the eggs of fish C. melanotaenia can overcome the difficulty of continuously keeping cultures and recruiting healthy animals in sufficient numbers to be used in toxicity tests. In order to determine the applicability of this species as a test organism, three different reference substances were evaluated in 96-h acute toxicity tests: Copper sulfate (CuSO4 x 5H2O), sodium dodecil sulfate (C12H25NaO4S), and sodium chloride (NaCl). Sensitivity ranged as follows: copper sulfate (0.05-0.13 mg/L), sodium dodecil sulfate (10.7-19.0 mg/L), and sodium chloride (1.44-1.96 g/L). We conclude that C. melanotaenia shows potential as a test organism in toxicity tests; however, further research should be conducted with other substances and should be compared with the research on other species before we can reach more conclusive results.

Cytotoxic effects of 10% citric acid and EDTA-T used as root canal irrigants: an in vitro analysis.

EDTA-T and 10% citric acid used as root canal irrigants lead to more visible dentinal tubules than 5% sodium hypochlorite associated with 3% hydrogen peroxide. However, these cleansing agents must be compatible with apical periodontal tissue. We analyzed the cytotoxicity of 10% citric acid and EDTA-T in cultured fibroblasts using Trypan blue. The solutions were diluted to 1%, 0.1%, and 0.01% and applied to NIH 3T3 cell cultures. Cells grown on fresh DMEM served as a control. After 0, 6, 12, and 24 h (short-term assay, viability) and 1, 3, 5, and 7 days (long-term assay, survival), the cells were counted using a hemocytometer. In short-term tests, cell viability ranged from 85% to 99% for all experimental groups with no statistical differences when compared with control cultures, except for the group treated with 1% EDTA-T, which caused a progressive decrease in cell viability. In long-term tests, all cultures increased in number from day 1 to the end of the experimental period, showing no inhibition of cell proliferation, except for the cultures treated with 1% EDTA-T, which totally prevented cell growth. All dilutions of 10% citric acid were more biocompatible than EDTA-T. Cultures treated with citric acid had a higher percentage of viable cells in the short-term assays, and the cells retained their self-renewal capacity.

[The effect of SDS, sodium dodecyl sulfate, on the metabolism and swimming capacity of Cyprinus carpio]. / Efeito do DSS, dodecil sulfato de sódio, no metabolismo e na capacidade de natação de Cyprinus carpio.

Synthetic agents are important sources of pollution in Brazil, especially in the large urban centers. Of these, SDS has been largely employed as a reference substance in toxicity tests with aquatic organisms. Studies on the effect of this substance on the physiology and behavior of fish are scanty. In this study the metabolism and swimming capacity of Cyprinus carpio, at a given swimming velocity (10.15 cm/sec), were analyzed in relation to acute exposition to different concentrations of SDS (1 ppm, 5 ppm, 10 ppm). The metabolism and swimming capacity of a fish are the product of many integrated complex physiological processes that can be directly related to variations in environmental conditions. The results show that oxygen consumption increases while swimming capacity decreases with increasing concentrations of SDS in all size classes studied. At the highest concentration employed (10 ppm), swimming capacity was reduced 5 times and oxygen consumption increased 2.8 times in relation to the control. In general, the pollutant effects on swimming activity are more pronounced in smaller fish whereas the effects on oxygen consumption is more pronounced in larger ones.