Repeated exposure to stress stimuli during ethanol consumption prolongs withdrawal-induced emotional abnormality in mice

In silico, in vitro, and in vivo investigation of antioxidant potential and toxicity of ethyl ferulate

By submitting this manuscript, each author certifies that they have made a direct and substantial contribution to the work reported in the manuscript. In this manuscript the conception, design, investigation, acquisition of data and analysis, interpretation of data and writing of the article were conducted by author Camila Bomfim de Sá under the guidance of professors Margareth de Fátima Formiga Melo Diniz, Hilzeth de Luna Freire Pessôa and Caliandra Maria Bezerra Luna Lima, who also approved the final version of the manuscript. Professor Damião Pergentino de Sousa and his student Mayara Castro de Morais performed the production, synthesis and chemical characterization of ethyl ferulate (EF). Professor Abrahão Alves de Oliveira Filho assessed the in silico tests. PhD student Andressa Brito Lira participated in the critical review of the text for important intellectual content and assisted in the in vitro antioxidant activity and cytotoxicity tests. Kardilandia Mendes de Oliveira participated in acute oral toxicity tests evaluating the biochemical parameters. Students, Tafaela Dias and Cinthia Rodrigues Melo also assisted in the acute oral toxicity testing and preparing of slides for histopathological analysis. Pathologist Alexandre Rolim da Paz analyzed the histopathology results. EF, a phenolic compound of the large class of phenylpropanoids, is derived from ferulic acid and is produced both naturally and synthetically. Its principal pharmacological activities are: anti-inflammatory and antioxidant activity. This study aimed to investigate the in silico, in vitro and in vivo toxicity and antioxidant activity of EF. The in silico prediction showed more than 20 biological activities as well as good absorption at the biological membranes and no theoretical toxicity. However, EF presented high environmental toxicity. EF presented low hemolytic potential and exerted protective activity for the erythrocyte membrane for only blood type O. EF presented antioxidant activity against H₂O₂ at all concentrations and all blood types, but no effect against phenylhydrazine, being unable to prevent its oxidative effects. In the acute nonclinical toxicological trial, the treated animals presented behavioral changes (e.g., sedation). Feed intake was higher for the 2000 mg/kg group, but with no significant difference in weight change. The biochemical parameters presented no differences between treated and control animals, and the organs remained intact with no change. Thus, EF presents a low toxic profile and this study provides important information about the toxicity of this compound, suggesting future safe use.

Isopropyl Caffeate: A Caffeic Acid Derivative-Antioxidant Potential and Toxicity

Phenolic compounds, among them isopropyl caffeate, possess antioxidant potential, but not without toxicity and/or adverse effects. The present study aimed to evaluate the antioxidant activity and toxicity of isopropyl caffeate through in silico, in vitro and in vivo testing. The results showed that isopropyl caffeate presents no significant theoretical risk of toxicity, with likely moderate bioactivity: GPCR binding, ion channel modulation, nuclear receptor binding, and enzyme inhibition. Isopropyl caffeate induced hemolysis only at the concentrations of 500 and 1000 μg/ml. We observed types A and O erythrocyte protection from osmotic stress, no oxidation of erythrocytes, and even sequestrator and antioxidant behavior. However, moderate toxicity, according to the classification of GHS, was demonstrated through depressant effects on the central nervous system, though there was no influence on water and food consumption or on weight gain, and it did present possible hepatoprotection. We conclude that the effects induced by isopropyl caffeate are due to its antioxidant activity, capable of preventing production of free radicals and oxidative stress, a promising molecule with pharmacological potential.

Non-clinical acute and chronic toxicity evaluations of Cissus sicyoides L. (Vitaceae) hydroalcoholic leaf extract

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The Cissus sicyoides species has several pharmacological activities.

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The ethanolic extract from the leaves of Cissus caused few blood changes at the 40.5 mg/kg dose in the acute study.

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In the chronic study, EHA showed no toxic effects at the popular dose (4.5 mg/kg).

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Only the 13.5 mg/kg dose in the chronic trial showed blood changes.

Cissus sicyoides (Cs) has been traditionally used to treat diabetes and belongs to the family Vitaceae, and is known as “vegetable insulin". This study aimed to evaluate the acute and chronic non-clinical toxicity of hydroalcoholic extract from the leaves of Cissus sicyoides (EHA-Cs). The acute test was performed in Wistar rats, administering a single dose of 40.5 mg/kg. Behavioral parameters for pharmacological screening were observed to detect signs of Central Nervous System activity; consumption of daily food and water, and weight evaluation. After day 14, the animals were euthanized and blood samples were collected for laboratory analyses of hematological and biochemical parameters. The chronic tests were administered in doses of 4.5, 13.5 and 40.5 mg/kg. The same parameters were observed together with body temperature, glucose, exploration activity (test on the open field), and motor activity (diagnostic tests on the Rota-rod). For the group given the highest dosage during the study, histopathological examinations of vital organs were performed. For acute toxicity, there were no CNS level effects, changes in water and food consumption, or hematologic parameters. However, there was a significant decrease in weight gain for the treated females. Biochemical analyses of the treated animals presented increased levels of AST (aspartate aminotransferase) in females, uric acid levels in females and males, and amylase in males. In the chronic toxicity tests, water consumption was higher for females (at the dosages of 13.5 and 40.5 mg/kg) and for males (at 40.5 mg/kg). At the dosages of 4.5 and 13.5 mg/kg, feed consumption increased for females, while for males it decreased along with weight gain. Blood analysis presented an increase in albumin and changes in erythrocytes and hemoglobin for males (at the dose of 13.5 mg/kg). Glycemia in females (13.5 mg/kg dose) was significantly less, presenting only slight drops at the other doses. The changes were reversible in the satellite group. EHA-Cs revealed a relatively low toxicity profile (at the popular use dose), and only small changes in hematological and biochemical parameters at the dose of 13.5 mg/kg (3x the popular use dosage). In addition, EHA-Cs did not promote histological changes in vital organs such as the heart, lungs, liver and kidneys.