Comparação entre dois protocolos de tratamento de ceratoconjuntivite seca experimentalmente induzida em coelhos / Comparison of two treatment protocols of experimentally induced keratoconjunctivitis sicca in rabbits

O objetivo deste estudo foi avaliar e comparar a eficácia de dois protocolos de tratamento de ceratoconjuntivite seca (CCS) experimentalmente induzida em coelhos: uma formulação oftálmica tópica composta por álcool polivinílico 1,4%, adicionado com acetilcisteína 10% e pilocarpina 1% (AAP), e outro protocolo com o uso do óleo de semente de linhaça (OL) tópico em forma de colírio, durante 12 semanas. Foram utilizados 15 coelhos machos, adultos, da raça Nova Zelândia, alocados aleatoriamente em três grupos: grupo C (controle), grupo AAP (formulação oftálmica) e grupo L (OL tópica). Os animais foram avaliados semanalmente pelo teste lacrimal de Schirmer, teste de fluoresceína e teste de Rosa Bengala; uma vez por mês, pelo exame de citologia esfoliativa ocular; ao final do experimento, pela análise histopatológica da córnea e conjuntiva. Os resultados demonstraram que houve um aumento maior na produção lacrimal quando utilizada a formulação oftálmica, e uma resolução mais rápida das úlceras de córnea, bem como diminuição no número de células desvitalizadas quando utilizado o óleo de semente de linhaça, além de aumento no número de células caliciformes em ambos os grupos de tratamento. A associação desses dois protocolos pode ser no futuro uma alternativa no tratamento da CCS.

The objective of this study was to evaluate and compare the effectiveness of two treatment protocol of experimentally induced keratoconjunctivitis sicca (KCS) in rabbits, a topical ophthalmic formulation composed by 1.4% povinilic alcohol added with 10% acetylcysteine and 1% pilocarpine (AAP) and another protocol with the topical use of the linseed seed oil (LO) in eye drop form f or 12 weeks. Fifteen male New Zealand white rabbits were aleatory allocated in 3 groups: Group C (Control), Group AAP (ophthalmic formulation) and Group L (LO topical). The animals were evaluated weekly using the Schirmer's tear test, fluorescein test and Rose Bengal test monthly for ocular cytology, and at the end of the experiment for histopathological analysis of cornea and conjunctive. The results demonstrated that there was a larger increase in the tear production when the ophthalmic formulation was us ed and a faster rapid resolution of corneal ulcers and decrease in the number of devitalized cells when linseed seed oil was used, besides an increase in the number of caliciform cells in both treatment groups. The association of those two protocols can be a future alternative in the treatment of KCS.

Genotoxicity of the medicinal plant Maytenus robusta in mammalian cells in vivo.

Plants belonging to the Celastraceae family have been used in traditional medicine for their analgesic, anti-inflammatory and anti-ulcerogenic properties, among others. Maytenus ilicifolia is the principal species of this family, and is used in the treatment of gastric ulcers. However, owing to its inadequate management in Brazil, the species is becoming extinct and is being substituted with Maytenus robusta, which also displays gastroprotective activity. The aim of this study was to evaluate the genotoxic effects of M. robusta hydroalcoholic extract in vivo, using the comet assay and micronucleus test. Three doses (50, 250 and 500 mg/kg body weight) were administered to mice orally 2 times at 24-h intervals. Cytotoxicity was assessed by scoring 200 consecutive total polychromatic and normochromatic erythrocytes to calculate their ratio. Parametric (analysis of variance/Tukey) and non-parametric (Kruskal-Wallis/Dunn post hoc) tests were used to evaluate the results according to the nature of the data distribution. The results showed a significant increase in the frequency of DNA damage on leukocytes at the 2 higher doses tested, but the extract did not enhance micronucleus frequency in bone marrow cells. Our findings showed that after 48 h of treatment, M. robusta hydroalcoholic extract had weak genotoxic effects but no clastogenic effects in mice cells.

In vitro genotoxicity assessment of caffeic, cinnamic and ferulic acids.

Phenols are a large and diverse class of compounds, many of which occur naturally in a variety of food plants; they exhibit a wide range of biological effects, including antibacterial, anti-inflammatory, antiallergic, hepatoprotective, antithrombotic, antiviral, anticarcinogenic, and vasodilatory actions. We examined the genotoxic and clastogenic potential of three phenolic compounds: caffeic, cinnamic and ferulic acids, using the comet and micronucleus assays in vitro. Drug-metabolizing rat hepatoma tissue cells (HTCs) were used. Three different concentrations (50, 500 and 1500 µM) of these phenolic acids were tested on the HTCs for 24 h. The caffeic, cinnamic and ferulic acids were not genotoxic by the comet assay (P > 0.05). However, the micronucleus test showed an increase in the frequency of micronucleated cells for the three compounds, indicating that these substances have clastogenic effects in HTC.

Effects of experimental amitraz intoxication in cats

This work studied the effects of experimental amitraz intoxication in cats. Sixteen cats were randomly divided equally into two groups: amitraz group - animals received 1.5 percent amitraz at 1mg/kg IV; and the control group - animals without amitraz. Physiological parameters from blood, cardiorespiratory system, and sedation indicators were quantified over time up to 360 minutes. Blood profile, urea, creatinine, alananine aminotransferase and aspartate aminotransferase were not affected by amitraz. Sedation, loss of reflexes, hypothermia, bradycardia, bradyarrhythmia, hypotension, bradypnea, mydriasis, besides transitory hyperglycemia, hypoinsulinemia and decrease of cortisol levels were observed in cats experimentally exposed to amitraz. The alpha2-adrenergic effects induced by amitraz intoxication in cats are very similar to the same effects reported in others species, contributing with more information about this type of intoxication to veterinary toxicology

Este trabalho estudou os efeitos da intoxicação experimental por amitraz em 16 gatos, distribuídos, aleatoriamente, em dois grupos: grupo amitraz - animais receberam amitraz a 1,5 por cento na dose de 1,0 mg/kg IV; e grupo controle - animais sem amitraz. Parâmetros fisiológicos sangüíneos, do sistema cardiorespiratório e de sedação foram aferidos até 360min. Perfil sangüíneo, uréia, creatinina, alanina aminotransferase e aspartato aminotransferase não foram afetados pelo amitraz. Sedação, perda de reflexos, hipotermia, bradicardia, bradiarritmias, hipotensão, bradipnéia, midríase, além de transitória hiperglicemia, hipoinsulinemia e diminuição dos níveis de cortisol, foram observados nos gatos experimentalmente expostos ao amitraz. Os efeitos alfa 2-adrenérgicos induzidos pela intoxicação por amitraz em gatos são muito similares aos mesmos efeitos relatados em outras espécies, contribuindo com mais informações dessa intoxicação para a toxicologia veterinária

Anti-inflammatory and antinociceptive activities of extract, fractions and populnoic acid from bark wood of Austroplenckia populnea.

Austroplenckia populnea (Reiss) Lund is a Brazilian plant from "cerrado", which belongs to Celastraceae family, popularity know as "marmelinho-do campo, mangabeira-brava, mangabarana, vime and maria-mole". This plant is used in folk medicine to treat dysenteries and inflammatory disorders, such as rheumatism. Austroplenckia populnea bark hydroalcoholic crude extract, and its hexane, chloroform and ethyl acetate fractions, obtained by partition, as well as the isolated populnoic acid were investigated for their anti-inflammatory (carrageenan, dextran and histamine-induced rat paw oedema, histamine-induced increase in vascular permeability, and granulomatous tissue induction) and analgesic activities (writhing and hot plate tests). The ED(50) (oral) of the crude extract for the inhibition of carragenan-induced rat paw oedema assay was determined to be 200 mg/kg, which was also used in the assays with the extract and its fractions in all other experiments. Populnoic acid was administered in the dose of 50 mg/kg. Crude extract, hexane and chloroform fractions (200 mg/kg), and indomethacin (10 mg/kg) inhibited significantly (p<0.05) the formation of the carrageenan-induced rat paw oedema, measured in third hour of experiment (peak of oedema formation) by 43.2%, 37.3%, 31.1% and 59.3%, respectively. There was a significant reduction (p<0.05) in dextran-induced rat paw oedema in all groups, while in the assay using histamine as the oedematogenic agent, only the groups treated with populnoic acid (50 mg/kg) and cyproheptadine (10 mg/kg) displayed significant reduction (p<0.05). The populnoic acid and cyproheptadine reduced the peak of oedema formation (1st hour) by 41.3% and 34.7%, respectively. Only for the groups treated with populnoic acid (50 mg/kg) and cyproheptadine (10 mg/kg) it was observed a significant (p<0.05) reduction in histamine-induced increase in vascular permeability (44.8% and 80.3%, respectively). Granulomatous tissue formation was significantly inhibited (p<0.05) by both hexane fraction (46.0%) and dexamethasone (66.2%). In the analgesic assays, the crude extract and its hexane and chloroform fractions, as well as indomethacin diminished significantly the number of writhings (p<0.05) by 69.6%, 47.2%, 44.8% and 62.8%, respectively. On the other hand, none assayed sample displayed significant result in the hot plate test. Based on the obtained results it is suggested that extracts of Austroplenckia populnea bark and populnoic acid display anti-inflammatory activity, supporting its folkloric use to treat inflammatory disorders.