RESUMO
Stem bromelain [EC 3.4.22.32] is a thiol-endopeptidase and orally recommended in traditional medicine due to its analgesic activity, but the mechanisms are not known. Proenkephalin is expressed in the nervous system, but also in the gastrointestinal tract, where it can be assessed by ingested stem bromelain. Here we demonstrated that stem bromelain hydrolyses synthetic proenkephalin fragments after basic amino acid residues flanking the enkephalin sequences. We also observed with in vivo studies that oral administration of bromelain reduced jejunum proenkephalin levels and increased the serum enkephalin in mice. Effective anti-nociceptive effects in mice were observed 3 h after oral administration of 3 mg/kg stem bromelain by the acetic acid-induced writhing test. However, with higher doses this effect is reduced due to hydrolysis of enkephalin that possibly occurs by the presence of ananain in commercial pineapple stem bromelain preparations, that is also a thiol-protease with broad specificity. The analgesic effects were also evaluated by hot-plate and formalin tests and the obtained results indicated that enkephalin generated in intestine acts in periphery where it also can have anti-inflammatory activity.
Assuntos
Anti-Inflamatórios/metabolismo , Bromelaínas/farmacologia , Encefalinas/metabolismo , Jejuno/metabolismo , Precursores de Proteínas/metabolismo , Administração Oral , Animais , Masculino , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Our study analyzed 152 samples of alcoholic beverages collected from the states of São Paulo and Minas Gerais, Brazil, using gas chromatography with flame ionization detection (GC-FID) and mass spectrometry (GC-MS), Fourier transform infrared spectroscopy (FT-IR), and inductively coupled plasma atomic emission spectrometry (ICP-AES). The methanol content varied from 20 to 180 ppm in 28 samples, and the limit of the accepted level of 200 ppm was exceeded in only one sample. High content of cyanide derivatives and ethyl carbamate, above the accepted level of 150 ppb, was observed in 109 samples. Carbonyl compounds were also observed in 111 samples, showing hydroxy 2-propanone, 4-methyl-4-hepten-3-one, furfural, and 2-hydroxyethylcarbamate as main constituents. Copper was found at concentrations above 5 ppm in 26 samples; the maximum value observed was 28 ppm. This work evaluated the human health risk associated with the poor quality of suspected unrecorded alcohols beverages.
RESUMO
Hydroalcoholic extracts from species Hypericum brasiliense Choisy (HB) and Hypericum cordatum (Vell. Conc.) N. Robson (HC), were evaluated on the central nervous system (CNS) in some pharmacological tests. Signs of toxicity were observed for both species during the initial screening when high doses of up to 100 mg/kg (i.p.) and 1000 mg/kg (oral) were utilized. HC presented greater toxicity, with LD(50) of 269 mg/kg, as compared to HB (537 mg/kg). Alterations in sleeping time and in motor coordination were not observed both for HB and for HC. On the other hand, both species showed signs of general depressant action on the CNS, verified by decreased motor activity. Furthermore, animals treated with HB presented an increase in response time to thermal stimulus with doses of 50 mg/kg (i.p.) and 500 mg/kg (oral) suggesting possible analgesic action. Both HB and HC were tested in animal models to verify antidepressant action (forced swimming and hypothermy induced by apomorphine). In these tests, neither of the plants inhibited hypothermy, nor did they reduce immobility time in forced swimming.
Assuntos
Analgésicos/farmacologia , Antidepressivos/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Hypericum , Dor/tratamento farmacológico , Fitoterapia , Extratos Vegetais/farmacologia , Administração Oral , Analgésicos/administração & dosagem , Analgésicos/uso terapêutico , Analgésicos/toxicidade , Animais , Antidepressivos/administração & dosagem , Antidepressivos/uso terapêutico , Antidepressivos/toxicidade , Apomorfina , Relação Dose-Resposta a Droga , Hipotermia/induzido quimicamente , Hipotermia/tratamento farmacológico , Injeções Intraperitoneais , Dose Letal Mediana , Camundongos , Atividade Motora/efeitos dos fármacos , Medição da Dor/efeitos dos fármacos , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Extratos Vegetais/toxicidade , Ratos , Ratos Wistar , Sono/efeitos dos fármacosRESUMO
A pharmacological assessment of the standardized extract (BNT-08) of Pfaffia glomerata roots was performed in young mice submitted to acute treatment with several doses (i.p.), in young and old mice submitted to chronic oral treatment for 150 days or with water (control groups) and in old mice at a dose of 100 mg/kg of extract. Acute tests involved an initial screening, spontaneous movements, rota-rod, barbiturate sleeping time and passive avoidance were carried out. The chronic test involved mortality assessment, body weight and learning and memory in a T-maze left/right discrimination test and in the passive avoidance model. Of the acute tests only the sleeping time test showed relevant differences between the groups. With the chronic treatment, a relevant decrease of the number of sessions necessary for learning in the group of old mice treated with the extract was evident. A partial reversal of the memory de fi cit induced by age in the old mice treated with the extract was found in the passive avoidance test. The results suggest that the standardized extract from Pfaffia glomerata roots promoted an increase in both learning and memory of old mice treated in the chronic test.