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1.
J Ethnopharmacol ; 311: 116436, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-37003399

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Mayaro virus (MAYV) is an arbovirus endemic to the Amazon region, which comprises the states of the North and Midwest region of Brazil and encompasses the largest tropical forest in the world, the Amazon Forest. The confirmation of its potential transmission by Aedes aegypti and recent cases in Brazil, mainly in large centers in the northern region, led to the classification of Mayaro fever as an emerging disease. Traditional medicine is commonly used to treat various diseases, mainly by local riverside populations. Some species of the genus Maytenus, which have similar morphologies, are popularly used to treat infections and inflammations. In this context, our research group has studied and confirmed the antiviral activity of several plant-derived compounds. However, several species of this same genus have not been studied and therefore deserve attention. AIM OF THE STUDY: This study aimed to demonstrate the effects of ethyl acetate extracts of leaves (LAE) and branches (TAE) of Maytenus quadrangulata against MAYV. MATERIALS AND METHODS: Mammalian cells (Vero cells) were used to evaluate the cytotoxicity of the extracts. After cell infection by MAYV and the treatment with the extracts, we evaluated the selectivity index (SI), the virucidal effect, viral adsorption and internalization, and the effect on viral gene expression. The antiviral action was confirmed by quantifying the viral genome using RT-qPCR and by analyzing the effect on virus yield in infected cells. The treatment was performed based on the effective concentration protective for 50% of the infected cells (EC50). RESULTS: The leaves (LAE; EC50 12.0 µg/mL) and branches (TAE; EC50 101.0 µg/mL) extracts showed significative selectivity against the virus, with SI values of 79.21 and 9.91, respectively, which were considered safe. Phytochemical analysis revealed that the antiviral action was associated with the presence of catechins, mainly in LAE. This extract was chosen for the subsequent studies since it reduced the viral cytopathic effect and virus production, even at high viral loads [MOI (multiplicity of infection) 1 and 5]. The effects of LAE resulted in a marked reduction in viral gene expression. The viral title was drastically reduced when LAE was added to the virus before infection or during replication stages, reducing virus production up to 5-log units compared to infected and untreated cells. CONCLUSION: Through kinetic replication, MAYV was not detected in Vero cells treated with LAE throughout the viral cycle. The virucidal effect of LAE inactivates the viral particle and can intercept the virus at the end of the cycle when it gains the extracellular environment. Therefore, LAE is a promising source of antiviral agents.


Assuntos
Alphavirus , Catequina , Maytenus , Animais , Chlorocebus aethiops , Antivirais/farmacologia , Antivirais/química , Catequina/farmacologia , Células Vero , Alphavirus/genética , Mamíferos
2.
J Ethnopharmacol ; 261: 113180, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-32730884

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Maytenus robusta Reissek (Celesteraceae), popularly named as cafezinho do mato or coração de bugre, is employed to treat inflammatory digestive diseases in the south of Brazil. However, despite popular usage, the effects of this species on an experimental model of ulcerative colitis are unknown. AIM OF THE STUDY: To evaluate the effects of M. robusta extract (HEMR) on colon and liver from mice with colitis induced by dextran sulfate sodium (DSS). MATERIALS AND METHODS: Firstly, the cytotoxicity of HEMR and its effects on ROS and nitrite production in IEC-6 cells were evaluated. The experimental colitis was established by adding 3% DSS on drinking water of mice and the effects of HEMR (1-100 mg/kg, p.o, once a day by 7 days) in colonic and hepatic tissues were analyzed. RESULTS: The HEMR (1-100 µg/mL) did not alter the cell viability but reduced nitrite production of IEC-6 stimulated by LPS. Moreover, HEMR (100 mg/Kg) attenuates macro and microscopic alterations in the colon from mice exposed to DSS, as evidenced by a reduction of the colon shortening, attenuation of the epithelial erosion, submucosal edema and preservation of the Goblet cells integrity, as well as the restoration of mucin depletion. The treatment with HEMR increased GSH amount, reduced LOOH levels and normalizes CAT activity in the colon. The group treated with HEMR showed increased GST activity, reduced MPO activity and decreased inflammatory cytokines secretion (TNF and IL-6) in the colonic tissue. In the liver, HEMR increased GST activity, decreased the GPx activity and reduced IL-6 levels. Furthermore, the HEMR treatment reduced AST and ALT serum levels in mice exposed to DSS. Finally, the HEMR was able to reduce intestinal transit. CONCLUSIONS: HEMR treatment minimizes inflammation of the colon and maintaining the antioxidant homeostasis. In addition, HEMR may be a potential tool to prevent hepatic injury secondary to ulcerative colitis.


Assuntos
Anti-Inflamatórios/farmacologia , Colite/prevenção & controle , Colo/efeitos dos fármacos , Fármacos Gastrointestinais/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Fígado/efeitos dos fármacos , Maytenus , Extratos Vegetais/farmacologia , Animais , Anti-Inflamatórios/isolamento & purificação , Antioxidantes/farmacologia , Linhagem Celular , Colite/induzido quimicamente , Colite/metabolismo , Colite/patologia , Colo/metabolismo , Colo/patologia , Citocinas/metabolismo , Sulfato de Dextrana , Modelos Animais de Doenças , Feminino , Fármacos Gastrointestinais/isolamento & purificação , Motilidade Gastrointestinal/efeitos dos fármacos , Mediadores da Inflamação/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Fígado/metabolismo , Maytenus/química , Camundongos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Ratos
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