RESUMO Objetivo: Realizar uma revisão de escopo das metanálises publicadas sobre a doença pelo coronavírus 2019 (COVID-19), avaliando suas principais características, tendências de publicação e qualidade metodológica. Métodos: Uma busca bibliométrica foi realizada em PubMed®, Scopus e Web of Science, com foco em metanálises sobre a doença pelo COVID-19. Foram extraídos dados bibliométricos e descritivos dos artigos incluídos, e a qualidade metodológica foi avaliada usando a ferramenta A Measurement Tool to Assess Systematic Reviews. Resultados: Um total de 348 metanálises foram consideradas elegíveis. A primeira delas foi publicada em 26 de fevereiro de 2020, e, desde então, o número dessas publicações cresceu rapidamente. A maioria foi publicada em periódicos de infectologia e virologia. Grande parte é proveniente da China, seguida dos Estados Unidos, da Itália e do Reino Unido. Em média, as metanálises incluíram 23 estudos e 15.200 participantes. Em geral, a qualidade metodológica foi baixa, e apenas 8,9% delas podem ser consideradas de algum grau de confiabilidade Conclusão: Embora algumas metanálises bem conduzidas sobre a doença pelo COVID-19 tenham sido publicadas, a maioria apresenta baixa qualidade. Todos os envolvidos na abordagem da doença pelo COVID-19, incluindo formuladores de políticas, pesquisadores, editoras e periódicos, devem dar prioridade a metanálises de alta qualidade, realizadas apenas quando os dados são viáveis, e desencorajar as de baixa qualidade ou conduzidas com métodos subótimos.

ABSTRACT Objective: To carry out a scoping review of the meta-analyses published regarding about coronavirus disease 2019 (COVID-19), evaluating their main characteristics, publication trends and methodological quality. Methods: A bibliometric search was performed in PubMed®, Scopus and Web of Science, focusing on meta-analyses about COVID-2019 disease. Bibliometric and descriptive data for the included articles were extracted and the methodological quality of the included meta-analyses was evaluated using A Measurement Tool to Assess Systematic Reviews. Results: A total of 348 meta-analyses were considered eligible. The first meta-analysis about COVID-19 disease was published on February 26, 2020, and the number of meta-analyses has grown rapidly since then. Most of them were published in infectious disease and virology journals. The greatest number come from China, followed by the United States, Italy and the United Kingdom. On average, these meta-analyses included 23 studies and 15,200 participants. Overall quality was remarkably low, and only 8.9% of them could be considered as of high confidence level. Conclusion: Although well-designed meta-analyses about COVID-19 disease have already been published, the majority are of low quality. Thus, all stakeholders playing a role in COVID-19 deseases, including policy makers, researchers, publishers and journals, should prioritize well-designed meta-analyses, performed only when the background information seem suitable, and discouraging those of low quality or that use suboptimal methods.

The medicinal plants Panax ginseng C. A. Meyer (Araliaceae) and Heteropterys tomentosa A. Juss (Malpighiaceae) are widely and separately used by the Brazilian population as phytotherapeutics for the same medicinal purposes as tonics and to improve cognition. A chemical analysis was carried out on hydroethanolic extracts of powdered roots from P. ginseng and H. tomentosa using HPLC-DAD-ESI-MS/MS (High Performance Liquid Chromatography coupled to Diode-Array Detector and Electrospray Ionization - Mass Spectrum/Mass Spectrum). The ginsenosides Rg1, Rf, mRg and mRf were the main constituents in a hydroethanolic extract from P. ginseng, while in the hydroethanolic extract from H. tomentosa, caffeoylquinic acid derivatives and astilbin isomers were the main constituents. Concentration-time-effect curves were generated in cultures of astrocytes that were incubated with hydroethanolic extracts of these species to elucidate their toxicities. The P. ginseng extract was nontoxic at all of the tested times and concentrations. The hydroethanolic extract from H. tomentosa demonstrated toxicity at a concentration of 1000 µg/mL. P. ginseng extract had no protective effect against staurosporine. Many studies have demonstrated the neuroprotective effect of ginsenosides, caffeoylquinic derivatives and flavonoids.

RESUMO Objetivo Avaliar a composição fitoquímica do extrato hidroetanólico das partes aéreas de Turnera diffusa Willd (Turneraceae; T. diffusa) e sua toxicidade em astrócitos. Métodos Análises químicas do extrato hidroetanólico de partes aéreas de T. diffusa foram feitas por HPLC-DAD-ESI-MS/MS. Os ensaiosin vitro utilizaram culturas de astrócitos para avaliar morte celular. Resultados Flavonas-C, O-diglicosídeos, como, luteolina-8-C-[6-deoxi-2-O-raminosil]-xilo-hexos-3-ulosideo, apigenina-8-C-[6-deoxi-2-O-raminosil]-xilo-hexos-3-ulosideo e apigenina-7-O-6”-p-cumaroilglucosídeo foram os principais constituintes encontrados neste extrato hidroetanólico. Uma curva tempo-concentração demonstrou toxicidade desse extrato na concentração de 1.000µg/mL, na cultura de astrócitos após 6 e 24 horas de incubação. Conclusão Nas análises fitoquímicas, importantes antioxidantes, sobretudo flavonoides, foram observados. Extratos de T. diffusa apresentaram efeitos citotóxicos em altas concentrações, ocasionando aumento de morte celular em cultura de astrócitos.

ABSTRACT Objective To evaluate the phytochemical composition of hydroethanolic extracts from powdered aerial parts of Turnera diffusa Willd (Turneraceae; T. diffusa), as well as its toxicity in astrocytes. Methods Chemical analyses of hydroethanolic extract from powdered aerial parts ofT. diffusa were carried out using HPLC-DAD-ESI-MS/MS.In vitro assays using astrocytes culture were performed to evaluate cell death. Results Flavone-C, O-diglycosides, such as, luteolin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside, apigenin-8-C-[6-deoxy-2-O-rhamnosyl]-xylo-hexos-3-uloside and apigenin-7-O-6”-p-coumaroylglucoside were the main compounds found in this hydroethanolic extract. Concentration time-effect demonstrated the toxicity of this extract at a concentration of 1,000µg/mL in astrocyte culture, after 6 and 24 hours of incubation. Conclusion In phytochemical analyses, important antioxidants (mainly flavonoids) were observed. T. diffusa extracts presented cytotoxic effect in high concentrations, leading to increased cell death in astrocyte culture.

OBJETIVO: Plantas medicinais, como Panax ginseng C.A. Mey, Turnera diffusa Willd. Ex Schult. e Heteropterys tomentosa O. Mach. são amplamente utilizadas pela população como tônicas e para melhora da cognição. O presente estudo verificou se essas plantas poderiam ter algum efeito protetor na morte celular por apoptose, podendo este ser um dos mecanismos de ação dessas substâncias. MÉTODOS: Ratos machos Wistar idosos (n=24) foram divididos em quatro grupos. Durante 30 dias, três grupos receberam tratamento com extratos hidroalcoólicos das plantas e um grupo recebeu solução salina. Um quinto grupo com ratos machos Wistar adultos jovens (n=4) recebeu solução salina durante o mesmo período. Utilizando-se a técnica de TUNEL, avaliou-se a porcentagem de apoptose no hipocampo desses animais. RESULTADOS: Não foram observadas diferenças entre a porcentagem de células apoptóticas no hipocampo de animais idosos e de animais jovens controles. A porcentagem de apoptose no hipocampo dos animais idosos tratados cronicamente com os extratos das três plantas também não diferiu da porcentagem de apoptose do hipocampo dos animais idosos do grupo controle. CONCLUSÃO: O tratamento com os extratos hidroalcoólicos de Panax ginseng, Turnera diffusa e Heteropterys tomentosa não influenciou a apoptose das células hipocampais de ratos idosos.

OBJECTIVE: To verify if the medicinal plants Panax ginseng C.A. Mey, Turnera diffusa Willd. ex Schult., and Heteropterys tomentosa O. Mach., which are amply used by the population as tonics and cognition enhancers, could have a protective effect on cell death by apoptosis, since this could be one of the mechanisms of action of these substances. METHODS: Aged male Wistar rats (n=24) were divided into four groups. Over 30 days, three groups received treatments with hydroalcoholic extracts of the plants, and one group received saline solution. A fifth group with young adult male Wistar rats (n=4) received saline solution during the same period. Using the TUNEL technique, the percentage of apoptosis in the hippocampus of these animals was evaluated. RESULTS: No differences were observed between the percentage of apoptotic cells in the hippocampus of aged animals and of young control animals. The percentage of apoptosis in the hippocampus of aged animals treated chronically with the extracts from the three plants also did not differ from the percentage of apoptosis in the hippocampus of the control group of aged animals. CONCLUSION: Treatment with the hydroalcoholic extracts of Panax ginseng, Turnera diffusa, and Heteropterys tomentosa did not influence the apoptosis of the hippocampal cells of aged rats.