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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 metaanalyses 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 welldesigned 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. [ABSTRACT FROM AUTHOR]

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 of T. 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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]