Abstract There have been several efforts to minimize the effects caused by the COVID-19 virus around the world. Vaccines were developed in record time and alternative therapies were studied and applied in several countries, such as the use of plasma from recovered patients. Identifying, systematically evaluating and summarizing the best available scientific evidence on the efficacy and safety of using plasma from recovered COVID-19 patients remains the objective of this study. The studies carried out showed that the application of convalescent plasma contributes to the reduction of mortality, viral load and length of hospital stay. However, the effectiveness of the therapy still raises doubts due to the number of patients evaluated in clinical studies, in addition to its high cost and limitations in terms of availability and implementation, with the drug being authorized only for hospital use.

Resumo Houve vários esforços para minimizar os efeitos causados pelo vírus COVID-19 em todo o mundo. As vacinas foram desenvolvidas em tempo recorde e terapias alternativas foram estudadas e aplicadas em vários países, como o uso de plasma de pacientes recuperados. Identificar, avaliar sistematicamente e resumir as melhores evidências científicas disponíveis sobre a eficácia e segurança do uso de plasma de pacientes recuperados com COVID-19 continua sendo o objetivo deste estudo. Os estudos realizados mostraram que a aplicação de plasma convalescente contribui para a redução da mortalidade, carga viral e tempo de internação hospitalar. No entanto, a eficácia da terapia ainda gera dúvidas devido ao número de pacientes avaliados em estudos clínicos, além de seu alto custo e limitações em termos de disponibilidade e implementação, sendo o medicamento autorizado apenas para uso hospitalar.

Abstract Seeds of guarana (Paullinia cupana Kunth, Sapindaceae) feature diverse pharmacological functions, for example, antimicrobial, antioxidant, anticarcinogenic, stimulating, and cognitive functions, as well as liver protection and weight loss. Many of these actions are probably due to the high content of methylxanthines and tannins in its seeds. In Brazil, the world's largest producer of guarana, the plant material is predominantly used in the soft drinks industry, although it is also used in the cosmetic and pharmaceutical industries. Although the Amazon region has the largest cropping area, the state of Bahia is the main guarana producer in Brazil (71%). This review focuses mainly on the possible pharmacological actions of guarana that have been investigated. Moreover, it discusses less-considered topics, such as the toxicology and quality control of seeds and extractives of guarana that will ultimately influence the safety of its use. In addition, it presents a detailed discussion of the methods used to prepare herbal drugs and their extracts, focusing on the importance of standardization and on the direct impact of preparatory factors, on the pharmacological properties of guarana extracts.

Neste trabalho investigou-se o efeito de pulsos de rafinose e ultra-som, na liberação de invertase de Saccharomyces cerevisiae livre e imobilizado em Luffa cylindrica. A cultura de células livres foi submetida a pulso de rafinose 2% e irradiada por 2 min, nas taxas de diluição 0,12 e 0,46 h-1. A cultura de células imobilizadas foi submetida a pulso de rafinose e irradiada por 1, 2 e 4 min, em taxa de diluição 0,10 h-1. Em células imobilizadas, o pulso de rafinose aumentou a atividade invertásica de 5,38 para 7,27 U/mg. Entretanto a aplicação do ultra-som, em cultivo de células livres na taxa de diluição 0,12 h-1, obteve-se os melhores resultados. A atividade variou de 25,08 para 29,38 U/mg, enquanto que o aumento em células imobilizadas foi de 5,22 para 9,70 U/mg, quando sonicadas por 2 min. Esses resultados demonstram que a aplicação de ultra-som, em cultivo contínuo de células livres, pode ter um grande potencial de aplicação em processos biotecnológicos.

This study investigated the effect of raffinose and ultrasound pulses on invertase release from free S. cerevisiae and S. cerevisiae immobilized in Luffa cylindrica. The free cell culture was submitted to 2% raffinose pulse and irradiated for 2 minutes at 0.12 and 0.46 h-1 dilution rates. The immobilized cell culture was submitted to raffinose pulse and irradiated for 1, 2 and 4 minutes, at 0.10 h-1 dilution rate. In immobilized cells, the raffinose pulse increased the invertase activity from 5.38 to 7.27 U/mg. Ultrasound application in free cell culture at the 0.12 h-1 dilution rate gave the best results. The activity varied from 25.08 to 29.38 U/mg while the increase in immobilized cells was from 5.22 to 9.70 U/mg when sonicated for two minutes. These results showed that ultrasound application in continuous culture could have great potential for application in biotechnological techniques.