COVID-19 pandemic: Multilevel dental technical guidelines based on new scientific evidence

The COVID-19 pandemic imposed restrictive measures on dentistry in different regions of the world, ranging from stoppage of care to only permission for urgent and emergency dental services. Thus, new biosafety guidelines for resuming activities, whether in single dental offices, large clinics or dental education activities, are urgently required. In this sense, herein, guidelines that incorporate common points of the main protocols found in the literature for the resumption of dental activities at their different levels, whether in the scope of care or education, are presented. Furthermore, we present the incorporation of measures that allow an increase in the level of biosafety, such as the control of the dental team, the inclusion in the history of conjunctivitis as a possible alert for COVID-19, and the use of the pulse oximeter to assess the risk of silent hypoxemia, which may indicate a complication of COVID-19. In addition, new perspectives for directing research and innovation for biosafety in dentistry are discussed

In vitro assessment for cytotoxicity screening of new antimalarial candidates

In antimalarial research there are no standard procedures to determine the toxicity of a drug candidate. Among the alternatives available, in vitro cytotoxicity assays are the most widely used to predict toxic effects of future therapeutic products. They have the advantage over the in vivo assays, in that they offer the possibility to restrain the number of experimental variables. The objective of the present study was to compare in vitro cytotoxic methods by testing various compounds currently used to treat malaria against different cell lines. Neutral red (NR) uptake and methylthiazoletetrazolium (MTT) colorimetric in vitro assays were used to determine preliminary toxicity of commercially available antimalarial drugs against tumor and non-tumor cells lines. Toxicity through brine shrimp lethality bioassay and hemolytic activity were also evaluated. Significant differences were observed in the tests measured by NR uptake. The tumor cell lines TOV-21G and HepG2 and non-tumor WI-26VA4 cells showed relatively uniform toxicity results, with TOV-21G being the most sensitive cell tested, presenting the lowest concentration to cause death to 50% of viable cells (CC50) values. The results of this study support the use of TOV-21G, HepG2 and WI-26VA4 cells lines as the choice for cytotoxicity tests to evaluate potential bioactive compounds

Antiplasmodial activity of aryltetralone lignans from Holostylis reniformis

Extracts from Holostylis reniformis were tested in vivo against Plasmodium berghei and in vitro against a chloroquine-resistant strain of Plasmodium falciparum. The hexane extract of the roots was the most active, causing 67% reduction of parasitemia in vivo. From this extract, six lignans, including a new (7 ' R,8S,8 ' S)-3 ',4 '-methylenedioxy-4,5-dimethoxy-2,7 '-cyclolignan-7-one, were isolated and tested in vitro against P. falciparum. The three most active lignans showed 50% inhibitor concentrations of <= 0.32 mu M. An evaluation of minimum lethal dose (30%) values showed low toxicity for these lignans in a hepatic cell line (Hep G2A16). Therefore, these compounds are potential candidates for the development of antimalarial drugs

COVID-19 Vaccines: Bioethical Consideration

15 páginasLa pandemia de la covid-19 ha tenido impactos inconmensurables en la economía, la educación y la socialización, además de la pérdida de millones de vidas. Por lo tanto, se ha acelerado el desarrollo de un número sin precedentes de candidatos a vacunas contra la covid-19 para controlar la pandemia. A su vez, la autorización para su uso de emergencia por parte de la Organización Mundial de la Salud permitió el inicio de la inmunización de la población a través de vacunas que aún se encuentran en ensayos clínicos. Aquí presentamos una perspectiva de los preceptos bioéticos de autonomía, no maleficencia, beneficencia y justicia en el contexto del uso de emergencia de vacunas contra la covid-19. Además, se enfatiza la importancia de la vigilancia en todas las etapas del desarrollo de la vacuna con el fin de detectar efectos adversos y asegurar el cumplimiento de los preceptos bioéticos.The COVID-19 pandemic produced immeasurable impacts on the economy, education, and socialization, besides the loss of mi-llions of lives. Thus, there has been an accelerated development of an unprecedented number of COVID-19 vaccine candidates to control the pandemic. The World Health Organization’s emergency use authorization of COVID-19 vaccines still in clinical trial allowed immunizing the population. This paper presents a perspective of the bioethical precepts of autonomy, non-maleficence, beneficence, and justice in the emergency use of COVID-19 vaccines. Furthermore, it emphasizes the importance of surveillance at all stages of vaccine development to detect adverse effects and ensure compliance with bioethical precepts

Vacinas contra a covid-19: consideração bioética

The COVID-19 pandemic produced immeasurable impacts on the economy, education, and socialization, besides the loss of millions of lives. Thus, there has been an accelerated development of an unprecedented number of COVID-19 vaccine candidates to control the pandemic. The World Health Organization’s emergency use authorization of COVID-19 vaccines still in clinical trial allowed immunizing the population. This paper presents a perspective of the bioethical precepts of autonomy, non-maleficence, beneficence, and justice in the emergency use of COVID-19 vaccines. Furthermore, it emphasizes the importance of surveillance at all stages of vaccine development to detect adverse effects and ensure compliance with bioethical precepts.La pandemia de la covid-19 ha tenido impactos inconmensurables en la economía, la educación y la socialización, además de la pérdida de millones de vidas. Por lo tanto, se ha acelerado el desarrollo de un número sin precedentes de candidatos a vacunas contra la covid-19 para controlar la pandemia. A su vez, la autorización para su uso de emergencia por parte de la Organización Mundial de la Salud permitió el inicio de la inmunización de la población a través de vacunas que aún se encuentran en ensayos clínicos. Aquí presentamos una perspectiva de los preceptos bioéticos de autonomía, no maleficencia, beneficencia y justicia en el contexto del uso de emergencia de vacunas contra la covid-19. Además, se enfatiza la importancia de la vigilancia en todas las etapas del desarrollo de la vacuna con el fin de detectar efectos adversos y asegurar el cumplimiento de los preceptos bioéticos.A pandemia ocasionada pela covid-19, além da perda de milhões de vidas, vem trazendo consequências incomensuráveis para a economia, a educação e a socialização. Portanto, vem sendo acelerado o desenvolvimento de um número sem precedentes de candidatos a vacinas contra a covid-19 para controlar a pandemia. Por sua vez, a autorização para seu uso emergencial por parte da Organização Mundial da Saúde permitiu o início da imunização da população por meio de vacinas que ainda se encontram em ensaios clínicos. Aqui, apresentamos uma perspectiva dos princípios bioéticos de autonomia, não maleficência, beneficência e justiça no contexto do uso emergencial de vacinas contra covid-19. Além disso, é enfatizada a importância da vigilância em todas as etapas do desenvolvimento da vacinação a fim de detectar efeitos adversos e assegurar o cumprimento dos princípios bioéticos

Structure-based drug design studies of the interactions ofent-kaurane diterpenes derived from Wedelia paludosa with the Plasmodium falciparumsarco/endoplasmic reticulum Ca2+-ATPase PfATP6

Malaria is responsible for more deaths around the world than any other parasitic disease. Due to the emergence of strains that are resistant to the current chemotherapeutic antimalarial arsenal, the search for new antimalarial drugs remains urgent though hampered by a lack of knowledge regarding the molecular mechanisms of artemisinin resistance. Semisynthetic compounds derived from diterpenes from the medicinal plant Wedelia paludosawere tested in silico against the Plasmodium falciparumCa2+-ATPase, PfATP6. This protein was constructed by comparative modelling using the three-dimensional structure of a homologous protein, 1IWO, as a scaffold. Compound 21 showed the best docking scores, indicating a better interaction with PfATP6 than that of thapsigargin, the natural inhibitor. Inhibition of PfATP6 by diterpene compounds could promote a change in calcium homeostasis, leading to parasite death. These data suggest PfATP6 as a potential target for the antimalarial ent-kaurane diterpenes

Antiplasmodial Activity of Hydroalcoholic Extract from Jucá (<i>Libidibia ferrea</i>) Pods

Malaria is an infectious and parasitic disease caused by protozoa of the genus Plasmodium, which affects millions of people in tropical and subtropical areas. Recently, there have been multiple reports of drug resistance in Plasmodium populations, leading to the search for potential new active compounds against the parasite. Thus, we aimed to evaluate the in vitro antiplasmodial activity and cytotoxicity of the hydroalcoholic extract of Jucá (Libidibia ferrea) in serial concentrations. Jucá was used in the form of a freeze-dried hydroalcoholic extract. For the cytotoxicity assay, the(3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) method with the WI-26VA4 human cell line was used. For the antiplasmodial activity, Plasmodium falciparum synchronized cultures were treated with serial concentrations (0.2 to 50 μg/mL) of the Jucá extract. In terms of the chemical composition of the Jucá extract, gas chromatography coupled to mass spectrometry measurements revealed the main compounds as ellagic acid, valoneic acid dilactone, gallotannin, and gallic acid. The Jucá hydroalcoholic extract did not show cytotoxic activity per MTT, with an IC50 value greater than 100 µg/mL. Regarding the antiplasmodial activity, the Jucá extract presented an IC50 of 11.10 µg/mL with a selective index of nine. Because of its antiplasmodial activity at the tested concentrations and low toxicity, the Jucá extract is presented as a candidate for herbal medicine in the treatment of malaria. To the best of our knowledge, this is the first report of antiplasmodial activity in Jucá