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Brazil has the second-highest COVID-19 death rate worldwide, and Rio de Janeiro is among the states with the highest rate in the country. Although vaccine coverage has been achieved, it is anticipated that COVID-19 will transition into an endemic disease. It is concerning that the molecular mechanisms underlying clinical evolution from mild to severe disease, as well as the mechanisms leading to long COVID-19, are not yet fully understood. NMR and MS-based metabolomics were used to identify metabolites associated with COVID-19 pathophysiology and disease outcome. Severe COVID-19 cases (n = 35) were enrolled in two reference centers in Rio de Janeiro within 72 h of ICU admission, alongside 12 non-infected control subjects. COVID-19 patients were grouped into survivors (n = 18) and non-survivors (n = 17). Choline-related metabolites, serine, glycine, and betaine, were reduced in severe COVID-19, indicating dysregulation in methyl donors. Non-survivors had higher levels of creatine/creatinine, 4-hydroxyproline, gluconic acid, and N-acetylserine, indicating liver and kidney dysfunction. Several changes were greater in women; thus, patients’ sex should be considered in pandemic surveillance to achieve better disease stratification and improve outcomes. These metabolic alterations may be useful to monitor organ (dys) function and to understand the pathophysiology of acute and possibly post-acute COVID-19 syndromes.

Snakebites produce several toxic effects in victims, such as hemorrhage, tissue necrosis, hemostatic, renal, or cardiotoxic alterations, inflammation, and death. To counteract these symptoms, antivenom is the official treatment. Although such therapy prevents death, it does not efficiently neutralize necrosis or other local effects, leading to amputation or morbidities of the affected limb. Therefore, the search for better and more efficient therapies deserves attention; further, plants have been used to ameliorate a number of diseases and medical conditions, including snakebites, for many years. Thus, the aim of this work was to evaluate the antivenom effect of the crude extract, fractions (aqueous and diethyl acetate), and subfractions derived from the aqueous fraction (P1, P2, P3, and P4) of the plant Stryphnodendron adstringens against in vitro (coagulation and proteolytic) and in vivo (edema, hemorrhage, and myotoxic) activities caused by Bothrops jararacussu venom. Overall, all extracts inhibited the toxic effect of B. jararacussu venom, but with different potencies, regardless of whether plant samples were incubated together with venom or injected before or after venom injection into animals; the crude extract and aqueous fraction were found to be the most effective. Indeed, phytochemical and mass spectrometry analysis of S. adstringens samples revealed the presence of flavonols, tannins, and saponins. In conclusion, the plant S. adstringens may represent a promising natural source of molecules to treat the toxic effects associated with envenomation by B. jararacussu snakebites. • Performance of the plant Stryphnodendron adstringens against snake venom activities. • Stryphnodendron adstringens inhibited Bothrops jararacussu venom activities. • Stryphnodendron adstringens is rich in flavonols, saponins, and tannins. • Stryphnodendron adstringens is a strategy against Bothrops jararacussu envenomation. [ABSTRACT FROM AUTHOR]