A resorcinarene derivative of vanillin, resvan, was synthesized and characterized by spectroscopic techniques. We measured the cytotoxicity (in vivo and in vitro), antioxidant and anti-Toxoplasma activities of vanillin and the resorcinarene compound. Here we show that vanillin has a dose-dependent behavior with IC 50 of 645 µg/mL through an in vitro cytotoxicity assay. However, we could not observe any cytotoxic response at higher concentrations of resvan (IC 50 > 2,000 µg/mL). The in vivo acute toxicity assays of vanillin and resvan exhibited a significant safety margin indicated by a lack of systemic and behavioral toxicity up to 300 mg/kg during the first 30 min, 24 h or 14 days after administration. The obtained derivative showed greater antioxidative activity (84.9%) when comparing to vanillin (19.4%) at 1,000 μg/mL. In addition, vanillin presents anti-Toxoplasma activity, while resvan does not show that feature. Our findings suggest that this particular derivative has an efficient antioxidant activity and a negligible cytotoxic effect, making it a potential target for further biological investigations.

The current pandemic of coronavirus disease 2019 (COVID‐19), transmitted person‐to‐person by severe acute respiratory syndrome of coronavirus 2 (SARS‐CoV‐2), poses a threat to global public health. To present, these are still no clinically approved antibodies or drugs specific for SARS‐CoV‐2, which makes it difficult for controlling the associated pandemic, limited to monitoring and containment. This situation generates a new need for the development of safe and effective treatments. Since SARS‐CoV‐2 shares phylogenetic traits with SARS‐CoV and MERS‐CoV, antiviral medicines may provide some insight into the development of COVID‐19 therapeutics. Besides that, they are being prioritized several FDA‐approved drugs due to the pandemic state. Despite recent advances in the control of the current COVID‐19 pandemic, challenges such as the rapid virus spread and the socioeconomic cost of this outbreak remain for the inexistence of therapeutics agents against SARS‐CoV‐2. From this moment, the in vivo evaluation of FDA‐approved drugs, which until then appears to be effective are recommended, such as chloroquine, hydroxychloroquine, remdesivir, favipiravir, nitazoxanide, and ivermectin; besides new targets: Mpro, spike glycoprotein, and TMPRSS2 inhibitors. Therefore, these investigations are needed to prove the efficacy and safety of these potential candidates, including their side effects.

Toxoplasma gondii is the causative protozoan agent of toxoplasmosis, which is a common infection that is widely distributed worldwide. Studies revealed stronger clonal strains in North America and Europe and genetic diversity in South American strains. Our study aimed to differentiate the pathogenicity and sulfadiazine resistance of three T. gondiiisolates obtained from livestock intended for human consumption. The cytopathic effects of the T. gondii isolates were evaluated. The pathogenicity was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) using a CS3 marker and in a rodent model in vivo. Phenotypic sulfadiazine resistance was measured using a kinetic curve of drug activity in Swiss mice. IgM and IgG were measured by ELISA, and the dihydropteroate synthase (DHPS) gene sequence was analysed. The cytopathic effects and the PCR-RFLP profiles from chickens indicated a different infection source. The Ck3 isolate displayed more cytopathic effects in vitro than the Ck2 and ME49 strains. Additionally, the Ck2 isolate induced a differential humoral immune response compared to ME49. The Ck3 and Pg1 isolates, but not the Ck2 isolate, showed sulfadiazine resistance in the sensitivity assay. We did not find any DHPS gene polymorphisms in the mouse samples. These atypical pathogenicity and sulfadiazine resistance profiles were not previously reported and served as a warning to local health authorities.

Ocular toxoplasmosis is widely distributed in Natal and other cities in Rio Grande do Norte state, with special relevance for bilateral lesions in 56.9% of the patients assessed, the most frequent being type I with intraocular disposition in the macula.

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