Mayara Tania Pinheiro

The objective was to determine the phytochemical composition and evaluate the in silico and in vivo biocidal activity of the essential oil of Cymbopogon citratus (DC.) Stapf in an Aedes aegypti model. The phytochemical composition was analyzed using Gas Chromatography coupled to the Mass Spectrometer, while molecular docking was used to evaluate the potential for inhibition of Acetylcholinesterase. The ovicidal, larvicidal, and adulticidal activities were investigated to evaluate the capacity of the essential oil to inhibit egg hatching and to cause mortality in larvae and adults of A. aegypti. The phytochemical analysis revealed the presence of 11 different compounds, with emphasis on β-myrcene (24.03%), β-citral (27.45%), and Neral (35.36%). In molecular docking, the compounds Geraniol (3.96%) and Linalool (2.77%) proved to be the best inhibitors. As for insecticidal activities, the essential oil of C. citratus was effective in inhibiting the hatching of A. aegypti eggs and was highly toxic to larvae. However, toxicity in adults of A. aegypti was incipient. These results indicate that the essential oil of C. citratus has potential as a candidate for the development of new insecticides aimed at controlling the immature stages of A. aegypti, possibly due to the inhibition of the enzyme acetylcholinesterase.

Acmella oleracea (L.) R. K. Jansen, popularly known as jambu in Northern Brazil, is widely used in folk medicine and local cuisine. Its consumption in different ways reinforces the need for safety assessments. In this study, the major compounds found in the hydroethanolic extract of A. oleracea flowers (EHFAO) were characterized by ultra‐performance liquid mass spectrometry (UHPLC‐ESI‐QTOF‐MS/MS). The effects of oral administration of 100/mg/kg of EHFAO extract over 60 days in male spontaneously hypertensive (SHR) and Wistar (WR) rats and the in silico ADME/Tox predictions, lipophilicity, and water solubility were accomplished for the compounds identified. Spilanthol was detected as the foremost major compound at a concentration of 97.7%, followed by 1.53% scopoletin and 0.77% d‐limonene. The treatment with EHFAO did not alter the animals´ weight over the studied period. Moderate alterations were observed solely in the hepatic enzymes AST (WR = 97 UI/L and SHR = 150 UI/L ^∗p < 0.05) and ALT (WR = 55 UI/L and SHR = 95 UI/L ^∗p < 0.05), while no relevant histopathological alterations were found. The in-silico study confirmed the in vivo findings, as the identified compounds were considered highly bioactive orally, due to their drug similarity profiles, adequate lipid solubility, bioavailability, and pharmacokinetics. Therefore, the chronic treatment with EHFAO was found safe at the concentration of 100/mg/kg, with no interference in the blood pressure levels neither appreciable toxic effects.