Biological evaluation of 1,3-benzodioxole acids points to 3,4-(methylenedioxy) cinnamic acid as a potential larvicide against Aedes aegypti (Diptera: Culicidae).

Aedes aegypti serves as the primary vector for viruses like dengue, Chikungunya, Zika, and yellow fever, posing a significant public health challenge in Brazil. Given the absence of approved vaccines for these diseases, effective mosquito control becomes paramount in preventing outbreaks. However, currently available chemical insecticides face issues related to toxicity and the emergence of resistance, necessitating the exploration of new active compounds. Drawing inspiration from natural products, we identified the 1,3-benzodioxole group as a key pharmacophore associated with insecticidal activity. Therefore, this study aimed to synthesize and assess the larvicidal activity of 1,3-benzodioxole acids against Ae. aegypti, as well as their toxicity in mammals. Among the compounds evaluated, 3,4-(methylenedioxy) cinnamic acid (compound 4) demonstrated larvicidal activity. It exhibited LC50 and LC90 values of 28.9 ± 5.6 and 162.7 ± 26.2 µM, respectively, after 24 h of exposure. For reference, the positive control, temephos, displayed both LC50 and LC90 values below 10.94 µM. These findings underline the significance of the 3,4-methylenedioxy substituent on the aromatic ring and the presence of a double bond in the aliphatic chain for biological activity. Furthermore, compound 4 exhibited no cytotoxicity towards human peripheral blood mononuclear cells, even at concentrations up to 5200 µM. Lastly, in mice treated with 2000 mg kg-1, compound 4 showed mild behavioral effects and displayed no structural signs of toxicity in vital organs such as the kidney, liver, spleen, and lungs.

Anticancer activity of ß-Lapachone derivatives on human leukemic cell lines.

ß-lapachone is a 1,2-naphthoquinone of great therapeutic interest that induces cell death by autophagy and apoptosis in tumor cells due to oxidative stress increasing. However, its high toxicity in healthy tissues limits its clinical use, which stimulates the planning and synthesis of more selective analogs. The aim of this study was to investigate the cytotoxic activity of three thiosemicarbazones derived from ß-lapachone (BV2, BV3 and BV5) in leukemia cells. Cytotoxicity tests were performed on tumor cells (HL-60, K562, K562-Lucena and MOLT-4) and normal peripheral blood mononuclear cells (PBMCs). Subsequently, the mode of action of compounds was accessed by optical microscopy, transmission electron microscopy or fluorescence microscopy. Flow cytometry analysis was performed to investigate apoptosis induction, cell cycle, DNA fragmentation and mitochondrial depolarization. All derivatives inhibited tumor cell growth after 72 h (IC50 < 10 µM to all cell lines, including the resistant K562-Lucena) with less toxic effects in PBMC cells, being BV3 the most selective compound with selective index (SI) of 275 for HL-60; SI of 40 to K562; SI of 10 for MOLT-4 and SI of 50 to K562-Lucena compared to ß-lapachone with SI of 18 to HL-60, SI of 3.7 to K562; SI of 2.4 to MOLT-4 and SI of 0.9 to K562-Lucena. In addition, the K562 or MOLT-4 cells treated with BV3 showed characteristics of both apoptosis and autophagy cell death, mainly by autophagy. These results demonstrate the potent cytotoxic effect of thiosemicarbazones derived from ß-lapachone as promising anticancer drugs candidates, encouraging the continuity of in vivo tests.

The Fatty Acid Composition of Vegetable Oils and Their Potential Use in Wound Care.

OBJECTIVE: To evaluate the similarities among fatty acid compositions of vegetable oils sold in the Brazilian market and those present in a reference health product used to treat wounds. METHODS: The relative amounts of fatty acids in 21 types of vegetable oils, purchased in the Brazilian market, were assessed using gas chromatography-mass spectrometry and flame ionization detection. MAIN RESULTS: The studied oils had similar fatty acid compositions to the reference product (caprylic acid, 18.8%; capric acid, 17.4%; oleic acid, 27.5%; and linoleic acid, 28.1%). The presence of caprylic acid (10.45% ± 0.07%), capric acid (5.8% ± 0.75%), lauric acid (45.63% ± 0.93%), and myristic acid (16.33% ± 2.23%) were detected in all the vegetable oils tested. Oleic acid (52.94% ± 12.54%) was present in andiroba, avocado, canola, copaiba, olive, palm, pequi, and pracaxi oils and featured prominently in olive oil (75.8%). Linoleic acid (57.09% ± 8.47%) was present in corn, cottonseed, grapeseed, passion fruit, and sunflower oils and in mixed oils (olive with soybean and sunflower with corn and canola). CONCLUSIONS: Most of the vegetable oils tested are products of plants from tropical climates, where they are abundant and easy to cultivate. It is possible that a balanced composition of fatty acids obtained from natural sources could be an effective alternative treatment for wounds.