Clenilma Marques Brandão

Control of Aedes aegypti larvae is essential to reduce arbovirus transmission; however, increasing insecticide resistance and environmental concerns highlight the urgent need for sustainable alternatives. In this study, a solvent-free thermoresponsive nanogel (NGLp), based on Pluronic F127 and Carbopol 974P, was developed to encapsulate Lippia pedunculosa Hayek essential oil (EOLp), aiming to enhance larvicidal performance through improved dispersion and prolonged availability of bioactive constituents. The essential oil was obtained by hydrodistillation and chemically characterized by GC–MS and NMR, identifying 28 constituents (96.65%), with rotundifolone (62.68%) and limonene (20.74%) as the major compounds. Nanogels were prepared using a low-energy cold method, and the optimized formulation (1% w/w EOLp) exhibited a nanometric Z-average size (239.9 nm; PdI 0.474) and a negative zeta potential (−22.3 ± 3.90 mV), indicating a nanoscale but relatively polydisperse dispersion with moderate electrosteric stabilization. FTIR analysis confirmed the physical incorporation of the essential oil within the nanogel matrix. Larvicidal assays against third-instar A. aegypti larvae demonstrated dose- and time-dependent activity, with 100% mortality achieved at concentrations ≥50 μg mL–1 after 48–72 h. The progressive increase in mortality at intermediate concentrations over time indicates time-dependent larvicidal efficacy, as reflected by the reduction in LC50 and LC90 values from 38.6 and 46.0 μg mL–1 at 24 h to 31.6 and 40.9 μg mL–1 at 48 h, with further improvement at 72 h. Although this temporal profile is compatible with prolonged availability of the encapsulated oil, direct release studies would be required to confirm a sustained-release mechanism. These findings demonstrate that the thermoresponsive nanogel enhances the efficacy of L. pedunculosa essential oil, supporting its potential as a sustainable and eco-compatible nanoplatform for mosquito control.

The search for sustainable and effective bioactive compounds from plant sources has intensified due to their potential applications in both healthcare and vector control. In this study, a thermoresponsive nanogel based on Pluronic F127 and Carbopol 974P was developed to incorporate the essential oil of Duguetia stelechantha (EODs; essential oil of D. stelechantha), aiming to improve its physicochemical stability and evaluate its biological activity in a nanostructured delivery system. The optimized formulation containing 1% (w/w) EODs (nGDs) exhibited suitable physicochemical stability and pronounced thermoresponsive behavior, with a reversible sol–gel transition occurring between 19 and 26 °C. Rheological analysis revealed increased viscosity and enhanced structural organization upon oil incorporation, while FTIR and DLS results confirmed the successful encapsulation of EODs and its influence on intermolecular interactions and nanostructural dynamics. Biological assays demonstrated that free EODs exhibited higher immediate leishmanicidal activity against Leishmania amazonensis promastigotes, whereas nGDs showed a time-dependent response, suggesting a possible modulation of essential oil availability within the nanogel matrix. Morphological analysis confirmed significant parasite damage following treatment. Additionally, nGDs exhibited strong larvicidal activity against Aedes aegypti, with LC50 and LC90 values of 97.7 ± 6.4 and 177.7 ± 18.3 μg/mL, respectively. Overall, the developed thermoresponsive nanogel provides a stable platform for incorporating EODs and may contribute to modulating its biological response, although specific release and temperature-dependent biological assays are still required to confirm the functional role of the sol–gel transition. This system represents a promising eco-friendly platform for dual antiparasitic therapy and vector control applications.

Controlling the arbovirus vector Aedes aegypti represents a growing public health challange, intensifying the search for alternatives to combat the mosquito. In this context, the present study aims to evaluate the larvicidal activity of essential oils from three Piper species and their mixtures, as well as their preliminary toxicity and in silico acetylcholinesterase (AChE) inhibitory potential. The essential oils and mixtures were characterized by GC–MS. The larvicidal activity test was performed against third-stage larvae, and a preliminary toxicity test was preformed against Artemia salina. The results showed that the oils had a high content of phenylpropanoids such as safrole, dillapiole, and eugenol, as well as their derivatives. The mixtures showed lower toxicity when compared to the pure oils. P. aduncum oil showed the highest larvicidal action (LC₅₀ = 26.2 µg/mL), followed by P. callosum (LC₅₀ = 53.2 µg/mL), while P. divaricatum had the lowest activity (LC₅₀ = 123.8 µg/mL). Among the mixtures, the combination of P. divaricatum and P. aduncum stood out for its synergistic effect. Molecular docking analyses suggested that phytoconstituents interact favorably with AChE, supporting a neurotoxic mechanism associated with enzyme inhibition. Thus, Piper essential oils and mixtures are promising alternatives for the control of A. aegypti.

Background/Objectives:A. aegypti larval control is essential for reducing arbovirus transmission; however, increasing insecticide resistance and environmental concerns demand sustainable alternatives. This study reports the development of a solvent-free, thermoresponsive Pluronic F127/Carbopol 974P nanogel (NGLp) encapsulating Lippia pedunculosa Hayek essential oil (OELp) to enhance larvicidal performance through improved dispersion and controlled release (Figure ). Methods: OELp was obtained by hydrodistillation and chemically characterized by GC–MS and NMR. Nanogels were prepared using a low-energy cold method (F127 20% w/w; Carbopol 0.2% w/w), selecting the most stable formulation (1% w/w OELp). The system was characterized by FTIR, dynamic light scattering (DLS), zeta potential, and scanning electron microscopy (SEM). Larvicidal activity was evaluated against third-instar A. aegypti larvae (20–60 μg mL−1; 24, 48, and 72 h), and LC50/LC90 values were estimated by logistic fitting. Results: OELp contained 28 identified constituents (96.65%), predominantly rotundifolone (62.68%) and limonene (20.74%), with NMR confirming rotundifolone as the major compound. The optimized nanogel exhibited nanometric size (239.9 nm; PdI 0.474) and a negative zeta potential (−22.3±3.90 mV), indicating electrosterically stabilized dispersion. FTIR confirmed physical incorporation of OELp. The nanogel demonstrated dose- and time-dependent larvicidal activity, achieving 100% mortality at ≥50 μg mL−1 (48–72 h). Mortality at intermediate concentrations increased over time (e.g., 53% at 30 μg mL−1 at 72 h), indicating sustained release. LC50/LC90 values decreased from 38.6/46.0 μg mL−1 (24 h) to 31.6/40.9 μg mL−1 (48 h), with further improvement at 72 h. Conclusions: NGLp enhances larvicidal performance through improved dispersion and sustained release of OELp, supporting its potential as a sustainable and eco-compatible nanoplatform for mosquito control.

Essential oil (EO) nanoformulations are emerging as green nanotechnology strategies against Aedes aegypti and Aedes albopictus mosquitoes, which are vectors of arboviruses such as dengue. For the first time, we investigated the larvicidal influence of polysorbate (PS₈₀) against A. albopictus mosquito using simplex centroid design (SCD) in the formulation of EODr nanoemulsions derived from the species Dizygostemon riparius (Plantaginaceae), a plant native to the Cerrado region of Maranhão, Brazil. In addition, we present the ecotoxicological profile of the formulation against A. salina microcrustaceans. EODr was extracted by hydrodistillation, and its chemical profile was analyzed by GC-MS-FID and NMR (¹H, ¹³C, DEPT-135, and 2D). The nanoformulations were characterized by DLS, PDI, ZP, and TEM. The chemical profile indicated the presence of compounds such as fenchol, fenchyl acetate, caryophyllene, and caryophyllene oxide. The SCD contributed to the development of nanostructured formulations with spheroidal morphology, demonstrating effective larvicidal action against A. albopictus mosquitoes with lower toxicity than commercial chemical larvicides.

Climacteric is a period in which several symptoms are triggered in women's health, bringing about profound changes of both positive and negative nature. Among these, the onset of menopause, characterized by the last menstruation, stands out, which results in the reduction of the woman's reproductive capacity. In this sense, intimate lubricating gels were manufactured to combat atrophic vaginitis in climacteric women. This research aimed to prepare and develop intimate lubricating gels based on water and hydroalcoholic extract of medicinal plants (phytoestrogens) aiming at revitalizing the vaginal mucosa and improving the quality of life of climacteric women. The preliminary stability assessment revealed that the gels produced presented organoleptic and physicochemical parameters by the ANVISA Cosmetic Product Stability Guide, given that they showed signs of constancy throughout the evaluation. Therefore, the gels produced are capable of mitigating vaginal dryness, genital burning (dyspareunia), irritation, lack of lubrication and discomfort during sexual intercourse and recurrent urinary infections.

Objetivo: Avaliar a atividade antimicrobiana do extrato da polpa do fruto Crescentia cujete frente a cepas bacterianas relevantes para a aquicultura. Métodos: A planta, reconhecida por suas propriedades medicinais, foi submetida aos processos de obtenção da polpa, liofilização e extração do extrato bruto. Em seguida, foram realizados testes fitoquímicos para identificar os metabólitos secundários presentes. A atividade antibacteriana foi analisada pelo método de disco-difusão, utilizando diferentes concentrações do extrato. Resultados: Os testes revelaram uma atividade antibacteriana expressiva frente às cepas analisadas, sugerindo que o extrato pode ser uma alternativa promissora aos antibióticos sintéticos utilizados na aquicultura. Conclusão: Os resultados indicam a necessidade de novos estudos para compreender os mecanismos de ação do extrato e testar sua eficácia em diferentes formulações, contribuindo para a promoção da saúde e a sustentabilidade na produção aquícola.

Arboviruses, transmitted by mosquitoes like Aedes aegypti, pose significant public health challenges globally, particularly in tropical regions. The rapid spread and adaptation of viruses such as Dengue, Zika, and Chikungunya have emphasized the need for innovative control methods. Larvicide property of essential oils has emerged as a potential alternative to conventional insecticides. This work showed the development of an eco-friendly nanogel using a low-energy, solvent-free method, incorporating the copolymer F127 and carbopol 974p with a high concentration of essential oil from Pectis brevipedunculata (Gardner) Sch.Bip. (Pb). The resulting nanogel displayed excellent physical stability and was maintained under varying temperature conditions. Characterization techniques, including FTIR and DLS, confirmed the stable incorporation of essential oil (EOPb) within the nanogel matrix. The in vitro assays against Aedes aegypti larvae revealed that at 500 μg/mL, the mortality rates was 96.0% ± 7.0 after 24 h and 100.0% ± 0.0 after 48 h. The positive control group treated with temephos, achieved 100% mortality at both time points, validating the experimental conditions and providing a benchmark for assessing the efficacy of the nGF2002Pb nanogel. These results indicate that the nGF2002Pb demonstrates a pronounced concentration-dependent larvicidal effect against Aedes aegypti, offering an innovative and sustainable approach for arbovirus vector control.