OBJETIVO: Avaliar a ação cicatrizante de própolis verde e vermelha, correlacionando ao teor de flavonoides MÉTODOS: Foi realizada a quantificação de flavonoides totais dos extratos etanólicos de própolis verde e vermelha para posterior incorporação em pomada base a 20%. Utilizou-se 20 ratos Wistar distribuídos em quatro grupos: solução salina a 0,9% (S), pomada base (B), pomada própolis verde (G), pomada própolis vermelha (R), todos submetidos à confecção de lesões excisivas na região mediana do dorso. Os ratos foram tratados diariamente durante 15 dias. Neste período foram observados peso; temperatura corporal; diâmetro das feridas. Para análise histológica, amostras das feridas foram coletadas. Ao fim do experimento foram realizadas coleta sanguínea e remoção do rim e fígado para análises bioquímica e histológica. RESULTADOS: Os teores de flavonoides totais das própolis verde (4,50 %) e vermelha (5,92 %) foram elevados (>2 %), mas, embora a segunda apresente teor maior que a primeira, a evolução da própolis verde, macro e histologicamente, foi melhor na reparação das feridas. Não foram observadas nefro ou hepatotoxicidade, resultado corroborado pelos ensaios bioquímicos (TGP e albumina). A própolis influiu na redução de colesterol total, triglicerídeos e glicemia. CONCLUSÃO: Não foi possível correlacionar o teor de flavonoides totais com a ação cicatrizante da própolis. O dado revela a necessidade da elucidação dos flavonoides encontrados em cada classe de própolis para desvendar qual (ou quais) flavonoide(s) seria(m) representativo(s) no processo cicatricial.

The present work is devoted to the study of polymer/layered silicate nanocomposite (PLN) of alginate–bentonite as a bead matrix for the entomopathogenic fungus Beauveria bassiana strain CPATC032. In particular, we investigate the encapsulation efficiency and surface morphology of beads presenting different concentrations of bentonite, where the effects associated with the drying method of the samples were analyzed. The internal structure of alginate–bentonite beads are studied by means of X-ray diffraction and Fourier transform infrared spectroscopy, determining the impact of the drying process on the crystalline structure of bentonite domains inside the polymeric matrix. By using Scanning Electron Microscopy (SEM) and fluorescence microscopy techniques, we identify a monolithic distribution profile for beads inside the PLN matrix, which is independent of the concentration of bentonite and of the drying method employed. However, our results demonstrated that the in vitro release of the fungus is sensitive to the bead preparation method due to the emergence of a barrier phenomenon as the concentration of silicate is increased. Swelling degree and release kinetics were also investigated, where a strong dependence on the drying method was observed.

Lipases have key roles in insect lipid acquisition, storage, and mobilization and are also fundamental to many physiological processes in insects. Lipids are an important component of insect diets, where they are hydrolyzed in the midgut lumen, absorbed, and used for the synthesis of complex lipids. The South American palm weevil Rhynchophorus palmarum is one of the most important pests on commercial palm plantations. However, there are few studies about lipid digestion for this insect. In this work, we have described the biochemical characterization of the lipase activity in the posterior midgut of the R. palmarum palm weevil. Lipase activity was highest between the temperatures of 37 °C and 45 °C and at pH 6.5. Lipase activity was also sensitive to variations in salt and calcium concentrations. Lipases have been described structurally as enzymes with the Ser-His-Asp Catalytic Triad, containing an active serine. The serine protease inhibitor PMSF (phenylmethane sulfonyl fluoride) inhibited the lipases from R. palmarum, demonstrating the importance of a serine residue for this activity. The ability of the lipases to hydrolyze p-Nitrophenyl esters with different chain lengths has revealed the activities of a broad range of substrates. The lipase activities of R. palmarum increased in the presence of reduced glutathione (GSH) and dithiothreitol (DTT), while in the presence of oxidized glutathione (GSSG), activities were drastically reduced. To our knowledge, this study has provided the first information about lipase activity in the R. palmarum palm weevil.

The main objectives of this study were to develop and characterize hydrophilic polymeric membranes impregnated with poly-lactic acid (PLA) nanoparticles (NPs) combined with red propolis (RP). Ultrasonic-assisted extraction was used to obtain 30% (w/v) red propolis hydroalcoholic extract (RPE). The NPs (75,000 g mol⁻¹) alone and incorporated with RP (NPRP) were obtained using the solvent emulsification and diffusion technique. Biopolymeric hydrogel membranes (MNPRP) were obtained using carboxymethylcellulose (CMC) and NPRP. Their characterization was performed using thermal analysis, Fourier transform infrared (FTIR), total phenols (TPC) and flavonoids contents (TFC), and antioxidant activity through the radical scavenging assay with 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and Ferric reducing antioxidant power (FRAP). The identification and quantification of significant RP markers were performed through UPLC-DAD. The NPs were evaluated for particle size, polydispersity index, and zeta potential. The TPC for RPE, NPRP, and MNPRP was 240.3 ± 3.4, 191.7 ± 0.3, and 183.4 ± 2.1 mg EGA g⁻¹, while for TFC, the value was 37.8 ± 0.9, 35 ± 3.9, and 26.8 ± 1.9 mg EQ g⁻¹, respectively. Relevant antioxidant activity was also observed by FRAP, with 1400.2 (RPE), 1294.2 (NPRP), and 696.2 µmol Fe2+ g⁻¹ (MNPRP). The primary markers of RP were liquiritigenin, isoliquiritigenin, and formononetin. The particle sizes were 194.1 (NPs) and 361.2 nm (NPRP), with an encapsulation efficiency of 85.4%. Thermal analysis revealed high thermal stability for the PLA, nanoparticles, and membranes. The DSC revealed no interaction between the components. FTIR allowed for characterizing the RPE encapsulation in NPRP and CMC for the MNPRP. The membrane loaded with NPRP, fully characterized, has antioxidant capacity and may have application in the treatment of skin wounds.

Propolis is a natural substance produced by bees and is known to have antimicrobial activity. Our aim was to evaluate the antimicrobial effect of micellar nanocomposites loaded with an ethyl acetate extract of Brazilian red propolis as a cavity cleaning agent and its influence on the color and microtensile bond strength (μTBS) of the dentin/resin interface. An ultra-performance liquid chromatography coupled with a diode array detector (UPLC-DAD) assay was used to determine the flavonoids and isoflavones present in an ethyl acetate extract of Brazilian red propolis (EARP) and micellar nanocomposites loaded with EARP (MNRP). The antimicrobial activity of EARP and MNRP was tested against Streptococcus mutans, Lactobacillus acidophilus, and Candida albicans. One of the following experimental treatments was applied to etched dentin (phosphoric acid, 15 s): 5 μL of MNRP (RP3, 0.3%; RP6, 0.6%; or RP1, 1.0% w/v), placebo, and 2% chlorhexidine digluconate. Single Bond adhesive (3 M/ESPE) was applied and a 4-mm-thick resin crown (Z350XT, 3 M/ESPE) was built up. After 24 h, the teeth were sectioned into sticks for the μTBS test and scanning electron microscopy. Spectrophotometry according to the CIE L*a*b* chromatic space was used to evaluate the color. Data were analyzed using one-way ANOVA and the Tukey test or Kruskal-Wallis test and the same test for pairwise comparisons between the means (P < 0.05). The UPLC-DAD assay identified the flavonoids liquiritigenin, pinobanksin, pinocembrin, and isoliquiritigenin and the isoflavonoids daidzein, formononetin, and biochanin A in the EARP and micellar nanocomposites. EARP and MNRP presented antimicrobial activity against the cariogenic bacteria Streptococcus mutans and Lactobacillus acidophilus, and for Candida albicans. ΔE values varied from 2.31 to 3.67 (P = 0.457). The mean μTBS for RP1 was significantly lower than for the other groups (P < 0.001). Dentin treated with RP1 showed the shortest resin tags followed by RP6 and RP3. The EARP and (MNRP) showed antimicrobial activity for the main agents causing dental caries (Streptococcus mutans and Lactobacillus acidophilus) and for Candida albicans. MNRP at concentrations of 0.3 and 0.6% used as a cavity cleaner do not compromise the aesthetics or μTBS of the dentin/resin interface.