Pterodon pubescens oil nanoemulsions: physiochemical and microbiological characterization and in vivo anti-inflammatory efficacy studies

Abstract Pterodon pubescens (Benth.) Benth., Fabaceae, fruits have been investigated for their anti-inflammatory and antinociceptive activities, and have demonstrated effectiveness in inflammatory conditions. A physiochemical and microbiological stability study was conducted to investigate two nanoemulsion-based delivery systems of two different hydrophilic surfactants (polyethylene glycol-40H castor oil or polyethylene glycol-40 castor oil). The nanoemulsions, containing P. pubescens oil, lecithin, hydrophilic surfactant and water, were analyzed for droplet size distribution, polydispersity index, pH, consistency index, stability against centrifugal force, and active content/vouacapan derivatives. The physicochemical characteristics were followed for 365 days. The nanoemulsion system was evaluated for anti-inflammatory activity by using with a peritonitis model, immediately after preparation and after 365 days of storage at 25 °C. The stability study demonstrated that proper storage (25 °C) preserved the characteristics of the nanoemulsion containing 7.5% polyethylene glycol-40H castor oil, 5% lecithin, and 5% P. pubescens oil. Further, it ensured a shelf life of 365 days as a phytotherapeutic formulation. In the peritonitis assay induced by carrageenan, nanoemulsion prepared with polyethylene glycol-40H castor oil (125 mg/kg) reduced leukocyte migration, even after 365 days of storage (25 °C), highlighting its potential for the treatment of inflammatory diseases. However, further studies are needed to confirm its clinical effectiveness.

Evaluation of RbCl and CrCl3 as markers of Triatoma brasiliensis (Hemiptera: Reduviidae) nymphs: persistence and influence of Rb and Cr on triatomine biology

In order to mark Triatoma brasiliensis, the vector of Chagas disease in Brazil, two chemical compounds, rubidium chloride (RbCl) and chromium chloride (CrCl3), were tested. First, 199 N2-N5 nymphs were fed on blood with 0.025M RbCl. Rb marker positivity ranged from 2.5 percent (N3)-70 percent (N2), with a maximum persistence of 98 days. Second, 265 N2-N5 nymphs were fed on blood containing 0.0015M CrCl3. Cr marker positivity ranged up to 93 percent (N5), with a maximum persistence of 119 days. Finally, we blood fed 213 T. brasiliensis to investigate whether CrCl3 altered the biology of this insect. The developmental time of T. brasiliensis was unaltered, but the survival of the Cr-marked group was lower than that of the control group. Differences in the mean fecundity of the control (mean of 156.1) and experimental (mean of 135.6) groups were not statistically significant and 100 percent of the egg batches of females Cr-marked as nymphs were positive. In conclusion, CrCl3 is a useful tool for marking T. brasiliensis nymphs due to its high positivity and persistence.

Developmental and reproductive patterns of Triatoma brasiliensis infected with Trypanosoma cruzi under laboratory conditions

The aim of this work was to study the interaction between Trypanosoma cruzi-1 and Triatoma brasiliensis. A group of 1st instar nymphs was initially fed on T. cruzi-infected mice and a control group was fed on uninfected mice. From the second feeding onwards, both groups were otherwise fed on non-infected mice. The resulting adults were grouped in pairs: infected male/uninfected female, uninfected male/infected female, infected male and female and uninfected male/uninfected female. The infection affected only the 1st instar nymphs, which took significantly more time to reach the 2nd instar than uninfected nymphs. The differences in the molting time between the infected and uninfected nymphs from the 2nd to the 5th instars were not statistically significant. Both groups presented similar rates of nymphal mortality and reproductive performance was not significantly affected by infection in any of the treatments.

Biological activity of Bacillus thuringiensis strains against larvae of the Blowfly Chrysomya putoria (Wiedemann) (Diptera: Calliphoridae)

Different strains of Bacillus thuringiensis Berliner were proved to be a powerful biologic insecticide against larvae of several insect orders. Due to the epidemiological importance of blowflies of the Chrysomya Robineau-Desvoidy genus in the production of secondary cutaneous myiasis and mechanic transmission of pathogenic agents, the performance of two strains of B. thuringiensis (LFB-FIOCRUZ 907 and LFB-FIOCRUZ 856) was tested against larvae of Chrysomya putoria (Wiedemann). The LFB-FIOCRUZ 907 strain was tested in four different concentrations, added to the diet; the LFB-FIOCRUZ 856 strain was tested in three concentrations. C. putoria larvae showed sensibility to the treatment with the LFB-FIOCRUZ 907 strain at the tested concentrations. The higher concentration presented the best efficiency, causing higher mortality and reducing larval weight and adult emergence more intensely. The LFB-FIOCRUZ 856 strain showed low toxicity, sliglity reducing emergence time of adults at 326 mg/ 25 g concentration and larval weight at 326 mg/ 25 g and 86 mg/ 25 g concentrations.

Diferentes linhagens de Bacillus thuringiensis Berliner têm provado ser poderoso inseticida biológico contra larvas de várias ordens de insetos. Dada a importância epidemiológica das moscas do gênero Chrysomya Robineau-Desvoidy na produção de miíases cutâneas secundárias e transmissão mecânica de agentes patogênicos, avaliou-se a atividade de duas linhagens de B. thuringiensis (LFB-FIOCRUZ 907 e LFB-FIOCRUZ 856) sobre larvas de Chrysomya putoria (Wiedemann). A linhagem LFB-FIOCRUZ 907 foi testada em quatro diferentes concentrações misturadas à dieta e a linhagem LFB-FIOCRUZ 856 em três concentrações. As larvas de C. putoria apresentaram sensibilidade ao tratamento com a linhagem LFB-FIOCRUZ 907, nas concentrações testadas, sendo a concentração mais alta a de maior eficiência, causando maior mortalidade e reduzindo mais intensamente o peso larval e a taxa de emergência dos adultos. A linhagem LFB-FIOCRUZ 856 apresentou toxicidade muito baixa, redizindo ligeiramente a emergência dos adultos na concentração de 326 mg/ 25 g e o peso larval nas concentrações de 326 mg/ 25 g e 86 mg/ 25 g.