Energetic supplementation for maintenance or development of Apis mellifera L. colonies

The nutritional requirements of honeybees (Apis mellifera) for their complete development need to be supplied through food sources available in the environment, since honeybees are insects that depend directly on blossoming food sources. However, at certain times a food-supply reduction can promote nutritional stress, thus necessitating food supplementation for maintenance or production stimulus of the colonies. Thus, the determination of optimal energy supplementation can assist in the maintenance and production of colonies. Methods: Twenty Apis mellifera beehives were used (with five beehives per treatment): CTL, control (without feeding); SJ, sugarcane juice; SS, sugar syrup; and IS, inverted sucrose. We evaluated the food consumption, population development, and physiological state (expression of vitellogenin and hexamerin 70a genes) of each colony. Results: The results showed that the supplementation of colonies with sugar syrup resulted in an intermediate consumption level (894.6 ± 291 mL) and better development (384.9 ± 237.3 and 158.3 ± 171.6 cm2, sealed and open brood, respectively). Furthermore, this diet ensured that the colonies were in a good physiological state, as bees fed this diet presented the highest relative expression levels of vitellogenin and hexamerin 70a among all the diets tested. Conclusions: Therefore, sugar syrup is concluded to be the best artificial energetic food for use in the supplementation of honeybee colonies.(AU)

Melittin induces in vitro death of Leishmania (Leishmania) infantum by triggering the cellular innate immune response

Abstract Background Apis mellifera venom, which has already been recommended as an alternative anti-inflammatory treatment, may be also considered an important source of candidate molecules for biotechnological and biomedical uses, such as the treatment of parasitic diseases. Methods Africanized honeybee venom from Apis mellifera was fractionated by RP-C18-HPLC and the obtained melittin was incubated with promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Cytotoxicity to mice peritoneal macrophages was evaluated through mitochondrial oxidative activity. The production of anti- and pro-inflammatory cytokines, NO and H2O2 by macrophages was determined. Results Promastigotes and intracellular amastigotes were susceptible to melittin (IC50 28.3 μg.mL−1 and 1.4 μg.mL−1, respectively), but also showed mammalian cell cytotoxicity with an IC50 value of 5.7 μg.mL−1. Uninfected macrophages treated with melittin increased the production of IL-10, TNF-α, NO and H2O2. Infected melittin-treated macrophages increased IL-12 production, but decreased the levels of IL-10, TNF-α, NO and H2O2. Conclusions The results showed that melittin acts in vitro against promastigotes and intracellular amastigotes of Leishmania (L.) infantum. Furthermore, they can act indirectly on intracellular amastigotes through a macrophage immunomodulatory effect.

Estudo de adulteração em méis brasileiros através de razão isotópica do carbono / A study of adulteration in brazilian honeys by carbon isotope ratio

Neste trabalho, objetivou-se analisar isotopicamente méis comercializados nas regiões Sul e Sudeste do Brasil, para a detecção de fraude. Foram colhidas amostras comerciais com registro no Serviço de Inspeção Federal, Estadual ou Municipal. As amostras foram submetidas à combustão no Analisador Elementar EA 1108 CHN e analisadas no espectrômetro de massas de razão isotópica DELTA-S (Finningan Mat). Os valores isotópicos (δ13C) dos méis in natura foram comparados aos de suas respectivas proteínas (padrão interno). Foram consideradas adulteradas as amostras cuja diferença entre o valor isotópico da proteína e do mel foi igual ou inferior a -1‰. As amostras consideradas adulteradas pela análise isotópica foram submetidas a testes químicos qualitativos que não foram capazes de indicar adulteração para algumas delas. Das 61 amostras analisadas, 18,0 por cento encontram-se adulteradas, sendo 11,5 por cento na Região Sudeste e 6,5 por cento na Região Sul. Ao contrário dos testes químicos, a análise isotópica mostrou-se eficaz em identificar e quantificar a adulteração de méis comerciais.

The aim of this study was the isotopic evaluation of honey traded in the Southern and Southeastern Brazilian regions, to detect fraud. Commercial samples, registered in the municipal, State or Federal Inspection Service, were collected and submitted to combustion in the EA 1108 CHN Elemental Analyzer and analyzed in the DELTA-S (Finningan Mat.) isotope ratio mass spectrometer. The isotopic values (δ13C) of in natura honey were compared to their respective proteins (internal standard). Samples whose difference between the isotopic value of protein and honey was equal or inferior to -1‰ were considered adulterated. The samples considered adulterated were submitted to qualitative chemical tests which were unable to show adulteration for some of them. Among the 61 samples analyzed, 18.0 percent were adulterated; 11.5 percent in the Southeastern and 6.5 percent in the Southern region. Unlike chemical tests, isotopic analysis has shown to be efficient to identify and quantify adulteration in commercial honey.

Synergistic effect of propolis and antibiotics on the Salmonella Typhi

O objetivo do presente trabalho foi investigar um possível efeito sinérgico entre extrato alcoólico de própolis do Brasil e Bulgária com alguns antibióticos (Amoxilina, Ampicilina e Cefalexina) utilizados contra Salmonella Typhi. Própolis do Brasil e Bulgária mostraram uma atividade antibacteriana, embora a amostra da Bulgária tenha sido mais eficiente. Ambas as amostras apresentaram um efeito sinérgico com os antibióticos estudados. Pode-se concluir que as amostras de própolis possuem atividade antibacteriana, bem como apresentam efeito sinérgico com antibióticos utilizados contra Salmonella Typhi.

Propolis: anti-Staphylococcus aureus activity and synergism with antimicrobial drugs

Propolis is a natural resinous substance collected by bees from tree exudates and secretions. Its antimicrobial activity has been investigated and inhibitory action on Staphylococcus aureus growth was evaluated. The in vitro synergism between ethanolic extract of propolis (EEP) and antimicrobial drugs by two susceptibility tests (Kirby and Bauer and E-Test) on 25 S. aureus strains was evaluated. Petri dishes with sub-inhibitory concentrations of EEP were incubated with 13 drugs using Kirby and Bauer method and synergism between EEP and five drugs [choramphenicol (CLO), gentamicin (GEN), netilmicin (NET), tetracycline (TET), and vancomycin (VAN)] was observed. Nine drugs were assayed by the E-test method and five of them exhibited a synergism [CLO, GEN, NET, TET, and clindamycin (CLI)]. The results demonstrated the synergism between EEP and antimicrobial drugs, especially those agents that interfere on bacterial protein synthesis.