Ocotea quixos Lam. essential oil: In vitro and in vivo investigation on its anti-inflammatory properties

Here we investigated the anti-inflammatory properties of Ocotea quixos essential oil and of its main components, trans-cinnamaldehyde and methyl cinnamate, in in vitro and in vivo models. Ocotea essential oil and trans-cinnamaldehyde but not methyl cinnamate significantly reduced LPS-induced NO release from J774 macrophages at non-toxic concentrations, inhibited LPS-induced COX-2 expression and increased forskolin-induced cAMP production. The essential oil (30–100 mg/kg os) and trans-cinnamaldehyde (10 mg/kg os) in carrageenan-induced rat paw edema showed anti-inflammatory effect without damaging gastric mucosa. In conclusion we provide the first evidence of a significant anti-inflammatory gastro-sparing activity of O.quixos essential oil.     

In vitro antimicrobial resistance of staphylococci isolated from canine urinary tract infection

This study determined the diversity of species and antimicrobial resistance of staphylococci isolated from dogs with a presumptive diagnosis of urinary tract infection (UTI). Urine samples from 348 dogs with clinical signs of UTI, according to clinical examination and urinalysis, were processed for isolation of Staphylococcus. Colonies in pure culture were identified by biochemical reactions and tested for susceptibility to 15 antimicrobials. Seventy isolates of staphylococci were obtained (20.1%). Staphylococcus pseudintermedius was the most frequent species (32.8%), followed by S. epidermidis (18.6%), S. simulans (15.7%), S. schleiferi schleiferi (11.4%), S. aureus (11.4%), S. schleiferi coagulans (7.2%) and S. saprophyticus (2.9%). All the isolates were resistant to at least 1 drug and 77.1% were multiresistant. The study reports the alarming antimicrobial resistance of members of the Staphylococcus genus isolated from canine UTI and highlights the importance of coagulase-negative staphylococci in its etiology.     

Effect of elatol, isolated from red seaweed Laurencia dendroidea, on Leishmania amazonensis

In the present study, we investigated the antileishmanial activity of sesquiterpene elatol, the major constituent of the Brazilian red seaweed Laurencia dendroidea (Hudson) J.V. Lamouroux, against L. amazonensis. Elatol after 72 h of treatment, showed an IC(50) of 4.0 μM and 0.45 μM for promastigote and intracellular amastigote forms of L. amazonensis, respectively. By scanning and transmission electron microscopy, parasites treated with elatol revealed notable changes compared with control cells, including: pronounced swelling of the mitochondrion; appearance of concentric membrane structures inside the organelle; destabilization of the plasma membrane; and formation of membrane structures, apparently an extension of the endoplasmic reticulum, which is suggestive of an autophagic process. A cytotoxicity assay showed that the action of the isolated compound is more specific for protozoa, and it is not toxic to macrophages. Our studies indicated that elatol is a potent antiproliferative agent against promastigote and intracellular amastigote forms, and may have important advantages for the development of new anti-leishamanial chemotherapies.     

Determination of carbofuran in pesticide formulations by flow injection spectrophotometry

A flow injection spectrophotometric method for the determination of carbofuran in commercial pesticide formulations was developed. The determination involves on‐line hydrolysis of the extracted carbofuran at room temperature with sodium hydroxide. The resulting carbofuran‐phenol is coupled with diazotized 4‐aminobenzoic acid in order to achieve an appropriate selectivity and sensitivity for the spectrophotometric measurements. The calibration curve is linear over the range 1–10 mg litre⁻¹ of carbofuran. The proposed method has a detection limit of 0.15 mg litre⁻¹ of carbofuran and a sample frequency of 120 injections per hour. The relative standard deviation of six independent determinations of a sample containing 1 mg litre⁻¹ carbofuran was 0.6%. The suitability of the proposed procedure for the determination of carbofuran in commercial pesticide formulations was studied. The procedure provides results comparable to those obtained by liquid chromatographic analysis. © 2000 Society of Chemical Industry     

Authentication of the botanical origin of honey by front-face fluorescence spectroscopy. A preliminary study

The potential of front-face fluorescence spectroscopy for the authentication of unifloral and polyfloral honey types (n = 57 samples) previously classified using traditional methods such as chemical, pollen, and sensory analysis was evaluated. Emission spectra were recorded between 280 and 480 nm (excit: 250 nm), 305 and 500 nm (excit: 290 nm), and 380 and 600 nm (excit: 373 nm) directly on honey samples. In addition, excitation spectra (290-440 nm) were recorded with the emission measured at 450 nm. A total of four different spectral data sets were considered for data analysis. After normalization of the spectra, chemometric evaluation of the spectral data was carried out using principal component analysis (PCA) and linear discriminant analysis (LDA). The rate of correct classification ranged from 36% to 100% by using single spectral data sets (250, 290, 373, 450 nm) and from 73% to 100% by combining these four data sets. For alpine polyfloral honey and the unifloral varieties investigated (acacia, alpine rose, honeydew, chestnut, and rape), correct classification ranged from 96% to 100%. This preliminary study indicates that front-face fluorescence spectroscopy is a promising technique for the authentication of the botanical origin of honey. It is nondestructive, rapid, easy to use, and inexpensive. The use of additional excitation wavelengths between 320 and 440 nm could increase the correct classification of the less characteristic fluorescent varieties.     

Characterization of gonadotropic cells during continuous and seasonal spermatogenesis of two freshwater fish species: a histochemical and immunohistochemical study

This work describes gonadotropic (GtH) cells and their morphological and immunohistochemical changes during the spermatogenic cycle of Serrasalmus maculatus (continuous spermatogenesis) and Pimelodus maculatus (seasonal spermatogenesis). GtH cells, widely distributed in the proximal pars distalis of the adenohypophysis, were characterized as round-shaped cells with eccentric nucleus, and cytoplasm with basophilic secretory granules and a variable number of vacuoles for both species. Immunohistochemistry against β-follicle-stimulating hormone (Fsh) and β-luteinizing hormone (Lh) in adjacent sections showed two separated GtH-producing cell populations, and a third population where both GtHs are expressed in the same cell for both species. In the seasonal spermatogenesis of P. maculatus, GtH cells seemed to be more abundant during developing and spawning capable phases. In contrast, no cyclic changes were detected in the continuous spermatogenesis of S. maculatus, except for the strong immunoreaction for Fsh and Lh in males with intense spermiogenesis. We conclude that changes reported here might reflect the type of spermatogenic cycle (seasonal or continuous) which are under different regulatory mechanisms (environmental and internal cues) controlling the reproduction in these species.     

Induction of triploidy in spotted sand bass (Paralabrax maculatofasciatus Steindachner, 1868) by cold shock

Conditions for the induction of triploidy with cold shock of fertilized eggs of the spotted sand bass Paralabrax maculatofasciatus (Steindachner) were investigated. Different temperatures (12, 8 and 4 °C), timing of cold shock application (5, 10 and 15 min after fertilization) and duration of the shock (5, 10, 15 and 20 min) were tested. Triploidy was determined using flow cytometry at 12 h after larvae hatched. Triploids were produced only when the cold shock treatment was applied 5 min after fertilization. No significant difference was observed in the percentage of triploidy between temperature and the shock duration. At 8 and 4 °C, 100% triploidy was obtained at different durations of cold shock. Survival was significantly lower at 12 or 4 °C than at 8 °C. No significant difference was observed for shock duration at the temperature of 8 or 12 °C; however, at 4 °C, survival was significantly lower at longer durations. We recommend induction of triploidy by applying cold shock at 8 °C for a duration of 15–20 min starting at 5 min after fertilization, in the spotted sand bass.     

Nitrogen concentrations and proportions of ammonium and nitrate in the nutrition and growth of yellow passion fruit seedlings

Abstract

Despite the importance of nitrogen (N) supply to plants, there are still doubts concerning the optimal relations of ammonium and nitrate in the nutrition of yellow passion fruit seedlings. This study aims to evaluate the interaction between nitrogen concentrations and ammonium and nitrate proportions in the nutrition, growth, and dry matter production of passion fruit seedlings grown in a substrate with a nutrient solution. The experiment was conducted in a greenhouse in randomized complete block design with three replications in a 4 × 5 factorial design, consisting of four N concentrations (2.5, 5.0, 10.0 and 20.0?mmol L^?1) and five ammonium proportions (0, 25, 50, 75 and 100% in relation to the total N supply). At 60?days after transplanting, green color index; accumulation of N, potassium, calcium, and magnesium in roots and shoots; stem diameter; leaf area; root length; nitrogen use efficiency (NUE); and dry matter of roots and shoots were evaluated. For the formation of seedlings of yellow passion fruit, the nutrient solution should have 13?mmol L^?1 of N, with 40% of this nutrient in the form of ammonium. The passion fruit is a plant tolerant to ammonium. However, a critical concentration above 5.7?mmol L^?1 of NH₄⁺ in the nutrient solution decreases absorption of cations, NUE, and production of dry matter.