Use of essential oil on digestive health and blood parameters of maintenance horses / [Uso de óleo essencial na saúde digestiva e nos parâmetros sanguíneos de cavalos em manutenção]

Essential oils (EO) such as carvacrol represent a wide range of mainly volatile aromatic plant compounds which hold antioxidant, antibacterial and antifungal potential, in addition to other properties of interest to animal health, such as the ability to modulate the microbiome. Current horse care commonly involves an intensive management system with an excessive use of concentrated feed, which can lead to severe digestive and metabolic disorders. Studies with EO in horses are limited, but the use of carvacrol essential oil (CEO) can promote benefits in microbial fermentation. The objective was to investigate the effect of different quantities of CEO on the apparent total digestibility of nutrients, microbial profile in the feces and postprandial blood glucose and insulin response when added to the equine diet. Eight Mini-Horse geldings were used (42±6 months; 135±15 kg BW) and fed with a proportion of 60% concentrate and 40% grass hay. The treatments were: 0, 100, 200 and 300 ppm of CEO. The addition of CEO up to 300 ppm did not influence the apparent digestibility of nutrients or the postprandial plasma glucose and insulin response. The use of CEO maintained the fermentative digestive health of horses fed with concentrate diets.(AU)

Os óleos essenciais (EO), como o carvacrol, são descritos por representarem ampla gama de compostos principalmente voláteis de plantas aromáticas, com potencial antioxidante, antibacteriano, antifúngico, entre outras propriedades de interesse para a saúde animal, como a modulação do microbioma. Atualmente, os cavalos são submetidos a manejo intensivo, com uso excessivo de ração concentrada, o que pode causar graves distúrbios digestivos e metabólicos. Em cavalos, estudos com EO são limitados, mas o uso de óleo essencial de carvacrol (CEO) poderia promover benefícios na fermentação microbiana. O objetivo da presente pesquisa foi investigar o efeito de diferentes quantidades de óleo essencial de carvacrol, adicionadas à dieta de equinos, sobre a digestibilidade aparente total de nutrientes, o perfil microbiano por meio das fezes e a resposta sanguínea pós-prandial de glicose e insulina. Foram utilizados oito cavalos castrados, da raça Mini-Horse (42±6 meses), 135±15kg PV, alimentados na proporção de 60% concentrado e 40% feno de capim. Os tratamentos foram: 0, 100, 200 e 300ppm de CEO. A adição de CEO até 300ppm não influencia a digestibilidade aparente dos nutrientes e a resposta de glicose e insulina plasmática pós-prandial. O uso de EO demonstra manter a saúde digestiva fermentativa quando os cavalos são alimentados com dieta rica em concentrado.(AU)

Effect of mouse antisera targeting the Phlebotomus papatasi midgut chitinase PpChit1 on sandfly physiology and fitness

In sandflies, the absence of the peritrophic matrix (PM) affects the rate of blood digestion. Also, the kinetics of PM secretion varies according to species. We previously characterised PpChit1, a midgut-specific chitinase secreted in Phlebotomus papatasi (PPIS) that is involved in the maturation of the PM and showed that antibodies against PpChit1 reduce the chitinolytic activity in the midgut of several sandfly species. Here, sandflies were fed on red blood cells reconstituted with naïve or anti-PpChit1 sera and assessed for fitness parameters that included blood digestion, oviposition onset, number of eggs laid, egg bouts, average number of eggs per bout and survival. In PPIS, anti-PpChit1 led to a one-day delay in the onset of egg laying, with flies surviving three days longer compared to the control group. Anti-PpChit1 also had a negative effect on overall ability of flies to lay eggs, as several gravid females from all three species were unable to lay any eggs despite having lived longer than control flies. Whereas the longer survival might be associated with improved haeme scavenging ability by the PM, the inability of females to lay eggs is possibly linked to changes in PM permeability affecting nutrient absorption.

Effects of dehulling, cooking and storage conditions on protein quality and digestibility of soybeans / Efecto del descascarado, cocción y almacenamiento sobre la calidad de la proteína y digestibilidad de la soya

Soybeans were debulled, stored under two environmental conditions [25ºC/75 por ciento RH (Env. 1) and 38ºC/90 por ciento RH (Env. 2)], optimally cooked and assayed for trypsin inhibitor and protein quality with laborary rats. Dehulling not significantly effects protein quality (PER and NPR) and protein digestibility of raw and cooked soybeans. Raw soybeans diets were significantly poorer in protein quality and digestibility when compared with cooked counterparts. PER values of dehulled-cooked soybean diets decreased significantly (p<0.05) as seeds were stored for up to 3 months under either environment. These were no significant differences in PER values due to etorage suring the period from 3 a 6 months. PER values for whole-cooked soybean diets exhibited a significant decline only when stored for 6 months under Env. 2

Effect of cimetidine on intestinal absorption & digestive functions in mice.

Oral administration of cimetidine, an antiulcerogenic drug, at a dose of 100 mg per kg body weight in mice, caused significant inhibition of glucose and amino acid uptake in small intestinal segments either after 2 and 24 h (single treatment) or 15 days (daily). Cimetidine also caused a significant decrease in intestinal brush border membrane associated enzymes, sucrase, lactase, maltase and alkaline phosphatase, but increases the activity of leucine aminopeptidase. Kinetic analysis indicated that cimetidine decreased the maximum of apparent initial enzyme velocity (Vmax) of disaccharidases, while substrate affinity constant (Km) was not altered, indicating the noncompetitive nature of inhibition. However, the inhibition of alkaline phosphatase was found to be of mixed type as both Km and Vmax were altered. In vitro addition of cimetidine also produced significant inhibition of enzymes, the inhibition constant (Ki) for sucrase, lactase, maltase and alkaline phosphatase being 22.8, 4.5, 11.5 and 4.8 mM, respectively. It was further observed that in vitro addition of cimetidine also decreased Vmax in case of maltase, sucrase and lactase, Km was unchanged, whereas in case of alkaline phosphatase there was a decrease in Vmax and increase in Km, as compared to the controls.

Effect of antiulcerogenic drug, ranitidine, on intestinal absorption and digestive functions in mice.

Oral administration of antiulcerogenic drug ranitidine significantly inhibits glucose and amino acid uptake in small intestinal segments. It also inhibits activities of brush border membrane disaccharidases and alkaline phosphatase but increases the activity of leucine aminopeptidase. Kinetic analysis reveals noncompetitive and mixed type of inhibition for disaccharidases and alkaline phosphatase, respectively. In vitro addition of the drug to membrane preparation shows similar type of results as seen in vivo with the inhibition constant (ki) for sucrase, lactase, maltase and alkaline phosphatase as 12.5, 5, 11.5 and 19.5 mM, respectively.