Deficiência de riboflavina em frangos de corte (Gallus gallus) - relato de caso / Riboflavin deficiency in broiler chickens (Gallus gallus) - a case report / Deficiencia de riboflavina en pollos de engorde (Gallus gallus) - relato de caso

Os micronutrientes executam funções bioquímicas específicas nos seres vivos, algumas das quais são fundamentais à vida. Dentre os micronutrientes, as vitaminas merecem atenção por participarem como cofatores de reações metabólicas e permitirem maior eficiência dos sistemas de síntese no organismo animal. Em meio às vitaminas, a riboflavina apresenta algumas particularidades, especialmente para aves, por ser provavelmente a vitamina mais limitante nesta espécie. A riboflavina está envolvida no metabolismo de carboidratos, gorduras e proteínas, apresentando papel preponderante na cadeia transportadora de elétrons, no processo de respiração celular e no processo de obtenção de energia por parte da célula, atuando na manutenção da integridade das membranas mucosas, pele, olhos e sistema nervoso. A deficiência de riboflavina resulta em alterações no metabolismo e efeito patológico em vários tecidos, sendo a epiderme e a bainha de mielina dos axônios as mais comprometidas. O principal sinal clínico da deficiência de riboflavina em aves jovens é a paralisia dos dedos curvos. O trabalho tem como objetivo relatar a ocorrência de um caso clínico de deficiência de riboflavina em um lote comercial de frangos de corte (Gallus gallus) alimentado exclusivamente com dieta de origem vegetal, que apresentou paralisia dos dedos curvos aos quatro dias de idade. Após diagnóstico presuntivo, o lote foi suplementado com 2,5mg/Kg de riboflavina via água de bebida, e apresentou melhora significativa horas após o início da suplementação, em que 95% das aves se recuperaram até os doze dias pós suplementação e os 5% restante persistiram com os sinais clínicos até o abate.

Micronutrients perform specific biochemical functions in living organisms, some of which are essential to life. Among the micronutrients, vitamins deserve special attention for participating as cofactors in metabolic reactions and allowing greater efficiency of synthesis systems in an animal organism. In the midst of vitamins, riboflavin presents some particularities, especially for poultry, because it is probably the most limiting vitamin in this species. Riboflavin is involved in the metabolism of carbohydrates, fats and proteins, presenting key role in the electron transport chain, the process of cellular respiration and in the process of obtaining energy from the cell, acting in the maintenance of the integrity of mucous membranes, skin, eyes and nervous system. Riboflavin deficiency results in changes in metabolism and pathological effect in various tissues in which the epidermis and the myelin sheath of axons are the most involved. The main clinical sign of riboflavin deficiency in young poultry is the curled toe paralysis. This paper aims to report the occurrence of a clinical case of riboflavin deficiency in a batch of commercial broiler chickens (Gallus gallus) fed exclusively with vegetable diet that had curled toe paralysis at four days of age. Following presumptive diagnosis, the batch was supplemented with 2.5 mg/kg of riboflavin in drinking water, and showed significant improvement some hours after the beginning of supplementation; 95% of the poultry recovered up to twelve days after supplementation and the remaining 5% had persistent clinical signs until slaughter.

Los micronutrientes desempeñan funciones bioquímicas específicas en los seres vivos, algunas de las cuales son fundamentales a la vida. Entre los micronutrientes, las vitaminas merecen atención por participaren como cofactores de reacciones metabólicas y permiten mayor eficiencia de los sistemas de síntesis en el organismo animal. Entre las vitaminas,nla riboflavina presenta algunas peculiaridades, especialmente para las aves, siendo probablemente la vitamina más limitanteb en esta especie. La riboflavina está implicada en el metabolismo de carbohidratos, grasas y proteínas, presentando papel importanteen la cadena de transporte de electrones, en el proceso de respiración celular y en el proceso de obtención de energía de la célula, actuando en el mantenimiento de la integridad de las membranas mucosas, piel, ojos y sistema nervioso. La deficiencia de riboflavina resulta en alteraciones en el metabolismo y efecto patológico en varios tejidos, siendo la epidermis y la vaina de mielina de los axones las más comprometidas. La principal señal clínica de la deficiencia de riboflavina en aves jóvenes es la parálisis de los dedos curvados. El estudio tiene como objetivo relatar la ocurrencia de un caso clínico de deficiencia de riboflavina en un lote comercial de pollos de engorde (Gallus gallus), alimentados exclusivamente con dieta de origen vegetal, que mostró parálisis de los dedos curvados en cuatro días de edad. Después del diagnóstico presuntivo, el lote fue suplementado con 2,5 mg / kg de riboflavina vía agua potable, y presentó mejora significativa horas después del inicio de la suplementación, donde 95% de las aves se recuperaron hasta los doce días pos suplementación y los 5% restante persistieron con señales clínicos hasta la matanza.

Nano-composition of riboflavin-nafion functional film and its application in biosensing.

A novel nafion-riboflavin membrane was constructed and characterized by the scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-visible spectroscopy and cyclic voltammetric techniques. The estimated average diameter of the designed nanoparticles was about 60 nm. The functional membrane showed a quasi-reversible electrochemical behaviour with a formal potential of -562 +/- 5 mV (vs Ag/AgCl) on the gold electrode. Some electrochemical parameters were estimated, indicating that the system has good and stable electron transfer properties. Moreover, horseradish peroxidase (HRP) was immobilized on the riboflavin-nafion functional membrane. The electrochemical behaviour of HRP was quasi-reversible with a formal potential of 80 +/- 5 mV (vs Ag/AgCl). The HRP in the film exhibited good catalytic activity towards the reduction of H2O2. It shows a linear dependence of its cathodic peak current on the concentration of H2O2, ranging from 10 to 300 (micro)M.

Photoilluminated riboflavin/riboflavin-Cu(II) inactivates trypsin: Cu(II) tilts the balance.

Riboflavin (RF) upon irradiation with fluorescent light generates reactive oxygen species like superoxide anion, singlet and triplet oxygen, flavin radicals and substantial amounts of hydrogen peroxide (H2O2). H2O2 can freely penetrate cell membrane and react with a transition metal ion like Cu(ll), generating hydroxyl radical via the modified metal-catalyzed Haber-Weiss reaction. Earlier, it was reported that trypsin-chymotrypsin mixture served as an indirect antioxidant and decreased free radical generation. Thus, in the present study, we used photoilluminated RF as a source of ROS to investigate the effect of free radicals on the activity of trypsin. We also compared the damaging effect of photoilluminated RF and RF-Cu(ll) system using trypsin as a target molecule. RF caused fragmentation of trypsin and the effect was further enhanced, when Cu(II) was added to the reaction. Results obtained with various ROS scavengers suggested that superoxide radical, singlet and triplet oxygen were predominantly responsible for trypsin damage caused by photoilluminated RF. On the other hand, when Cu(ll) was added to the reaction, hydroxyl radical was mainly responsible for trypsin damage. A mechanism of generation of various ROS in the reaction is also proposed. Trypsin did not show any antioxidant effect with RF alone or with RF-Cu(II) combination.