Systemic effects of oral tolerance in bone healing.

Bone fractures cause acute inflammation that, despite being important for initial repair, may delay the healing of the damaged bone. Parenteral injection of dietary protein has been shown to decrease inflammation and accelerate the repair of skin wounds and other inflammatory pathologies. Thus, our aim was to evaluate whether the intraperitoneal (i.p.) immunization with zein, an abundant protein in rodent chow, would favor bone healing. Wistar rats received i.p. immunization: saline (SG), adjuvant (AG) and zein associated with adjuvant (ZG). Then, a 2 mm of defect bone was performed on the right tibia, and on days 7, 14, 28 and 45 thereafter, analyses were performed. The results showed that the injection of zein reduced inflammation without impairing bone mineralization. Moreover, biomechanical tests demonstrated higher levels of maximum force (N) in ZG, indicating better mechanical resistance in relation to the others. The computerized tomography also indicated lower levels of medullary content in the ZG than in the SG, suggesting the absence of trabeculae in the medullary region in the ZG. These findings suggest that the injection of zein in previously tolerated animals may improve bone repair, leading to mechanically functional bone formation.

Potencial de cicatrização da Psidium Guajava e Myrciaria cauliflora em feridas cutâneas: avaliação histológica em estudo de modelo experimental / Potential healing of Psidium guajava and Myrciaria cauliflora in skin wounds histological evaluation in experimental model study

Introdução: O uso de plantas na medicina fitoterápica é uma alternativa à medicina tradicional, por cota de seus efeitos anti inflamatórios, antimicrobianos e antioxidantes, potencialmente eficazes no auxílio do processo cicatricial. Objetivo: O estudo avaliou, por análise histológica, o potencial dos extratos aquosos da Psidium guajava e da Myrciaria cauliflora no reparo de feridas de segunda intenção. Método: Foram utilizadas 20 ratas Wistar adultas, distribuídas aleatoriamente em quatro grupos de 5 animais, com tratamento tópico diário das lesões de 6 mm de diâmetro: Controle Positivo (CP) - solução aquosa de Bepantol® 5%; Controle Negativo (CN) - água bidestilada estéril; e Grupos Experimentais (GO) - extrato aquoso da casca do caule da goiabeira 10% e (JU) - extrato aquoso da folha da jabuticabeira 1 g/mL. Cinco e dez dias após a lesão, os fragmentos de tecido contendo a ferida foram coletados e fixados em formalina tamponada. Foram realizados cortes histológicos de 5 mm e as lâminas foram coradas com Hematoxilina-Eosina para serem analisadas por microscopia de luz. Por uma análise qualitativa, percebe-se que há diferenças na cinética de fechamento das feridas, pois o uso dos extratos e do Bepantol®, possibilitaram reepitelização mais rápida e menor quantidade de células inflamatórias agudas. Aos 10 dias, nos animais JU sugere-se processo de reparo avançado, com boa vascularização e pouca inflamação, e no grupo GO sugere-se formação de cicatriz menor em comprimento que a dos demais grupos, com deposição de fibras de colágeno mais próximas topograficamnete da pele intacta. Conclusão: Considerando-se os resultados obtidos no presente estudo, com 5 e 10 dias não há evidências de que qualquer tratamento foi de fato impactante e mudou de forma expressiva a cicatrização das feridas.

Introduction: The use of plants in herbal medicine is an alternative to traditional medicine due to its anti-inflammatory, antimicrobial and antioxidant effects, potentially effective in the healing process. Objective: The study evaluated, by histological analysis, the potential of aqueous extracts of Psidium guajava and Myrciaria cauliflora in the repair of second intention wounds. Method: Twenty adult female Wistar rats were randomly assigned to four groups of five animals each. The animals received daily topical treatment in 6 mm diameter lesions. The groups were: Positive Control (CP) - aqueous solution of Bepantol® 5%; Negative Control (CN) - sterile bidistilled water; Experimental Groups (GO) - aqueous extract of guava stem bark at 10% and (JU) - aqueous extract of jabuticaba leaf at 1 g/mL. Five and ten days after injury, tissue fragments containing the wound were collected and fixed in formalin. Sections of 5 µm thickness were performed and stained with HematoxylinEosin for analysis by microscopy. From a qualitative analysis there are no differences in the kinetics of wound closure, since the use aqueous extract and Bepantol®, allowed faster reepithelization and fewer acute inflammatory cells. At 10 days, in JU group, an advanced repair process was observed, with good vascularization and low inflammation, and in the GO group, scar formation is suggested to be smaller than that of the other groups, with deposition of collagen fibers closer to the intact skin. Conclusion: Considering the results obtained in the present study, at day 5 and day10, there is no evidence that any treatment was in fact impacting and significantly altering the woud healing.