Aplicação tópica de Aloe vera e vitamina E em úlceras induzidas na língua de ratas submetidas à radioterapia : avaliação clínica e histológica

Detalhes bibliográficos
Ano de defesa: 2015
Autor(a) principal: Cuba, Letícia de Freitas lattes
Orientador(a): Figueiredo , Maria Antonia Zancanaro de
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul
Programa de Pós-Graduação: Programa de Pós-Graduação em Odontologia
Departamento: Faculdade de Odontologia
País: Brasil
Palavras-chave em Português:
Área do conhecimento CNPq:
Link de acesso: http://tede2.pucrs.br/tede2/handle/tede/5956
Resumo: Head and neck cancer (HNC) has been a worldwide public health problem. Squamous cell carcinomas account for about 80% of these neoplasms and the main treatment modalities are surgery, radiotherapy (RT), chemotherapy (CT) or a combination between them. RT acts locally destroying tumor cells. However, this therapy is not selective and also affects rapid renewal cell groups such as the salivary glands, oral mucosa and skin, resulting in a wide range of deleterious effects, being oral mucositis (OM) one of these. This condition is characterized by painful ulcerations that can progress to severe conditions that compromise the course of cancer treatment. The etiology of OM is oxidative stress (OS) generated by RT, that would be able to induce the production of reactive oxygen species (ROS) responsible for cellular damage and initiation of injuries. Antioxidants (AOX) are agents produced by humans or acquired by diet and vitamin supplements that eliminate ROS and minimize OS.The objective of this study was to assess the effect of 2 types of antioxidants, vitamin E (VE) and Aloe vera (AV) in prevention and management of radioinduced OM in a murine model by clinical and histological analysis. The animals were randomly divided into 3 groups of 12 animals each (400 mg VE, 70% AV and control) and 2 time periods (5 and 7 days). They were irradiated with a single dose of 30 Gy, and after 24h, a lesion was produced on the ventral tongue of each animal. The products were applied daily in their respective group until euthanasia. On clinical evaluation, it was observed the presence of inflammatory signs, presence or absence of induced ulcer and measurement of their size. Lesions were present more frequently in the control group animals in both periods of observation.The size of the ulcers was greater in the control group compared with the groups AV and VE (5 days: p = 0.006; 7 days: p = 0.002). Under microscopic analysis, the degree of inflammation differed between the study groups and experimental periods. At 5 days, the statistical difference was not significant amongst groups. However, after 7 day period, the animals in the control group displayed intense inflammation, while those in groups VE and AV exhibited mild to moderate inflammation (p = 0.002). Given the severity of OM injuries and their implications to the patient, it urges the search of alternative therapies to prevent or reduce clinical manifestations. The results of this study suggest that VE and AV may contribute to minimize inflammatory response and improve the healing of induced tongue lesions of rats submitted to radiation.