Estudo da toxicidade e atividade antitumoral do óleo essencial de hyptis umbrosa salzm. (lamiaceae) e da fenchona, seu componente majoritário

• Ano de defesa: 2013
• Autor(a) principal: Rolim, Thaísa Leite
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraí­ba; BR; Farmacologia; Programa de Pós-Graduação em Produtos Naturais e Sintéticos Bioativos; UFPB
• Palavras-chave em Português: Hyptis umbrosa; Óleo essencial; Atividade antitumoral; Toxicidade; Essential oil; Antitumor activity; Toxicity; CIENCIAS BIOLOGICAS::FARMACOLOGIA
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/tede/6822

Cancer is the name given to a collection of hundreds of different diseases that result from the progressive accumulation of mutations. Its treatment has been benefited from studies that are based on research of natural sources. Several compounds and plant derivatives have shown antitumor activity, including essential oils. Hyptis umbrosa Salzm. is popularly known as aleluia do serrote and alfazema-do-mato and is rarely reported in the literature. The fenchone monoterpene is the major component of the essential oil from the leaves of this species (24.8%). This study aimed to evaluate the toxicity and antitumor activity in vitro and in vivo of O.E.H. and fenchone. In hemolysis assay of mice erythrocytes it was obtained a CH50 value of 494.9 μg/mL for O.E.H. and greater than 3000 μg/mL for fenchone, suggesting moderate and low toxicity of the samples respectively for these non-tumor cells, which are commonly affected by antineoplastic therapy. The O.E.H. showed weaker antitumor effect in vitro on human tumor cell lines, while fenchone did not alter cell viability at any of the concentrations tested. After acute administration of O.E.H. depressant and excitatory effects were observed in central nervous system of animals treated with 2000 mg/kg of oil. Although it hasn t shown antitumor activity in vitro, O.E.H. (50, 100, or 150 mg / kg) and fenchone (30 or 60 mg / kg) showed significant activity in vivo of Ehrlich ascites carcinoma model (EAC) after nine days of treatment, given the parameters of volume, weight and viability of the cells. The treatment with O.E.H. induced cycle arrest in the G0/G1 phase and increased sub-G1, suggesting induction of cell death by apoptosis. In conjunction with the results of staining with Annexin V-PI, where there was a slight increase of cells stained with Annexin V as well as with Annexin V-PI, it can be inferred that possibly apoptotic cells were phagocytosed. The fenchone induced cycle arrest in S phase, and significantly increased the percentage of cells stained with Annexin V-PI, without increasing marking only with Annexin V, wich suggests that cell death by necrosis is occurring. There was also an increase in median survival of animals transplanted with Ehrlich tumor and treated with essential oil. The toxicological analyzes show that the treatment with O.E.H caused a body weight decrease and lower hematological and biochemical toxicity after nine days. The treatment with fenchone induced changes in ALT and AST parameters suggestive of fibrosis. Histopathologic analysis confirmed the evidence of hepatotoxicity especially for OEH, however, the damage was moderate and reversible. The O.E.H. induced an increase in the number of micronucleated erythrocytes, in the micronucleus essay, only the highest dose tested (300 mg / kg). Therefore, we can infer that O.E.H. and fenchone shows an antitumor activity in vivo with moderate toxicity, which is not a limiting factor for the continuation of the pre-clinical studies. The findings suggested that fenchone is not the only component responsible for the oil activity as it showed activity only at double of the dose associated with its quantity in that oil.