Essential oil of Hymenaea courbaril: formulation, effect on fibroblasts and epithelial cells of Pterygium in vitro and local and systemic toxicity tests in vivo

Abstract

The pterygium is a conjunctival lesion which has a multifactorial genesis and affects many people in Brazil. Until the moment, it is considered there is no ideal treatment for pterygium carriers. On the other hand, there are a popular believe at the North-East of Brazil about the use of an infusion based on Hymenaea courbaril to be applied in eyes of pterygium carriers with benefic effects popularly reported. In order to evaluate the anti-inflammatory effect of this oil plant on pterygium tissues we proposed this project with the purpose of investigating the toxicity of Hymenaea courbaril in pre-clinical studies, evaluating since the chemical composition and effects on the cells of the ocular surface and either local and systemic toxicity. For this purpose we must develop six studies: 1: Obtaining and chemical characterization of the essential oil of Hymenaea courbaril - the oil obtained of the plant should be assessed as to its chemical characteristics for liquid chromatography in gas phase and mass spectrometer. The essential oil will be carried out by distillation by vapor drag from the resin of the plant. 2: Processing of essential oil of Hymenaea courbaril in phytotherapic using technology systems of scattered nanoparticules, containing essential oil of Hymenaea courbaril, with high-capacity of permeation. Biocompatible system will be developed and characterized for ocular administration, using ultrasonication or homogenization technology of high pressure. 3: Study of dose-effect of the essential oil of Hymenaea courbaril - evaluation of the effect of different concentrations of the essential oil of Hymenaea courbaril on fibroblasts and epithelial cells proliferation in culture of cells. The cells will be obtained from pterygium excision. The main purpose of this is to establish the curve of effect of dose/response. 4: Evaluation of effect of the essential oil of Hymenaea courbaril on culture of cells of the capsule of Tenon and of epithelial cells from pterygium carriers and the normal conjunctiva - evaluation of 20 specimen of pterygium and of normal conjunctiva comparing the effect of this phytotherapic on the cell proliferation of the capsule of Tenon and the conjunctival epithelium cells from pterygium and normal tissues, before and after the exposure to Hymenaea courbaril oil, during 3 minutes. It should also be studied the supernatant of cultures, in order to verify the presence of inflammatory cytokines. 5: Systemic toxicity study of the essential oil of Hymenaea courbaril - 60 adult rats, divided into four groups of 10 animals will receive essential oil of Hymenae courbaril by oral administration, one dose a day/ 7 days a week/28 days. Vegetal oil of soya beans shall be administered for the control group in a way similar to the tested groups. Attention to the occurrence of secretion, autonomic signs, and pupil size will be taken. After 28 days, the sensorial reactivity to auditory, visual and proprioceptive stimuli and also motor activity will be assessed. Study of weight and ingestion of food and water in metabolic cages once a week and hematologic and biochemical examination after 28 days will be done. Histologic parameters of vital organs will be studied after death. 6: Local (ocular) toxicity study of the essential oil of Hymenaea courbaril- the OCDE guidelines for chemical tests will be followed in order to assess the acute eye irritation in 5 rabbit, in the concentration of the IC 50, with a dose of 0,1 mL 4X/day /7 days, in the eye right of animals and the left will be the control, examined every day during 21 days. All the results to be obtained will be transferred to Excel Table and they should receive statistical processing. (AU)