Efeito do óleo essencial de copaíba (Copaifera multijuga Hayne) sobre a morfologia hepática e cardíaca em um modelo de inflamação induzida por zymosan: um estudo estereológico

Abstract

Stereology is the gold standard of quantitative methods, whose efficacy is justified by its rigorous uniform systematic sampling at random at all levels of quantitative analysis. By making it possible to obtain 3-D information from 2-D sections, stereology allows the quantitative identification of an organ or structure, proving to be a fundamental tool in histopathological studies. Rheumatoid Arthritis (RA) is an autoimmune disease that affects a portion of the world population, associated with a high risk of morbidity and premature death due to extra-articular manifestations, especially cardiovascular diseases. Although currently available treatments have good results in local disease control (articulation), they present a high cost and side effects, which leads to an increase in the demand for alternative treatments. Copaiba oil is a natural product widely used in amazonian folk medicine not only for its various therapeutic effects but also for its low cost and easy access. Therefore, the present thesis aimed to evaluate, through stereology, the systemic action of copaiba oil (Copaifera multijuga Hayne) in an animal model of RA induced by zymosan (Zy). For such, Zy was injected in the region of the plantar cushion and in the knee joint of the left paw (BALB/c females, n= 36). Thirty minutes before induction, the mice were orally treated with vehicle solution or copaiba oil (300 or 600 mg/kg) or diclofenac, according to the experimental group. After 96 hours of experimentation, the animals were anesthetized and euthanized. Blood, heart and liver were collected for biochemical and stereological analyzes, respectively. There was no change in organs volume. Zy caused histological changes in the liver, but not in the heart. Copaiba led to increased vacuolization in the cytoplasm of cardiomyocytes and reversed the liver damage caused by Zy. In conclusion: (i) stereology is able to detect minimal morphological changes in the targets investigated; (ii) Zy has a systemic effect on the experimental induction model of Rheumatoid Arthritis; (iii) copaiba had a hepatoprotective effect; (iv) additional studies are needed to establish the true role of copaiba in the heart.