Avaliação farmacológica da fração ácida do óleo de copaíba intercalada em hidróxidos duplos lamelares

Abstract

Copaiba oil is traditionally used in the Amazon region of Brazil for pharmacological purposes as pain and inflammation. The acidic fraction of copaiba oil (FAOC) consists of diterpenes and, among them, excels copalic acid as major component, being endowed with anti inflammatory activity in vitro. In addition to the research for new active principles, there is also interest in management models that optimize the action of drugs. For this, an alternative is the controlled release of drugs, which can be obtained by the intercalation of these in Lamellar Double Hydroxides (HDLs). Thus, this study aimed to evaluate the antinociceptive and anti-inflammatory activity of the FAOC and FAOC intercalates in HDL (FAOC-HDL) in vivo models of nociception and inflammation. Male (Mus musculus) mice (4 to 6 weeks old, weight 25-35g) were divided into groups (n = 6) and treated orally (0.1mL/10g), with negative control (vehicle), HDL, FAOC, FAOC-HDL, and positive control, 1h, 24h and 48h before each test. First, was determined the median effective dose (DE50) and then the experimental models of acetic acid-induced abdominal contraction, formalin test, croton oil induced ear edema, carrageenan-induced paw edema test and peritonitis induced by carrageenan. The ED 50 found was FAOC (98 mg/kg) and FAOC-HDL (222.9 mg/kg). After 1 h of treatment, FAOC (98 mg/kg) and FAOC-HDL (222.9 mg/kg) significantly inhibited the number of abdominal writhing respectively in 49.99% (22,67± 1,56) and 56,99% (19,5 ± 2,69), the paw licking time in the formalin test was 28.93% (113.6 ± 12.45) and 60.79% (62.67 ± 11, 02) in the second phase of the test, development of ear edema in 25.59% (2.53 ± 0.21) and 47.65% (1.78 ± 0.20) and development of paw edema in the 2nd and 3rd hour of the test and the migration of total leukocytes by 73.17% (1.95 ± 0.38) and 75.69% (1.77 ± 0.28) and neutrophils in 62.82 (1.61 ± 0.31), 91.0% (0.39 ± 0.10) in the peritonitis. There was also a significant effect on treatment with FAOC-HDL (222.9 mg/kg) after 24 h of treatment, inhibiting the number of abdominal writhes in 58.34% (20.0 ± 3.97), lambda time of the paw in the formalin test 33.97% (98.83 ± 13.64), the development of ear edema in 57.05% (2.47 ± 0.36) and the development of paw edema in the 3rd hour of the test in 30.28%, (0.27 ± 0.02). Thus, the results obtained show antinociceptive and anti-inflammatory effect of the FAOC and, underpinning this effect by the controlled release of FAOC intercalates in HDL.