Abstract
Purpose :
The search for new drugs has found in plants an important source of biologically active compounds. The Hymenaea courbaril is a tree that grows in South America forests and its essential oil has proved anti-inflammatory effects. Due to the involvement of chronic inflammation in pterygium genesis, we investigated the chemical composition of H. courbaril essential oil and its anti-inflammatory effects on pterygium fibroblasts.
Methods :
The essential oil was obtained by hydro-distillation using a Clevenger-type apparatus and the identification of the chemical constituents by gas chromatography coupled to mass spectrometry. Primary cultures of pterygium fibroblasts were exposed to the H. courbaril essential oil main compounds: trans-caryophyllene and alpha-humulene, separately and together, in triplicates. The cell viability was accessed with MTT assay after 12, 24, 48 and 72 hours of exposure. The IL-1b, IL-6, IL-8, TNF-a and IL-10 levels in the conditioned medium were measured by ELISA, at 12, 24 and 48 hours after exposure. The controls were exposed to the vehicles, in each corresponding concentration. The data were analyzed statistically using Friedman repeated measures analysis of variance on ranks.
Results :
The main compounds of H. courbaril essential oil are trans-caryophyllene (46,24%), oxide caryophyllene (14,67%) and α-humulene (9,19%). The MTT test showed that α-humulene, trans-caryophyllene and both drugs together had the same cytotoxic effect when used in concentrations of 0.5 to 5μM. The IL-6 levels showed statistically significant reduction (P=0.041) at 48 hours after exposure to trans-caryophyllene at 25 mM. The IL-1b, IL-8, IL-10 and TNF-α levels were not detected.
Conclusions :
The trans-caryophyllene compound from H. courbaril essential oil in concentration of 25μM presented significant anti-inflammatory effect on IL-6 production of pterygium fibroblasts after 48 hours of exposure when compared to controls. So, H. courbaril can be therefore a potential alternative adjuvant agent in the treatment of pterygium.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.