Pterodon polygalaeflorus Essential Oil Modulates Acute Inflammation and B and T Lymphocyte Activation

The increased life expectancy of the population has led to increasing incidences of cancer, chronic inflammatory and autoimmune diseases. Thus the continuous search for new drugs is necessary because ineffectiveness and adverse effects have been described for standard drugs. Essential oils are important sources of bioactive metabolites and several clinical trials have been developed using them. The Pterodon genus has been used in traditional medicine to treat rheumatic disorders, thus this work investigated the properties of essential oil from Pterodon polygalaeflorus fruits (EsOPpg) on acute inflammation and lymphocyte activation. The essential oil was obtained by hydrodistillation and its components were identified by GC/MS. The anti-inflammatory response was assessed using the air pouch model. Antinociceptive potential was evaluated using the writhing model. Lymphocyte phenotyping, cell cycle and apoptosis were analyzed by flow cytometry. EsOPpg promoted a reduction in leukocyte counts and protein concentration in the exudate, and reduced vasodilatation and inflammatory cell infiltrate in air pouch tissue. No anti-nociceptive effect was demonstrated for the doses tested. EsOPpg inhibited lymphocyte proliferation, arresting the cell cycle in G(1) phase, and induced apoptosis in these cells. EsOPpg downregulated both the total number of CD8(+) T cells and the activated subpopulation (CD8(+)CD69(+)), while promoting upregulation of the total number of CD19(+) and CD19(+)CD69(+) B cells. In conclusion, Pterodon polygalaeflorus essential oil diminished the acute inflammatory response and inhibited lymphocyte proliferation, reducing neutrophil recruitment into the cavity and air pouch tissue and promoting distinct modulations of the activation level of each lymphocyte subpopulation.