Estudo da atividade anti-inflamatória in vitro e in vivo de princípio ativo isolado dos frutos de Pterodon polygalaeflorus

Abstract

The genus Pterodon (Fabaceae) comprises five native species to Brazil, known as "Sucupira branca”. Its fruits are widely used in folk medicine to treat rheumatism, sore throat and other disorders of inflammatory nature. The biological activities of the species of the genus were demonstrated in several studies, and many of them relate the anti-inflammatory and analgesic effects to their constitution of furan diterpenes. Thus, this work aimed to evaluate the anti-inflammatory potential this class of compounds obtained from fruits of P. polygalaeflorus through in vitro and in vivo models. Fruits of P. polygalaeflorus were macerated in dichloromethane for 15 days, obtaining the dichloromethane extract (EDPg) with 39% yelding. EDPpg was fractionated and of its fractions was isolated a compound from a white precipitate, by crystallization/ recrystallization techniques, characterized by GC-MS, 1H and 13H NMR and by comparison with literature data as the diterpene 6α, methyl-7β-dihydroxyivouacapane-17β-oate (Ppg-01). Chromatographic analysis indicated a high purity compound. Ppg-01 inhibited (p<0.01) the NO production (58.2%) with 50 μg/mL, and cell migration (p<0.001) in the transwell model (59%), com 10 -μg/mL, in LPS-stimulated RAW 264.7 macrophages. In vivo, Ppg-01 reduced up to 53.8% (p<0.05) the carrageenan-induced edema in SW mice, reducing dermis thickening and inflammatory cell infiltration in the assessed paw tissue (histologically). In the collagen-induced arthritis (CIA) model, Ppg-01 decreased the arthritis index by up to 52.8% (p<0.01), reducing the severity score of the disease. The radiographic analysis of the paws revealed a protective effect against bone degradation and ankyloses, and the histological analysis of the femorotibial and tarsal joint showed lower synovial hyperplasia, with greater joint and bone integrity. The body weight of the animals was not affected by the treatment with Ppg-1, as well as the relative weight of the liver and kidneys. The relative weight of the thymus (p<0.01) and popliteal lymph node (p<0.05) was reduced by treatment with Ppg-01, as well as the total cell count of the spleen (p<0.05) and popliteal lymph node (p<0.01). In the analysis of lymphocytes, Ppg-01 caused a reduction (p<0.01) in the total number of activated T CD8+ (CD8+CD69+) and activated B cells (CD19+CD69+) in the inguinal lymph node. In the spleen, the treatment decreased the total number of T CD4+ cells (p<0.05), activated T CD4+ (CD4+CD69+) (p<0.001) and CD19+CD69+ cells (p<0.05). The evaluation of hematological parameters of the CIA animals showed that the treatment with Ppg-01 did not change the hematocrit and total lymphocyte counts, and increased the total leukocyte, monocyte, and segmented counts. These results allow us to conclude that the Ppg-01 diterpene has potential acute and chronic anti-inflammatory activity and suggests that it may be one of the active principles responsible for the biological activities attributed to Pterodon species.