Fracionamento biomonitorado de fração isolada do extrato hexânico de Pterodon polygalaeoflorus

Abstract

The genus Pterodon comprises some species widely distributed over the central region of Brazil. Its fruits are commercially available on the market of the medicinal flora, being widely used by their pharmacological properties as antipyretic, anti-inflammatory and analgesic. The aim of this work was to guide the fractionation of hexanic extract of <i>Pterodon polygalaeflorus</i> Benth. fruits (ExPpg), using acute inflammation models (paw edema and air pouch). The extract fractionation was done by column chromatography on silica and the samples were analyzed by thin layer chromatography and gas chromatography coupled with mass spectrometer. Paw edema was induced in SW mice by (s.c.) injection of carrageenan in the right paw. One hour before the carrageenan inoculation, animals were orally treated with vehicle (EtOH 15, 1.25 Tween-20), indomethacin (10 mg/kg bow.) or ExHPpg/fractions/sub-fractions of Ppg. In the air pouch model, the cavity was developed in SW mice through sterile air injection (s.c.) on the back and the inflammation induced by carrageenan inoculation in this cavity. An hour before carrageenan injection the animals were orally treated with the vehicle, indomethacin (10 mg/kg) or ExHPpg/Fr2Ppg/sub-fractions. After four hours the air pouch exudate was collected for the total and differential leukocyte counts (fast Panotic) and protein determination (biuret reaction), and the skin of the air pouch was removed to macroscopic and histological analyses (HE). In vitro neutrophil migration was performed by transwell assay. After demonstration of the anti-edematogenic effect of ExHPpg, this extract was fractionated into four fractions. The Fr2Ppg fraction, most active in paw edema model, also inhibited, in the lowest dose tested, the different inflammatory parameters evaluated in air pouch model. Then, it was sub-fractioned in five sub-fractions. The SF 2.1 and SF 2.2 were the sub-fractions with higher anti-inflammatory effects in the air pouch model. In relation to the carrageenan control group, ExHPpg, Fr2Ppg, SF 2.1 and SF 2.2, in 0.02 mg/kg dose, showed inhibitions of 70.6%, 62.8%, 54.7% and 79% in the total leukocyte counts in the exudate and reductions of 76.8%, 76.9%, 71.1% and 73.3% in the protein concentration, respectively. With the 0.2 mg/kg dose, reductions were observed only for total leukocyte counts after treatment with ExHPpg or SF 2.1 (62.9 and 48.62, respectively), and for protein concentration in animals treated with SF 2.1 and SF 2.2 (reductions of 68.2% and 30.4%, respectively). Macroscopic and histological analyses of air pouch tissues showed important reductions of vasodilation and inflammatory infiltrate by treatment with ExHPpg, Fr2Ppg, SF 2.1 and SF 2.2. In the transwell assay the Fr2Ppg exhibited inhibition of 31.4% of neutrophil migration. The SF 2.1 and SF 2.2 sub-fractions were analyzed by GC-MS, identifying some major compounds. Concluding, this work confirms the anti-inflammatory potential of <i>Pterodon polygalaeflorus</i> species and shows an effective ExHPpg fractionation in relation to the composition and anti-inflammatory effect.