Efeito da fisalina e, isolada da Physalis angulata, em modelos de dermatite de contato induzida por tpa e oxazolona em camundongos

Abstract

The physalin E (PHY E), isolated from the aerial parts of Physalis angulata (Solanaceae), was assessed in models of contact dermatitis induced by 13-acetate-12-o-tetradecanoyl-phorbol (TPA) and oxazolone (OXA) in mice. The irritant contact dermatitis was induced by acute topical administration of TPA (2,5 mg/ear) and evaluated after 4h. The PHY E topically applied to ear at 0,125;0,25 and 0,5 mg/ear and dexamethasone (Dexa), topically, a dose of 0,05 mg/ear, reduced significantly the edema ear induced by TPA in 33,1; 38,7; 39 and 95,2%, respectively. In the same doses, PHY E as well as Dexa, reduced by 45,7; 52,5; 67,6 and 83,4%, respectively, the activity of myeloperoxidase (MPO) in tissue. Oral administration of PHY E (3,10 and 30 mg/kg) and DEXA (1 mg/kg) decreased the ear edema by 34,8; 40,7;47,3 and 46,6% respectively. The same doses, PHY E as well as Dexa, reduced by 39,3; 46,7;54,3% and 81,7%, respectively, the activity of myeloperoxidase (MPO) tissue. The PHY E (0,5 mg/ear) was able to reduce the tissue levels of TNF-α of 8,71±1.18 pg/ml (vehicle) to 2,95±0.81 pg/ml and dexamethasone (0,05 mg/ear) to 2,35±0.94 pg/ml, showing a reduction of 66.2 and 73%, respectively.The administration of mifepristone (25 mg/kg,sc),a steroid antagonist, reversed the effects of PHY E and Dexa, orally and topically, on reducing the edema,myeloperoxidase activity and levels of TNF-α. In the immunohistochemical analysis for TNF-α and NF-κB, PHY E (0,5 mg/ear) and dexamethasone (0,05 mg/ear) reduced the intensity of marking the TNF-α and NF-κB, and mifepristone reversed this effect. The anti-inflammatory action of the PHY E in the model of the dermatitis TPA-induced were confirmed by histopathological findings, with the reduction of edema and inflammatory infiltration of mono and polymorphonuclear. The chronic dermatitis was induced by application of 20 µl solution of TPA (2,5 mg/ear) was applied topically every other day for 10 days, PHY E topically applied (0,125, 0,25 and 0,5 mg/ear) reduced significantly the edema of the ear, 19; 23; 30,3%,and Dexa (0,05 mg/ear) decreased by 32,6%.In the same doses, PHY E and Dexa reduced tissue activity of MPO in 30; 38,8;50,8 and 56,6%, respectively. Oral administration. PHY E (3, 10 and 30 mg/kg) reduced significantly the ear edema chronic in 8, 14,8 and 17%, respectively, and Dexa (1 mg/kg) reduced in 20.7%. In the same doses,PHY E and Dexa reduced activity of MPO in 43.1, 54.5, 59.3 and 65% respectively The model of contact dermatitis induced by oxazolone (OXA, 1%/ear) caused an epidermal hyperplasia where the INF-γ played crucial role. PHY E oral and topical, has significantly reduced the epidermal hyperplasia of 7 th to 19 th day of observation Physalin E (0,5 mg/ear topically) decreased levels of IFN-γ in 43,5% and Dexa (0,05 mg/ear topically) to 37,5% when compared to vehicle. Our results, as evidenced by histological study, demonstrate the anti-inflammatory effect of physalin in the model of contact dermatitis allergic. In conclusion, the results obtained showed that PHY E presented anti-inflammatory activity either when was used by oral and topical route in the models of contact dermatitis TPA and Oxazolone-induced in mice, possible trought the interaction with glucocorticoids receptors.