Topically Applied Diterpenoids from Egletes viscosa (Asteraceae) Attenuate the Dermal Inflammation in Mouse Ear Induced by Tetradecanoylphorbol 13-Acetate- and Oxazolone(Pharmacology)

元データ 2008-08-01

概要

The diterpene compounds, centipedic acid (CA) and 12-acetoxyhawtriwaic acid lactone (AHAL, tanabalin) isolated from the flower buds of Egletes viscosa LESS. (Asteraceae) were evaluated on acute and chronic models of mouse ear dermatitis. A single topical application of CA (0.125; 0.25 and 0.5mg/ear) or AHAL (0.125, 0.25, 0.5mg/ear) immediately before 12-O-tetradecanoylphorbol-13-acetate (TPA, 2.5 μg/ear) caused a dose-related significant inhibition of ear inflammatory edema and influx of polymorphonuclear cells, as evidenced by a decrease in ear thickness and reduced myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) in ear tissue homogenates. The maximal obtained inhibition for both ear edema and neutrophil influx were almost similar to that of topically applied dexamethasone (0.05 mg/ear). The extent of inhibitions for the respective treatments of CA (0.5 mg/ear), AHAL (0.5 mg/ear), or dexamethasone (0.05 mg/ear) were in the order of 63%, 61% and 81% for the ear edema, and 90%, 95% and 95% for the neutrophil influx. Also, at similar doses, both diterpenes and dexamethasone effectively inhibited the delayed-type hypersensitivity reaction induced by repeated topical application of 1% oxazolone (OXA, 20 μl/ear), as evidenced by significant decreases in ear thickness and interferon-γ (INF-γ) levels in ear tissue. Histopathological analysis revealed a marked decrease in epidermal hyperplasia and neutrophil infiltration in animals pretreated with CA or AHAL, in a manner similar to dexamethasone. These data provide evidence for the anti-dermatitis effect of Egletes viscosa diterpenes, by mechanisms that involve a reduced neutrophil influx and decreased production of inflammatory cytokines, TNF-α and IFN-γ.

著者

Brito Gerly Department of Morphology, Federal University of Ceará
Cunha Geanne Department Of Physiology And Pharmacology Faculty Of Medicine Federal University Of Ceara
Santos Flavia Department Of Physiology And Pharmacology Post-graduate Programme In Medical Sciences Faculty Of Med
Rao Vietla Department Of Physiology And Pharmacology Post-graduate Programme In Medical Sciences Faculty Of Med
Rao Vietla Departament Of Physiology And Pharmacology Federal University Of Ceara (fm)
Brito Gerly Department Of Morphology Federal University Of Ceara
Silveira Edilberto Department Of Organic And Inorganic Chemistry Federal University Of Ceara
Sousa Daniel Department Of Physiology And Pharmacology Faculty Of Medicine Federal University Of Ceara
CALOU Iana Department of Physiology and Pharmacology, Faculty of Medicine, Federal University of Ceara
Calou Iana Department Of Physiology And Pharmacology Faculty Of Medicine Federal University Of Ceara
Santos Flavia Departament Of Physiology And Pharmacology Federal University Of Ceara (fm)

関連論文