Design and synthesis of functionalized 4-aryl-Catechol derivatives as new antiinflammtory agents with in vivo efficacy.

Oxidative stress and inflammation are two conditions that coexist in many multifactorial diseases and the discovery of antioxidants is an attractive approach that can simultaneously tackle two or more therapeutic targets of the arachidonic acid cascade. We report that the simple structural variations on the 4-aryl-benzene-1,2-diol side-arm of the scaffold significantly influence the selectivity against 5-LOX vs 12- and 15-LOX. Derivatives 4 a-l were evaluated for their antioxidant activity, using the DPPH, and ferric ion reducing antioxidant power (FRAP) methods. Docking simulations proposed concrete binding of the catechol series to 5-LO. Selected active compound 4-(3,4-dihydroxyphenyl)dibenzofuran (4l) was also tested in different in vivo mouse models of inflammation. 4l (0.1 mg/kg; i.p.) impaired (I) bronchoconstriction in ovalbumin-sensitized mice challenged with acetylcholine, (II) exudate formation in carrageenan-induced paw edema, and (III) zymosan-induced leukocyte infiltration in air pouches. These results pave the way for investigating the therapeutic potential of 4-aryl-benzene-1,2-diol, as novel multitarget therapeutic drugs, able to regulate the complex inflammatory cascade mechanisms.

Aberrant inflammation and resistance to glucocorticoids in annexin 1-/- mouse.

The 37-kDa protein annexin 1 (Anx-1; lipocortin 1) has been implicated in the regulation of phagocytosis, cell signaling, and proliferation and is postulated to be a mediator of glucocorticoid action in inflammation and in the control of anterior pituitary hormone release. Here, we report that mice lacking the Anx-1 gene exhibit a complex phenotype that includes an altered expression of other annexins as well as of COX-2 and cPLA2. In carrageenin- or zymosan-induced inflammation, Anx-1-/- mice exhibit an exaggerated response to the stimuli characterized by an increase in leukocyte emigration and IL-1beta generation and a partial or complete resistance to the antiinflammatory effects of glucocorticoids. Anx-1-/- polymorphonuclear leucocytes exhibited increased spontaneous migratory behavior in vivo whereas in vitro, leukocytes from Anx-1-/- mice had reduced cell surface CD 11b (MAC-1) but enhanced CD62L (L-selectin) expression and Anx-1-/- macrophages exhibited anomalies in phagocytosis. There are also gender differences in activated leukocyte behavior in the Anx-1-/- mice that are not seen in the wild-type animals, suggesting an interaction between sex hormones and inflammation in Anx-1-/- animals.