No abstract

This study suggests that thymol is a promising compound to be used in treatment of inflammatory processes as well as wound healing. The pharmacological actions of Lippia gracilis in popular medicine practices may be related, at least in part, to the presence of thymol in the essential oil.

No abstract

The EO of Lippia gracilis leaves shows antinociceptive and anti-inflammatory activities.

The nitric oxide-mediated actions are mostly due to cyclic GMP (cGMP) formation, but cGMP-independent mechanisms, such as tyrosine nitration, have been suggested as potential signaling pathways modulating the NO-induced responses. However, the mechanisms that lead to tyrosine nitration in platelets are poorly studied, and the protein targets of nitration have not been identified in these cells. Therefore, we have used the model of platelet adhesion to fibrinogen-coated plates to investigate the cGMPindependent mechanisms of the NO-donor sodium nitroprusside (SNP) that leads to inhibition of platelet adhesion. SNP concentration-dependently inhibited platelet adhesion, as observed at 15-min and 60-min adhesion. Additionally, SNP markedly increased the cGMP levels, and the soluble guanylate inhibitor ODQ nearly abolished the SNP-mediated cGMP elevations in all experimental conditions used. Nevertheless, ODQ failed to affect the adhesion inhibition obtained with 1.0 mM SNP at 15 min. On the other hand, superoxide dismutase or peroxynitrite (ONOO ؊ ) scavenger epigallocatechin gallate significantly reversed the inhibition of platelet adhesion by SNP (1 mM, 15 min). Western blot analysis in SNP (1 mM, 15 min)-treated platelets showed a single tyrosine-nitrated protein with an apparent mass of Ϸ105 kDa. Nanospray LC-MS͞MS identified the human ␣-actinin 1 cytoskeletal isoform (P12814) as the protein contained in the nitrated SDS gel band. Thus, tyrosine nitration of ␣-actinin, through ONOO ؊ formation, may be a key modulatory mechanism to control platelet adhesion.protein nitration ͉ sodium nitroprusside ͉ peroxynitrite ͉ human platelet ͉ soluble guanylate cyclase B lood platelets play a key role in maintaining the integrity of the vascular system through their ability to arrest bleeding and to promote repair of injured blood vessels (1). Platelet adhesion is the first step to begin the haemostatic process, and fibrinogen is responsible to mediate both platelet adhesion and aggregation through binding to the platelet membrane glycoprotein IIb-IIIa (integrin ␣ IIb ␤ 3 ) (2). In nonactivated platelets, the majority of GPIIb͞IIIa is in a low-affinity state. However, they are capable of binding directly to immobilized fibrinogen and von Willebrand factor, because in this nonactivated state, the platelets attach to domains of fibrinogen distinct of those seen after platelet activation (3).The nitric oxide (NO)-dependent inhibition of platelet adhesion to the subendothelium is essential in preventing excessive aggregation and thrombus formation. It is well accepted that NO-mediated actions are due to activation of the soluble guanylate cyclase leading to an increase of cyclic GMP (cGMP; ref. 4). The NO donor sodium nitroprusside (SNP) has been shown to spontaneously release NO for prolonged time periods (5, 6), leading to inhibition of platelet adhesion in vivo (7) and in vitro (8,9). Although the reduction of platelet adhesion by SNP is accompanied by increased cGMP levels, cGMP-independent mechanisms have also been proposed...