New prostaglandin derivative for glaucoma treatment.

A hydrogen sulphide-releasing derivative of latanoprost acid (ACS 67) was synthesized and tested in vivo to evaluate its activity on reduction of intraocular pressure and tolerability. Glutathione (GSH) and cGMP content were also measured in the aqueous humour. The increased reduction of intraocular pressure, with a marked increase of GSH and cGMP and the related potential neuroprotective properties, make this compound interesting for the treatment of glaucoma. This is the first time that an application of a hydrogen sulphide-releasing molecule is reported for the treatment of ocular diseases.

Anti-inflammatory effects of low molecular weight heparin derivative in a rat model of carrageenan-induced pleurisy.

Low molecular weight heparin derivatives are characterized by low anti-coagulant activity and marked anti-inflammatory effects that allow for these molecules to be viewed as a new class of non-steroidal anti-inflammatory drugs (NSAIDs). We show here that K5NOSepiLMW, an O-sulphated heparin-like semi-synthetic polymer of the D-glucuronic acid-N-acetyleparoson disaccharide unit with low molecular weight, has marked anti-inflammatory effects in a rat model of acute inflammation, the carrageenan-induced pleurisy, commonly used to test NSAID efficacy. A 30-min. pre-treatment with K5NOSepiLMW (0.1, 0.5 and 1 mg/kg b.wt., given intrapleurally) attenuated the recruitment of leucocytes in the lung tissue and the pleural exudate, inhibited the induction of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2), thereby abating the generation of nitric oxide and pro-inflammatory prostaglandins such as PgE(2) and PGF(1alpha), reduced the inflammation-induced nitroxidative lung tissue injury, as shown by tissue thiobarbituric acid-reactive substances and nitrotyrosine, and blunted the local generation of cytokines such as interleukin-1beta and tumour necrosis factor-alpha. All these parameters were markedly increased by intrapleural carrageenan in the absence of any pre-treatment. The anti-inflammatory action of K5NOSepiLMW is specific, as judged by the lack of therapeutic effects of B4/110, a biologically inactive cognate polysaccharide, given in the place of the authentic molecule. Moreover, K5NOSepiLMW showed similar effects as celecoxib (1 mg/kg b.wt), a COX-2 inhibitor and well-known NSAID. This study provides further insight into the mechanisms underlying the beneficial effects of heparin derivatives in inflammation and identifies K5NOSepiLMW as a novel, promising anti-inflammatory drug.

A carbon monoxide-releasing molecule (CORM-3) abrogates polymorphonuclear granulocyte-induced activation of endothelial cells and mast cells.

We hypothesized that circulating polymorphonuclear granulocytes (PMNs), vascular endothelial cells (ECs), and perivascular mast cells (MCs) may initiate and sustain the inflammatory response through the generation of the superoxide anion (O(2)(*-)) by PMNs primed by inflammatory stimuli, which in turn evoked the overexpression of adhesion molecules from ECs and release of histamine by MCs. To pin-point the role of carbon monoxide (CO) in curbing vascular inflammation, we studied the effect of a water-soluble CO-releasing molecule [tricarbonylchloro-glycinate-ruthenium (II); CORM-3] on an experimental model of vascular inflammation. The model consists of coincubating formyl-methionyl peptide (fMLP) -primed human PMNs with rat ECs or with rat MCs. The effects of CORM-3 were evaluated by measuring the generation of O(2)(*-) and the expression of CD11b in fMLP-primed PMNs; the expression of ICAM-1 and CD203c in ECs and MCs, respectively; and the release of histamine from MCs. Our results show that the chemotactic peptide fMLP primes PMNs to generate O(2)(*-) and overexpress CD11b, both events being central to the inflammatory process, while CORM-3 significantly decreases these events (IC(50)=1.66 microM for O(2)(*-) production; 1.20 microM for CD11b expression in human PMNs). The experiments also show that fMLP-primed PMNs increase the CD54 expression by coincubated ECs, and the expression of CD203c and the release of histamine by coincubated MCs. Once again, CORM-3 abolishes these events (IC(50)=6.78 microM for CD54 expression in ECs; 1.18 microM for CD203 expression; 1.15 microM for histamine release in MCs). Thus, CORM-3 exerts a powerful anti-inflammatory action by down-regulating the oxidative burst in PMNs, the overexpression of adhesion molecules in PMNs and ECs, the release of histamine, and the overexpression of an activation marker by MCs.