Captopril was markedly inhibited. Furthermore, the phagocytic activity of PMNLs was significantly reduced in acetaminophen-treated cells. Thus, acetaminophen causes significant inhibition of the human PMNL functions in vitro. The therapeutic plasma level of acetaminophen is within the range of concentrations used in this study and it is possible, although there is no direct evidence, that the drug may have the same effect on PMNL function in vivo (Ali Shalabi, 1992).
When skin is exposed to UV radiation, free radicals are generated (Pathak and Stratton, 1969). Methimazole (648), 2-mercaptobenzimidazole and indomethacin abolished the erythema response after topical application. Methimazole is a potent scavenger of hydroxyl radicals (Taylor et al., 1984) and it was suggested that the suppression of the UV-induced inflammatory lesions observed could be a consequence of oxygen free radical-scavenging by the thiocarbamide compounds. This action appeared more likely in influencing the inflammatory response in vivo than inhibition of the prostaglandin synthetase system. The topical use of radical scavenging compounds during radiotherapy may protect surface tissues (Ferguson et al., 1985).
The effect of metronidazole (649) on the generation of ROS has been examined both in neutrophils and in a xanthine/xanthine oxidase system. Metronidazole had an antioxidant effect, which was not due to the scavenging of reactive oxygen metabolites, but to action on neutrophil function. It was proposed that the beneficial effects of metronidazole in the treatment of papulopustular rosacea might in part be attributable to this anti-inflammatory effect (Miyachi et al., 1986b).
Chlorpromazine (650) and promethazine (651) are well established
chlorpromazine promethazine to inhibit carbon tetrachloride-induced lipid peroxidation in rat liver microsomes (Slater, 1968; Poli et al., 1989). Chlorpromazine inhibits lipid peroxidation in rat brain and liver (Hoshi et al., 1990), as well as reducing oxidative injury to cardiac phospholipid by membrane stabilization (Janero and Burghardt, 1989). Polarographic studies demonstrated that the half-wave potential of substituted phenothiazines is dependent on the alkyl substituent on the nitrogen atom, and that unsubstituted derivatives have lower oxidation potentials (Kabassakalian and McGlotten, 1959). This has been confirmed in recent electrochemical studies of phenothiazines (Zimova et al., 1990). Chlorpromazine and a series of related phenothiazines have been evaluated as cytoprotective agents using primary cultures of neuronal cells exposed to hydrogen peroxide. While the phenothiazines unsubstituted at the nitrogen atom exhibited cytoprotective effects, chloropromazine was totally ineffective. Although multiple mechanisms may be involved, the inhibition data reported are in the rank order of potency predicted by the compounds' antioxidant capacity as measured electrochemically and by their ability to inhibit iron-dependent lipid peroxidation in vivo (Yu et al., 1992).
Chlorpromazine and trifluoperazine (652) were as effective as probucol in inhibiting copper-catalysed oxidation of LDL and its subsequent recognition and catabolism by mouse peritoneal macrophages (Breugnot et al., 1990). The authors suggested that lipophilic agents such as probucol and phenothiazines, in addition to their antioxidant capacity, may alter the physical properties of the phospholipid membrane and thereby render the lipoprotein more resistant to oxidative attack. Trifluoperazine exhibits a protective effect on mitochondrial damage induced by copper n/pro-oxidants (Pereira et al., 1992).
Lidocaine (653), an antiarrhythmic and local anaesthetic agent, reduced in coronary sinus the levels of conjugated dienes, a marker of lipid peroxidation, during reperfusion of postischaemic myocardium, possibly through membrane stabilization (Lesnefsky et al., 1989). The effect of a series of antiarrhythmic agents on lipid peroxidation induced by iron/ascorbate, using rat hepatic microsomes, has been studied. A trend toward a parabolic
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Rosacea and Eczema are two skin conditions that are fairly commonly found throughout the world. Each of them is characterized by different features, and can be both discomfiting as well as result in undesirable appearance features. In a nutshell, theyre problems that many would want to deal with.