Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin. To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin express...

Scrophularia genus belonging to the family of Scrophulariaceae, is a medicinal plant widely distributed in Iran. In the present study,the anti-malarial activity of different extracts of three Iranian endemic species of Scrophularia including S. frigida, S. subaphylla and S. atropatana, was screened by an in-vitro preliminary assay. The plant materials were extracted successively with n-hexane, ...

Hematin catalysis of unsaturated lipide oxidation is probably a primary reaction in many types of pathological unsaturated fat oxidation in viva (l-3) and in the spoilage of frozen meat products by oxidative fat rancidity (4). Some of the properties of hematin catalysis have been described (4-8), but knowledge of the reaction mechanism and the reaction products is relatively meager. The catalyt...

The relationship of rabbit Cx-reactive protein (CxRP) and the enzymatic activity of hepatic and kidney catalases in rabbits following i.v. hematin administration has been examined sequentially. The early increases in rab bit liver and kidney catalatic activities were accompanied by the corresponding decreases in ßCxRP and an early appearance of 7 CxRP after hematin administration. Immunoelectr...

1. Two important methods for the study of malarial pigment are described. (a) A method for obtaining a solution of malarial pigment from fixed tissues without the removal of a trace of hemoglobin from the red blood corpuscles. (b) A method for obtaining an iron reaction in malarial pigment. 2. By comparing the bleach reactions and solubility of melanins and malarial pigment, the dissimilarity o...

The role of hem&in in hemoglobin and bile pigment metabolism is not clearly defined. Opinion has been divided over the questions of whether or not hematin is a normal degradation product of hemoglobin and whether or not it is converted to bile pigment. Bingold observed that the occurrence of hen&in in the plasma is associated with a variety of pathologic conditions (1). The conditions in which ...

In malaria pathophysiology, divergent hypotheses on the inhibition of hematin crystallization posit that drugs act either by the sequestration of soluble hematin or their interaction with crystal surfaces. We use physiologically relevant, time-resolved in situ surface observations and show that quinoline antimalarials inhibit β-hematin crystal surfaces by three distinct modes of action: step pi...

Digestion of hemoglobin in the food vacuole of the malaria parasite produces very high quantities of redox active toxic free heme. Hemozoin (β-hematin) formation is a unique process adopted by Plasmodium sp. to detoxify free heme. Hemozoin formation is a validated target for most of the well-known existing antimalarial drugs and considered to be a suitable target to develop new antimalarials. H...

A mutant of Micrococcus pyogenes var. aureus isolated in 1952 has been used to investigate the biosynthesis of certain hematin enzymes. This strain has been described and its hemin requirements analysed in a series of papers (Jensen and Thofern 1953a, b, c, d; 1954). Since the present study is very closely related to and based upon the previous results, a brief summary is indicated: (1) The hem...

We have carried out a study of the reaction of 13Irydroperoxy-9-cis, 11-trans-octadecadienoic acid (linoleic acid hydroperoxide) with hematin. The major products are erythro-ll-hydroxy-l2,13-epoxy-S-octadecenoic acid, threo11-hydroxy12,13-epoxy-9-0~tadecenoic acid, 9,12,13-trihydroxy-lO-octadecenoic acid, 13-keto-9,ll-octadecadienoic acid, and 13-hydroxy-9,ll-octadecadienoic acid. Several minor...