N,N'-Propylenedinicotinamide (Nicaraven) is presently being developed for the treatment of cerebral stroke including subarachnoid hemorrhage. This drug is promising because some data suggest it to have an ability to scavenge the hydroxyl radical under physiological conditions in vivo, while it also has a high permeability through the blood brain barrier. Using the kinetic constant of the reacti...

We recently described that hydrogen peroxide (H2O2) stimulates the synthesis of tetrahydrobiopterin (BH4) through the induction of the rate-limiting enzyme GTP-cyclohydrolase I (GTPCH), and increases tetrahydrobiopterin content in vascular endothelial cells. Tetrahydrobiopterin is easily oxidized by peroxynitrite (ONOO-), but not by hydrogen peroxide. The aim of this study was to determine the ...

1. The concentration-dependent scavenging abilities of zinc DL-methionine, zinc sulfate, zinc gluconate, zinc picolinate and selected free radical scavengers, including superoxide dismutase (SOD), catalase, mannitol, allopurinol and DL-methionine, were examined against biochemically generated superoxide anion, hydroxyl radical and hypochlorite radical plus hypochlorous acid, by chemiluminescenc...

A novel mechanism for cleavage of three typical α(1→2), α(1→4) and β(1→4) glucosidic bonds induced by hydroxyl free radical was examined with DFT theory at B3LYP/6-31+G(d,p) level using PCM water solvent model. It was found that the hydrogen abstraction from the CH bonds outside the saccharide rings could induce the hydrogen transfer from the hydroxyl at the radical carbon to the oxygen atom of...

Numerous diseases are induced by free radicals via lipid peroxidation, protein peroxidation and DNA damage. It has been known that a variety of plant extracts have antioxidant activities to scavenge free radicals. Whether Polygonum cuspidatum Sieb. et Zuce has antioxidant activity is unknown. In this study, dried roots of Polygonum cuspidatum were extracted by ethanol and the extract was lyophi...

Antioxidant potential of leaves of three different species of Annona was studied by using different in vitro models eg., 1,1-diphenyl-2-picryl hydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothizoline-6-sulphonate) (ABTS), nitric oxide, superoxide, hydroxy radical and lipid peroxidation. The ethanolic extract of A. muricata at 500 microg/ml showed maximum scavenging activity (90.05%) of ABTS radical...

Chitosan (CS) is an abundant and renewable polysaccharide that is reported to exhibit a great variety of beneficial properties. However, the poor solubility of chitosan in water limits its applications. In this paper, we successfully synthesized single N-quaternized (QCS) and double N-diquaternized (DQCS) chitosan derivatives, and the resulting quaternized materials were water-soluble. The degr...

The total flavonoids of Houttuynia cordata are determined by UV-Vis spectrophotometry. The extraction condition of flavonoids from Houttuynia cordata includes: the extraction temperature is 70 ̊C, solid-liquid ratio is 1:20, solvent is 80% ethanol, extraction time is 65 min. We studied the antioxidation of flavonoids in Houttuynia cordata, and results showed that flavonoids had strong reducing c...

free radicals involved in a number of diseases due to the oxidative damage to dna, lipids, and proteins and which can result in failure of cellular functions. dried plant bulbs and leaves methanolic and ethanolic extracts were prepared. total antioxidant activities of the methanolic extracts of romulea ramiflora and gagea fibrosa were determined using β-caroten-linoleic acid assay. romulea-bulb...

In this present study our aim was to evaluate In vitro antioxidant and free radical scavenging potential of methanolic extracts of Bauhinia variegata Linn. Different parts of Bauhinia variegata like leaves, bark and flowers have free radical scavenging activity by hydroxyl radical scavenging method. All extracts have different level of antioxidant activity. Methanol extracts was found to be goo...