background: superoxide radicals are produced during oxidative metabolic processes, and removed by superoxide dismutase (sod) enzymes. controversial results have been reported regarding the tissue and plasma concentration of sod in patients with breast cancer. methods: venous blood was obtained from study participants and activity of sod enzyme was determined in 100 women. comparison was made be...

The production of superoxide free radicals in pellet and supernatant fractions of glyoxysomes, specialized plant peroxisomes from watermelon (Citrullus vulgaris Schrad.) cotyledons, was investigated. Upon inhibition of the endogenous superoxide dismutase, xanthine, and hypoxanthine induced in glyoxysomal supernatants the generation of O(2) (-) radicals and this was inhibited by allopurinol. In ...

Plant plasma membranes are known to produce superoxide radicals, while the production of the hydroxyl radical, previously detected in complex plant tissues, is thought to occur in the cell wall. The mechanism of production of superoxide radicals by plant plasma membranes is, however, under dispute. It is shown, using electron paramagnetic resonance spectroscopy with a 5-diethoxyphosphoryl-5-met...

In peroxisomes isolated from pea leaves (Pisum sativum L.) the production of superoxide free radicals (O(2) (-)) by xanthine and NADH was investigated. In peroxisomal membranes, 100 micromolar NADH induced the production of O(2) (-) radicals. In the soluble fractions of peroxisomes, no generation of O(2) (-) radicals was observed by incubation with either NADH or xanthine, although xanthine oxi...

In recent years there is an upsurge in the areas related to newer developments in prevention of disease especially the role of free radicals and antioxidants. So it will be pertinent to examine the possible role of ‘free radicals’ in disease and ‘antioxidants’ in its prevention, especially the current status of the subject matter and future prospects. Numerous short-lived and highly reactive ox...

The water-soluble polysaccharide (SCP) was isolated from Semen Coicis through hot water extraction followed by ethanol precipitation. The polysaccharide was deproteinized by using the Sevag reagent, and the polysaccharide was free of proteins as scan by UV Spectra in 260 nm and 280 nm. In order to evaluate its antioxidant activities, Free radicals scavenging activities on superoxide radicals, h...

The objective of the study was to investigate the in vitro antioxidation activity of lycium barbarum polysaccharides (LBP). Ultraviolet spectrophotometry was adopted to determine the capability of LBP to clear superoxide anions, hydroxyl radicals, DPPH free radicals and ABTS free radicals. The result showed that the law for LBP to clear superoxide anions, hydroxyl radicals and DPPH free radical...

Myeloperoxidase uses hydrogen peroxide to oxidize numerous substrates to hypohalous acids or reactive free radicals. Here we show that neutrophils oxidize melatonin to N(1)-acetyl-N(2)-formyl-5-methoxykynuramine (AFMK) in a reaction that is catalyzed by myeloperoxidase. Production of AFMK was highly dependent on superoxide but not hydrogen peroxide. It did not require hypochlorous acid, singlet...