Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0037116 (silicosis)
 1,822 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of tetrandrine, a benzylisoquinoline alkaloid useful in the treatment of silicosis, on a broad range of human neutrophil activities was examined in vitro. Random movement, chemotaxis and phagocytosis were significantly suppressed. There was minimal but significant inhibition of lysosomal enzyme secretion from specific (secondary) but not azurophil (primary) granules. The same concentration of tetrandrine (10 micrograms/ml) caused marked depression of hexose-monophosphate shunt activity and hydrogen peroxide production, but inhibition of superoxide anion generation was observed even at a concentration of 0.1 microgram/ml. This discrepancy was attributed to the capacity of tetrandrine to scavenge oxygen radicals, as shown by experiments using hypoxanthine-xanthine oxidase to generate superoxide. These potent antiphagocytic and antioxidant properties of tetrandrine may account for some of its remarkable anti-inflammatory effects.
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PMID:Antiphagocytic and antioxidant properties of plant alkaloid tetrandrine. 335 73

Tetrandrine is a benzylisoquinoline alkaloid that has been used in China as an antifibrotic drug to treat the lesions of silicosis. Its mechanism in the treatment of silicosis is unclear. Electron spin resonance (ESR) spin trapping was employed to investigate the antioxidant properties of tetrandrine. The spin trap used was 5,5-dimethyl-1-pyrroline N-oxide (DMPO). Tetrandine efficiently reacted with hydroxyl (.OH) radicals with a reaction rate of approximately 1.4 x 10(10) M-1 s-1. The .OH radicals were generated by the Fenton reaction [Fe(II) + H2O2) as well as by reaction of chromium(V) with H2O2. Similar results were obtained using .OH radicals generated by reaction of freshly fractured quartz particles with aqueous medium. Tetrandrine also scavenged superoxide (O2-) radicals produced from xanthine/xanthine oxidase. The effect of tetrandrine on lipid peroxidation induced by freshly fractured quartz particles was evaluated using linoleic acid as a model lipid. The results showed that tetrandrine caused a significant inhibition on freshly fractured quartz-induced lipid peroxidation.
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PMID:Antioxidant activity of tetrandrine and its inhibition of quartz-induced lipid peroxidation. 756 20