Inhibition of Reactive Nitrogen Species in Vitro and ex Vivo by Trypsin Inhibitor from Sweet Potato 'Tainong 57' Storage Roots
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- 作者：Guan-Jhong Huang ; Ming-Jyh Sheu ; Hsien-Jung Chen ; Yuan-Shiun Chang ; Yaw-Huei Lin
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2007
- 出版时间：July 25, 2007
- 年：2007
- 卷：55
- 期：15
- 页码：6000 - 6006
- 全文大小：292K
- 年卷期：v.55,no.15(July 25, 2007)
- ISSN：1520-5118
文摘
Peroxynitrite (ONOO-), formed from a reaction of superoxide and nitric oxide, is one of the mostpotent cytotoxic species known to oxidize cellular constituents including essential proteins, lipids,and DNA. ONOO- induces cellular and tissue injury, resulting in several human diseases such asAlzheimer's disease, atherosclerosis, and stroke. Due to the lack of endogenous enzymes responsiblefor ONOO- scavenging activity, finding a specific ONOO- scavenger is of considerable importance.In this study, the ability of trypsin inhibitor (TI), isolated from sweet potato storage roots (SPTI), toscavenge 
ON and ONOO- was investigated. The data obtained show that TI generated a dose-dependent inhibition on production of nitrite and superoxide radicals. The IC50 value of TI on superoxideradical was 143.2 ± 4.29 
g/mL. SOD activity staining was used to confirm SOD activity of SPTI.SPTI also caused a dose-dependent inhibition of the oxidation of dihydrorhodamine 123 (DHR) byperoxynitrite. A calculated IC50 value of 809.1 ± 32.36 g/mL was obtained on the inhibition ofperoxynitrite radical. Spectrophotometric analyses revealed that TI suppressed the formation ofONOO--mediated tyrosine nitration through an electron donation mechanism. In further studies, TIalso showed a significant ability to inhibit nitration of bovine serum albumin (BSA) in a dose-dependentmanner. In vivo TI inhibited lipopolysaccharide-induced nitrite production in macrophages in aconcentration-dependent manner with an IC50 value of 932.8 ± 29.85 g/mL. The present studysuggested that TI had an efficient reactive nitrogen species scavenging ability. TI might be a potentialeffective NO and ONOO- scavenger useful for the prevention of NO- and ONOO--involved diseases.
ON and ONOO- was investigated. The data obtained show that TI generated a dose-dependent inhibition on production of nitrite and superoxide radicals. The IC50 value of TI on superoxideradical was 143.2 ± 4.29 g/mL. SOD activity staining was used to confirm SOD activity of SPTI.SPTI also caused a dose-dependent inhibition of the oxidation of dihydrorhodamine 123 (DHR) byperoxynitrite. A calculated IC50 value of 809.1 ± 32.36 g/mL was obtained on the inhibition ofperoxynitrite radical. Spectrophotometric analyses revealed that TI suppressed the formation ofONOO--mediated tyrosine nitration through an electron donation mechanism. In further studies, TIalso showed a significant ability to inhibit nitration of bovine serum albumin (BSA) in a dose-dependentmanner. In vivo TI inhibited lipopolysaccharide-induced nitrite production in macrophages in aconcentration-dependent manner with an IC50 value of 932.8 ± 29.85 g/mL. The present studysuggested that TI had an efficient reactive nitrogen species scavenging ability. TI might be a potentialeffective NO and ONOO- scavenger useful for the prevention of NO- and ONOO--involved diseases.