Oregonin from the Bark of Alnus japonica restrained ischemia-reperfusion-induced mesentery oxidative stress by inhibiting NADPH oxidase activation.
OBJECTIVE
NADPH oxidase activation results in ROS overproduction that is the pathological basis of I/R injury. This study aimed to investigate potential effects of ORG on I/R-induced ROS production in rat mesenteric microvasculature and underlying mechanisms.


METHODS
Mesenteric I/R in Male Wistar rats (200~250 g) was induced by ligation of the mesenteric artery and vein for 10 minutes followed by reperfusion for 60 minutes by releasing of the occlusion. The rats were infused intravenously with or without ORG (5 mg/kg per hour) 10 minutes before ischemia (pretreatment) or 20 minutes after reperfusion (posttreatment). The DHR fluorescence intensity on, the leukocytes adherent to, and mast cell degranulation out of mesenteric venules were determined using an intravital microscope. NADPH oxidase subunit p47(phox) membrane translocation in intestine tissues was detected by Western blotting.


RESULTS
Pre- or posttreatment with ORG inhibited I/R-induced DHR fluorescence intensity on the venular walls and leukocytes adhesion, ORG pretreatment inhibited mast cell degranulation as well. Furthermore, the translocation of p47(phox) from cytosol to membrane was suppressed markedly by ORG after I/R.


CONCLUSIONS
The results suggested that ORG restrained I/R-induced ROS production, which might be correlated with its inhibitive effect on NADPH activation.
Faculty of Pharmaceutical Sciences, Nagasaki International University, Nagasaki, Japan.
Nguyen Huu
NH
Tung
Kai
K
Sun
Jing-Yu
JY
Fan
Yukihiro
Y
Shoyama
Jing-Yan
JY
Han
D029661:Alnus / Q000737:chemistry*; D000818:Animals; D015550:Cell Degranulation / Q000187:drug effects; D036381:Diarylheptanoids / Q000737:chemistry / Q000494:pharmacology*; D007962:Leukocytes / Q000201:enzymology / Q000473:pathology; D008297:Male; D008407:Mast Cells / Q000201:enzymology / Q000473:pathology; D008643:Mesentery / Q000201:enzymology*; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D024301:Plant Bark / Q000737:chemistry*; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000201:enzymology* / Q000473:pathology
D036381:Diarylheptanoids; C409456:oregonin; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1
DHR; leukocyte adhesion; mast cell degranulation; p47phox subunit