Inhibition of nitric oxide synthase expression in activated microglia and peroxynitrite scavenging activity by Opuntia ficus indica var. saboten.
Activated microglia by neuronal injury or inflammatory stimulation overproduce nitric oxide (NO) by inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) such as superoxide anion, resulting in neurodegenerative diseases. The toxic peroxynitrite (ONOO-), the reaction product of NO and superoxide anion further contributes to oxidative neurotoxicity. A butanol fraction obtained from 50% ethanol extracts of Opuntia ficus indica var. saboten (Cactaceae) stem (SK OFB901) and its hydrolysis product (SK OFB901H) inhibited the production of NO in LPS-activated microglia in a dose dependent manner (IC50 15.9, 4.2 microg/mL, respectively). They also suppressed the expression of protein and mRNA of iNOS in LPS-activated microglial cells at higher than 30 microg/mL as observed by western blot analysis and RT-PCR experiment. They also inhibited the degradation of I-kappaB-alpha in activated microglia. Moreover, they showed strong activity of peroxynitrite scavenging in a cell free bioassay system. These results imply that Opuntia ficus indica may have neuroprotective activity through the inhibition of NO production by activated microglial cells and peroxynitrite scavenging activity.
Lee
Ming Hong
MH
College of Pharmacy, Sookmyung Women's University, 52 Hyochangwon-Gil, Yongsan-Gu, Seoul, Korea.
Kim
Jae Yeon
JY
Yoon
Jeong Hoon
JH
Lim
Hyo Jin
HJ
Kim
Tae Hee
TH
Jin
Changbae
C
Kwak
Wie-Jong
WJ
Han
Chang-Kyun
CK
Ryu
Jae-Ha
JH
D000818:Animals; D002460:Cell Line; D015870:Gene Expression / Q000187:drug effects; D020672:I-kappa B Proteins / Q000378:metabolism; D051379:Mice; D017628:Microglia / Q000187:drug effects*; D018696:Neuroprotective Agents / Q000494:pharmacology; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors*; D029747:Opuntia; D030421:Peroxynitrous Acid / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000494:pharmacology*
D020672:I-kappa B Proteins; D018696:Neuroprotective Agents; D010936:Plant Extracts; D030421:Peroxynitrous Acid; D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I