Aged garlic extract enhances production of nitric oxide.
Nitric oxide (NO) controls several physiological functions of the cardiovascular system. Three kinds of NO synthases (NOSs), neuronal constitutive NOS (ncNOS), inducible NOS (iNOS) and endothelial constitutive NOS (ecNOS), were responsible for NO biosynthesis. This study investigated the effect of aged garlic extract (AGE) on NO production by measuring the NO metabolites nitrite and nitrate in the plasma of mice. AGE (2.86 g/kg, p.o.) temporarily increased NO production by 30-40% from 15 to 60 min after administration. The time course of the fluctuation in NO levels in the AGE-treated group was clearly different to that in a group of mice treated with lipopolysaccharides, a typical iNOS inducer. Arginine (63 mg/kg, p.o.) at the equivalent dose of AGE did not increase NO production. However diphenyleneiodonium chloride (1 mg/kg, i.p.), a selective cNOS inhibitor, administered prior to AGE, overcame the effect of AGE. These results indicate that AGE increased NO production by activating cNOS, but not iNOS. The arginine contained in AGE was not responsible for the effect. AGE may be a useful tool for the prevention of cardiovascular disease.
Morihara
Naoaki
N
Healthcare Research Institute, Wakunaga Pharmaceutical Co. Ltd., 1624 Shimokotachi, Kodacho Takatagun, 739 1195, Hiroshima, Japan. morihara_n@wakunaga.co.jp
Sumioka
Isao
I
Moriguchi
Toru
T
Uda
Naoto
N
Kyo
Eikai
E
D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005737:Garlic / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D051379:Mice; D009566:Nitrates / Q000097:blood*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D009573:Nitrites / Q000097:blood*; D009574:Nitro Compounds / Q000494:pharmacology; D009861:Onium Compounds / Q000494:pharmacology; D010936:Plant Extracts / Q000008:administration & dosage / Q000494:pharmacology; D013997:Time Factors; D019323:omega-N-Methylarginine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D008070:Lipopolysaccharides; D009566:Nitrates; D020030:Nitric Oxide Donors; D009573:Nitrites; D009574:Nitro Compounds; D009861:Onium Compounds; D010936:Plant Extracts; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; C007517:diphenyleneiodonium; C061872:FK 409; D019001:Nitric Oxide Synthase