Inhibitory Effect of Fermented Papaya Preparation on Hydroxyl Radical Generation from Methylguanidine

• Published in: Journal of Clinical Biochemistry and Nutrition Vol. 43; no. 3; pp. 185 - 190
• Main Authors: Noda, Yasuko, Murakami, Shinki, Mankura, Mitsumasa, Mori, Akitane
• Format: Journal Article
• Language: English
• Published: Japan SOCIETY FOR FREE RADICAL RESEARCH JAPAN 2008; Japan Science and Technology Agency; the Society for Free Radical Research Japan
• Subjects: hydroxyl radical; methylguanidine; Original; papaya; papaya; hydroxyl radical; methylguanidine
• ISSN: 0912-0009; 1880-5086
• DOI: 10.3164/jcbn.2008062

We have previously shown that extremely high level of guanidino compounds such as methylguanidine (MG), known as a neurotoxin and also a nephrotoxin, generate reactive oxygen species (ROS) using an electron spin resonance (ESR) technique with spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). In this in vitro study, the inhibitory effect of fermented papaya preparation (SAIDO-PS501:PS-501) on hydroxyl radical (·OH) generation from MG was examined using an ESR spectrometry, and it was found that PS-501 suppressed ·OH generation from MG in a dose-dependent manner. The ID50 value of PS-501 was 8 mg/ml. On the contrary, glucose itself did not suppress ·OH generation from MG up to100 mg/ml, whereas PS-501 almost completely suppressed ·OH generation from MG at a dose of 100 mg/ml. These results imply that PS-501 itself may have a beneficial effect of preventing ROS- and MG-related diseases.