Biol. Pharm. Bull.

Biol. Pharm. Bull., 29(3),467-471, March 2006

Regular Articles

Scavenging of Reactive Oxygen Species by Eriobotrya japonica Seed Extract

Junko YOKOTA,^*^,a Daisuke TAKUMA,^a Atsuhide HAMADA,^a Masahide ONOGAWA,^b Saburo YOSHIOKA,^a Masahiko KUSUNOSE,^b Mitsuhiko MIYAMURA,^b Shojiro KYOTANI,^b and Yutaka NISHIOKA^a,b

^a Department of Biomedical Science, Kochi Medical Graduate School; and ^b Department of Pharmacy, Kochi Medical School Hospital; Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan. * To whom correspondence should be addressed. e-mail: yokotaj@med.kochi-u.ac.jp

We have clarified that Eriobotrya japonica seed extract has strong antioxidative activity, and is effective for the prevention and treatment of various diseases, such as hepatopathy and nephropathy. In this study, to investigate the influences of components of Eriobotrya japonica seed extract on its antioxidative activity, extracts were prepared using various solvents (n-hexane (Hex), ethyl acetate (EtOAc), n-butanol (n-BuOH), methanol (MeOH) and H₂O) and the antioxidative activity of the solvent fractions and components was evaluated based on the scavenging of various radicals (DPPH and O₂⁻) measured by the ESR method and the inhibition of Fe³⁺-ADP induced NADPH dependent lipid peroxidation in rat liver microsomes. The radical scavenging activities and inhibitory activities on lipid peroxidation differed among the solvent fractions and components. In the n-BuOH, MeOH and H₂O fractions, radical scavenging activity and inhibitory activity on lipid peroxidation were high. In addition, these fractions contained abundant polyphenols, and the radical scavenging activity increased with the polyphenol content. In the low-polar Hex and EtOAc fractions, the radical scavenging activity was low, but the lipid peroxidation inhibition activity was high. These fractions contained β-sitosterol, and the inhibitory activity on lipid peroxidation was high. Based on these findings, the antioxidative activity of Eriobotrya japonica seed extract may be derived from many components involved in a complex mechanism, resulting in high activity.

Key words Eriobotrya japonica; ESR; natural antioxidant; LPO

Regular Articles

Scavenging of Reactive Oxygen Species by Eriobotrya japonica Seed Extract

Junko YOKOTA,*,a Daisuke TAKUMA,a Atsuhide HAMADA,a Masahide ONOGAWA,b Saburo YOSHIOKA,a Masahiko KUSUNOSE,b Mitsuhiko MIYAMURA,b Shojiro KYOTANI,b and Yutaka NISHIOKAa,b

a Department of Biomedical Science, Kochi Medical Graduate School; and b Department of Pharmacy, Kochi Medical School Hospital; Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan. * To whom correspondence should be addressed. e-mail: yokotaj@med.kochi-u.ac.jp

Junko YOKOTA,^*^,a Daisuke TAKUMA,^a Atsuhide HAMADA,^a Masahide ONOGAWA,^b Saburo YOSHIOKA,^a Masahiko KUSUNOSE,^b Mitsuhiko MIYAMURA,^b Shojiro KYOTANI,^b and Yutaka NISHIOKA^a,b

^a Department of Biomedical Science, Kochi Medical Graduate School; and ^b Department of Pharmacy, Kochi Medical School Hospital; Kohasu, Oko-cho, Nankoku, Kochi 783-8505, Japan. * To whom correspondence should be addressed. e-mail: yokotaj@med.kochi-u.ac.jp