Affiliations: Research & Development Division, Kikkoman
Corporation, Noda City, Chiba 278-0037, Japan. Tel.: +81 04 7123 5551; Fax:
+81 04 7123 5553; E-mail: tariga@mail.kikkoman.co.jp
Abstract: Proanthocyanidins, which belong to a class of polyphenols, are
widely distributed throughout the plant kingdom. Most people ingest trace
amounts of proanthocyanidins through foods such as red wine and cranberry
juice. However, the functional properties of proanthocyanidins have been little
understood. Since 1983, we have studied the antioxidative functions, preventive
actions on diseases and utilization of proanthocyanidins. The antioxidative
activities of proanthocyanidins were found to be much stronger than vitamin C
or vitamin E in aqueous systems. The mechanisms for their antioxidative actions
were shown to involve radical scavenging, quenching, and enzyme-inhibiting
actions. The preventive actions of proanthcyanidins on diseases relating to
reactive oxygen species was examined using animal tests. Proanthocyanidin-rich
grape seed extract was showed to have preventive actions on diseases such as
atherosclerosis, gastric ulcer, large bowel cancer, cataracts and diabetes. In
human intervention trials, grape seed extract was shown to have preventive
effects on the increase in lipid peroxides in human plasma after exercise and
on muscle fatigue after training. The uses and manufacturing techniques of
proanthocyanidin products were subsequently developed. The products were
launched as antioxidants in food additives, ingredients in nutritional
supplements, and cosmetics.
