Utilization of Inedible Parts of Aralia cordata with High-Content Chlorogenic Acid Cultivated in Tokyo

Abstract

Aralia cordata is called “Udo” and is one of the famous herbaceous perennial plants found in Korea, China, and Japan. In Japan, aerial parts of A. cordata have been consumed. Furthermore, its rhizome and root are utilized as crude drugs known as “dokukatsu” and “wakyoukatsu”, respectively. A. cordata is cultivated as a vegetable in many places in Japan, and one of the production areas is Tokyo. A. cordata made in Tokyo is known as a high-quality “Udo” product (aerial part) using a unique cultivation method, known as “Udo muro”. “Udo muro” blocks light and maintains optimal temperature and humidity throughout the year, facilitating the soft cultivation of udo. However, the roots of A. cordata cultivated in Tokyo are all discarded. Thus, the utilization of the A. cordata root cultivated in Tokyo might lead to sustainability and income improvement for farmers. In this study, we investigated the effect of “Udo muro” with or without cultivation and drying temperature on chlorogenic acid (CA) contents in A. cordata root and compared it with A. cordata produced in other areas (“wakyoukatsu”) by a quantitative analysis of the CA content using high-performance liquid chromatography. The results indicate that the CA content of the roots of A. cordata grown in Tokyo was higher than those grown in other areas. Furthermore, the usefulness of A. cordata root was evaluated using inhibitory activity tests such as nitric oxide production and melanin production using Raw264.7 and B16F10 cell lines, respectively.