Gynura bicolor DC. (Okinawa spinach): A comprehensive review on nutritional constituents, phytochemical compounds, utilization, health benefits, and toxicological evaluation.

Functional food plants are nature's gift to human beings to help them battle against various ailments for thousands of years. With the global pursuit of improving the quality of life, there is an increasing demand for functional plants in the world's diet. There is a long history of using Gyruna bicolor not only as a vegetable but also as a medicinal herb in East and Southeast Asia. It has been found in G. bicolor that there is a broad spectrum of nutrients and plant bioactives. G. bicolor has been acknowledged by local people as a useful source of medicine for several therapeutic treatments. This paper provides a comprehensive review of G. bicolor from updated research literature. Botanical characteristics, cultivation information, traditional uses, phytochemistry, nutrient values, as well as biological activities are discussed. The storage, processes, proposals for product development, and toxic assessment of G. bicolor are also covered. It is expected that the paper will encourage further research thereby contributing to open avenues for scientific applications of G. bicolor as a valuable plant with multiple health benefits.