The present invention relates to a therapeutic agent or prophylactic agent for a disease requiring promotion of osteogenesis or enhancement of bone morphogenetic protein production, an agent for promotion of osteogenesis or an agent for enhancement of bone morphogenetic protein production, and a food, beverage or feed for promotion of osteogenesis or enhancement of bone morphogenetic protein production, characterized in that each comprises as an effective ingredient a processed product derived from a plant. Also, the present invention relates to a method for measuring an enhancing action for bone morphogenetic protein production, a method for screening a substance having an enhancing action for bone morphogenetic protein production, and a method for preparing a substance having an enhancing action for bone morphogenetic protein production, each method using a specified cell.