This effect may be involved in the scavenging effect of sugar on hydroxyl radical because lateral root initiation in B. falcatum root culture was promoted by stresses such as drought or heat, and active oxygen species that the addition of hydrogen peroxide or methylviologen contributed. As saikosaponin was accumulated only on lateral roots and original roots were losing their function to root tissues during the culture in that culture system, the prompt increase of lateral root formation was crucially important. However, as sucrose is also an energy source, a two-step culture was adopted, with the addition of 1% sucrose at the beginning of the culture and 6%sucrose thereafter at 14 days when lateral roots had emerged.