... flavonoids such as quercetrin. Allantoin, leucocyanidin, tannins, and the plant sterols sitosterol, stigmasterol, and campesterol have also been identified. The ... mechanism of most herbs. The combination of the entire plant components synergistically can often produce superior results as compared ... Use of Horse Chestnut Extract 1. Horse chestnut is a plant. Its seed, bark, flower, and leaves are used ...