For ages, people have recognized the importance of healing herbs. This is because human beings have coevolved with plants over the past few million years. Most of the degenerative diseases viz., AIDS, cancer, diabetes, ageing, etc., that afflict humanity have their origin in toxic free radical reactions. Most free radical damage to cells involves active oxygen species (AOS). In fact,human is not genetically adapted to survive past middle age hence antioxidant supplementation of our diet is needed to ensure a healthier elderly population. This concept has captured the attention of scientists to prove the medicinal properties of herbs using the scientific tools. Herbs, rich source of antioxidants, are considered effective in counteracting AOS related disorders. This book documents a scientific record of the antioxidant activities of Withania and Rauwolfia, reputed for curing several diseases. AOS scavenging capacity was evinced in various parts of these herbs. This book will prove a useful reference for the professionals in pharmaceutics and aayurveda, or anyone else who may be using plant parts as a natural source of antioxidants or dietary products.