The basic concept of interaction is discuseed in the book. If these interactions between different herbs are studied, best utilization of the available herbal therapies can be done which can give a valuable treatment and cure with low number of side effects to the society. An attempt is made in this book to study the interataction of two well known herbal plants which are widely used in Indian system of traditional medicine for treating various diseases like hyperlipidemia, diabetes etc. The book contains seven chapters which covers the following topics: Introduction of herbs, hyperlipdemia and antioxidant; Review of literature of the two well known antidiabetic and antihyperlipidemic plants Gymnema sylvestre R. Br. and Azadirachta india A. Juss.; Aim and plan of work for the interaction study; Material and methods used to interaction; Result and discussion; Summary and conclusion; Annexures which include the approval certificate by Animal Ethics Commity to conduct the study. I wish that this book will help in consolidating my understanding of aspects of natural products and its interaction.