Natural products are a consistent source of potentially effective compounds for the treatment of several disorders. It is believed that the tropical and Middle East regions have the most abundant supplies of natural products across the globe. Secondary metabolites obtained from plants have been employed by humans to treat health disorders, acute infections and chronic illness for a large number of years. Natural products have been greatly replaced by synthetic drugs in the past 100 years. Estimates of 200, 000 natural products in plant species have been revised upward as mass spectrometry methodologies have advanced. For advancing countries the recognition and use of endogenous medicinal plants as cures for cancers have become appealing. This book covers important topics such as antibacterial drug discovery, resources for drug discovery, colon cancer: current treatments and preclinical models, etc.