Natural Products/Bioactive Compounds as a Source of Anticancer Drugs

Simple Summary Cancer is considered as a large group of diseases involving abnormal cell growth, which results in an alarming rise in the mortality rate at the worldwide level. Presently, the main point of interest in pharmaceutical research is the development of the novel and efficient anticancer drugs based on natural sources. In this regard, plants, and some microbial species, due to their composition, ecology, phytochemical, and ethnopharmacological properties, play a significant role. Accordingly, a series of plant-derived bioactive compounds are in the clinical development phase against cancer. The present review highlights the significance of several medicinal plants, plant extracts, and their bioactive compounds for their potential anticancer activities. The presented results can be useful for researchers in developing novel anticancer drugs, public health specialists, and for the public in general. Cancer is one of the major deadly diseases globally. The alarming rise in the mortality rate due to this disease attracks attention towards discovering potent anticancer agents to overcome its mortality rate. The discovery of novel and effective anticancer agents from natural sources has been the main point of interest in pharmaceutical research because of attractive natural therapeutic agents with an immense chemical diversity in species of animals, plants, and microorganisms. More than 60% of contemporary anticancer drugs, in one form or another, have originated from natural sources. Plants and microbial species are chosen based on their composition, ecology, phytochemical, and ethnopharmacological properties. Plants and their derivatives have played a significant role in producing effective anticancer agents. Some plant derivatives include vincristine, vinblastine, irinotecan, topotecan, etoposide, podophyllotoxin, and paclitaxel. Based on their particular activity, a number of other plant-derived bioactive compounds are in the clinical development phase against cancer, such as gimatecan, elomotecan, etc. Additionally, the conjugation of natural compounds with anti-cancerous drugs, or some polymeric carriers particularly targeted to epitopes on the site of interest to tumors, can generate effective targeted treatment therapies. Cognizance from such pharmaceutical research studies would yield alternative drug development strategies through natural sources which could be economical, more reliable, and safe to use.