Glycosides in the Treatment of Gastrointestinal Tract Cancer

Gastrointestinal (GI) carcinomas are tumors that impact the digestive system and its supporting organs. Esophageal, gastric and colorectal cancers are among the common cancers in the gastrointestinal tract. GI cancers are responsible for about 2.7 million deaths of the 8.2 million mortalities that occur from cancers every year around the globe. Chemoprevention is the method of intervening in this mechanism by essential dietary control or the addition of nutraceuticals to the daily nutritional intake. The initial stages of cancer growth, known as oncogenesis, have sparked a lot of emphasis on the function of dietary food. The intensity of the epidemiological studies attracted research scholars' interest in the mechanisms underlying the anti-proliferative activities; however, investigation has indeed discovered lots of new phytochemicals in vegetables and fruits which might prevent the development of carcinogenesis. In cancer treatment, drugs obtained from plant sources have a significant role in cancer treatment. The plant alkaloids isolated from Catharanthus roseus, such as vincristine and vinblastine, are clinically used to treat testicular carcinomas, leukemia, and breast cancer. Paclitaxel is isolated from Taxus brevifolia and is used in the management of lung cancer, breast cancer and ovarian cancer. In the 1960s, there has been initial proof of the in vitro cytotoxic impact of glycosides on human cancer cell lines and their in vivo anti-tumor activities. Cardiac glycosides are Na+/K+ATPase inhibitors and elevate the Ca+2 concentrations, which in turn leads to a positive inotropic effect and is thus used as cardio-tonic in the management of congestive heart failure. Cardiac glycosides have recently been documented to play roles in initiating, developing and metastasizing the tumor by controlling cell viability and mortality pathways. It has been reported that Na+/K+ATPase inhibitor causes cell death by inducing autophagy, apoptosis and synthesis of free radical species. Notwithstanding the advances in cancer treatments, the need for new medicinal products and treatments to enhance their effectiveness and to decrease the toxicity of existing regimes is strong and unequaled, although a broad objective is to improve the therapeutic results of GI cancers. This chapter briefly describes the glycosides, gastrointestinal malignancies and the diverse types of glycosi- des involved in the management of GI malignancies and the clinical trials under progress for the clinical efficacy.

Keywords: Clinical status, GI cancer, Glycosides, Mechanistic pathway.