Terpenoıds in the Treatment of Gastrointestinal Tract Cancer

Gastrointestinal cancers are the most common cancer group, accounting for approximately one-fourth of the total cancer incidence and one-third of cancer-related deaths in developing countries. Treatments for the disease include surgery, radiation, and administration of chemotherapy components, such as docetaxel, mitomycin, and cisplatin injection. However, due to the side effects seen in these treatments and for the purpose of supporting the treatment, the trend towards medicinal herbs and phytonutrients, which have certain biological activities and potential benefits to human health, including the prevention of diseases, has increased. Natural products and their derivatives are consistently the most successful source of phytonutrients and pharmaceutical leaders. Terpenoids are one of the most important families of natural compounds known for their medicinal value. Terpenoids are found in higher plants, algae, mosses, liverworts, and lichens, as well as insects, microbes or marine organisms; and have been shown to exhibit anti-infective, anti-inflammatory, and antitumoral properties. Recently, research activities on the preclinical and/or clinical potential of this class of components in cancer have continuously risen. In this review, the molecular basis of the antitumoral effect of terpenoids is presented, with special emphasis on the latest developments in this field, comprising recently enlightened findings of the potential of monoterpenoids, diterpenoids, triterpenoids and tetraterpenoids as antitumoral agents. Furthermore, this review will summarize promising terpenoid compounds in combination therapy with conventional chemotherapeutic agents.