Taro (Colocasia esculenta L): Review on Its botany, morphology, ethno medical uses, Phytochemistry and pharmacological activities

Abstract

Natural products are the best sources of drugs and drug leads and this remains true today although the fact that many pharmaceutical companies have focused on natural products research for two decades. Colocasia esculenta (L) Schott (C. esculenta, Family Araceae) is an annual herbaceous plant with a long history of usage in traditional medicine in several countries across the world and is grown for its edible corm as staple foods throughout the tropical and subtropical regions. In India it is known as Aravi, Alukam, Kesavedantu, Chamadumpa. Corm and leaves of this plant are widely used as vegetables in Indian traditional food system. It was a widely used as a vegetable crop for nutritional and medicinal purposes. Nutritionally, C. Esculenta contains more than twice the carbohydrate content of potatoes and yield 135 kcals per 100 gm. C. Esculenta contains about 11% protein on a dry weight basis. This is more than yam, cassava or sweet potato. It contains 85-87% starch on dry matter basis with small granules size of 3-18μm and other nutrients such as minerals, vitamin C, thiamin, riboflavin, oxalic acid and niacin better than other cereals. C. Esculenta leaves, like higher plants, is rich in protein. Phytochemical analysis showed that the major constituents of C. Esculenta leaves are flavonoids, β-sitosterol, steroids, tarin, polysaccharides (TPS1 and TPS2), alkaloids, polyphenols, and saponins ect., The plant also has the property to reduce fever and pain. The pharmacological studies revealed that the plant exerted many pharmacological activities, including central nervous effects, antioxidant, anti-inflammatory, analgesic, anti-lipid peroxidative activity, antidiabetic, anti-carcinogenic, hepatoprotective, immunoprotective and antimicrobial effects. There is requiring isolating active constituents, their biological test, molecular mechanisms, experimental defense and legalization of therapeutic uses of C. esculenta. Various traditional claims of the plant are still remain to be validated scientifically. Future research should focus on the pharmacological properties, phytochemistry, clinical trials and pharmacokinetics of C. esculenta which will enhance the therapeutic potential of the species. Clinical trials for the reported preclinical studies should be performed urgently to further validate the claims on humans.