Nature is an attractive source of new therapeutic agents and a variety of phytochemicals have proved to be very valuable in the prevention and treatment of various diseases. Many of the important drugs isolated from plants during the past 50 years have revolutionized modern medicinal practice (Dar et al., 2017). The use of herbal medicines and phytonutrients or nutraceuticals continues to expand rapidly across the world with many people now resorting to these products for the treatment of various health challenges in different national healthcare settings (WHO, 2004). It is estimated that up to 80% of the world's population living in the developing countries rely on herbal medicinal products as a primary source of healthcare and traditional medical practice as an integral part of the culture in their communities (Ekor, 2013). The medicinal compounds derived from various plants could be divided into three major biochemical classes: alkaloids (vinblastine, vincristine, pilocarpine, berberine, caffeine, piperine etc.), flavonoids (quercetin, kaempferol, chrysin, naringenin, genistein, rutin etc.) and terpenoids (artemisinin, taxol, digitoxin, azadarachtin, camphor, limonene etc.) (Takshak, 2018). These compounds have also gained importance in the area of nutraceuticals, which have positive health effects and may prove to be advantageous in the treatment of diseases like cancer, cardiovascular diseases and diabetes (Crozier et