Oxidative stress (OS) is the imbalance between cellular production of reactive oxygen species (ROS) and the ability of cells to scavenge them. OS has been implicated as a potential contributor to the pathogenesis of several diseases, such as cancer, diabetes and heart disease. ROS cause the damage of many cellular components including lipids, proteins and nucleic acids, such as DNA leading to subsequent cellular death by modes of necrosis or apoptosis. The damage can become more widespread due to weakened cellular antioxidant defense systems. All biological systems have antioxidant defense mechanism that protects against oxidative damages and repairs enzymes to remove damaged molecules. However, this natural antioxidant mechanism can be inefficient, hence dietary intake of antioxidant compounds is important. Consumption of fruits and vegetables is known to lower the risk of several diseases, such as cancer, cardiovascular diseases and stroke caused by OS and such health benefits are mainly imposed due to the presence of phytochemicals, such as polyphenols, carotenoids and vitamin E and C.
Although the phenolic compounds are commonly found in both edible and non edible herbs, cereals, fruits, vegetables, oils, spices and other plant materials[5, 6], scientific information on antioxidant properties of endemic plants, limited to certain regions and known only by local populations, is still rather scarce. Therefore, the assessment of such properties remains an interesting and useful task, particularly to find new promising sources of natural antioxidants for functional foods and/or nutraceuticals[6, 7].
Morus alba (locally known as Tut, commonly known as white mulberry, family: Moraceae) has been domesticated over thousands of years and adapted to the wide area of tropical, subtropical, and temperate zones of Asia, Europe, North and South America, Africa and India. It is extensively cultivated for leaf yield in sericulture. Tut fruits contain phenolics and flavonoids contents, vitamin, fat (mainly linolic acid, palmitic acid, oleic acid) and minerals, and its leaves have fixed oil, carbohydrate, protein, tannin, alkaloids, sterol, flavonoids, glycosides and saponin[10, 11]. Fruits, root and stem barks and leaves of Tut plant have been used in the treatment of inflammation, jaundice and hepatitis, cancer, diabetes, dislipidemia, diarrhoea, dyspepsia, edema, fever, headache, hypertension, purgative, anthelminthic and wounds[12–15]. Leaves of Tut plant have been reported to use in the treatment of depression, anxiety, cerebral ischemia, hepatic disease, cancer, diabetes, dislipidemia and ulcer[10, 16–20]. However, there are only few reports on antioxidant activities of different parts of Tut plant. Therefore, in this study, we evaluated the comparative antioxidant activity of methanolic extractives from different parts of Tut plant and made a statistical correlation between phenolic contents and antioxidant activity.