13Fr e e R a d . A n t i ox .Re s e a r c h A r t i c l e West Bengal, apdas.nbu@gmail.com; senarnab_nbu@hotmail.com
INTRODUCTIONOxygen plays a vital role in the survival of life on earth. However, during it's utilization in various life processes, a tiny amount of oxygen gets reduced to different free radicals like hydrogen peroxide, superoxide, nitric oxide, hydroxyl radicals etc. [1,2] All these reactive oxygen radicals are accountable for various health hazards to human life causing the development of degenerative diseases.[3] Antioxidant molecules, on the other hand, can slow down or cease the activity of these harmful oxygen species by being oxidizing themselves. Plants often contain good amount of natural antioxidants. [4,5] Different phytochemicals like phenols, flavonols, carotenoids, proanthocyanidins, vitamin C and E can be utilized to scavenge the excess free radicals from human body. [6] Canna edulis Ker Gawler, is a medium sized perennial flowering plant found in the north eastern Himalayan regions of India.[7] The plants bear broad, flat, blackish green leaves with spectacular red flowers. Besides, it also tickles our test buds as it is known to be edible and mainly consumed by the Indian tribes like Lepchas, Bhutias and Nepalis. [8] Different parts of the plants like rhizomes, leaves and seeds are used as medicines by the tribal communities of North eastern India.[9] Amongst various plant parts the extracts of rhizomes are rich source of polyphenolic compounds like phenols and flavonoids, [10] which in turn provide the evidences of antioxidative properties of the plant.
ABSTRACT
Introduction:Canna edulis Ker Gawler, grown in the sub Himalayan region containing starchy rhizome are used by the tribal people as food and herbal medicine. Methods: Investigations were done to find out 2,2-diphenyl-1-picryl hydrazyl (DPPH) radical scavenging activity, total flavonols and total proanthocyanidin contents, nitric oxide (NO) scavenging activity, hydroxyl radical scavenging activity of different solvent fractions of aquous extract of C. edulis rhizome. Among the cellular molecules, lipids containing unsaturated fatty acids with more than one double bond are particularly susceptible to action of free radicals. The resulting reaction, known as lipid peroxidation and anti lipid peroxidation activity has been performed using goat liver homogenate. Results: Six out of 29 fractions showed DPPH free radical inhibition above 75% and were used for further phytochemical screening. Diethyl ether : ethyl acetate (1:3) fraction showed the maximum inhibition percent. Highest amount of total flavonol and total proanthocyanidins were recorded in diethyl ether : ethyl acetate (1:3) fraction. Maximum NO scavenging activity and hydroxyl radical inhibition activity were observed in bioactive diethyl ether : ethyl acetate (1:1) fraction. Inhibition of lipid peroxides was maximum in ethyl acetate fraction. Data from thin layer chromatography (TLC) revealed the presence of phenolic compounds in all fractions, whereas flavono...