Moonmun, et al.: Antioxidant and Antibacterial Activity of Heliconia rostrataRhizomes of Heliconia rostrate, (family: Heliconiaceae) have been well known for antiophidic property. Ethnobotanically, rhizome of this plant has also been used to cure jaundice, intestinal pain and hypertension. This study aimed at evaluating the antioxidant and antimicrobial potency of two extracts of rhizomes of H. rostrata to find out the one, which exhibited better activity. Methanol and ethanol extract of the dried and defatted rhizomes were prepared and were subjected to qualitative and quantitative estimation of phytoconstituents, antioxidant assay and antibacterial evaluation. The methanol extract was found to give better yield than the ethanol extract. All phytoconstituents detected in the methanol extract were found in the ethanol extract also except for the glycoside content, which was found only in the methanol extract. Total phenolic and flavonoid content was higher in the ethanol extract compared to the methanol extract, whereas total tannin content was higher in the methanol extract. Both ethanol and methanol extracts exhibited antioxidant and antibacterial potency. The antioxidant activities of both extracts were found to be equal, while the ethanol extract exerted significantly higher antibacterial activity compared to the methanol extract.
Key words: Heliconiaceae, rhizome, phytoconstituents, antioxidant, antimicrobialMedicinal plants offer alternative therapies with spectacular opportunities [1] . Heliconia rostrata, popularly known as false bird of paradise and hanging lobster claw (family: Heliconiaceae) is a shrub that is reported to contain calcium, nitrogen, potassium, magnesium, iron, phosphorous, chlorine, sulphur, sugar, carbohydrate, starch and protein [2] . This plant is reported to be well known for antiophidic property [3] . Ethnobotanically, the traditional people of Malaysia used these rhizomes to cure jaundice, intestinal pain and hypertension [4] . However, not much of experimental evidence was documented.Oxygen, the most important component for the survival of living being is highly reactive and can do serious damage to healthy cells of the body as a free radical. Oxidation produces free radicals, which can start chain reactions in the cell leading to cell damage and even cell death [5] . An antioxidant terminates these radical reactions by removing free radical intermediates, which causes ageing and disease like atherosclerosis, cancer, cardiovascular diseases and CNS disorders [6] thus, play a vital role in inhibiting or delaying the oxidation at the cellular level [7] . Synthetic antioxidants, butylatedhydoxytoluene (BHT), butylatedhydroxyanisole (BHA) and tert-butyl hydroquinone (TBHQ) are being evaluated in many countries for their potential health hazard and have been found to promote liver damage and causing cancer to laboratory animals [8] . In comparison, the plant sources prove to have less or no side effect [6] , thus channelizing the interest towards the nature for antioxidant potency.Re...