Antioxidant Activity and Total Phenolic Content of Gagea fibrosa and Romulea romiflora

Abstract

Free radicals involved in a number of diseases due to the oxidative damage to DNA, lipids, and proteins and which can result in failure of cellular functions. Dried plant bulbs and leaves methanolic and ethanolic extracts were prepared. Total antioxidant activities of the methanolic extracts of Romulea ramiflora and Gagea fibrosa were determined using beta-carotenlinoleic acid assay. Romulea-Bulb-Ethanol (RBE) extract showed the highest (89.64 +/- 1.25%) but, Romulea-Leaves-Ethanol (RLE) extract showed the lowest (33.23 +/- 1.13%) antioxidant activity. The lowest antioxidant activity of the Gagea leaves extract (GLE - Gagea-Leaves-Ethanol, 46.18 +/- 0.09%) was higher (p < 0.05) then Romulea Leaves Extract (RLE -33.23 +/- 1.13%). This may be related with the structure of the plant's leaves cells. The DPPH radical scavenging assay was used to determine the antiradical activities. Gagea-Leaves-Methanol extract (GLM -61.16 +/- 1.46%) has higher DPPH radical scavenging activity than Romulea-Bulb-Methanol extract (RBM -51.27 +/- 0.94%). Generally leaf extracts have the highest free radical scavenging activity. The total phenolic content of extracts was determined using to the Folin-Ciocalteu method. RBE has the highest phenolic content (74,12 +/- 4,6 mg/100 g plant extract). R. ramiflora and G. fibrosa have the antioxidant and free radical scavenging activities. These properties are due to the number of the hydroxyl groups of the phenolic compounds, but not amount of them.