In Vitro Antioxidant Activity of Crude Methanolic Flavonoids from Stem Bark of Gmelina Arborea Roxb.

Hydrogen peroxide free radical scavenging assay of fractionated flavonoids of crude methanolic stem bark extract of Gmelina arborea was determined according to Ruch et al (1999). five Different concentrations, 20 kg/ml, 40 µg/ml, 60 µg/ml, 80 µg/ml and 100 µg/ml of the sample tested showed respective concentration dependent percentage free radical scavenging activity 73%, 69%, 56%, 31% and 23% the highest activity was found at 100 µg/m/ and the lowest activity at 20 µg/ml of the crude flavonoids. The result obtained was compared with that of standard antioxidant drug (ascorbic acid) using various concentrations; 20 kg/ml, 40 µg/ml, 60 µg/ml, 80 µg/ml and 100 kg/ml. Which have percentage free radical scavenging activity of 98.55%, 97.2%, 96.81, 95.8% and 94.5% respectively. From the results obtained shows that flavonoids of Gmelina arborea stem bark is a good natural antioxidant agent, which could be used for treatment of diabetics and cardio vascular diseases. It is recommended that the crude flavonoids should be screened to isolate the bioactive compounds with antioxidant activity.