The dried extract was dissolved in respective solvents prior to assay. The total phenolic content (mg of catechin/1 mg) was determined

using Folin–Ciocalteu reagent5 and total flavonoid content (catechol equivalents/1 mg) was determined by aluminium chloride method.6 The reductive ability of the extracts was determined by potassium ferricyanide reduction method.7 The hydrogen or electron donation ability of the plant extracts was measured from bleaching of the purple colour of DPPH.8 Scavenging activity of extracts on superoxide anion radicals was determined based on the reduction of nitroblue tetrazolium (NBT).9 Hydroxyl radical scavenging and the ferrous ion-chelating potential of the extracts were measured following deoxyribose assay10 and ferrozine assay11 respectively. Thiobarbituric acid reactive substance assay 3-Methyladenine supplier was employed FRAX597 clinical trial to determine anti-lipid peroxidation assay using goat liver homogenate.12 All analyses were carried

out in triplicates. Data were presented as mean ± SD. Radical scavenging activity of extracts was expressed in terms of percentage of inhibition. DPPH, superoxide radical scavenging, hydroxyl radical scavenging and metal ion-chelating assay were calculated using the following equation: % Inhibition = (Absorbance of control − Absorbance of sample)/Absorbance of control × 100, and the anti-lipid peroxidation percentage was calculated using the formula: % ALP = (Absorbance of Fe2+ induced peroxidation-Absorbance of sample)/Absorbance of Fe2+ induced peroxidation-Absorbance of control × 100. The IC50 value was determined using Easy Plot software. The total phenolic contents of aqueous and methanolic extracts of A. solanacea leaves were 0.030 ± 0.01 and 0.040 ± 0.02 mg of catechin equivalents/1 mg dried extract respectively and the corresponding flavonoid contents were 0.257 ± 0.02 and 0.404 ± 0.03 mg of catechol equivalents/1 mg dried aqueous and methanolic extracts. Both the extracts showed powerful reducing power that increased linearly with concentration. The methanolic extract demonstrated powerful reduction

potential as compared to aqueous extract (Fig. 1). The IC50 values of methanolic and aqueous extracts for DPPH radical scavenging activity were 198.43 ± 1.30 over and 378.67 ± 2.5 μg/ml (Fig. 2) respectively which showed a marked difference with ascorbic acid standard (IC50 = 7.6 ± 0.20 μg/ml). The methanolic extract exhibited superoxide radical scavenging activity (Fig. 3) with an IC50 value of 1634. 97 ± 4.08 μg/ml and showed a significant difference when compared with butylated hydroxy anisole (IC50 value of 23.6 ± 0.86 μg/ml). The percentage inhibition of hydroxyl radical scavenging activity of the aqueous and methanolic extracts was found to be 62.81% and 92.89% respectively at 2000 μg/ml. Compared to all the other assays, at the lowest concentration (25 μg/ml) tested, the methanolic extract of A. solanacea was the one that showed higher (86.71%) free radical scavenging ability.