Pyrus pashia: A persuasive source of natural antioxidants

Pyrus pashia Buch. & Ham. was subjected to extraction with methanol. Methanolic extracts of fruit, bark and leaf were partitioned separately with four organic solvents in order of increasing polarity, asn-hexane, chloroform, ethyl acetate and n-butanol after dissolving in distilled water. Phytochemical screening revealed the presence of phenolics, flavonoides, alkaloids and cardiac glycosides in large amount in chloroform, ethyl acetate and n-butanol soluble fractions. The antioxidant activity of crude methanolic extracts, all the obtained fourorganic fractions and remaining aqueous fractions was evaluated by different methods such as: 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity, ferric reducing antioxidant power (FRAP) assay and total antioxidant activity by phosphomolybdenum complex method as well as determination of total phenolics. The results of antioxidant activity exhibited that chloroform soluble fraction of fruit showed the highest value of percent inhibition of DPPH (48.16 ± 0.21 μg/ml) at the concentration of 10 μg/ml. Ethyl acetate soluble fraction displayed the lowest antioxidant activity having IC50 value of bark as (8.64 ± 0.32 μg/ml) relative to butylated hydroxytoluene (BHT), having IC50 of 12.1 ± 0.92 μg/ml. The ethyl acetate soluble fraction of bark revealed the highest FRAPs value (174.618 ± 0.11TE µM/ml) among all the three parts. This fraction also showed the highest value of total antioxidant activity as (1.499 ± 0.90), determined by phosphomolybdenum complex method. Moreover, this fraction also conferred the highest phenolic content (393.19 ± 0.72) as compared to other studied fractions of fruit and leaf.