Antioxidant capacity, antibacterial activity and β sitosterol isolated from chloroform fraction of root extracts of Parkinsonia aculeata

Abstract

Parkinsonia aculeata is alarge spinous shrub or small tree belonging to family Fabaceae. Ethyl acetate and n-butanol extract of plant were evaluated for total phenolic and flavonoid content, antibacterial and antioxidant activity by four complementary test systems, namely 2,2-diphenyl-1-picrylhydrazyl (DPPH), hydrogen peroxide, reducing power and ferrous ion-chelating assay. The crude chloroform extract of Parkinsonia aculeata roots was subjected to column chromatography for separation and isolation of β sitosterol. Phytochemical screening of plant roots extracts revealed the presence of alkaloids, flavonoids, phenolic, amino acids, carbohydrates, steroids and triterpenoids.In DPPH, hydrogen peroxide and ferrous ion-chelating assay, IC50 value of ethyl acetate extract was 60.97, 59.51, 444.09 µg/ml and n-butanol extract was236.14, 80.324, 345.24 µg/ml respectively. Further, the extract showed inhibitory activity for gram positive (Staphylococcus aureus, Bacillus subtilis) and gram negative (Escherichia coli, Pseudomonas aeruginosa) bacteria at different concentration. The maximum antibacterial activity of chloroform extract was exhibited against B. subtilis at concentration 16 µg/ml when compared with amoxicillin. The isolation and purification afforded white crystalline powder, which was subjected to physical and chemical identification by melting point and TLC.The compound was concluded as β‐sitosterol described for the first time in the root extract ofParkinsonia aculeata.The results clearly indicate that P. aculeata roots are effective in scavenging of free radicals and have the potential powerful antioxidant. Thus the result obtained in the present study indicates that P. aculeata roots extract could be considered as a potential source of natural antioxidant and that could be used as an effective source against bacterial diseases.