In vitro antioxidant activity of hydro alcoholic extract from the fruit pulp of Cassia fistula Linn

The present study is aimed to investigate antioxidant activity of the extracts of Cassia fistula Linn. (Leguminosae) fruit pulp. Cassia fistula Linn., a Indian Laburnum, is widely cultivated in various countries and different continents including Asia, Mauritius, South Africa, Mexico, China, West Indies, East Africa and Brazil as an ornamental tree for its beautiful bunches of yellow flowers and also used in traditional medicine for several indications. The primary phytochemical study and in vitro antioxidant study was performed on hydro alcoholic extract of fruit pulp. Phytochemical screening of the plant has shown the presence of phenolic compounds, fatty acids, flavonoids, tannins and glycosides. Phenolic content was measured using Folin-Ciocalteu reagent and was calculated as gallic acid equivalents. Antiradical activity of hydro alcoholic extract was measured by DPPH (2,2-diphenyl-1- picrylhydrazyl) assay and was compared to ascorbic acid. Ferric reducing power of the extract was also evaluated by Oyaizu method. In the present study, three methods were used for evaluation of antioxidant activity. First two methods were for direct measurement of radical scavenging activity and third method to evaluate the reducing power. Results indicate that hydro alcoholic fruit pulp extracts have marked amount of total phenols which could be responsible for the antioxidant activity. These in vitro assays indicate that this plant extract is a significant source of natural antioxidant, Cassia fistula fruit pulp extract shows lower activity in DPPH and total phenol content as compared with standard which might be helpful in preventing the progress of various oxidative stresses.