Antioxidant Activities and HPLC-DAD Based Phenolic Content Determination of Bauhinia scandens

Aim of Study: Bauhinia scandens L. (Leguminosae) is a valuable plant used for various ailments. This study investigated the in vitro antioxidant potential and quantification of selected bioactive plant polyphenol compounds of the ethanolic extracts of Bauhinias scandens (EEBS). Study Design: Assessment of antioxidant activities and HPLC-DAD based phenolic contents analysis. Place and Duration of Study: Department of Pharmacy, Gono Bishwabidyalay, Savar, Dhaka, Bangladesh, between March 2015 and February 2016. Methodology: DPPH free radical scavenging, total phenolic and total flavonoid content assay were used to evaluate in vitro antioxidant capacity. Moreover, phenolic compounds were identified and quantified by HPLC-DAD. Results: EEBS showed good free radical scavenging effects with IC50 13.5 µg/ml whereas for standard ascorbic acid, IC50 value was 8.25 µg/ml. For EEBS, total phenolic content was 47.33 ±0.01 mg GAE/gram of dry extract while total flavonoid content was 6.59 ±0.04 mg QE/g dry extract. The experimental results indicated that EEBS contained a high concentration of gallic acid, ellagic acid and rosmarinic acid (215.39, 72.24 & 50.96 mg/100 g of dry extract, respectively). Vanillin was also detected at moderate concentration in EEBS (39.85 mg/100 g of dry extract). Vanillic acid and syringic acid were also detected at lower concentration (12.34 & 17.15 mg/100 g of dry extract, respectively). Conclusion: Experimental results suggest that ethanolic extracts of Bauhinias scandens contain high amount of phenolic constituents which could be responsible for the biological activities of this plant extract.