Rapid extraction of andrographolide from Andrographis paniculata Nees by three phase partitioning and determination of its antioxidant activity

Three phase partitioning (TPP) process was developed for recovery of andrographolide (AP) from the leaves of Andrographis paniculata. AP is a potent anti-inflammatory agent and possesses antioxidant, anticarcinogenic and antidiabetic activity. Optimization of TPP process parameters such as pH, ammonium sulfate saturation, slurry to t-butanol ratio, time and solid to solvent ratio on the extraction efficiency was performed for enhanced yield of AP. Under optimum conditions of extraction (40% w/w ammonium sulfate, 120 min time, pH 7, 1:40 solute to solvent, 1:1 slurry to t-butanol ratio, 40 °C) the maximum AP yield of 26.55 mg/g was obtained. Considering soxhlet extraction as the reference for comparison, TPP showed 62.5% yield in 120 min whereas batch extraction produced 59.89% yield in 140 min. To investigate the antioxidant potential of A. paniculata extract, an in vitro assay (2,2-diphenyl-1-picrylhydrazyl assay) of t-butanol and aqueous layer was performed. Also total phenolic content of both the layers were determined using Folin Ciocalteu reagent. Total phenolic content and antioxidant activity of t-butanol layer was higher as compared to aqueous fraction. A positive correlation of R2=0.988 between total phenolic content and % scavenging of t-butanol layer was observed. The result showed that t-butanol extract of A. paniculata exhibited high antioxidant activity and has the potential to be used as a source of natural antioxidant.