Screening of different extraction methods for maximum production of total flavonoids, tannins, and antioxidants from Centella asiatica

The study was carried out to maximise the extraction efficiency of different extraction methods and evaluate the total flavonoid, tannin, and antioxidant activity of the wellknown medicinal herb Centella asiatica. A total of nine extraction methods were used viz. squeezing of fresh leaves, extraction of fresh leaves and oven-dried powder using boiled water, ethanol, methanol, and acetone as solvents, respectively. Different in vitro assays were used to maximize the extraction of total flavonoid content, and total tannin content. The antioxidant activities in terms of total phenolic content (TPC), DPPH(1,1-Diphenyl-2- picrylhydrazyl) radical scavenging assay, and ferric reducing antioxidant power (FRAP) of C. asiatica were also evaluated. The extract from oven-dried powder using 70% acetone exhibited the maximum flavonoid (3.0533±0.1069 mg QE/g) and tannin content (0.7800±0.0100 mg TAE/g). The powder extract using 70% acetone also exhibited the highest total phenolic content (13.883±0.050 mg GAE/g), DPPH (70.630±2.310%) and FRAP value (166.670±2.260 mg AAE/100g). The acetone extract of dried C. asiatica powder was found to be the best extraction procedure for tannin, total flavonoids, and antioxidant production. The findings of this study might be helpful in extracting natural antioxidants from C. asiatica and improve the existing literature.