Comparative Study on In-Vitro Antioxidant activities by ABTS, DPPH, FRAP Assessment Methods and Phytochemical Analysis in Different Solvents Extracted from Tridax procumbens

ABSTRACT

Tridax procumbens is a wild herb distributed throughout India. It has been extensively used in the ayurvedic system of medicine for various ailments in India as it contains a major portion of polyphenols and antioxidants. This study compared the antioxidant potential and content of phytochemical constituents in different solvents (ethanol, methanol, acetone, toluene, hexane, dichloromethane, chloroform, ethyl acetate, water, 60% aqueous methanol, 60% aqueous ethanol, and 60% aqueous acetone) extracted from the whole plant of Tridax procumbens. The content of phytochemical constituents was evaluated by determining total flavonoid content (TFC), total phenolic content (TPC), total saponin content (TSC), and total tannin content (TTC) in solvent extracts. The antioxidant assessment was carried out by the 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonate) radical cation (ABTS^·+) assay, the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) assay and the ferric reducing antioxidant power (FRAP) assay methods. The highest extraction yield was found in 60% aqueous methanol while the hexane extract showed the lowest extraction yield. Methanol extract shows the highest TPC (251.64±1.87 mg GAE/g), TFC (235.87±7.57 mg QCE/g), TTC (160.11±2.07 mg GAE/g) while ethanol extract gives the highest TSC (519.18±3.11 mg ESE/g). The inhibitory concentration (IC₅₀) was found lowest in methanol extract for DPPH (2.17 ± 0.16 µg/ml), FRAP (2.81 ± 0.32 µg/ml) and ABTS (3.52 ± 0.46 µg/ml) assay. The comparative study showed the maximum correlation between total phenolic content and antioxidant potential. As methanol extract contains major phytochemical constituents which are responsible for the free radical scavenging activity showed the highest antioxidant potential hence it could serve as potential antioxidant medicine for physiological damage.