Evaluation of free radical scavenging activity of an ayurvedic formulation, Panchvalkala
1Department of Pharmacognosy and Phytochemistry, B. V. Patel Pharmaceutical Education Research Development (PERD) Centre, Thaltej, Ahemdabad - 380 054, India 2Department of Biosciences, South Gujarat University, Surat - 395 007, India
M Rajani, Department of Pharmacognosy and Phytochemistry, PERD, India, E-mail: [email protected]
We report the free radical scavenging activity of an Ayurvedic preparation Panchvalkala and its individual components (stem bark of Ficus benghalensis , F. glomerata , F. religiosa , F. virens and Thespesia populnea ). Being stem barks, these samples contain phenolics (ranging from 3.5% to 10.8% w/w) and tannins (1.6% to 7.0% w/w). This prompted us to study the free radical scavenging activity of Panchvalkala and its components which was evaluated in three in vitro models viz . 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity, superoxide radical scavenging activity and reducing power assay. Panchvalkala and its individual components showed significant antiradical activity by bleaching 1,1-diphenyl-2-picrylhydrazyl radical (EC 50 ranging from 7.27 to 12.08 µg) which was comparable to pyrogallol (EC 50 4.85 µg). Thin layer chromatography of the methanol extracts when sprayed with 0.2% 1,1-diphenyl-2-picrylhydrazyl in methanol revealed several bands with antiradical activity as seen by bleaching of 1,1-diphenyl-2-picrylhydrazyl. All the samples showed good superoxide scavenging potential (EC 50 ranging from 41.55 to 73.56 µg) comparable to ascorbic acid (EC 50 45.39 µg) in a dose-dependent manner. The reduction ability, Fe 3+ to Fe 2+ transformation was found to increase with increasing concentrations of all the sample extracts.