PHARMACOGNOSTICAL SCREENING AND DETERMINATION OF ANTIOXIDANT ACTIVITY OF NELUMBO NUCIFERA GAERTN ETHANOL SEED EXTRACT BY DIFFERENT IN VITRO MODELS

摘要

Objective: To perform the pharmacognostical screening and determination of antioxidant activity of Nelumbo nucifera Gaertn ethanol seed extract by different in vitro models. Methods: The different pharmacognostical parameters were evaluated as per standard protocols with some modifications. The various concentrations of ethanol seed extract of Nelumbo nucifera were evaluated for antioxidant activity using the standard in vitro methods like hydrogen peroxide (H 2 O 2 ) scavenging assay, nitric oxide (NO) radical scavenging assay, reducing power capacity assessment, β-Carotene bleaching assay, ferric thiocyanate method (FTC) and thiobarbituric acid (TBA) assay. Results: Extractive values, ash values and moisture content values of Nelumbo nucifera were found to be as per the IP 2007 and Ayurvedic pharmacopoeia standard. Among the four extracts viz. Petroleum ether, chloroform, ethanol and aqueous, the ethanol extract showed significant antioxidant activity. The ethanol seed extract of Nelumbo nucifera (NNSE) exhibited high antioxidant activity (IC 50 = 12.65 µg/ml) in 1, 1-diphenyl-2-picryldydrazyl (DPPH) radical scavenging assay. In FTC method the absorbance of NNSE increased slowly, which shows strong antioxidant ability. The thin layer chromatography (TLC) of the extract revealed 6 spots with the Rf values 0.41, 0.47, 0.59, 0.65, 0.67, 0.74 with the solvent system of toluene: ethyl acetate: formic acid (5:4:0.5, v/v/v). The high-performance thin layer chromatography (HPTLC) revealed the spots at Rf values 0.65 and 0.68. These fractions obtained by preparative TLC also confirmed the same. Conclusion: The present investigation suggested that the NNSE has significant antioxidant activity. These results clearly indicate that Nelumbo nucifera is effective against free radical mediated diseases, thus replacing the synthetic ones.