Comparative study of total phenolic content and antioxidant activity of Nepeta pogonsperma hexane and hydroalcoholic extracts

The genus Nepeta (Lamiaceae) comprises ۲۸۰ species that are distributed over a large part of central and southern Europe, and west, central, and southern Asia. About half of the existing species are recorded in Iran [۱]. Nepeta species are widely used in folk medicine because of their antispasmodic, diuretic, antiseptic, antitussive, antiasthmatic, and febrifuge activities. The feline attractant properties of several Nepeta species have been known for a long time [۲]. This study was designed to examine the total phenolic content and in vitro antioxidant activity of the various extracts of Nepeta pogonsperma including hexane and hydroalcoholic extracts. The amounts of total phenolics solvent extracts for the aerial parts of plant were determined spectrometrically. According to the obtained results hydroalcoholic extract of the plant showed higher phenolic content with ۱۸۹.۷ mg Gallic acid equivalents per gram extract, while the hexane extract was found to contain lower amounts of phenolic compounds (۵۹.۵ mg GAEs/g extract). Antioxidant activities and phytochemical compositions of the extracts were found to be in correlation with each other. The higher phenolic compounds containing hydroalcoholic extracts also possess higher antioxidant activity. Phosphomolybdenum assay were used for measuring the antioxidant activities of the extracts. Total antioxidant activities of N. pogonsperma hydroalcoholic and hexane extracts were found to be ۷۶.۸ and ۴۱.۴ mg AAEs/g extract, respectively. The prepared extracts of the plant were also analyzed for their radical scavenging activities on DPPH radicals.

Keywords:

Extract , Medicinal plants , Nepeta