In vitro antioxidant and antimicrobial assays of acetone extracts from Nepeta meyeri Bentham.

Abstract

BACKGROUND AND OBJECTIVIES: Nepeta species are used as diuretic, diaphoretic, antitussive, antispasmodic, antiasthmatic, febrifuge, emmenagogue, sedative agents, insecticidal, acaricidal, antiviral, anti-inflammatory and antioxidant. Acetone extract of Nepeta meyeri (Labiatae) was screened for antioxidant and antimicrobial activities. The antioxidant prop erties of the extract were investigated by using various methods established in vitro systems such as 1,1-diphenyl-2-picrylhydrazyl (DPPH)/nitric oxide (NO) radical scavenging activity. Reducing power and total phenolic substance analysis and also antimicrobial activity of acetone extract of Nepeta meyeri were tested against six gram negative, seven gram positive bacteria and the yeast strain using the disc diffusion method. Acetone extract of the plant examined exhibited a significant concentration-dependent inhibition of DPPH and NO* radical. Furthermore, Nepeta meyeri showed very high reducing power. In DPPH radical and NO* scavenging assays the IC50 value of extract was 672.2 microg/ml and 165.32 microg/ml, respectively. The amounts of total phenolic compounds were also determined and 12.86 microg pyrocatechol equivalents of phenols were detected in the extract. The data obtained from these in vitro models clearly demonstrated antioxidant potential of acetone extract of Nepeta meyeri. The extract revealed antibacterial activity against all gram positive bacteria but not was active against gram negative bacteria.