Antioxidant Properties and Phenolic Composition of Salvia virgata from Turkey

Several biochemical reactions generate reactive oxygen species and these are capable of damaging crucial bio-molecules (1). Free radicals are very important in food products, because oxidative degradation of lipids is one of the main factors limiting their shelf-life (2). In recent years, natural antioxidants have been focused on because of the harmful effects of synthetic antioxidants (3). S. officinalis L. (Lamiaceae), is an important source of antioxidants used and have wider implications for the dietary intake of natural antioxidants (3). Turkey is an important country for Salvia species. The flora of Turkey includes 88 species of the genus Salvia.

The 70% methanol and water extracts were prepared from the aerial parts of S. virgata Jacq. collected from Bursa, Turkey. All the extracts were analyzed by HPLC and in in vitro antioxidant assays. The 1,1-diphenylpicrylhydrazin (DPPH°), 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS⁺°) radical scavenging activity and β-carotene bleaching methods were used. Total phenolic compounds and reductive activity of the extracts were also analyzed. BHT, BHA, ascorbic acid, gallic acid and rosmarinic acid were used as positive controls.

Phenolics rich extract of aq. methanol showed more scavenging activity on DPPH° than water extract whereas water extract more scavenged the ABTS⁺° radical. The aq. methanol extract more reduced the ferric(III) to ferro(II) in a certain proportion than water extract. All extracts were inhibited linoleic acid peroxidation in β-carotene bleaching test and shown more activity than rosmarinic acid. Rosmarinic acid was found as the main component and caffeic acid, ferulic acid and luteolin-7-O-glycoside were identified in the extracts.

References: 1. Kumaran A, Joel Karunakaran R (2006) Food Chem 97: 109–114.

2. Pizzalle L et al. (2002)J Sci Food Agric 82: 1645–1651.

3. Kintzios SE (2000) Sage The Genus Salvia. Harwood Academic Publishers, 27–53 and 185–192.