Free radicals, species with one or more unpaired electrons, are produced in normal or pathological cell metabolism, from xenobiotics, or through ionising radiation. Electron acceptors such as O2 react easily with free radicals generating reactive oxygen species (ROS). The primary derivatives of oxygen are superoxide anion radicals (O2.-), hydrogen peroxide (H2O2), hydroxyl radicals (.OH) and the single oxygen (1O2). ROS are continuously generated in cells exposed to an aerobic environment, and have been associated with many diseases. Thus, antioxidant defence systems have co-evolved with aerobic metabolism to counteract oxidative damage from ROS. Antioxidant enzymes such as superoxide-dismutase (SOD), peroxidase (P-ase) and catalase (C-ase), as well as some other natural antioxidants constitute a system that keeps ROS at low concentrations. Recent investigations showed that the antioxidant properties of plants could be correlated with oxidative stress defence and different human diseases including cancer, atherosclerosis and the ageing process.
According to the Kew Index the genus Salvia (Lamiaceae) comprises of more than 900 species, widespread all over the world. In the flora of Serbia, 15 species of this genus have been described. Salvia reflexa Hornem. is a new plant species, spreading in the region. It is an adventive plant growing as weed in row crops and ruderal vegetation along roads. S. reflexa is still phytochemically and pharmacologically almost uninvestigated. Therefore the aim of this study was to investigate its antioxidant properties in order to evaluate its medicinal value and to point to easy accessible natural antioxidants source that could be used as a possible food supplement or in cosmetics and pharmaceutical industry.
The aboveground parts of S. reflexa were collected during full blossoming in Summer 1998, at the locality Kavilo in north Vojvodina (Serbia).
In this study, the quantities of O2.- and .OH radicals, malonyl dialdehyde (MDA), reduced glutathione (GSH) and content of total flavonoids were determined, as well as the activities of antioxidant enzymes SOD and P-ase. The potential antioxidant activity of the test sample has been assessed based on scavenging activity of the stable DPPH free radicals. In addition, a phytochemical screening for secondary biomolecules presence was performed.
The results presented in our study show that Salvia reflexa Hornem. were exposed to the negative influence of ROS but it also possesses effective antioxidant ability indicating its possible medicinal and industrial value.