The essential oils and extracts obtained from many plants have recently gained popularity and scientific interest because of their uses in the food, drug, and perfumery industries [1]. Scientists have been interested in biologically active compounds isolated from plant species for the elimination of pathogenic microorganisms because of the resistance that they have built against antibiotics [2]. Plant products could be useful in preserving food storages from contamination [3], whereas the synthetic antioxidants that have been used previously are now toxicologically suspect [4, 5].

Salvia, the largest genus of Lamiaceae. Sixty species of the genus Salvia are found in Iran, of which 17 are endemic.

Salvia limbata C. A. Mey. is a native plant of Iran. Some members of this genus are of economic importance since they have been used as flavoring agents in perfumery and cosmetics. For example, clary sage (S. sclarea) is commercially cultivated and its essential oil is widely used as flavoring [6]. Meadow sage (S. pratensis) is used in cosmetics and has some medicinal properties [7].

Some of the phenolic compounds or essential oils of plants belonging to this genus have also shown excellent antimicrobial activity [8] and scavenging ability against active oxygen radicals [9], as well as inhibiting lipid peroxidation [10]. Consequently, the corresponding extracts have been used to stabilize fat and fat-containing foods [11]. The antioxidant activity of various species of Salvia has been reported previously [12–15].

As far as our literature survey could ascertain, the antimicrobial and antioxidant activities of essential oil and various extracts of Salvia limbata have not been published previously, although there are some reports on the essential oil composition [16 – 18] and norsesterterpenes and diterpenes isolated from this species [19, 20].

In the present study, the antimicrobial and antioxidant capacities of the essential oils and various extracts of S. limbata from two different regions in Iran (Takab and Mashhade Ardehal) are investigated.

The aerial parts of S. limbata C. A. Mey. were collected during the flowering stage in July 2003 from Takab (West Azerbaijan province, SL1) and Mashhade Ardehal (Kashan province, SL2).

The air-dried and ground aerial parts of plants (120 g) were subjected to hydrodistillation for 3 h using a Clevenger type apparatus. The oils were obtained in 0.08% and 0.24% (w/w) yields for the SL1 and SL2 samples, respectively. The essential oils were dried over anhydrous Na2SO4 and stored at 4°C until tested and analyzed (Table 1 and 3) [21].

TABLE 1. Chemical Composition of the Essential Oils of Salvia limbata*, %
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TABLE 3. Antimicrobial Activity of the Oils and Their Main Components of Two Samples of Salvia limbata
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Ten grams of air-dried and powdered plants were extracted with methanol at room temperature for 24 h. After evaporation of the solvent under reduced pressure, the remaining crude materials (M) were suspended in water and extracted with n-hexane to yield water soluble (M-W) and water insoluble (M-H) subfractions (Table 2) [22].

TABLE 2. Antioxidant Activities of Various Extracts of S. limbata against DPPH (IC50) [22]
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Chemical Composition of the Essential Oils. The chemical composition of the essential oil of S. limbata obtained from two different locations is summarized in Table 1, where all compounds are listed in order of their elution from DB-1 column. As shown, 46 and 56 components representing 96.2% and 98.7% of the total oils obtained from SL1 and SL2 samples were characterized, respectively. α-Pinene (24.4%), β-pinene (21.9%), and 1,8-cineole (7.7%) were the major compounds in SL1, while in SL2, trans-caryophyllene (9.9%), 1,8-cineole (9.2%), and spathulenol (8.1%) were found to be the most abundant constituents. Thirty-four compounds were common in both samples; however, in some cases considerable difference in the percentages was observed. For example, α-pinene and β-pinene were found in a total amount of 46.3% in SL1 while they amounted up to 9.6% in SL2. Several compounds were also found in only one of the two samples, of which α-terpineol (0.8%) in SL1 and sclareol (4.9%) and viridiflorol (4.0%) in SL2 were the most outstanding examples.

In a recent paper, the oils of S. limbata collected from two areas in eastern Turkey were reported to contain α-pinene (11.2–24.3%), β-pinene (10.0–20.9%), and sabinene (14.6–17.4%) as the major constituents [16]. Mirza et al. identified 26 compounds in the essential oil of S. limbata and reported germacrene D (25.7%), linalyl acetate (16.1%), and linalool (17.5%) as the major components [17]. These differences might have been derived from local, climatic, and seasonal factors.