Essential oil composition of the aerial parts of fresh and air-driedSalvia palaestinaBenth. (Lamiaceae) growing wild in Jordan

Chemical composition, cholinesterase, and α-glucosidase inhibitory activity of the essential oils of some Iranian native Salvia species

BACKGROUND

The plants from Salvia genus contain widely distributed species which have been used in folk medicine as well as pharmaceutical and food industries.

METHODS

The chemical composition of 12 native Iranian Salvia species (14 plants) was identified using gas chromatography-mass spectrometry (GC-MS). Also, the inhibitory activity of all essential oils (EOs) was evaluated toward α-glucosidase and two types of cholinesterase (ChE) using spectrophotometric methods. The in vitro α-glucosidase inhibition assay was performed by the determination of p-nitrophenol (pNP) obtained from the enzymatic dissociation of p-nitrophenol-α-D-glucopyranoside (pNPG) as the substrate. In vitro ChE inhibitory assay was conducted based on the modified Ellman's procedure using the measurement of 5-thio-2-nitrobenzoic acid produced from the hydrolysis of thiocholine derivatives as the substrate, in the presence of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE).

RESULTS

Totally, 139 compounds were detected and caryophyllene oxide and trans-β-caryophyllene were the most abundant compounds in all EOs. The yield of EOs extracted from the plants were also calculated in the range of 0.06 to 0.96% w/w. Herein, α-glucosidase inhibitory activity of 8 EOs was reported for the first time and among all, S. spinosa L. was found to be the most potent inhibitor (90.5 inhibition at 500 μg/mL). Also, the ChE inhibitory activity of 8 species was reported for the first time and our results showed that the BChE inhibitory effect of all EOs was more potent than that of AChE. The ChE inhibition assay indicated that S. mirzayanii Rech.f. & Esfand. collected from Shiraz was the most potent inhibitor (72.68% and 40.6% at the concentration of 500 μg/mL, toward AChE and BChE, respectively).

CONCLUSIONS

It seems that native Salvia species of Iran could be considered in the development of anti-diabetic and anti-Alzheimer's disease supplements.

Essential Oil Compositions of Two Populations of Salvia samuelssonii Growing in Different Biogeographical Regions of Jordan

The composition of the essential oils of flowering aerial parts of Salvia samuelssonii Rech. fil. (Lamiaceae Section Aethiopis), collected in two different biogeographical regions, has been analyzed. Sample1, collected in a Mediterranean-like region, “As-Subayhi”, contains mainly monoterpenes (54.2%), sesquiterpenes (27.6%) and phenylpropanoids (10.5%), while sample 2, collected in the Irano-Turanian region, “Al-Adasiyyah”, contains mainly phenylpropanoids (30.6%), monoterpenes (24.9%) and sesquiterpenes (21.2%). In Sample1, the most representative constituents were sabinene (21.5%), cis-chrysanthenyl acetate (20.8%), germacrene D (9.3%) and myristicin (5.9%), while in sample 2, myristicin (24.1%), sclareoloxide (6.3%), and germacrene D (5.7%) were main constituents. The rate of oxygenated derivatives in the Irano-Turanian sample was higher than the Mediterranean sample. Myristicin is an unusual constituent of Salvia species.