In this research, the radical scavenging activity and reducing power of the ethyl acetate fraction and subfractions of Salvia mirzayanii (SM) have been investigated. The plant material was initially extracted with ethanol. The fractionation was carried out using liquid-liquid extraction, then the ethyl acetate fraction, which showed the greatest antioxidant activity, was selected. This fraction was submitted to column chromatography on a Sephadex LH 20 column eluted with pure MeOH to obtain subfractions A-G. No significant differences exist between the IC50 of Salvia mirzayanii ethyl acetate subfraction C (IC50 = 37.9 ± 0.85), F (IC50 = 40.05 ± 1.4) and quercetin (38.84 ± 0.86), (P > 0.05), indicating that the radical scavenging capacity of these two subfractions and quercetin (antioxidant standard) were similar. The reducing power of the ethyl acetate fraction was less than that of all subfractions, except for subfraction A. The greatest amount of phenolic compounds was found in subfraction E (55.23 ± 4.2) and the lowest in subfraction F (5.23 ± 0.18). The greatest total flavonoid content was established in subfraction D (1.84 ± 0.01) and the lowest was in subfraction A (0.108 ± 0.007).
Context: Glucosidases are a group of enzymes playing crucial roles in digestion of carbohydrates. Glucosidase inhibitors can reduce carbohydrate digestion rate and have the potential to prevent development of type 2 diabetes. The Labiatae is one of the largest plant families grown globally and many studies that have isolated new pharmaceutical compounds. In folk medicine, some of Labiatae plants such as Zataria multiflora Boiss, Salvia mirzayanii Rech. F. & Esfand, and Otostegia persica Boiss are consumed for the treatment of diabetes. Objectives: This study investigates the inhibitory effects of different fractions of three mentioned species extracts on α-glucosidase. Materials and methods: Ethanol extracts of these plants leaves were fractionated using petroleum ether, chloroform, ethyl acetate, and n-butanol solutions. The duration of this study was 12 months. To measure enzyme inhibition, 5 μL of the enzyme, 20 μL of substrate and samples were used and for evaluation mode of inhibition, constant amounts of α-glucosidase were incubated with rising concentrations of substrate (PNPG). Results: The results revealed that the ethyl acetate fraction of Zataria multiflora (IC50 = 0.35 ± 0.01 mg/mL) and petroleum ether fraction of Salvia mirzayanii (IC50 = 0.4 ± 0.11 mg/mL) were the most potent inhibitors of α-glucosidase in comparison with the other samples and acarbose as the standard (IC50 = 7 ± 0.19 mg/mL). All of the samples exhibited noncompetitive-uncompetitive inhibition. Discussion and conclusion: It can be inferred from this study that α-glucosidase inhibitory potential of the studied extracts may be a marker of antidiabetic potential of these extracts.
In an attempt to identify herbal drugs which may become useful in the prevention of diabetes, antioxidant potentials and α-amylase inhibition by the ethanol extracts of two plants belonging to Lamiaceae family, Otostegia persica and Zataria multiflora, and their different fractions were studied. Also, inhibition of α-amylase by Salvia mirzayanii and its fractions was evaluated. All of the samples exhibited antioxidant activities, among which ethyl acetate fraction of Zataria multiflora ( mg GAE/g) was found to contain the highest amounts of phenols and the ethyl acetate fraction of Zataria multiflora (218 ± 2.76 mg QUE/g) had the most values of flavonoids. Ethyl acetate fraction of Zataria multiflora (IC50 = μg/ml) was shown to have the most reducing power and the ethyl acetate fraction of Zataria multiflora (IC50 = μg/ml) exhibited the highest DPPH radical scavenging. The ethyl acetate fraction of Otostegia persica (%) showed the highest α-amylase inhibitory activity which was similar to acarbose used as a standard. Mode of α-amylase inhibition of the most samples was uncompetitive except for ZMC, OPP, OPC, and SMP which presented competitive inhibition. The present findings showed that studied samples may have some compounds with antioxidant and antidiabetic effects.
Juniperus excelsa M.B subsp. Polycarpos (K.Koch), collected from south of Iran, was subjected to hydrodistillation using clevenger apparatus to obtain essential oil. The essential was analyzed by gas chromatography/mass spectrometry (GC/MS) and studied for antimicrobial, antifungal and antioxidant activities. The results indicated α-pinene (67.71%) as the major compound and α-cedral (11.5%), δ3-carene (5.19%) and limonene (4.41%) in moderate amounts. Antimicrobial tests were carried out using disk diffusion method, followed by the measurement of minimum inhibitory concentration (MIC). All the Gram positive and Gram negative bacteria were susceptible to essential oil. The oil showed radical scavenging and antioxidant effects.