Phytofabrication of Silver Nanoparticles (AgNPs) with Pharmaceutical Capabilities Using Otostegia persica (Burm.) Boiss. Leaf Extract

In the last years, the plant-mediated synthesis of nanoparticles has been extensively researched as an affordable and eco-friendly method. The current study confirms for the first time the capability of the Otostegia persica (Burm.) Boiss. leaf extract for the synthesis of silver nanoparticles (AgNPs). The phytofabricated AgNPs were characterized by ultraviolet–visible spectroscopy (UV-Vis), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and zeta potential analysis. Moreover, the total phenolic and flavonoids contents, and the antioxidant, antibacterial, antifungal, and anti-inflammatory properties of the phytofabricated AgNPs and the O. persica leaf extract were assessed. The results showed that the produced AgNPs were crystalline in nature and spherical in shape with an average size of 36.5 ± 2.0 nm, and indicated a localized surface plasmon resonance (LSPR) peak at around 420 nm. The zeta potential value of −25.2 mV pointed that the AgNPs were stable. The phytofabricated AgNPs had lower total phenolic and flavonoids contents than those for the O. persica leaf extract. The abovementioned AgNPs showed a higher antioxidant activity as compared with the O. persica leaf extract. They also exhibited significant antibacterial activity against both Gram-positive (Staphylococcus aureus, Bacillus subtilis, and Streptococcus pyogenes) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, and Salmonella typhi) bacteria. In addition, appropriate antifungal effects with the minimum inhibitory concentration (MIC) values of 18.75, 37.5, and 75 µg mL−1 against Candida krusei, Candida glabrata, and Candida albicans, respectively, were noted for this new bionanomaterial. Finally, the phytofabricated AgNPs showed dose-dependent anti-inflammatory activity in the human red blood cell (RBC) membrane stabilization test, being higher than that for the O. persica leaf extract. The resulting phytofabricated AgNPs could be used as a promising antioxidant, antibacterial, antifungal, and anti-inflammatory agent in the treatments of many medical complications.

Evaluation of Antioxidant Potentials and α-Amylase Inhibition of Different Fractions of Labiatae Plants Extracts: As a Model of Antidiabetic Compounds Properties

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 (17.21±0.17 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 = 3.05±0.51 μg/ml) was shown to have the most reducing power and the ethyl acetate fraction of Zataria multiflora (IC50 = 32.17±1.82 μg/ml) exhibited the highest DPPH radical scavenging. The ethyl acetate fraction of Otostegia persica (99.39±0.94%) 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.