In this study, silver nanoparticles (AgNPs) were synthesized economically and simply using an environmentally friendly method with the extract obtained from agricultural waste olive leaves. AgNPs synthesized according to the analysis data were determined to have maximum absorbance at 433.5 nm wavelength, spherical appearance, 7.2 nm crystal nano size and −19.9 mV zeta potential. It was determined by the microdilution method with Minimum Inhibition Concentration (MIC) that AgNPs exert a suppressive effect on the growth of pathogen gram-negative, positive bacteria and yeast at very low concentrations. The cytotoxic effects of the particles were investigated on healthy cell lines (HDF) and cancerous cell lines (U118, CaCo-2, Skov-3). AgNPs showed up to 70% suppression in cancer cell lines.

Methanol, ethanol, acetone and chloroform extracts of powdered Hypericum heterophyllum prepared from leafs were investigated for their (i) phytochemical constituents, which was evaluated by LC-ESI-MS/MS and various known total bioactive methods; (ii) antioxidant capacity, which was evaluated by several in vitro assays such as DPPH, ABTS, H₂O₂, superoxide radical, and metal chelating; (iii) acetylcholinesterase (AChE) inhibitory activity; (iv) active constituents of the extracts with AChE in silico docking. Phytochemical analysis revealed that none of the extracts contained hypericin, pseudohypericin and hyperforin. Among the identified compounds, ethanol and acetone extracts had the highest number of compounds. The highest value of total phenolic content (132.7 mg GAE/g) was obtained with methanol extract, whereas the highest values of total flavonoid (61.8 mg QE/g) and flavanol (0.89 mg CE/g) content were recorded in acetone extract. Methanol extract displayed the most DPPH activity (24.9 mg TE/g), but ethanol extract (59.8 mg TE/g) showed the highest ABTS activity. Acetone extract displayed the best hydroxyl and superoxide radical scavenging activities with the values of 351.5 mg AAE/g, and 197.3 mg TE/g respectively. The chloroform extract exhibited the best AChE inhibition activity (11.07 µg/ml). In the docking study, quercetin-7-O-glucoside, diosgenin, and quercetin-3-glucoside were calculated to have a stronger MolDock Score than the reference ligand Donepezil. Our docking results have indicated that extracts contain compounds with a high affinity against the acetylcholinesterase enzyme. These data suggest that these extracts can be potentially important antioxidant supplements and drug candidates for AChE inhibition activity.

Nanoparticles are used in many areas due to their superior properties. Recently, producing these particles using environmentally friendly synthesis methods has become very popular. Within this context, in this study, gold nanoparticles (AuNPs) were synthesized by using a quick, eco-friendly method with the green leaf extract of Artemisia absinthium (wormwood). The grain size of the AuNPs was determined as 13.40 nm according to the Debye-Scherrer equation. The inhibitory effects of the AuNPs on the growth of the tested microorganisms were determined by the minimum inhibitory concentration (MIC) method. The MIC is described as the minimum concentration of an antimicrobial agent that inhibits the growth of a microorganism. The obtained AuNPs were showed inhibitory effects on S. aureus, S. pyogenes, E. coli, P. aeruginosa strains and C. albicans yeast at concentrations of 0.250, 0.125, 0.125, 0.033 and 0.66 mg mL-1 respectively.

Medicinal plants have been employed commonly in many countries to remedy of various ailments. In this study, Inula graveolens leaves (5.0 g) were extracted with methanol (100 mL) for 24 hours at room temperature. After filtration with Whatman 1 filter pater, the solvent was removed under reduced pressure to yield the crude extract. Quantification of natural products in methanol extract of Inula graveolens was determined by LC-MS/MS. Chlorogenic acid was determined as a chief product (3.5 mg/g extract). Furthermore, salicylic acid (0.055 mg/g extract), caffeic acid (0.054 mg/g extract), protocatechuic acid (0.026 mg/g extract), hesperidin (0.016 mg/g extract), rutin (0.0160 mg/g extract) were found in the methanol extract. Since Inula graveolens contains important bioactive compounds, it has the possibility to be used in pharmaceuticals and food.