Coumestrol (3,9-dihydroxy-6-benzofuran [3,2-c] chromenone) as a phytoestrogen and polyphenolic compound is a member of the Coumestans family and is quite common in plants. In this study, antiglaucoma, antidiabetic, anticholinergic, and antioxidant effects of Coumestrol were evaluated and compared with standards. To determine the antioxidant activity of coumestrol, several methods—namely N,N-dimethyl-p-phenylenediamine dihydrochloride radical (DMPD^•+)-scavenging activity, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulphonate) radical (ABTS^•+)-scavenging activity, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH^•)-scavenging activity, potassium ferric cyanide reduction ability, and cupric ion (Cu²⁺)-reducing activity—were performed. Butylated hydroxyanisole (BHA), Trolox, α-Tocopherol, and butylated hydroxytoluene (BHT) were used as the reference antioxidants for comparison. Coumestrol scavenged the DPPH radical with an IC₅₀ value of 25.95 μg/mL (r²: 0.9005) while BHA, BHT, Trolox, and α-Tocopherol demonstrated IC₅₀ values of 10.10, 25.95, 7.059, and 11.31 μg/mL, respectively. When these results evaluated, Coumestrol had similar DPPH^•-scavenging effect to BHT and lower better than Trolox, BHA and α-tocopherol. In addition, the inhibition effects of Coumestrol were tested against the metabolic enzymes acetylcholinesterase (AChE), butyrylcholinesterase (BChE), carbonic anhydrase II (CA II), and α-glycosidase, which are associated with some global diseases such as Alzheimer’s disease (AD), glaucoma, and diabetes. Coumestrol exhibited K_i values of 10.25 ± 1.94, 5.99 ± 1.79, 25.41 ± 1.10, and 30.56 ± 3.36 nM towards these enzymes, respectively.

Medicinal and aromatic plants such as Crocus cancellatus, Scilla Siberica subsp. armena, Juniperus oxycedrus subsp. oxycedrus and Anthriscus nemorosa have many different biological activities. While antioxidants are significant in preventing many diseases, inhibition of metabolic enzymes is also effective in preventing many diseases. In this study, antioxidant activities of water, ethanol, and dichloromethane extracts of four different medicinal and aromatic plant species were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH•) and 2,20-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS•+) radical scavenging and Cu2+, Fe+3, and Fe3+-2,4,6-tris(2-pyridyl)-S-triazine (TPTZ) reducing assays. Enzyme inhibition studies were performed with metabolic enzymes acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase I and II isoenzymes. The ethanol extract of A. nemorosa showed the highest activity in DPPH and ABTS assays (IC50: 17.36 µg mL-1, IC50: 7.02 µg mL-1). In the Fe3+ reducing assay, the dichloromethane extract of A. nemorosa showed the highest activity (1.96±0.060 µg mL-1). In the Cu2+ reducing assay, the dichloromethane extract of J. oxycedrus showed the highest activity (1.773±0.066 µg mL-1). In the Fe3+-TPTZ reducing assay, the ethanol extract of S. siberica showed the highest activity (1.256±0.011 µg mL-1). In the enzyme inhibition results, it was determined that all plants and all extracts inhibited the enzymes studied. As a result of this study, it was determined that these four medicinal and aromatic plants have high biological activities.