Biological activity studies on Hyssopi Herba from Turkey

Hyssopus officinalis L. (Hyssop) is one of the most popular herbs, mainly distributed in the Eastern Mediterranean to Central Asia. Hyssopi herba is used in tea blends for cough relief, antispasmodic effects, and to relieve catarrh [ 1 ]. The plant has recently attracted attention due to its phenolic content and promising biological activities, such as antimicrobial and antioxidant effects [ 2 ]. In the present study, the total phenolic and total flavonoid content were determined in two different commercial samples of Hyssopi herba. Additionally, neuroprotective activity and anticholinesterase activity tests were conducted as part of our study. Cell viability was evaluated using an MTS/PMS assay in a cellular model of oxidative stress after exposure to extracts at various concentrations (1-100 μg/mL), and the anticholinesterase activity studies were carried out using Ellman’s method. Methanolic extracts were prepared, and yields of extracts (H1 and H2) were calculated as 11.94% and 24.06%, respectively. In extract H1, total phenols and total flavonoids were determined to be 80.188±0.495 mg GAE/g and 71.929±2.538 mg QE/g, whereas in extract H2, total phenolic and flavonoid contents were found to be 282.394±14.036 mg GAE/g and 49.814±2.420 mg QE/g, respectively. The methanolic extracts (H1 and H2) did not show noticeable anticholinesterase inhibitory activity (AChE 37.7 and 11%; BChE 16 and 23%, respectively). Neuroprotection by the extracts in the presence of hydrogen peroxide was indicated by a significant reduction of cellular loss at concentrations less than 10 μg/mL ( p