Lavandula stoechas L. subsp. stoechas Üzerinde Biyolojik Aktivite Rehberli Çalışmalar

Abstract

Lavandula stoechas L. subsp. stoechas known as “karabaş otu” is used for diabetes and central nervous system disorders. This thesis focuses on scientifically validating the traditional usage of L. stoechas subsp. stoechas in treating diabetes and CNS disorders by using bioactivity-guided fractionation and phytochemical analysis studies in order to determine the compounds behind the biological activity. Investigations on the potential antidiabetic effect of the plant were carried out with α-amylase and α-glucosidase enzyme inhibition guided studies. As a result, no inhibition of α-amylase enzyme was observed in the extracts and main fractions. Two compounds were isolated from the fraction showing high α-glucosidase enzyme inhibition, using various chromatographic methods and the structures of the compounds were elucidated as ursolic acid and salvianolic acid B by using spectroscopic methods. Ursolic acid possesses strong α-glucosidase inhibition effect. To investigate the neuroactive potential effect of L. stoechas subsp. stoechas, the bioactivity-guided fraction was used, and assessing the brain-derived neurotrophic factor (BDNF) level was used as a biological screening tool to screen for the activity. Phytochemical analysis studies were carried out on the fraction with the highest BDNF protein level increase. As a result, four compounds were isolated and their structures were determined as luteolin 7-O-β-D-glucopyranoside, rosmarinic acid, eriodictyol, 1-nonadecene. The most active compounds that have been isolated/detected from the active fraction are ursolic acid and eriodictyol. In addition, the isolated pure compounds possess neuroprotective effects against H2O2-induced neuronal cell damage. Furthermore, it was determined that L. stoechas has strong antioxidant activity by using DPPH, SO, NO radical scavenging activity, CUPRAC and FRAP methods. In conclusion, our results support the traditional usage of L. stoechas subsp. stoechas for diabetes and CNS disorders.