Investigation of anticholinesterase activity of Berberis cretica roots

Alzheimer's disease ranks fifth among the illnesses in developed countries regarding mortality rates. Especially in industrialized countries, the probability of encountering Alzheimer's disease is increasing daily. As the quality-of-life increases, the human lifespan is prolonged, and the incidence of dementia-derived mental neurodegenerative diseases increases. These disorders act on short-term memory; It causes pathological damages such as speech disorder, analytical intelligence dysfunction, difficulty in remembering, loss of sense of place and direction, and delay in learning. Some species belonging to the Berberidaceae family naturally spread in our country. Anticancer, antidiabetes, antioxidant, antifungal, antimicrobial, anti-inflammatory and analgesic studies have been carried out on species of the Berberidaceae family. There are alkaloids in the roots of the species belonging to the Berberidaceae family. Therefore, since the drugs used in Alzheimer's disease are nitrogen-containing and have a cyclic skeleton, and with the hypothesis that alkaloid extracts and alkaloids to be obtained from the roots of Berberis cretica can inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes, which are directly related to the pathology of Alzheimer's disease, in this thesis study, the roots of Berberis cretica was studied. For this purpose, the roots were dried, ground and extracted with methanol. The alkaloids of the methanol extract (HPLC 1) were concentrated according to the Pelletier Method. The resulting alkaloid extract was fractionated over silica gel in vacuo. Fifteen fractions (Fr.Y3-Fr.Y18) were obtained from the alkaloid extract. Each fraction and the Berberine alkaloid were analyzed in an HPLC-DAD device connected to the ODS column. The anticholinesterase activity of the methanol extract of Berberis cretica root and the fractions of the alkaloid extract and berberine were performed against both enzymes. The AChE inhibitory activity (IC50<10 μg/mL) of the extracts, Fr.Y14 and Fr.Y15 fractions and the BChE inhibitory activity (IC50<1.56 μg/mL) of the Fr.Y4-11 fractions showed higher activity than galantamine used as a standard drug in mild Alzheimer's patients. According to these IC50 value results, it can be said that the BChE activity of the Fr.Y4-11 fractions is approximately 30 times more active than that of galantamine. Moreover, it is about 3.5 times more active than that of berberine. Consequently, there is a potential to obtain new drugs or raw drug materials (stocks) that can be used in Alzheimer's disease in the case of further studies, such as isolation of alkaloids and determination of toxicities that can be obtained from the roots of Berberis cretica.