Pretraživanje tradicionalnih europskih ljekovitih biljaka na inhibiciju acetilkolinesteraze i butirilkolinesteraze

Acetylcholinesterase (AChE) inhibitors are widely used for the symptomatic treatment of Alzheimer’s disease (AD) to enhance central cholinergic transmission. On the other hand, butyrylcholinesterase (BuChE) inhibitors were reported to produce significant increases in brain extracellular AChE without triggering severe peripheral or central side-effects. In the present study, we selected twelve plants used in traditional European medicine to treat different central nervous system (CNS) disorders or to improve memory. Methanolic and hexane extracts of these plants were tested for the AChE and BuChE inhibitory activity using Ellman’s colorimetric method. The most potent AChE and BuChE inhibition was observed in the hexane extracts of the flowers of Arnica chamissonis Less. susb. foliosa and Ruta graveolens L. herb at a concentration of 400 μg mL1. However, methanolic extracts of the flowers of Arnica chamissonis Less. susb. foliosa and the Hypericum perforatum L. herb demonstrated at the same concentration, selective inhibition only against AChE but not against BuChE. The other extracts did not show any significant AChE or BuChE inhibitory activity. Our results show that further investigations of the extracts of arnica, rue and St. John’s Wort are needed to identify the compounds responsible for the AChE and BuChE inhibitory activityInhibitori acetilkolinesteraze (AChE) povećavaju kolinergičku transmisiju u mozgu, pa se koriste za simptomatsko liječenje Alzheimerove bolesti (AD). S druge strane, inhibitori butirilkolinesteraze (BuChE) značajno povećavaju ekstracelularnu količinu AChE u mozgu, a da pri tome ne uzrokuju snažne nuspojave ni u središnjem ni i perifernom živčanom sustavu. Galantamin, jedan od odobrenih AChE inhibitora, alkaloid iz lukovica narcisa, pokazuje da su biljke značajni izvor novih potencijalnih AChE- i BuChE- inhibitora. U ovom radu, ispitivali smo učinak dvanaest biljaka koje se koriste u tradicionalnoj europskoj medicini na različite poremećaje središnjeg živčanog sustava i na poboljšanje pamćenja. Pomoću Ellmanove kolorimetrijske metode praćen je inhibitorni učinak metanolnih i heksanskih ekstrakata tih biljaka na AChE i BuChE. Najjači inhibitorni učinak pokazali su heksanski ekstrakti cvjetova Arnica chamissonis Less. susb. foliosa i nadzemnih dijelova Ruta graveolens L. u koncentraciji od 400 μg mL1. Međutim, metanolni ekstrakti cvjetova Arnica chamissonis Less. susb. foliosa i nadzemnih dijelova Hypericum perforatum L. u istim koncentracijama pokazuju selektivnu inhibiciju samo na AChE. Ostali ekstrakti bili su nedjelotvorni. Rezultati ukazuju na potrebu daljnjih ispitivanja ekstrakata arnike, rute i gospine trave da se utvrdi koji su sastojci ekstrakata odgovorni za inhibiciju AChE i BuChE

In-vitro evaluation of selected Egyptian traditional herbal medicines for treatment of alzheimer disease

BACKGROUND: Egyptians recognized the healing power of herbs and used them in their medicinal formulations. Nowadays, “Attarin” drug shops and the public use mainly the Unani medicinal system for treatment of their health problems including improvement of memory and old age related diseases. Numerous medicinal plants have been described in old literature of Arabic traditional medicine for treatment of Alzheimer’s disease (AD) (or to strengthen memory). METHODS: In this study, some of these plants were evaluated against three different preliminary bioassays related to AD to explore the possible way of their bio-interaction. Twenty three selected plants were extracted with methanol and screened in vitro against acetylcholinesterase (AChE) and cycloxygenase-1 (COX-1) enzymes. In addition, anti-oxidant activity using DPPH was determined. RESULTS: Of the tested plant extracts; Adhatoda vasica and Peganum harmala showed inhibitory effect on AChE at IC(50) 294 μg/ml and 68 μg/ml respectively. Moreover, A. vasica interacted reversibly with the enzyme while P. harmala showed irreversible inhibition. Ferula assafoetida (IC(50) 3.2 μg/ml), Syzygium aromaticum (34.9 μg/ml) and Zingiber officinalis (33.6 μg/ml) showed activity against COX-1 enzyme. Potent radical scavenging activity was demonstrated by three plant extracts Terminalia chebula (EC(50) 2.2 μg/ml), T. arjuna (3.1 μg/ml) and Emblica officinalis (6.3 μg/ml). CONCLUSION: Interestingly, differential results have been obtained which indicate the variability of the mode of actions for the selected plants. Additionally, the reversible interaction of A. vasica against AChE and the potent activity of F. assafoetida against COX-1 make them effective, new and promising agents for treatment of AD in the future, either as total extracts or their single bioactive constituents