Effect of isoquinoline alkaloids from two Hippeastrum species on in vitro acetylcholinesterase activity

Abstract

The treatment of neurological disorders and neurodegenerative diseases is related to the levels of acetylcholine (ACh) through the inhibition of acetylcholinesterase (AChE). Galanthamine, an important alkaloid isolated from the Amaryllidaceae family, is approved for the pharmacological treatment of Alzheimer's disease (AD) and acts by inhibiting the acetylcholinesterase (AChE) activity. In the present study, Ellman's method was used to verify the inhibition of AChE activity of some isoquinolines alkaloids such as galanthamine, montanine, hippeastrine and pretazettine. At the concentrations 1mM, 500 microm and 100 microm, galanthamine presented an AChE inhibition higher than 90%. Montanine inhibited, in a dose-dependent manner, more than 50% of the enzyme at 1mM concentration. With the concentrations 500 microm and 100 microm, 30-45% of AChE activity inhibition was detected. The alkaloids hippeastrine and pretazettine presented no significant inhibition of the AChE activity. The results demonstrate that montanine significantly inhibits AChE activity at the tested concentrations, suggesting the necessity of further investigations on this alkaloid use in treating neurological disorders.

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“…Several species in the Ipomoea family have been discovered to exhibit potent anticholinesterase activity in vitro such as the leaves of Ipomoea asarifolia 30 and Ipomoea aquatica Forsk 30 . In addition, isquinoline alkaloids isolated from Hippeastrum species demonstrated significant AChE inhibitory activity which also opens the possibility of the active component in I. muricata being an alkaloid 31 .…”

The Brazilian Amaryllidaceae as a source of acetylcholinesterase inhibitory alkaloids

“…Galanthamine (purity [ 99 %) used for the calibration curves was previously obtained by the authors, and codeine (purity C 99 %) used as internal standard was purchased from Sigma Aldrich (St. Louis, MO, USA). (Castilhos et al 2007;da Silva 2005;da Silva et al 2008;Pagliosa et al 2010;Giordani et al 2011a, b;de Andrade et al 2011;Sebben 2005).…”

“…vittatum and R. bifida, in which elevated levels of montanine were detected, also exhibited notable AChE inhibitory effects (Table 2). Montanine (25) has previously demonstrated remarkable activity against AChE obtained from rat brain, with more than 50 % inhibition at 1 mM (Pagliosa et al 2010). These results, together with psychobiological activities reported earlier for montanine (da Silva et al 2006), reinforce the potential of montanine-type derivatives as therapeutic candidates for AChE inhibition or other functions related to the central nervous system (da Silva et al 2006;Pagliosa et al 2010).…”

“…This has been shown to be particularly useful to studies of the Amaryllidaceae, extracts of which contain a large number of alkaloids (Kreh et al 1995;Wagner et al 2003). To this extent, several southern Brazilian Amaryllidaceae species have been examined for their alkaloid content and biological activity (da Silva et al 2006(da Silva et al , 2008Pagliosa et al 2010;Giordani et al 2011a, b;de Andrade et al 2011). In the present study, a GC-MS analysis was undertaken on nine Amaryllidaceae species which allowed for the identification of thirty-six alkaloids belonging to seven skeleton-types.…”

Phytochemistry of some Brazilian Plants with Aphrodisiac Activity

“…Recently, harmine and numerous related β-carboline derivatives were found as potent and specific inhibitors of cyclin-dependent kinases (CDKs), and the structure activity relationships (SARs) analysis demonstrated that the degree of aromaticity www.intechopen.com (Jin, 2011;Pagliosa et al, 2010) (Muthumani et al, 2010;Ueda & Yamamura, 1999a, 1999b Mimosa tenuiflora (Fabaceae) Table 3. Aphrodisiacs plants and their alkaloids, xanthines and others amines of the tricyclic ring and the positioning of substituents were crucial for inhibitory activity.…”