Iris domestica L Goldblatt Mabb syn Belamcanda chinensis
Iris domestica (L.) Goldblatt & Mabb. (syn. Belamcanda chinensis L.) DC. (Iridaceae) occurs naturally in South and East Asia. Despite the fact that former monotypic genus Belamcanda has been included in the extended genus Iris, this classification has been questioned (Wilson, 2011; Mavrodiev et al., 2014) and the final systematic position of this plant is possible to be changed. To avoid the nomenclature ambiguity, we use the commonly acknowledged pharmacognostic name of the drug Belamcandae chinesis rhizoma instead of full binomial name (I. domestica).
Rhizomes are a pharmacopoeial raw material of East and South-East Asian traditional phytotherapies under the pharmacognostic name Belamcandae chinensis rhizoma, also known under the TCM name she-gan. Pharmacological properties that have been confirmed by now, include: antiinflammatory, antidiabetic, antiosteoporotic, estrogenic, anti-allergic, anti-asthmatic, cytotoxic, and antimicrobial (Woźniak and Matkowski, 2015; Szandruk et al., 2018). Apart from the Chinese, Korean and a couple of other Asian Pharmacopoeias, also the European Pharmacopoeia has been monographing the raw material of this plant for several years, which proves its increasing popularity and usefulness around the world. The main class of compounds responsible for this broad spectrum of activity are polyphenols, among them isoflavones, xanthones, stilbenes, and phenolic acids. Several cytotoxic iridal triterpenes are also contributing to the overall phytochemical profile of the plant (Woźniak and Matkowski, 2015). In the literature, various methods of isolation and identification of main constituents from this raw material can be found. On the other hand, there is still some degree of inconsistency and ambiguity in the composition assessment. Despite previous reports showing no anti-AChE activity of methanol extract from she-gan (Kaufmann, 2016), we hypothesize that individual polyphenols due to their structural characteristics may demonstrate such activity, also against BChE. Tectorigenin has been shown to have anti-neuroinflammatory activity (Lim et al., 2018), and related Iris anatoxin a synthesis were active against cholinesterases (Conforti et al., 2009). The aim of this work was to develop and optimize the method of isolation and identification of polyphenolic compounds from Belamcandae chinensis rhizoma for further bioactivity testing towards in vitro inhibition of two cholinesterases - BChE and AChE. The most active compounds were also assessed for their affinity to these enzymes by the molecular docking study.
Results and discussion
Materials and methods
Acknowledgements S. Ślusarczyk received support from Polish National Center of Science postdoctoral grant FUGA (2014/12/S/NZ9/00715) under the appreciated mentoring of Prof. Dr. Anna Stochmal from IUNG Institute of Cultivation and Soil Science at Puławy, Poland. The valuable help in obtaining mass spectra from Dr. Mariusz Kowalczyk from the same Institute is kindly acknowledged. The cultivation and analysis of experimental plants is supported by the grant for special research facility funded by the Polish Ministry of Science and Higher Education (MNiSW grant decision No. 215259/E-394/SPUB/2016/1) and Medical University grant No. ST-D.030.17.028.01. This work has been funded by a grant from the Spanish Ministry of Economy and Competitiveness (CTQ2017-87974-R). This research was partially supported by the supercomputing infrastructure of University of Tromso (Norway), by the Plataforma Andaluza de Bioinformática of the University of Málaga (Spain). [email protected], and the NLHPC (ECM-02). The work was partially financed from grant no POLTUR/PLANT-ALZH/5/2015 (Poland).
Two cholinesterases Acetylcholinesterase (AChE) and its “sister” enzyme butyrylcholinesterase (BChE) are widely expressed throughout the animal kingdom . AChE and BChE share roughly 50% sequence homology and have relatively similar tertiary and quaternary structures. They both possess a catalytic triad of three amino acids (serine, glutamate and histidine) located deep inside a “gorge” in the tertiary structure , , . Evidence suggests that these enzymes emerged from a carboxylesterase superfamily, with “true” AChE first emerging hundreds of millions of years ago in Platyhelminthes . Higher vertebrates have one ACHE gene and one BCHE gene, while some lower species express multiple genes of one or both . The cyclostomes, jawless fish including the lamprey and hagfish, only express AChE, suggesting that BChE arose later in evolution by gene duplication and divergence from AChE , , .