In vitro and in silico evaluation of Ononis isoflavonoids as molecules targeting the central nervous system

PLoS One. 2022 Mar 17;17(3):e0265639. doi: 10.1371/journal.pone.0265639. eCollection 2022.

Abstract

Isoflavonoids with various structural elements show a promising potential effect on central nervous system activities. Despite their favorable medicinal properties, the pharmacokinetic characteristics of this thoroughly investigated group of natural phenolics have only been described to a limited extent. Regarding the lack of information about the BBB permeability of isoflavones, isoflavanones, and pterocarpans found in Ononis species, the aim of our study was to investigate their physico-chemical properties influencing their absorption and distribution. Furthermore, we aimed to characterize the possible MAO-B inhibiting features of Ononis isoflavonoids in silico. Octanol-water partitioning and BBB-PAMPA permeability of formononetin, calycosin D, onogenin, sativanone, medicarpin and maackiain were assessed for the first time in our study. The log P values ranged from 2.21 to 3.03 and log D7.4 values from 2.48 to 3.03, respectively, indicating optimal polarity for BBB permeation. The results of PAMPA-BBB expressed as log Pe values fell between -5.60 and -4.45, predicting their good permeation capability as well. The effective permeability values showed structure-dependent differences, indicating that the pterocarpan type skeleton was the most preferred type, followed by isoflavanones, then isoflavones. The methoxy or methylenedioxy substitution of the same skeleton did not influence the permeability significantly, contrary to an additional hydroxyl group. Membrane retention showed a similar structure dependent pattern to that of effective permeability, ranging from 16% to 70%. For the identification of volumes of chemical space related to particular biological activities the ChemGPS-NP framework was used. The MAO-B inhibitory potency and selectivity were also predicted and validated. Based on our results, MAO-B inhibitory potency could be predicted with good precision, but in the case of selectivity, only the direction could be concluded (favors MAO-B or MAO-A), not the magnitude. Our finding reflects that Ononis isoflavonoid aglycones show an excellent fit with the suggested parameters for BBB permeability and this is the first study to confirm the highly favorable position of these natural products for MAO-B inhibition.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Central Nervous System
  • Flavones*
  • Isoflavones* / chemistry
  • Monoamine Oxidase
  • Ononis* / chemistry

Substances

  • Flavones
  • Isoflavones
  • Monoamine Oxidase

Grants and funding

The financial support from the Bolyai fellowship (https://mta.hu/bolyai-osztondij) for S.B. and the support of EFOP‐3.6.3‐VEKOP‐16‐2017‐00009 from the Ministry of Human Capacities (https://www.palyazat.gov.hu/efop-363-vekop-16-felsoktatsi-hallgatk-tudomnyos-mhelyeinek-s-programjainak-tmogatsa) for N.G. are gratefully acknowledged. This work was supported by the ÚNKP‐18‐3‐III‐SE‐30 (http://www.unkp.gov.hu/) New National Excellence Program of the Ministry of Human Capacities (N.G) and by the Bolyai+ ÚNKP‐20-5-SE-31 (http://www.unkp.gov.hu/) New National Excellence Program of the Ministry of Human Capacities (S.B). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.