Benzophenanthridine alkaloid macarpine – biological effects and plant sources

Plants with quaternary benzophenanthridine alkaloids (QBAs) are used for a long time in traditional Chinese medicine for analgesic, anti-inflammatory, antiedemic, depurative or diuretic properties [1]. Wide range of effects of these plants had increased the number of studies in the biochemistry or pharmacology in recent years. A great deal of attention is devoted to the main alkaloids sanguinarine and chelerythrine. Besides these commercially available and well-known alkaloids, there are also minor alkaloids such as macarpine (MA) with limited information about its properties in literature. Among the rare QBAs, MA was reported as a promising fluorescent probe for cell nuclei labelling as well as for cell cycle visualisation in fluorescence microscopy and flow cytometry [2]. We have previously described strong antiproliferative effects of MA on several cancer cell lines [3], but this is the first documentation of their effect on malignant melanoma cells. Taking into account all the biological activities of quaternary benzophenanthridine alkaloids highlight their further application in cancer biology and therapy studies and justify the continuation in the research of MA that is dependent on the isolation of alkaloids from plants sources.

To the best of our knowledge, MA is in small quantities only in two plants from the family Papaveraceae, Macleaya microcarpa and Stylophorum lasiocarpum, both native to China. MA was not detected in aerial part of M. microcarpa, but in roots was determined in considerable amounts, especially in elder cultures. The alkaloid content was also determined in Chinese culture of M. microcarpa. In the roots of S. lasiocarpum MA was found in amounts readily comparable to sanguinarine. Given the limited quantity of MA in this plants, it was also taken in consideration its variable content during the vegetation period.

Acknowledgements: The financial support for this work from the Czech Ministry of Education, Youth and Sports (LH12176-KONTAKT II) and from the Science Foundation of Masaryk University (MUNI/A/0954/2013 and MUNI/A/0938/2013) is gratefully acknowledged.

References:

[1] Lei, Q.-f.; Zhao, X.-l.; Xu, L.-j.; Peng, Y.; Xiao, P.-g. Chemical Constituents of Plants from Tribe Chelidonieae and their Bioactivities. Chinese Herbal Medicines 2014; 6: 1.

[2] Slaninová I.; Slanina, J.; Táborská, E. Quaternary benzo[c]phenanthridine alkaloids – Novel cell permeant and red fluorescing DNA probes. Cytometry A 2007; 71: 700 – 708.

[3] Slaninová, I.; Slunská, Z.; Šinkora, J.; Vlková, M.; Táborská E. Screening of minor benzo(c)phenanthridine alkaloids for antiproliferative and apoptotic activities. Pharm Biol 2007; 45: 131 – 139.