Phytochemical and biological investigations on Carduus crispus L.

Abstract

As people are becoming older different forms of dementia are a major public health concern. After a screening of 50 plants used in the Traditional Mongolian Medicine on their acetylcholinesterase inhibitory effect the MeOH extract of Carduus crispus L. (Welted Thistle; Asteraceae) showed a pronounced activity of 60.5% at a conc of 1.000µg/ml. The biological test was performed by the method of Ellman [1, modif.]. Different plant parts (leaves, flowers, stem, roots) were extracted with solvents of different polarities. The highest activity was found in the MeOH mazerate of the leaves (60.9% at 1.000µg/ml) whereas the traditionally used hot water extracts were not as active (32.4% at 1.000µg/ml). The alcoholic extracts showed stronger effects (MeOHcold> MeOHhot> EtOHhot>> H2Ohot). The differences between leaf, flower and stem extracts have not been significant. Separation of MeOH extracts by polarity differences showed a pronounced activity of the n-butanol fraction (stem 59.2%, flower 66.2%, leaf 81.6% at 1.000µg/ml). Fractions with an activity up to 90.9% at 1.000µg/ml were obtained by the use of SPE. The compounds from these fractions isolated by SPE and RP-HPLC could be identified by spectroscopic methods as chlorogenic acid; neochlorogenic acid; p-coumarylquinic acid and apigenin derivatives. These results may substantiate the traditional use of the investigated plant for the improvement of cognition.