Content of free anthraquinone aglyca in anthranoid-containing herbal drugs/laxatives of the European Pharmacopoeia (Ph. Eur.)

The monographs of the Ph. Eur. for laxatives drugs undergo a modernization of the determination of the hydroxyanthracene glycosides to HPLC techniques whereby a determination/limitation of aglyca is actually discussed for Sennae folium and fructus, due to the postulated mutagenic and genotoxic effects of the aglyca, especially aloe-emodin [1, 2]. In regard to a limitation for aglyca the consideration of the contents in all applied laxative drugs would be reasonable. However, there are no reliable and comparable data available for the content of free aglyca.

The aim of the this study was to provide reliable comparison on the distribution and content of the aglyca aloe-emodin, chrysophanol, emodin, rhein and physcion in different batches of Aloe capensis, Frangulae cortex, Rhei radix, Rhamni purshiani cortex and Sennae folium and fructus measured by HPLC.

The drugs were extracted with acetonitrile/NaHCO₃ aq. and diluted with acidified water. A Nucleodur 100 – 3 C18 column was used as stationary phase. The mobile phase consists of acidified water and acetonitrile/methanol in a gradient. The detection was at 435nm.

Rhei radix has the highest amount of nearly all measured aglyca, the separation is shown in figure 1. Results of several samples in regard to the variations will be presented on the poster.

Fig. 1: HPLC Chromatogram from a Rhei radix sample

Considering a limitation of aloe-emodin, the herbal drugs of Sennae showed the lowest content whereas Aloe capensis and Rhei radix contain much higher amounts and therefore should be considered in the limit setting process. The method we developed is simple, precise and a helpful tool to support the discussion, if the analyses of aglyca in anthranoid-containing laxatives will become necessary.

References:

[1] Brusick & Mengs: Environ Mol Mutagen 1997; 29: 1 – 9

[2] Nesslany et al. Mutat Res-Gen Tox En 2009; 678: 13 – 19