A UHPLC-DAD Method for Quantification of Berberine and Protoberberine Alkaloids in Herbal Food Supplements Based on Berberis Aristata Extract and Evaluation of Their Biological Activity

A rapid ultra-high performance liquid chromatography with diode array detection (UHPLC-DAD) method for determination of bioactive compounds in Berberis aristata extracts containing berberine, aromoline, magnoflorine, berbamine, tetrahydropalmatine, tetrahydroberberine, jatrorrhizine, palmatine, and oxyberberine was developed. The stationary phase was Ascentis Express AQ C-18 (150 x 4.6 mm, 2.7 mu m core-shell particles with embedded polar modification). The method run time with gradient elution comprising 0.1 % aqueous phosphoric acid and acetonitrile (1.0 mL/min) was 9.2 min. Ultrasound-assisted solid-liquid extraction with methanol was used for extraction. The validated method yielded recovery from 94.60 % to 104.10 % and limits of quantification from 0.125 to 0.250 mg/L. The results of berberine content ranged from 82.99 % to 107.47 % of the declared amount. An alarmingly low content 0.46 % of declared amount of extract was also found. The biological activity and cytotoxic properties of Berberis aristata extract and berberine powder on the Hep-2 cell lines was also evaluated and corelated with the content of berberine and protoberberine alkaloids in individual extracts. The majority of food extracts showed the negligible cytotoxicity for Hep-2 cell lines while one containing the highest level of jathrorrhizine showed significant cytotoxicity. However, the inhibitory effect on the Hep-2 cell lines has not been clearly demonstrated.