Chromatographic analysis of a herbal formulation for the treatment of C-IBS

Abstract

A reversed phase HPLC method with PDA and (-)ESI-MS/MS detection has been developed for the determination of fourteen analytes in the extract of a 8 herb formulation used for the treatment of irritable bowel syndrome. Analytical methods were also developed for the analytes of interest in their respective individual herbs. The herb and analytes analysed were atractylodin in Cang Zhu (Atractylodes lancea), honokiol and magnolol in Hou Po (Magnolia officinalis), glycyrrhizic acid in Zhi Gan Cao (Glycyrrhiza uralensis), hesperidin in Chen Pi (Citrus reticulata), narirutin and hesperidin in Zhi Ke (Citrus aurantium), naringin and neohesperidin in Zhi Shi (Citrus immaturas aurantium), aloe-emodin, rhein, emodin, chrysophanol, and physcion in Da Huang (Rheum palmatum), and paeoniflorin in Bai Shao (Paeonia lactiflora). These analytes were seleceted based on a set of criteria which takes into account the bioavailability, reported bioactivity, physiological action related to its intended use and commercial availability of the standard. Three herbal mixtures were prepared using water, 35%, and 50% aqueous ethanol as the extraction solvent. The analytical method was then applied to the analysis of three commercially prepared dried extracts and the extraction efficiency of the different preparation methods compared. The herbal formulation was extracted by ultrasonication in pure methanol, followed by solvent - solvent partitioning to separate the analytes into two phases (aqueous and organic). The two partitioned extracts were analysed using a C18 column with a gradient mobile phase consisting of aqueous formic acid and pre-mixed acetonitrile: methanol containing THF. It was found that the extraction efficiencies were generally poor even for the overall "optimum" solvent of 35% aqueous ethanol. The extraction efficiencies ranged from 53% (for hesperidin) to 2% (for physcion) with an average extraction efficiency of 14%.

Date of Award	2009
Original language	English