Quantification of total polyphenol in artichoke preparations by Folin-Ciocalteu method

Abstract

There are a number of preparations containing artichoke extract are available on foreign and domestic pharmaceutical market with various forms such as tablets, capsules, sugar coated tablets, etc. The major components of artichoke extract are phenolic compounds. Therefore, the assessment of total polyphenol content in artichoke preparations are necessary to get an overview of the quality of these on the market currently. Artichoke leaf extract was used as a material to develop a method for quantitative analysis of total phenolic content by Folin-Ciocalteu reagent. Process validation was performed according to ICH guidelines. The quantitative procedure was applied to determine the total phenolic content in 19 commercial domestic and foreign artichoke preparations. The result of this study revealed that the quantitative procedure met all requirements including system suitability; linear range 7.5 - 120 µg/mL (R² = 0.99); the intra-day precision and the inter-day precision was 1.14 and 1.61%, respectively; recovery were 96.82 - 99.27% (RSD=1.68 - 2.35%). The content of total polyphenols in the artichoke preparations on the market were 10.7 - 134.1 mg GAE/g of dry weight. Therefore, the quantitative procedure met the validation requirements and was applicable to measure the total phenol content in artichoke extracts and products accurately. The commercial Artichoke products were analysed and showed variable quality significantly.