Total phenolic and flavonoid content in Boswellia serrata Roxb. resin extracts obtained with subcritical water

Boswellia serrata Roxb. is a tree that is mainly found in the dry regions of India. Its oleoresin, known internationally as Indian frankincense, is used in Ayurvedic, traditional Arabic and Chinese medicine. This gum resin contains 15-20% of boswellic, lupeolic and other pentacyclic triterpenic acids, of which the boswellic acids (beta-boswellic acid, keto-beta-boswellic acid and acetil-11-keto-beta-boswellic acid)have been shown to have anti-inflammatory, anticancer and antidiabetic properties and are used in the modern pharmaceutical industry. Besides its ability to prevent and treat various diseases (rheumatoid arthritis, osteoarthritis, Chron’s disease, ulcerative colitis and asthma), other biological functions of B.serrata resin should not be neglected.T he aim of this study was to analyze, for the first time, extracts of B. serrata resin obtained with subcritical water at different temperatures (110–190 °C) for their phenolic and flavonoid content. The total phenolic content (TPC) was determined by UV-spectrophotometry using the Folin-Ciocalteu method. The total flavonoid content (TFC) was also determined by UV-spectrophotometry using a simple method with AlCl3.With increasing extraction temperature, the TPC increased from 3.76 mg GAE/g DW at 110 °C to 13.78 mgGAE/g DW at 190 °C. The highest TFC was observed in the extract obtained at 170 °C (8.56 mg RE/g DW). The results of this study suggest that extracts of B. serrata resin obtained with subcritical water are a rich source of bioactive compounds that can be used in pharmaceuticals, dietary supplements and functional foods.