Free radical scavenging reactions and phytochemical analysis of triphala, an ayurvedic formulation

In order to understand the factors responsible for the potent antioxidant and radioprotecting ability of triphala, it has been evaluated for radical scavenging ability, xanthine oxidase inhibitory activity and phytochemical (phenolics) content. The radical scavenging experiments were carried out using fast reaction kinetic tools and the reactivity of triphala towards different radicals such as hydroxyl radicals, superoxide radicals, DPPH and ABTS was determined. When triphala was tested for superoxide radical scavenging activity using xanthine and xanthine oxidase assay, it was observed that in addition to reacting with superoxide radical, it also inhibited uric acid formation, indicative of xanthine oxidase enzyme inhibitory activity. Phytochemical analysis showed that triphala is rich in phenols/polyphenols (38 ± 3%) and tannins (35 ± 3%), while flavonoids were found to be absent. HPLC analysis showed that triphala contains 73 ± 5 mg gallic acid per gram of triphala, which was found to increase to 150 ± 5 mg/g upon acid hydrolysis. Relevance of these studies to the antioxidant and radio protection properties of triphala has also been discussed.