Metabolite profiling of cancer preventive polyphenols in a Terminalia chebula Retzius extract

Terminalia chebula (fam. Combretaceae) is a staple ayurvedic remedy and different drugs are prepared from its leaves, roots and bark; alone or in combination with other herbal drugs it represents an esteemed ayurvedic rasayana. The prolonged oral administration of its decoction is considered as a generic detoxifying agent at intestinal and hepatic level and is reputed as a way to “restore normal function” also under the perspective of a reduced risk of cancer, metabolic and cardiovascular diseases. This includes well-being maintenance and the prevention of a wide range of degenerative diseases involving inflammation, carcinogenesis and oxidative stress. Besides that, traditional uses of T. chebula decoction encompasses digestive, tonic, antipyretic, spasmolytic, astringent, expectorant, antiasthmatic, antiviral and hypoglycemic purposes and such bioactivities are related to the presence of polyphenolic compounds. However, no reports are available on the phytochemical profile of the traditional pharmaceutical form actually employed in the ayurvedic medicine and on its chemopreventive properties. In this study, a metabolite profiling of the polyphenol compounds of a T. chebula decoction was performed using HPLC-UV/DAD, HPLC-ESI-MS and MS2 with an ion trap mass analyzer. The analysis were carried out on an Ascentis C18 column (250 × 4.6 mm, 5 µm), with a mobile phase consisting of H2O and acetonitrile, both containing 0.1% HCOOH. The most relevant constituents were isolated by means of preparative chromatographic techniques from the aqueous and organic fractions obtained from the crude extract; the isolated compounds were characterized by relevant MS and MS2 data. In particular, chebulic acid, chebulanin, punicalagin, 1,6-di-O-galloyl-beta-D-glucose and corilagin were isolated from the aqueous phase; gallic acid, 3,4,6-tri-O-galloyl-beta-D-glucose, chebulagic acid, chebulinic acid, 1,2,3,4,6-penta-O-galloyl-beta-D-glucose were isolated from the organic phase. The crude decoction, enriched fractions and purified compounds were also tested for their antimutagenic properties against direct and indirect mutagens and for their ability to modulate the EphA2-ephrinA1 system.