Studying the effects of natural extracts with metabolomics: A longitudinal study on the supplementation of healthy rats with Polygonum cuspidatum Sieb. et Zucc.

Background: A longitudinal study was performed to evaluate the effects of Polygonum cuspidatum extract (standardized at 20% resveratrol) supplementation on healthy rats. The effects were explored by monitoring urinary metabolome changes using UPLC-HRMS and H-1 NMR-based approaches. The aim of the study was to explore the effects of P. cuspidatum supplementation on a healthy animal model using metabolomics, in order to determine possible modes of action and obtain information on bioactivity. Methods: Healthy Sprague-Dawley rats were orally supplemented with 100 mg/kg of dried P. cuspidatum extract for 49 days and 24-h urinary outputs were collected. Samples were analysed by untargeted UPLC-HRMS and H-1 NMR approaches and the obtained data sets were modelled by an adaptation of post transformation of PLS2 to longitudinal studies. Putative markers were discovered by a stability selection procedure and specific oxidative stress markers were monitored by a targeted HPLC-MS/MS analysis to assess the in vivo antioxidant activity of P. cuspidatum extract. Results: UPLC-HRMS and H-1 NMR platforms showed two different but complementary patterns of metabolites describing the changes ascribable to P. cuspidatum supplementation and using both approaches, a comprehensive resveratrol metabolism and urinary excretion could be observed. Markers of P. cuspidatum supplementation effects identified by UPLC-HRMS were mainly related to its antioxidant activity and to a possible adaptogenic activity. Urinary changes observed by H-1 NMR were mainly related to energy metabolism. UPLC-HRMS and H-1 NMR metabolomics approaches allowed the effects of a prolonged supplementation with P. cuspidatum on healthy rats to be observed. The statistical models built from both data sets showed metabolic changes in urines related to rat aging. (C) 2017 Elsevier B.V. All rights reserved.