Phytochemical characterization,antioxidant potential,and health risk assessment of Radix Oryzae Glutinosae

Radix Oryzae Glutinosae (ROG) has been used as a traditional anhidrotic agent in China. Ten samples were systematically assessed based on four aspects of their chemical profiles and antioxidant activity. The former was achieved using ultraviolet-visible spectra (UV), infrared absorption spectra (IR), proton nuclear magnetic resonance spectroscopy (¹H NMR), and inductively coupled plasma-mass spectrometry (ICP-MS) fingerprints, and antioxidant activity was assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, the 2,2′-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) assay, and the ferric reducing antioxidant power (FRAP) assay. The presence of amino acids, flavonoids, organic acids, and sugars was indicated in all samples. A hierarchical cluster analysis and a canonical discriminant analysis were introduced to interpret the results of the multi-pattern fingerprint. The results of the correlations between the individual elements and between each element with the different types of metabolites displayed many interesting patterns. In vitro studies revealed that all samples displayed antioxidant activities. A pollution status examination and heavy metal evaluation of the ROG samples were performed. The human health risk assessment associated with the intake of potentially harmful elements in herbs was calculated in terms of the estimated daily intake, the target hazard quotient, and the lifetime cancer risk. The Nemerow multi-factor pollution index results suggested that all samples belonged to the serious pollution level. The results of the noncarcinogenic risk assessment study indicated that the pattern of consumption of this herb in China seems to suggest an excessive health hazard associated with some toxic elements studied. The carcinogenic risk results suggested that there is a potential risk due to As, Cr, Cd, and Ni for consumers, and these may contribute to the population cancer burden through ROG ingestion. This study provides insights into the organic medicinal constituents and the trace elements of the herb. The results will enable this herb to be used more effectively and safely.