Study on human urinary metabolic profiles after consumption of kale and daikon radish using high-resolution mass spectrometry-based non-targeted and targeted metabolomic approach

Authors: SUN, JIANGHAO - Ohio University; CHARRON, CRAIG - Retired ARS Employee; ZHIHAO, LIU - University Of Maryland; Novotny, Janet; HARRINGTON, PETER DE - Ohio University; ROSS, SHARON - National Cancer Institute (NCI, NIH); SEIFRIED, HAROLD - National Cancer Institute (NCI, NIH); Chen, Pei

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2020
Publication Date: 11/18/2020
Citation: Sun, J., Charron, C.S., Zhihao, L., Novotny Dura, J., Harrington, P.B., Ross, S.A., Seifried, H.E., Chen, P. 2020. Study on human urinary metabolic profiles after consumption of kale and daikon radish using high-resolution mass spectrometry-based non-targeted and targeted metabolomic approach. Journal of Agricultural and Food Chemistry. 68:14307-14318. https://doi.org/10.1021/acs.jafc.0c05184.
DOI: https://doi.org/10.1021/acs.jafc.0c05184

Interpretive Summary: Brassica vegetables are one of the main sources of dietary glucosinolates and phenolics – compounds associated with reduced risk for disease. Little is known about the urinary metabolites that arise after consumption of kale. We conducted a dietary feeding study to detect urinary metabolites of glucosinolates and phenolics arising from the consumption of kale and daikon radish (a dietary source of a compound important in the metabolism of Brassica bioactive compounds). Metabolite profiles determined by non-targeted metabolomic studies can characterize the human response to kale and daikon radish intake. Eighteen endogenous metabolites were found to change with time after vegetable consumption. Using a targeted approach, a total of 18 metabolites were found in urine consisting of four from phenolics and fourteen from glucosinolates. Among these metabolites, several were reported for the first time in human urine. The kaempferol/quercetin phase II metabolites could possibly be used as marker compounds for kale consumption, while the 4-methylsulfinyl-3-butenyl isothiocyanate and its cysteine and N-acetyl cysteine conjugates are potential dietary marker compounds for daikon radish consumption. The combination of non-targeted and targeted metabolomic approaches can gain a full metabolite profile for human dietary intervention studies.

Technical Abstract: In the present study, urine samples were collected from healthy human volunteers to determine the metabolic fates of phenolic compounds and glucosinolates after a single meal of kale and daikon radish. The major glucosinolates and phenolic compounds in kale and daikon radish were measured. The urinary metabolome after feeding at different time periods was investigated. A targeted metabolite analysis method was developed based on the known metabolic pathways for glucosinolates and phenolic compounds. Using a targeted approach, a total of 18 metabolites were found in urine: 4 from phenolic compounds and 14 from glucosinolates. Among these metabolites, 4-methylsulfinyl-3-butenyl isothiocyanate, 4-methylsulfinyl-3-butenyl isothiocyanatecysteine, and 4-methylsulfinyl-3-utenylglucosinolate-N-acetyl cysteine were reported for the first time in human urine. The combination of non-targeted and targeted metabolomic approaches can gain a full metabolite profile for human dietary intervention studies.