Ecdysterone detection in anti-doping control: restricted use or regular diet?

Code: 20C07MP

Based on earlier results of our group ecdysterone is included in the 2020 Monitoring Program. As ecdysterone containing plants may be part of common human diet, discrimination between common dietary levels, excessive dietary intake of ecdysterone and supplementation for misuse is highly desired.

It is intended to perceive markers for classification of the type of ingestion. This may help to confirm or contradict athletes' claims in future anti-doping investigations.

Within the project high amounts of regular dietary compounds, i.e. spinach or quinoa, will be ingested by volunteers and urinary excretion compared to post administration urines after pure ecdysterone. Concentrations of ecdysterone will be monitored and potential metabolites or additional ecdysteroids from the plants sources will be uncovered. An investigation of the influence of the human microbiome on ecdysteroid metabolism will be included in the project.

Main Findings

In this study, ecdysterone was quantified in spinach and quinoa. Subsequently, quantitative analysis of ecdysterone and its metabolites in urine samples of human volunteers was conducted, following four different administration studies of sautéed spinach, smoothie from sautéed spinach leaves, quinoa and a combination of sautéed spinach and quinoa.

The purpose of the study was to investigate the human excretion of ecdysterone and metabolites following the consumption of ecdysterone-containing food sources, spinach and quinoa.

After all four administrations to humans (n=8, same participants for each) ecdysterone was excreted and quantified in all volunteers. The metabolite 14-deoxy-ecdysterone was also excreted by all volunteers although in certain cases in quantities below the lowest calibration point of the present study. The second metabolite, 14-deoxy-poststerone, was only detected and quantified in the urine of three volunteers (the same for all study arms). The maximum concentration of ecdysterone ranged between 0.08 and 5.5 μg/mL while for 14-deoxy-ecdysterone from 0.02 to 1.45 μg/mL, and for metabolite 14-deoxy-poststerone from 0.03 to 1.9 μg/mL.

Ecdysterone was not always the most abundant analyte found in the urine, since in certain volunteers 14-deoxy-ecdysterone or 14-deoxy-poststerone was excreted in higher amounts. Another aim of the current study was the comparison of ecdysterone and its metabolites excretion after the ingestion of spinach in different preparations and after the ingestion of sole quinoa and combined with spinach. For both sautéed and smoothie administrations the mean (SD) of the total excreted amount (%) of ecdysterone as unchanged plus the metabolites in urine was 1.4 (1.0) %, consequently no significant difference was observed. On the other hand, significant difference was found in the total excreted amount (%) between the consumption of sole quinoa (mean (SD) 2.6 (1.1) %) and combined with spinach (mean (SD) 1.7 (0.9) %).