Concomitant oral intake of purified clinoptilolite tuff (G-PUR) reduces enteral lead uptake in healthy humans

Karolina Samekova,Michael Freissmuth,Cornelius Tschegg,Johanna Irrgeher,Anastassiya Tchaikovsky,Anika Retzmann,Michael Wolzt,Ghazaleh Gouya,Claudia Meisslitzer,Christa Firbas,Thomas Prohaska,Christine Opper

doi:10.1038/s41598-021-94245-x

Karolina Samekova, Michael Freissmuth + Show 10 more

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https://doi.org/10.1038/s41598-021-94245-x

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Abstract

Lead exposure can cause substantial organ damage. Enteral lead absorption may be reduced by concomitant intake of clinoptilolite tuff, a zeolite from natural sources. This study aimed to assess the effect of purified clinoptilolite tuff (G-PUR) on enteral lead uptake in adults using stable lead isotope 204Pb as a tracer. In this randomized, placebo-controlled, double-blind, parallel-group study, 42 healthy participants were randomized to receive oral G-PUR 2.0 g, 2 * 2.0 g, or placebo, together with 2.5 µg of 204Pb in water. The enrichment of 204Pb caused by the tracer in blood and urine was measured by mass spectrometry. G-PUR was well tolerated. The mean maximum 204Pb enrichment of 0.505% of total blood lead was significantly higher (p < 0.0001) in the placebo group compared to G-PUR 2.0 g (0.073%) or G-PUR 2 * 2.0 g (0.057%) group. Normalized 204Pb AUC0-192 was 86.5, 11.9, and 8.5% * h without and with G-PUR 2.0 g, and G-PUR 2 * 2.0 g, respectively (p < 0.0001 vs. placebo). This smaller 204Pb exposure was paralleled by a reduced urinary excretion in subjects receiving G-PUR. Concomitant oral intake of purified clinoptilolite tuff reduced enteral uptake of 204Pb in healthy humans by approximately 90%. The reduced bioavailability is demonstrable by a decrease of 204Pb tracer enrichment in blood and urine.Trial registration: clinicaltrials.gov identifier: NCT04138693, registered 24/10/2019.

Highlights

Lead exposure can cause substantial organ damage
A substantial variability between subjects was noted for blood total Pb concentrations, which were lower in the G-PUR 2.0 g dose group (Table 3)
204Pb enrichment in blood increased to a mean Cmax of 0.505% of total Pb in the absence of G-PUR intake. 204Pb enrichment was slow and reached a plateau between 24 and 48 h, which was maintained until day 6 after dosing (Fig. 1)

Summary

Introduction

Enteral lead absorption may be reduced by concomitant intake of clinoptilolite tuff, a zeolite from natural sources. This study aimed to assess the effect of purified clinoptilolite tuff (G-PUR) on enteral lead uptake in adults using stable lead isotope 204Pb as a tracer. In this randomized, placebo-controlled, double-blind, parallel-group study, 42 healthy participants were randomized to receive oral G-PUR 2.0 g, 2 * 2.0 g, or placebo, together with 2.5 μg of 204Pb in water. Concomitant oral intake of purified clinoptilolite tuff reduced enteral uptake of 204Pb in healthy humans by approximately 90%. Glock Research Laboratories for Exploratory Drug Development, Center of Physiology and Pharmacology, Scientific Reports | (2021) 11:14796

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