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. 2020 Sep 14:7:1242-1254.
doi: 10.1016/j.toxrep.2020.08.030. eCollection 2020.

A toxicological evaluation of a fulvic and humic acids preparation

Timothy S Murbach  1 , Róbert Glávits  2 , John R Endres  1 , Amy E Clewell  1 , Gábor Hirka  2   3 , Adél Vértesi  3 , Erzsébet Béres  3 , Ilona Pasics Szakonyiné  2
Affiliations

A toxicological evaluation of a fulvic and humic acids preparation

Timothy S Murbach et al. Toxicol Rep. .

Abstract

Humic substances are ubiquitous in soils and waters. These complex superstructures are derived from the decomposition of dead plant and animal matter and are vital to soil health. Their heterogenous composition is specific to their site of origin and is comprised of weakly bound aggregates of small organic compounds that can sequester minerals and make them available to plants. As such, they may possess potential nutritional value for humans, and extractions of fulvic and humic acids can be produced that could be suitable for such purposes. For this reason, we evaluated the toxicological profile of a specific preparation (blk. 333) of fulvic and humic acids derived from a lignite deposit in Alberta, Canada and found it to lack genotoxic potential in a bacterial reverse mutation test, in vitro mammalian chromosomal aberration test, and in vivo mammalian micronucleus test. No general or organ toxicity was observed in Wistar rats following 90 days of continuous exposure, and a no observed adverse effect level (NOEAL) was determined at 2000 mg/kg bw/day, the highest tested dose. Our results suggest the feasibility of further evaluation for development of the preparation as a nutritional supplement in food.

Keywords: ANOVA, analysis of variance; CDFA, California Department of Food and Agricultural; Cl-HA, chlorinated humic acid; DME, Dulbecco’s modified Eagle’s; EFSA, European Food Safety Authority; FA, fulvic acid; FOB, functional observation battery; Fulvic acid; GLP, good laboratory practice; HA, humic acid; Humic acid; MPCE, micronucleated polychromatic erythrocytes; NOAEL; NOAEL, no observed adverse effect level; O3-HA, ozonated humic acid; O3/Cl2-HA, ozonated and chlorinated humic acid; OECD, Organisation for Economic Co-operation and Development; S9, post mitochondrial supernatant S9-mix Phenobarbital/β-naphthoflavone-induced rat liver S9 metabolic activation system; SCE, sister chromatid exchange; SD, Sprague-Dawley; SOP, standard operating procedure; SPF, specific pathogen-free; Safety; TG, test guideline; TSH, thyroid stimulating hormone; Toxicity; blk. 333; fT4, free thyroxine.

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Conflict of interest statement

Authors Timothy Murbach, John Endres, and Amy Clewell are salaried employees of AIBMR Life Sciences, Inc. (Seattle, WA, USA). AIBMR was contracted by the study sponsor, as an independent third party, to determine appropriate study protocols and dose selections, place the studies, approve the study plans, and monitor the toxicological studies herein described and to analyze and interpret the resulting data and prepare the manuscript. Author Gábor Hirka is owner and Managing Director at Toxi-Coop Zrt. (with test facilities in Budapest (90-day study) and Balatonfüred (genotoxicity studies), Hungary); authors Adél Vértesi, Erzsébet Béres, and Ilona Pasics Szakonyiné are salaried employees of Toxi-Coop; and author Róbert Glávits is an independent contractor to Toxi-Coop. Toxi-Coop was contracted by AIBMR to develop the study plans and conduct, analyze and interpret, and report the results of the toxicological studies herein described. The authors declare no additional conflicts of interest in regard to the research, authorship, and/or publication of this article.

Figures

None
Graphical abstract
Fig. 1
Fig. 1
Potential pseudostructures of a.) fulvic acid and b.) humic acid.
Fig. 2
Fig. 2
Male and Female Body Weight Development. (a) Male body weights. (b) Female body weights.
See this image and copyright information in PMC

References

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