Quantitative Structure-Activity Relationship, Ontology-Based Model of the Antioxidant and Cell Protective Activity of Peat Humic Acids

Abstract

Peat humic acids are well known for their wide range of biological effects which can be attributed to the complex chemical structure of naturally occurring humic substances. One of the promising tools is an ontology-based quantitative analysis of the relationship between physical and chemical parameters describing a chemical structure of peat humic acids and their biological activity. This article demonstrates the feasibility of such an approach to estimate the antioxidant and cell protective properties of the peat humic acids. The structural parameters of the peat humic acids were studied by electronic, fluorescence, infrared, 13C-NMR spectroscopy, titrimetric analysis, elemental C,H,N, and O- analysis, and gel chromatography. Antioxidant and antiradical activities were assessed by physicochemical methods of analysis: electronic paramagnetic resonance, cathodic voltammetry, ABTS•+ scavenging, assay of DPPH radical-scavenging activity, assay of superoxide radical-scavenging activity, iron chelating activity, and scavenging of hydroxyl radicals. Cytoprotective activity was evaluated by the neutral red-based cytotoxicity test in 3T3-L1 cell culture in a wide range of concentrations. Assessment of intracellular ROS production was carried out using a 2,7-dichlorodihydrofluoresceindiacetate (DCFDA) fluorescent probe. Intracellular ROS production was induced using two common prooxidants (tert-butyl hydroperoxide, Fe2+ ions). We suggested an ontology-based model for the antioxidant and cytoprotective activity of humic acids based on experimental data and numerical models. This model establishes the way to further research on the biological effects of humic acids and provides a useful tool for numerical simulation of these effects. Remarkable antioxidant and cell protective activity of humic acids makes them a promising natural source of new pharmaceutical substances that feature a wide range of biological effects.

Enhanced Antioxidant Activity and Reduced Cytotoxicity of Silver Nanoparticles Stabilized by Different Humic Materials

“…In this paper, we present and investigate a new class of AgNPs obtained by the “green synthesis” method based on natural HSs—high-molecular-weight organic compounds that are formed, transformed, and decomposed at intermediate stages of the organic matter mineralization process [ 53 ]. The use of HSs as a matrix allows the introduction of highly efficient nanoparticles, which allows highly reactive and biocompatible “nanocontainers” to be obtained.…”

Coal-Derived Humic Substances: Insight into Chemical Structure Parameters and Biomedical Properties

“…It is not possible to have a prior assumption about the chemical parameters and biological activity of a particular HS from a given raw material source; thus, each HS must be investigated individually. The literature describes a plethora of pharmacological effects for HSs derived from various raw sources, making these molecules very promising for the discovery and development of novel pharmaceuticals and next-generation food products [9][10][11][12][13][14][15][16][17][18][19][20].…”