A Study of the Antioxidant, Cytotoxic Activity and Adsorption Properties of Karelian Shungite by Physicochemical Methods

Abstract

This study reveals that fossil shungite samples exhibit antioxidant activity, can reduce oxidized components, and bind to free radicals. A sample of Sh20 (size fraction—20 μm) (1.30 mg equivalents of ascorbic acid/g of shungite; 3.46 mg equivalents of trolox/g of shungite; 0.99 mg equivalents of quercetin/g of shungite) had the maximal activity according to the amperometric method. The obtained data indicate that shungite has antioxidant properties, but these are approximately 1000 times less pronounced than those of quercetin. A ShT20 sample (size fraction—20 μm + heat treatment) was found to have the highest antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl radical and cytotoxicity. Further studies, including the optimization of the antioxidant extraction conditions of shungite, and the analysis of the qualitative and quantitative composition of the obtained extracts, are required for a more accurate interpretation of the results. Shungite can be applied as an alternative to activated carbon in water purification, due to its absorption, catalytic, antioxidant, regenerating, and antibacterial properties, as well as its high environmental safety and relatively low cost. It is possible to identify new structural forms of carbon within, and other valuable properties of, shungite substance, which will make it possible to create effective technologies for the practical use of shungite rocks, particularly in the production of fullerenes and other carbon nanoclusters.

Molecular Serum Albumin Unmask Nanobio Properties of Molecular Graphenes in Shungite Carbon Nanoparticles

“…The antioxidant and cytotoxic activity of shungite extracts has been reported elsewhere [ 54 ]. For the first time, redox properties of ShC NPs were discovered by EPR spectroscopy for model systems of water–spin probe–ShC NPs when the radical oxidation/reduction of the nitroxide spin probe 5DSC was triggered by the introduction of divalent iron ions into the system [ 55 ].…”

Role of Dietary Inclusion of Phytobiotics and Mineral Adsorbent Combination on Dairy Cows′ Milk Production, Nutrient Digestibility, Nitrogen Utilization, and Biochemical Parameters

“…In the studies of [ 24 , 25 , 45 , 47 , 48 ], it was noted that shungite has sorption to inorganic substances (heavy metals, dioxins, pesticide radicals, chlorine, benzene, etc.) and organic pollutants, such as ammonia, surfactants, and petroleum products.…”

“…In addition to organic sorbents of toxins, one of the alternative products is the use of modern sorbents based on shungite rocks with a particle size of up to 1 mm, which is extracted on an industrial scale from the Zazhoginsky deposit in the Republic of Karelia. In our research, we also used mineral additives based on a shungite substance with a particle size of 0.5–1.5 mm in a heat-treated form [ 24 , 25 ].…”

Nanoantioxidant Materials: Nanoengineering Inspired by Nature

“…Carbon-based materials exhibit antioxidant properties owing to their structural features, and sp 2 -hybridized carbon atoms that act as “traps” of free radicals [ 48 ]. Among them, shungite is known to exhibit specific antioxidant activity [ 49 , 50 ].…”