Antiviral activity of natural humic substances and shilajit materials against HIV-1: Relation to structure

Abstract

Natural products, such as humic substances (HS) and shilajit, are known to possess antiviral activity. Humic-like components are often called as carriers of biological activity of shilajit. The goal of this study was to evaluate anti-HIV activity of well characterized HS isolated from coal, peat, and peloids, and compare it to that of water-soluble organic matter (OM) isolated from different samples of Shilajit. The set of humic materials included 16 samples of different fractional composition: humic acid (HA), hymatomelanic acid (HMA), fulvic acid (FA). The set of shilajit OM included 19 samples of different geographic origin and level of alteration. The HIV-1 p24 antigen assay and cell viability test were used for assessment of antiviral activity. The HIV-1 Bru strain was used to infect CEM-SS cells. The obtained EC50 values varied from 0.37 to 1.4 mg·L -1 for the humic materials, and from 14 to 142 mg·L -1 for the shilajit OM. Hence, all humic materials used in this study outcompeted largely the shilajit materials with respect to anti-HIV activity: For the humic materials, the structure-activity relationships revealed strong correlation between the EC50 values and the content of aromatic carbon indicating the most important role of aromatic structures. For shilajit OM, the reverse relationship was obtained indicating the different mechanism of shilajit activity. The FTICRMS molecular assignments were used for ChEMBL data mining in search of the active humic molecules. As potential carriers of antiviral activity were identified aromatic structures with alkyl substituents, terpenoids, N-containing analogs of typical flavonoids, and aza-podophyllotoxins. The conclusion was made that the typical humic materials and Shilajit differ greatly in molecular composition, and the humic materials have substantial preferences as a natural source of antiviral agents as compared to shilajit.

A Systematic Study of the Antioxidant Capacity of Humic Substances against Peroxyl Radicals: Relation to Structure

“…Recently, HS have attracted increasing attention from the point of view of their use in medicine [ 9 ] due to their therapeutic potential against chronic inflammatory diseases [ 10 , 11 , 12 ], antiviral activity [ 13 , 14 , 15 ], beneficial effect in accelerating cutaneous wound healing [ 16 , 17 ], and chelating activity toward toxic metals [ 18 , 19 ].…”

Bioactivity of Humic Acids Extracted From Shale Ore: Molecular Characterization and Structure-Activity Relationship With Tomato Plant Yield Under Nutritional Stress

“…But, when it comes to the terrestrial soil organic matter (SOM) and its fractions, only a few publications arise (Kramer et al, 2004;Ohno et al, 2010;Piccolo et al, 2010;Ohno and Ohno, 2013;Zherebker et al, 2019), whereas investigations on other sources such as ores or compost are rare. A recent innovative approach has been incorporated in the pipeline of the studies on biologically active metabolites, where molecular formulas obtained by FT-ICR MS were sourced from public online databases with valuable results that helped gathering insights into the chemistry of HS (Fedoros et al, 2018;Orlov et al, 2019;Zhernov et al, 2020).…”

Effect of Broilers Chicken Diet Supplementation with Natural and Acidified Humic Substances on Quality of Produced Breast Meat

“…They are able to affect weight gains positively and enhance function of the immune system [ 10 ]. Certain modified forms of humic acid have been shown to possess antiviral activities [ 11 ]. Vašková et al [ 12 ] also studied the possibility of preventing the consequences of chronic lead poisoning by the administration of three different doses of HS into feed.…”