Abstract
This comprehensive review presents the results of an in-depth analytical literature search on the biological activity of humic substances and their possible pharmacological mechanisms of action. The unique chemical structure of humic substances has determined their widespread use in many economic sectors, including medicine. Thanks to modern advances in pharmaceuticals, pharmacology, and toxicology, it has been possible to demonstrate the multifaceted biological activity of humic substances and, consequently, the possibility of using them to treat and prevent many infectious and non-infectious pathologies, including diseases considered incurable. The article presents data on their immunotropic, antibacterial, antiviral (including HIV), antitumor, antioxidant and antiradical, cardiotropic, hepatoprotective, regenerative, detoxifying, and adaptogenic effects; their influence on the intestinal microbiome; studies of the toxic properties of humic substances and the safety of their use in medicine; and the current trend of using humic substances as unique matrices for creating next-generation bionanomaterials. An analysis of data on the intracellular mechanisms that play a key role in the implementation of the effects of humic substances is conducted. Thus, the natural genesis of humic substances, their multifaceted biological activity, and the absence of toxic and allergenic properties explain the growing interest of scientists from all over the world in their study.