Screening Methods for Bioactivity and Pharmacological Properties of Natural Products

Taylor Fairfax^*
*Correspondence: Taylor Fairfax, Department of Pharmaceutical and Medicinal Chemistry, University of Berlin, Berlin, Germany, Email:

Keywords

Natural products • Pharmacological properties • Drug discovery • Therapeutic applications • Mechanisms of action • Marine organisms • Bioavailability

Introduction

Screening methods of natural products for bioactivity and pharmacological properties of encompass a diverse array of experimental approaches and techniques used to evaluate the biological activities, therapeutic potential, and pharmacological properties of bioactive compounds derived from plants, microorganisms, marine organisms, and fungi. These screening methods play a crucial role in natural product research and drug discovery, enabling the identification of lead compounds with potential applications in pharmaceutical, agricultural, and industrial sectors. In vitro bioassays are widely used screening methods to assess the biological activities of natural products against specific molecular targets, cellular pathways, and physiological processes. These assays utilize cultured cells, tissues, or isolated biomolecules to evaluate the pharmacological effects, potency, and mechanisms of action of bioactive compounds. In vitro bioassays provide valuable insights into the molecular interactions, cellular responses, and therapeutic potential of natural products, facilitating the identification of lead compounds for further development. Cell viability assays measure the viability, proliferation, and cytotoxicity of cultured cells exposed to natural product extracts or purified compounds. These assays assess the impact of bioactive compounds on cell morphology, membrane integrity, metabolic activity, and cell proliferation using colorimetric, fluorometric, or luminescent readouts. Common cell viability assays include the MTT assay, Alamar Blue assay, resazurin assay, and lactate dehydrogenase release assay, which provide quantitative data on cell viability and cytotoxicity in response to treatment with natural products [1].

Literature Review

Enzyme inhibition assays evaluate the ability of natural products to inhibit specific enzymatic activities involved in physiological processes and disease pathways. These assays measure changes in enzyme activity, substrate turnover, or product formation following exposure to natural product extracts or isolated compounds. Enzyme inhibition assays are used to screen for potential inhibitors of proteases, kinases, oxidoreductases, and other enzyme classes implicated in cancer, inflammation, infectious diseases, and metabolic disorders. Examples include protease inhibition assays, kinase activity assays, and antioxidant enzyme assays, which assess the inhibitory effects of natural products on enzymatic reactions. Receptor binding assays assess the binding affinity and interaction of natural products with specific cellular receptors, ion channels, or signaling molecules implicated in disease pathways. These assays utilize radiolabeled ligands, fluorescent probes, or competitive binding assays to measure the binding kinetics, affinity, and specificity of natural products for target receptors. Receptor binding assays are essential for screening potential ligands, agonists, antagonists, or modulators of G protein-coupled receptors, ionotropic receptors, nuclear receptors, and other receptor classes involved in neurotransmission, hormone signaling, and immune responses [2].

Ion channel assays evaluate the effects of natural products on ion channel activity, membrane potential, and electrical excitability in excitable cells, neurons, and cardiac myocytes. These assays measure changes in ion flux, channel conductance, or membrane depolarization induced by natural product compounds using electrophysiological techniques, fluorescent dyes, or voltage-sensitive probes. Ion channel assays are used to screen for modulators of voltage-gated ion channels (e.g., sodium, potassium, calcium channels) and ligand-gated ion channels (e.g., glutamate receptors, nicotinic receptors) implicated in neurological disorders, cardiac arrhythmias, and sensory perception [3].

Antimicrobial susceptibility assays assess the antimicrobial activity and efficacy of natural products against bacterial, fungal, parasitic, and viral pathogens. These assays measure the inhibitory effects of natural product extracts or compounds on microbial growth, replication, or survival using agar diffusion assays, broth microdilution assays, or automated microbial growth analysis systems. Antimicrobial susceptibility assays provide quantitative data on minimum inhibitory concentrations (MICs), minimum bactericidal concentrations and inhibition zone diameters, which indicate the potency and spectrum of antimicrobial activity exhibited by natural products. Anti-inflammatory assays evaluate the anti-inflammatory effects and immunomodulatory properties of natural products in vitro using immune cell models, inflammatory mediators, and cytokine production assays. These assays measure the inhibition of pro-inflammatory cytokines (e.g., TNF-alpha, IL-6, IL-1beta), prostaglandins, and reactive oxygen species released by immune cells in response to inflammatory stimuli or microbial pathogens. Anti-inflammatory assays assess the potential of natural products to modulate inflammatory signaling pathways, attenuate immune responses, and alleviate inflammatory conditions associated with chronic diseases, autoimmune disorders, and inflammatory bowel diseases [4].

Antioxidant activity assays evaluate the antioxidant capacity and free radical-scavenging properties of natural products to protect cells and tissues against oxidative stress and lipid peroxidation. These assays measure the ability of natural product extracts or compounds to inhibit lipid oxidation, reduce reactive oxygen species levels, or scavenge free radicals using spectrophotometric methods, electron paramagnetic resonance spectroscopy, or chemiluminescence assays. Antioxidant activity assays assess the potential of natural products to mitigate oxidative damage, enhance cellular antioxidant defenses, and prevent oxidative stress-related diseases, including cardiovascular disorders, neurodegenerative diseases, and aging processes. Anticancer screening assays evaluate the cytotoxicity, apoptotic induction, and growth inhibitory effects of natural products against cancer cell lines, tumor xenograft models, and primary cancer cells. These assays measure changes in cell viability, proliferation, apoptosis, and cell cycle progression following treatment with natural product extracts or compounds using high-throughput screening platforms, flow cytometry, and fluorescence microscopy. Anticancer screening assays assess the potential of natural products to target cancer-specific pathways, inhibit tumor growth, and sensitize cancer cells to chemotherapy or radiotherapy, offering potential therapeutic strategies for cancer treatment and management [5].

Discussion

Neuroprotective assays assess the neuroprotective effects and neuronal viability-promoting properties of natural products against neurotoxic insults, oxidative stress, and neurodegenerative conditions. These assays utilize neuronal cell cultures, brain slice preparations, and animal models of neurodegeneration to evaluate the effects of natural product extracts or compounds on neuronal survival, synaptic function, and neurotransmitter release. Neuroprotective assays measure changes in neuronal morphology, mitochondrial function, and neuronal markers to assess the potential of natural products to enhance neuronal resilience, promote neuroregeneration, and mitigate neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, and stroke. Pharmacokinetic and toxicological screening assays assess the absorption, distribution, metabolism, excretion, and toxicity profiles of natural products to evaluate their pharmacokinetic properties and safety profiles for clinical development. These assays utilize in vitro models, such as liver microsomes, intestinal epithelial cells, and kidney cell lines, to predict drug metabolism, bioavailability, and potential drug-drug interactions. Pharmacokinetic screening assays assess the stability, solubility, permeability, and plasma protein binding of natural products, while toxicological screening assays evaluate acute toxicity, genotoxicity, mutagenicity, and adverse effects using standardized experimental protocols and regulatory guidelines. High-throughput screening platforms enable rapid, automated screening of large compound libraries to identify lead compounds with desired bioactivity and pharmacological properties. These platforms utilize robotics, liquid handling systems, and microplate-based assays to screen natural product extracts, purified compounds, or synthetic libraries against diverse biological targets and disease models. HTS platforms accelerate the drug discovery process, optimize screening workflows, and prioritize lead compounds for further characterization and development, facilitating the identification of novel therapeutic agents from natural sources.

Computational screening and virtual screening methods utilize computational modeling, molecular docking, and structure-based drug design to predict the bioactivity, binding affinity, and molecular interactions of natural products with target receptors, enzymes, or biological pathways. These in silico approaches analyze molecular structures, physicochemical properties, and pharmacophore features of natural product compounds to prioritize candidates for experimental validation and optimize lead optimization strategies. Computational screening and virtual screening methods complement experimental screening assays, streamline hit identification, and accelerate the discovery of bioactive compounds with therapeutic potential from natural sources. The integration of screening methods, multi-disciplinary approaches, and advanced technologies enhances the efficiency, reliability, and translational impact of natural product research in drug discovery and development. Collaborative efforts between academia, industry, and government agencies facilitate technology transfer, knowledge exchange, and innovation in screening methods for pharmacological and bioactivity properties of natural products. By leveraging the diversity, complexity, and therapeutic potential of natural sources, screening methods contribute to the identification of lead compounds, drug candidates, and therapeutic interventions for human health, agriculture, and industrial applications [6].

Conclusion

In summary, the screening methods of natural products are pivotal in advancing our understanding of these complex compounds and their potential therapeutic applications. The diverse array of techniques, from high-throughput screening to in vitro and in vivo assays, provides a comprehensive toolkit for evaluating the efficacy, safety, and mechanisms of action of natural products. These methods not only facilitate the identification of promising drug candidates but also aid in elucidating the underlying biological pathways and interactions involved. As research progresses, there is a growing need for innovative approaches that integrate modern technologies with traditional methodologies. Advancements such as genomics, proteomics, and bioinformatics offer new avenues for enhancing the precision and efficiency of screening processes. Moreover, overcoming challenges related to bioavailability, specificity, and toxicity remains crucial for translating natural products from the laboratory to clinical settings.

Acknowledgment

None.

Conflict of Interest

None.

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