Algae-Derived Bioactive Molecules for the Potential Treatment of SARS-CoV-2

Abstract

The recently emerged COVID-19 disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has adversely affected the whole world. As a significant public health threat, it has spread worldwide. Scientists and global health experts are collaborating to find and execute speedy diagnostics, robust and highly effective vaccines, and therapeutic techniques to tackle COVID-19. The ocean is an immense source of biologically active molecules and/or compounds with antiviral-associated biopharmaceutical and immunostimulatory attributes. Some specific algae-derived molecules can be used to produce antibodies and vaccines to treat the COVID-19 disease. Algae have successfully synthesized several metabolites as natural defense compounds that enable them to survive under extreme environments. Several algae-derived bioactive molecules and/or compounds can be used against many diseases, including microbial and viral infections. Moreover, some algae species can also improve immunity and suppress human viral activity. Therefore, they may be recommended for use as a preventive remedy against COVID-19. Considering the above critiques and unique attributes, herein, we aimed to systematically assess algae-derived, biologically active molecules that could be used against this disease by looking at their natural sources, mechanisms of action, and prior pharmacological uses. This review also serves as a starting point for this research area to accelerate the establishment of anti-SARS-CoV-2 bioproducts.

Keywords: COVID-19 treatment; algae compounds; antiviral agent; bioactive entities; immunomodulatory; pharmacological uses; therapeutic aspects.

Figure 1

A schematic of seaweed polysaccharides (SP) used as notable biotherapeutic agents against SARS-CoV-2. The figure was created with the “BioRender.com” template and exported under the terms of premium subscription.

Figure 2

The putative association between ACE2 shedding after SARS-CoV-2 infection. Reprinted from Viana et al. [56] with permission from Elsevier. Copyright 2021, Elsevier. License Number: 4993920853888.

Figure 3

A schematic of the COVID-19 viral immune response and the targets of common dermatologic immunomodulators. The SARS-CoV-2 virus attacks host cells by binding to their receptors present in the cell membrane. Upon the first infection, lung epithelial cells become the primary target, where the receptor-binding domain of the virus spikes binds to ACE2 receptors. SARS-CoV-2 infects the human lung epithelium via the receptor ACE2. Viral RNA activates endosomal and cytoplasmic sensors (TLR3/7 and MAVS, respectively). These receptors activate interferon regulatory factors (IRFs) and NFkB to induce inflammatory cytokines, including interferons (IFN). CD8 T cells induce apoptosis after the recognition of antigens on infected cells. Conversely, activated B cells differentiate into plasma cells that produce antibodies important for neutralizing viruses. This figure was created with the “BioRender.com” template and exported under the terms of premium subscription.

Figure 4

An array of algae-based antioxidants. The inner circle shows the diversity of biologically active antioxidants produced in a marine environment. The outer circle represents their novel therapeutic and biomedical potentialities. Reprinted from Bilal and Iqbal [101] with permission from Elsevier. Copyright 2021 Elsevier B.V. License Number: 4982940408845.