Anurans against SARS-CoV-2: A review of the potential antiviral action of anurans cutaneous peptides

Harnessing marine antimicrobial peptides for novel therapeutics: A deep dive into ocean-derived bioactives

Marine antimicrobial peptides (AMPs) are potent bioactive compounds with broad-spectrum activity against bacteria, viruses, and fungi, offering a promising alternative to traditional antibiotics. These small, cationic, and amphiphilic peptides (3-50 amino acids) are key components of marine organisms' immune defenses, adapted to harsh oceanic environments. Discovered in the 1980s, marine AMPs have garnered interest for their unique structures and potential applications in human health. However, despite the ocean's vast biodiversity, they remain underexplored compared to land-based AMPs. This review emphasizes the therapeutic potential of marine AMPs, including their modes of action, structural variety, and applications in drug development, tissue regeneration, and cancer treatment. Moreover, it discusses their antibacterial, antiviral, antifungal, and antiparasitic properties. Additionally, the review addresses strategies to enhance the therapeutic potential of marine AMPs and the challenges associated with their development. By examining the promising future of marine AMPs, this review aims to pave the way for new approaches to combat antimicrobial resistance and develop innovative treatments for various infectious diseases. The potential of marine AMPs as the "medicine bank of the new millennium" remains vast, providing a valuable resource for future drug discovery and sustainable practices across industries.

In silico antiviral effect assessment of some venom gland peptides from Odontobuthus doriae scorpion against SARS-CoV-2

SARS-CoV-2 is from the enveloped virus family responsible for the COVID-19 pandemic. No efficient drugs are currently available to treat infection explicitly caused by this virus. Therefore, searching for effective treatments for severe illness caused by SARS-CoV-2 is crucial. Scorpion venoms are significant sources of peptides with pharmaceutical potential, including antivirals. Although some studies have determined the antiviral effects of some scorpion peptides on other members of the Coronaviridae family, a few anti-SARS-CoV-2 effects of these peptides have been reported until now. This study assessed the antiviral effects of five predicted antimicrobial peptides with potential for antiviral activities from the Iranian yellow scorpion "Odontobuthus doriae" by computational methods. These peptides were selected from the cDNA library that our research team constructed. A 3D model of peptides was designed with I-TASSER. The models were refined using a 200 ns Molecular Dynamics (MD) simulation using Gromacs 2021.2 software. Refined models were Docked with the RBD domain of SARS-CoV-2 spike protein using HADDOCK software. The docking of human ACE2 peptide with the RBD domain was also assessed. The docked complexes (RBD-peptide and RBD-ACE2) were refined again by a 100 ns MD simulation and then analyzed. The results from molecular docking after molecular dynamics simulation showed that ODAMP2 and ODAMP5 after stabilizing analysis and according to MMPBSA results (with -59.24 kcal/mol and -51.82 kcal/mol, respectively) have a strong binding affinity to the RBD domain of COVID-19 spike protein compared to human ACE2 and some other studied components. Therefore, this peptide can be an excellent candidate for use as an agent to inhibit the RBD domain of SARS-COV2 virus in clinical studies for medicinal purposes after in vitro and in vivo laboratory evaluations.

Skin secretions of Leptodactylidae (Anura) and their potential applications

The skin of anuran species is a protective barrier against predators and pathogens, showing also chemical defense by substances that represent a potential source for bioactive substances. This review describes the current chemical and biological knowledge from the skin secretions of Leptodactylidae species, one of the most diverse neotropical frog families. These skin secretions reveal a variety of substances such as amines (12), neuropeptides (16), and antimicrobial peptides (72). The amines include histamine and its methylated derivatives, tryptamine derivatives and quaternary amines. The peptides of Leptodactylidae species show molecular weight up to 3364 Da and ocellatins are the most reported. The peptides exhibit commonly glycine (G) or glycine-valine (GV) as C-terminal amino acids, and the most common N-terminal amino acids are glutamic acid (E), lysine (K), and valine (V). The substances from Leptodactylidae species have been evaluated against pathogenic microorganisms, particularly Escherichia coli and Staphylococcus aureus, and the most active peptides showed MIC of 1-15 µM. Furthermore, some compounds showed also pharmacological properties such as immunomodulation, treatment of degenerative diseases, anticancer, and antioxidant. Currently, only 9% of the species in this family have been properly studied, highlighting a large number of unstudied species such as an entire subfamily (Paratelmatobiinae). The ecological context, functions, and evolution of peptides and amines in this family are poorly understood and represent a large field for further exploration.