Promising Marine Natural Products for Tackling Viral Outbreaks: A Focus on Possible Targets and Structure-activity Relationship.

Recently, people worldwide have experienced several outbreaks caused by viruses that have attracted much interest globally, such as HIV, Zika, Ebola, and the one being faced, SARSCoV- 2 viruses. Unfortunately, the availability of drugs giving satisfying outcomes in curing those diseases is limited. Therefore, it is necessary to dig deeper to provide compounds that can tackle the causative viruses. Meanwhile, the efforts to explore marine natural products have been gaining great interest as the products have consistently shown several promising biological activities, including antiviral activity. This review summarizes some products extracted from marine organisms, such as seaweeds, seagrasses, sponges, and marine bacteria, reported in recent years to have potential antiviral activities tested through several methods. The mechanisms by which those compounds exert their antiviral effects are also described here, with several main mechanisms closely associated with the ability of the products to block the entry of the viruses into the host cells, inhibiting replication or transcription of the viral genetic material, and disturbing the assembly of viral components. In addition, the structure-activity relationship of the compounds is also highlighted by focusing on six groups of marine compounds, namely sulfated polysaccharides, phlorotannins, terpenoids, lectins, alkaloids, and flavonoids. In conclusion, due to their uniqueness compared to substances extracted from terrestrial sources, marine organisms provide abundant products having promising activities as antiviral agents that can be explored to tackle virus-caused outbreaks.

Molecular Docking of Phytochemical Compounds of Momordica charantia as Potential Inhibitors against SARS-CoV-2.

BACKGROUND: Coronavirus disease 2019 (COVID-19) has been recently declared as a global public health emergency, where the infection is caused by SARS-CoV-2. Nowadays, there is no specific treatment to cure this infection. The main protease (Mpro) of SARS-CoV-2 and SARS spike glycoprotein- human ACE2 complex have been recognized as suitable targets for treatment, including COVID-19 vaccines. OBJECTIVE: In our current study, we identified the potential of Momordica charantia as a prospective alternative and a choice in dietary food during a pandemic. MATERIALS AND METHODS: A total of 16 bioactive compounds of Momordica charantia were screened for activity against 6LU7 and 6CS2 with AutoDockVina. RESULTS: We found that momordicoside B showed the lowest binding energy compared to other compounds. In addition, kuguaglycoside A and cucurbitadienol showed better profiles for drug-like properties based on Lipinski's rule of five. CONCLUSION: Our result indicates that these molecules can be further explored as promising candidates against SARS-CoV-2 or Momordica charantia can be used as one of the best food alternatives to be consumed during the pandemic.

Selective delivery of silver nanoparticles for improved treatment of biofilm skin infection using bacteria-responsive microparticles loaded into dissolving microneedles.

The treatment of infected chronic wounds has been hampered by development of bacterial biofilms and the low penetration of antibacterial compounds delivered by conventional dosage forms. Numerous bacterial biofilm formers have shown resistance to synthetic antibacterial agents. In this study, we explore the potential of silver nanoparticles (NPs) synthesized using green tea extract as antibiofilm agents against Staphylococcus aureus (SA) and Pseudomonas aeruginosa (PA) biofilms. Due to the toxicity of silver NPs, for the first time, silver NPs were incorporated into bacteria-responsive microparticles (MPs) prepared from poly (Ɛ-caprolactone) decorated with chitosan. The in vitro release of silver NPs from MPs increased up to 9-times in the presence of SA and PA, showing the selectivity of this approach. Incorporation of the MPs into dissolving microneedles (DMNs) could enhance the dermatokinetic profiles of silver NPs compared to DMNs containing silver NPs without MP formulations and conventional cream formulations. Furthermore, 100% of bacterial bioburdens were eradicated on ex vivo biofilm model in rat skin following 60 h of the administration of this system. The findings revealed here confirmed the feasibility of the loading of silver NPs into responsive MPs for improved antibiofilm activities when delivered using DMNs. Following on from these promising results, toxicity and in vivo pharmacodynamic studies should now be carried out in an appropriate model.