Marine Natural Products: Promising Candidates in the Modulation of Gut-Brain Axis towards Neuroprotection.

In recent decades, several neuroprotective agents have been provided in combating neuronal dysfunctions; however, no effective treatment has been found towards the complete eradication of neurodegenerative diseases. From the pathophysiological point of view, growing studies are indicating a bidirectional relationship between gut and brain termed gut-brain axis in the context of health/disease. Revealing the gut-brain axis has survived new hopes in the prevention, management, and treatment of neurodegenerative diseases. Accordingly, introducing novel alternative therapies in regulating the gut-brain axis seems to be an emerging concept to pave the road in fighting neurodegenerative diseases. Growing studies have developed marine-derived natural products as hopeful candidates in a simultaneous targeting of gut-brain dysregulated mediators towards neuroprotection. Of marine natural products, carotenoids (e.g., fucoxanthin, and astaxanthin), phytosterols (e.g., fucosterol), polysaccharides (e.g., fucoidan, chitosan, alginate, and laminarin), macrolactins (e.g., macrolactin A), diterpenes (e.g., lobocrasol, excavatolide B, and crassumol E) and sesquiterpenes (e.g., zonarol) have shown to be promising candidates in modulating gut-brain axis. The aforementioned marine natural products are potential regulators of inflammatory, apoptotic, and oxidative stress mediators towards a bidirectional regulation of the gut-brain axis. The present study aims at describing the gut-brain axis, the importance of gut microbiota in neurological diseases, as well as the modulatory role of marine natural products towards neuroprotection.

Targeting pivotal inflammatory pathways in COVID-19: A mechanistic review.

As an emerging global health crisis, coronavirus disease 2019 (COVID-19) has been labeled a worldwide pandemic. Growing evidence is revealing further pathophysiological mechanisms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Amongst these dysregulated pathways inflammation seems to play a more critical role toward COVID-19 complications. In the present study, precise inflammatory pathways triggered by SARS-CoV-2, along with potential therapeutic candidates have been discussed. Prevailing evidence has indicated a close correlation of inflammatory cascades with severity, pathological progression, and organ damages in COVID-19 patients. From the mechanistic point of view, interleukin-6, interleukin-1ß receptor, interferon-gamma, tumor necrosis factor-alpha receptor, toll-like receptor, receptor tyrosine kinases, growth factor receptor, Janus kinase/signal transducers and transcription pathway, mammalian target of rapamycin, cytokine storm and macrophage activation have shown to play critical roles in COVID-19 complications. So, there is an urgent need to provide novel mechanistic-based anti-inflammatory agents. This review highlights inflammatory signaling pathways of SARS-CoV-2. Several therapeutic targets and treatment strategies have also been provided in an attempt to tackle COVID-19 complications.