P-coumaric acid for COVID-19

BackgroundThe challenges posed by Coronavirus disease 2019 (COVID-19), including treatment resistance, pandemic threats, and vaccine failure, necessitate the need for locally sourced efficacious therapeutic interventions. We investigated the in-vitro antiviral effects of natural medicinal compounds from Artemisia spp., validated by molecular docking, on TNF-α levels in hospitalized SARS-CoV-2 patients from a designated Lagos COVID-19 isolation centre.MethodsBioactive chemicals in ethanol and dichloromethane (DCM) extracts from freshly collected, dried, and powdered A. afra and A. annua leaves were characterised using UHPLC. A cross-sectional study of 253 hospitalised SARS-CoV-2 patients was conducted to evaluate the extracts' antiviral activity through serum TNF-α modulation; and docking techniques to determine compound-TNF-α binding affinities.ResultsPhytochemical screening of A. annua revealed therapeutic constituents ((lactones, monoterpenes, flavonoids, and sesquiterpenes (artemisinin, rutin, and phenolic acids)) confirmed by UHPLC. The dichloromethane extract of A. afra demonstrated greater TNF-α inhibition in critically ill COVID-19 patients unlike ethanol extracts. Molecular docking validated TNF-α binding affinity for most isolated compounds. ConclusionsArtemisia spp. promises antiviral-proinflammatory cytokine regulation, justifying clinical COVID-19 prophylaxis/therapeutic research, especially against resistant SARS-CoV-2 variants. This could reduce vaccination dependency in impoverished nations while addressing vaccine efficacy and local immunity gaps.Rwanda J Med Health Sci 2025;8(2):181-197

The molecules that consist of propolis are generally polyphenols, and they have many activities such as antiviral, antibacterial and antifungal activities. In this study, it is aimed to investigate the inhibiting capacity of the interaction between ACE-2 and Spike RBS by propolis samples belong to three different cities (Trabzon, Kocaeli, Kırıkkkale). After determining the propolis sample exhibiting the highest inhibition effect, the phenolics within this sample were identified, individual assessments of the inhibition effects of each phenolic compound were conducted with Spike S1 (SARS-CoV-2): ACE2 Inhibitor Screening Colorimetric Assay Kit and supported by docking studies in silico. Propolis sample with the highest inhibition effect was determined as 'Kocaeli'. Then, the pure molecules known to be present in Kocaeli propolis were tested and found that p-OH benzoic acid, syringic acid, ferulic acid and gallic acid did not have any inhibitory effects on the Spike S1 (SARS-CoV-2): ACE2 interaction. The substances with the greatest inhibitory effect are; protocathecuic acid, caffeic acid, p-coumaric acid with the inhibition of 62.29%, 58.34%, 59.20%, respectively. The lowest IC50 value of the flavonoids was found to be 0.89 mM with caffeic acid. Over all in silico, in vitro experiments, and MTT analyses conducted in the literature have demonstrated that caffeic acid and protocatechuic acid can be used as a highly active compound against COVID-19.

Natural products and plant extracts exhibit many biological activities, including that related to the defense mechanisms against parasites. Many studies have investigated the biological functions of secondary metabolites and reported evidence of antiviral activities. The pandemic emergencies have further increased the interest in finding antiviral agents, and efforts are oriented to investigate possible activities of secondary plant metabolites against human viruses and their potential application in treating or preventing SARS-CoV-2 infection. In this review, we performed a comprehensive analysis of studies through in silico and in vitro investigations, also including in vivo applications and clinical trials, to evaluate the state of knowledge on the antiviral activities of secondary metabolites against human viruses and their potential application in treating or preventing SARS-CoV-2 infection, with a particular focus on natural compounds present in food plants. Although some of the food plant secondary metabolites seem to be useful in the prevention and as a possible therapeutic management against SARS-CoV-2, up to now, no molecules can be used as a potential treatment for COVID-19; however, more research is needed.