COVID-19 is caused by the SARS-COV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2) virus. This disease is presented with acute lung injury, endothelial dysfunction and multi-organ failure. During the COVID-19 pandemic, various adjuvant herbal therapies were used to manage the symptoms associated with COVID-19. This article will explore the science behind these herbal nutraceuticals in managing viral infection symptoms.
There are various reports on the antiviral potential of berberine. In a pre-clinical study, berberine suppressed SARS-CoV-2 replication in Vero cells when used at a micromolar concentration1. In a similar study, berberine chloride was shown to inhibit SARS-CoV-2 infection in Vero cells in a dose-dependent manner. Interestingly, berberine chloride reduced the infectivity of free virus particles2. Besides pre-clinical studies, various clinical studies highlight berberine's antiviral potential. In a clinical study, 39 Covid patients were enrolled and divided into two groups. One group received routine therapy, while another group received routine therapy in combination with berberine. A significant improvement in the level of circulating inflammatory mediators (IL-6, TNF-α and CRP) was observed in the berberine group3.
SARS-CoV-2 binds to human ACE2 receptors via the RBD domain of its spike protein. Withanone from W. somnifera was reported to inhibit the interaction between the ACE2 receptor and RBD domain at an IC50 of 0.33 ng/mL4. The ocular surface is considered an important route for SARS-CoV-2 transmission. In a study, it was observed that ACE2 expression was upregulated in inflamed human corneal epithelial cells, which was reduced by resveratrol treatment5. Another similar study reported that resveratrol inhibited SARS-CoV-2 infection in human primary bronchial epithelial cells cultured at the air-liquid interface6.
To conclude, nutraceuticals might help manage symptoms of COVID-19 and could help in the recovery process.
References
(1) Varghese, F. S.; van Woudenbergh, E.; Overheul, G. J.; Eleveld, M. J.; Kurver, L.; van Heerbeek, N.; van Laarhoven, A.; Miesen, P.; Den Hartog, G.; de Jonge, M. I.; van Rij, R. P. Berberine and Obatoclax Inhibit Sars-Cov-2 Replication in Primary Human Nasal Epithelial Cells in Vitro. Viruses 2021, 13 (2). https://doi.org/10.3390/v13020282.
(2) Rodriguez-Rodriguez, B. A.; Noval, M. G.; Kaczmarek, M. E.; Jang, K. K.; Thannickal, S. A.; Kottkamp, A. C.; Brown, R. S.; Kielian, M.; Cadwell, K.; Stapleford, K. A. Atovaquone and Berberine Chloride Reduce Sars-Cov-2 Replication in Vitro. Viruses 2021, 13 (12). https://doi.org/10.3390/v13122437.
(3) Zhang, B. Y.; Chen, M.; Chen, X. C.; Cao, K.; You, Y.; Qian, Y. J.; Yu, W. K. Berberine Reduces Circulating Inflammatory Mediators in Patients with Severe COVID-19. British Journal of Surgery 2021, 108 (1), e9–e11. https://doi.org/10.1093/bjs/znaa021.
(4) Balkrishna, A.; Pokhrel, S.; Singh, H.; Joshi, M.; Mulay, V. P.; Haldar, S.; Varshney, A. Withanone from Withania Somnifera Attenuates Sars-Cov-2 Rbd and Host Ace2 Interactions to Rescue Spike Protein Induced Pathologies in Humanized Zebrafish Model. Drug Des Devel Ther 2021, 15, 1111–1133. https://doi.org/10.2147/DDDT.S292805.
(5) Jiang, Z.; Zhang, H.; Gao, J.; Yu, H.; Han, R.; Zhu, L.; Chen, X.; Fan, Q.; Hao, P.; Wang, L.; Li, X. ACE2 Expression Is Upregulated in Inflammatory Corneal Epithelial Cells and Attenuated by Resveratrol. Invest Ophthalmol Vis Sci 2021, 62 (7). https://doi.org/10.1167/IOVS.62.7.25.
(6) Ter Ellen, B. M.; Kumar, N. D.; Bouma, E. M.; Troost, B.; van de Pol, D. P. I.; van der Ende-Metselaar, H. H.; Apperloo, L.; van Gosliga, D.; van den Berge, M.; Nawijn, M. C.; van der Voort, P. H. J.; Moser, J.; Rodenhuis-Zybert, I. A.; Smit, J. M. Resveratrol and Pterostilbene Inhibit Sars-Cov-2 Replication in Air–Liquid Interface Cultured Human Primary Bronchial Epithelial Cells. Viruses 2021, 13 (7). https://doi.org/10.3390/v13071335.
