historical research on prevention and treatment of coronavirus

As a scientist, I find my answers in a thorough investigation of research. I encourage others to follow suit because data provides us with knowledge, and knowledge empowers us. I have highlighted some of the research I have done below:

From: Zn(2+) Inhibits Coronavirus and Arterivirus RNA Polymerase Activity in Vitro and Zinc Ionophores Block the Replication of These Viruses in Cell Culture (2010)

"Increasing the intracellular zinc concentration can efficiently impair the replication of a variety of RNA viruses, including poliovirus and influenza virus. For some viruses this effect has been attributed to interference with viral polyprotein processing. In this study we demonstrate that the combination of Zn(2+) and PT at low concentrations (2 µM Zn(2+) and 2 µM PT) inhibits the replication of SARS-coronavirus (SARS-CoV) and equine arteritis virus (EAV) in cell culture. The RNA synthesis of these two distantly related nidoviruses is catalyzed by an RNA-dependent RNA polymerase (RdRp), which is the core enzyme of their multiprotein replication and transcription complex (RTC). Using an activity assay for RTCs isolated from cells infected with SARS-CoV or EAV--thus eliminating the need for PT to transport Zn(2+) across the plasma membrane--we show that Zn(2+) efficiently inhibits the RNA-synthesizing activity of the RTCs of both viruses."

"Enzymatic studies using recombinant RdRps (SARS-CoV nsp12 and EAV nsp9) purified from E. coli subsequently revealed that Zn(2+) directly inhibited the in vitro activity of both nidovirus polymerases. More specifically, Zn(2+) was found to block the initiation step of EAV RNA synthesis, whereas in the case of the SARS-CoV RdRp elongation was inhibited and template binding reduced. By chelating Zn(2+) with MgEDTA, the inhibitory effect of the divalent cation could be reversed, which provides a novel experimental tool for in vitro studies of the molecular details of nidovirus replication and transcription."

My advice: Consider zinc lozenges

From: Recent developments in anti-severe acute respiratory syndrome coronavirus chemotherapy (2011)

"Severe acute respiratory syndrome coronavirus (SARS-CoV) emerged in early 2003 to cause a very severe acute respiratory syndrome, which eventually resulted in a 10% case-fatality rate. Owing to excellent public health measures that isolated focus cases and their contacts, and the use of supportive therapies, the epidemic was suppressed to the point that further cases have not appeared since 2005. However, despite intensive research since then (over 3500 publications), it remains an untreatable disease. The potential for re-emergence of the SARS-CoV or a similar virus with unknown but potentially serious consequences remains high. This is due in part to the extreme genetic variability of RNA viruses such as the coronaviruses, the many animal reservoirs that seem to be able host the SARS-CoV in which reassortment or recombination events could occur and the ability coronaviruses have to transmit relatively rapidly from species to species in a short period of time."

Potential for natural remedies?

"Diterpenoids, sesquiterpenoids, triterpenoids, lignoids and curcumin were shown to inhibit SARS-CoV in the range of 3–10 µM [89]. The most selective of these compounds were a diterpenoid, 8b-hydroxyabieta-9(11),13-dien-12-one, with a SI of >557 and a lignin, savinin, with a SI >667. Betulinic acid with a SI of 180 and savinin were competitive inhibitors of SARS-CoV 3CL protease with Ki values of 8.2 ± 0.7 and 9.1 ± 2.4 µM, respectively. The study is somewhat problematic to interpret because the authors pretreated cells with compound prior to addition of the virus to cells. It is not clear whether the compound was removed from the plate wells prior to the addition of the virus. Thus, one cannot rule out the possibility that the inhibitory activity was due to a virucidal effect or the removal of virus receptor from cells. However, the authors do present some evidence suggesting that the observed effect was due to binding of these compounds to the spike protein of SARS. In addition, some test phytochemicals mentioned in the paper inhibited SARS 3CL protease activity in enzyme assays.

Traditional herbs from many geographical areas and environments have been considered as potential new drugs for treatment of viral infections, including those caused by SARS-CoV. An extract from the leaves of Toona sinensis Roem inhibited SARS-CoV replication with EC50 values ranging from 30 to 40 µg/ml and SI values ranging from 12 to 17 [90]. The extract was not toxic up to 500 µg/ml. It is, therefore, unknown as to how much of the antiviral activity could be attributed to physical inactivation of the virus. In addition, a variety of compounds have been extracted from the tender leaf of the Toona sinensis Roem plant, and it is unknown which one compound or combination of compounds was responsible for the activity reported above, or what the target of inhibition may have been. In another study, ginsenoside-Rb1 purified from Panax ginseng showed antiviral activity at 100 µM, although the toxicity of the compound is unknown"

My advice: Consider curcumin

From: Specific plant terpenoids and lignoids possess potent antiviral activities against severe acute respiratory syndrome coronavirus. (2007)

"In this study, 221 phytocompounds were evaluated for activity against anti-severe acute respiratory syndrome associated coronavirus (SARS-CoV) activities using a cell-based assay measuring SARS-CoV-induced cytopathogenic effect on Vero E6 cells. Ten diterpenoids (1-10), two sesquiterpenoids (11 and 12), two triterpenoids (13 and 14), five lignoids (15-19), curcumin (20), and reference controls niclosamide (21) and valinomycin (22) were potent inhibitors at concentrations between 3.3 and 10 microM. The concentrations of the 22 compounds to inhibit 50% of Vero E6 cell proliferation (CC50) and viral replication (EC50) were measured. The selective index values (SI = CC50/EC50) of the most potent compounds 1, 5, 6, 8, 14, and 16 were 58, >510, 111, 193, 180, and >667, respectively. Betulinic acid (13) and savinin (16) were competitive inhibitors of SARS-CoV 3CL protease with Ki values = 8.2 +/- 0.7 and 9.1 +/- 2.4 microM, respectively. Our findings suggest that specific abietane-type diterpenoids and lignoids exhibit strong anti-SARS-CoV effects."

"abietane-type diterpenoids"

Jatropha multifida

Anti-influenza virus activity of extracts from the stems of Jatropha multifida Linn. collected in Myanmar

"The H2O or CHCl3 extracts from the stems of J. multifida collected in Myanmar demonstrated the strongest inhibition of influenza A H1N1 viral infection or growth in MDCK cells, respectively. These results indicated that the stems of J. multifida could be regarded as an anti-influenza herbal medicine as well as a potential crude drug source for the development of anti-influenza compounds."

Toona sinensis

From: Toona sinensis Roem tender leaf extract inhibits SARS coronavirus replication. (2008)

Abstract Severe acute respiratory syndrome (SARS) is a life-threatening disease caused by the SARS coronavirus (SARS-CoV). The development of new antiviral agents for SARS-CoV is an important issue. We tried to find potential resource from Traditional Chinese medicine (TCM) for development of new drugs against SARS-CoV.

Methods Our team recruited the potential TCM formulae (also known as Kampo) from two TCM books, Shang-Han Lun (Discussion of Cold-Induced Disorders) and Wen-Bing Tiau-Bein (Differential Management of Febrile Diseases). Several herbs, which were believed to be beneficial for SARS by experienced TCM doctors were also recruited. In addition, a vegetable polular in Taiwan, China and Malaysia, the tender leaf of Toona sinensis Roem (also known as Cedrela sinensis, belongs to the family Meliacceae) was also recruited under the suggestion of botanic experts. These TCM products and plant extrats were then tested for the effectiveness against SARS-CoV in vitro.

Results Only TSL-1, the extract from tender leaf of Toona sinensis Roem was found to have an evident effect against SARS-CoV with selectivity index 12 approximately 17.

Conclusion This paper reports for the first time that extract from a vegetable, the tender leaf of Toona sinensis Roem, can inhibit SARS-CoV in vitro. Thererfore, the tender leaf of Toona sinensis Roem may be an important resource agninst SARS-CoV.

Final Thoughts

There have been several holistic remedies that have proven efficacious for treatment of viruses similar to COVID-19. I suggest you do your own research to determine the