|Posted by George Freund on February 11, 2020 at 12:30 PM|
Cells were fixed with 60 parts methanol to 40 parts acetone 72 h after infection. Virus was detected in serum from the patient with SARS by peroxidase staining. (A) mock infected cells. (B) infected cells without treatment. (C) infected cells treated with 4000 mg/L glycyrrhizin. (D) infected cells treated with 1000 mg/L glycyrrhizin.
Prof J Cinatl, PhD
B Morgenstern, PhD
Prof P Chandra, PhD
Prof H Rabenau, PhD
Prof HW Doerr, PhD
Published:June 14, 2003DOI:https://doi.org/10.1016/S0140-6736(03)13615-X
The outbreak of SARS warrants the search for antiviral compounds to treat the disease. At present, no specific treatment has been identified for SARS-associated coronavirus infection. We assessed the antiviral potential of ribavirin, 6-azauridine, pyrazofurin, mycophenolic acid, and glycyrrhizin against two clinical isolates of coronavirus (FFM-1 and FFM-2) from patients with SARS admitted to the clinical centre of Frankfurt University, Germany. Of all the compounds, glycyrrhizin was the most active in inhibiting replication of the SARS-associated virus. Our findings suggest that glycyrrhizin should be assessed for treatment of SARS.
A new coronavirus has been identified in patients with severe acute respiratory syndrome (SARS).1 SARS is an infectious disease with a high potential for transmission to close contacts. The outbreak of SARS in several countries has led to the search for active antiviral compounds to treat this disease.
Here, we assessed the antiviral activities of ribavirin, 6-azauridine, pyrazofurin, mycophenolic acid, and glycyrrhizin against two clinical isolates of coronavirus (FFM-1 and FFM-2) from patients with SARS admitted to the clinical centre of Frankfurt University, Germany. All the compounds are available commercially and have been used in patients for their antiviral, antitumour, and immunosuppressive activity. We visually scored cytopathogenicity induced by the virus 72–96 h after infection in 96-well microplates on confluent layers of Vero cells. The selectivity index was determined as the ratio of the concentration of the compound that reduced cell viability to 50% (CC50) to the concentration of the compound needed to inhibit the cytopathic effect to 50% of the control value (EC50). We determined the cytotoxicity of the drugs with an MMT cell-proliferative Kit I (Roche, Mannheim, Germany).
Ribavirin and mycophenolic acid, inhibitors of inosine monophosphate dehydrogenase, did not affect replication of the SARS-associated coronaviruses (SARS-CV) (table). The inhibitors of orotidine monophosphate decarboxylase, 6-azauridine and pyrazofurin, inhibited replication of SARS-CV at non-toxic doses with selectivity indices of 5 and 12, respectively. The most potent inhibitor of SARS-CV replication in Vero cells was glycyrrhizin, which had a selectivity index of 67.
Glycyrrhizin (or glycyrrhizic acid or glycyrrhizinic acid) is the chief sweet-tasting constituent of Glycyrrhiza glabra (liquorice) root. Structurally, it is a saponin used as an emulsifier and gel-forming agent in foodstuffs and cosmetics. Its aglycone is enoxolone assessed as a prodrug used in Japan to reduce the risk of liver cancer in people with chronic hepatitis C.
The most widely reported side effect of glycyrrhizin use via consumption of black licorice is reduction of blood potassium levels, which can affect body fluid balance and function of nerves. Chronic consumption of black licorice, even in moderate amounts, is associated with an increase in blood pressure, may cause irregular heart rhythm, and adverse interactions with prescription medicines.
The effects on body fluids are related to the inhibition of cortisol metabolism within the kidney, subsequent stimulation of the mineralocorticoid receptors, and decrease in blood levels of renin, potassium, and aldosterone, which collectively lead to increases in blood pressure.
Depending on amount and frequency of ingesting black licorice, other side effects may include:
So use wisely.