There is currently no definitive cure for Covid-19 disease. In mild cases that do not require hospitalization. There is a possibility of disease progression. Some plant extracts have been reported to have antiviral effects. In this study, the effectiveness of a constant dose of Licorice hydroalcoholic extract (glycyrrhizin) in Covid-19 outpatients was investigated.
A total of 40 mild to moderate outpatient Covid-19 cases were randomly assigned into either of the two groups of Licorice and placebo (20 people in each group). Patients in Licorice group were given 700 mg capsules of hydroalcoholic extract of Licorice, trice a day for 2 weeks, while patients in control group were given placebo containing Avicel 600 mg with the same rout. Venous blood samples were collected from all participants before starting the medication and on days three, seven, and 14 for laboratory parameters including quantitative CRP, WBCs, lymphocytes, and neutrophils counts. The clinical symptoms were also recorded.
Our results showed that Licorice extract decreased the rate of cough significantly on day seven (P=0.004); decreased the frequency of dyspnea significantly on day three (P=0.02). No significant differences were found in the frequency of nausea, diarrhea, body pain, sore throat, runny nose, dizziness, lethargy, and loss of taste or smell between the two groups. Patients in Licorice group showed significantly higher percentage of oxygen saturation on days three, seven, and 14. Other laboratory parameters did not show any changes between the two groups.
In general, the use of Licorice extract improved some clinical symptoms such as cough and dyspenea and only increased the oxygen saturation. Further studies with larger sample sizes at different stages of Covid-19 are suggested.