Table 3.

Effect of glycyrrhizin and boswellic acids on COVID-19 disease in clinical trials published through July 2022

Intervention/drugs	Patients	Design	Trial ID	Main outcomes	References
Glycyrrhizin capsule (GR) (60 mg) and boswellic acids (BA) capsule (200 mg) twice daily for 14 days	50 hospitalized patients with moderate COVID‑19 infection	Randomized, double-blind, placebo-controlled trial single-center trial	NCT04487964	GR + BA combination was effective in preventing mortality, shortening the time to recovery and improving prognosis or decreasing clinical status score on a 7-point scale. The laboratory parameters show significant difference between serum CRP and % lymphocyte of placebo group and intervention group supporting the improvement by GR + BA. It is safe, inexpensive, combination may be considered for use in mild to moderate infections of SARS-CoV-2 or COVID-19 variants	Gomaa et al. (2022)
Diammonium glycyrrhizinate (DG) in dose of 150 mg + vitamin C (VC)	207 COVID-19 patients from Tongji Hospital at Huazhong University (Wuhan, China)	Retrospective, single-center, observational study	Institutional Review Board of Ruijin Hospital, Shanghai Jiao Tong University School of Medicine (No. (2020) Linlun-34th)	DG + VC could reduce the incidence of new-onset complications in COVID-19 patients, and might influence the immune response in these patients. This results suggested that combined treatment of DG + VC is promising candidate for preventing the deterioration of COVID-19 patients	Tan et al. (2022)
Intranasal and oropharyngeal delivery of povidone-iodine 0.5% and glycyrrhizic acid 2.5 mg/ml	200 patients	Randomized-Blinded Controlled Study	PACTR registry under the number PACTR202101875903773	Combined PVI-GA nasal and oropharyngeal spray accelerates both laboratory and clinical recovery of SARS-CoV-2-infected patients in the early phases of the disease and reduces the household spread of the virus	Elsersy et al. (2022)
Viusid is natural product containing glycyrrhizinic acid 30 ml every 8 h for 21 days	60 hospitalized patients with mild to moderate symptoms of COVID-19	Randomized, open-label, controlled trial	MBAL “Sveti Mina” (RCT001/P4/2020)	Its use lead to faster recovery of the patients, decreasing of the hospital stay and milder course of the disease, with good safety and tolerability	Petrov et al. (2021)
Aftogel (licorice extract) oral mucoadhesive patches	125 outpatient with positive real-time PCR	Triple-blind randomized clinical trial	RCT20181208041886N2	The patch is effective in the eradication of SARS-CoV-2, which has colonized the nasopharyngeal area. Hence, this drug product has the potential for evaluation as a prophylactic	Pourahmad et al. (2022)
Inflawell Syrup (Boswellia extract formulation enriched for boswellic acids (BAs), 10 ml of syrup thrice daily (400 mg BAs)	47 hospitalized patients with moderate COVID-19	Randomized placebo-controlled double-blind clinical trial	IRCT20170315033086N10. IRCT is a primary registry in the WHO registry network	The treatment with BAs resulted in shorter hospital stay, alleviation of COVID-19 clinical symptoms, a significant decrease in the percentage of neutrophils and neutrophil-to-lymphocyte ratio (NLR) and decline in the level of proinflammatory cytokines	Barzin Tond et al. (2022)
Essential oil blend, the main active ingredient is frankincense (Boswellia carterii) inhaled twice daily for 14 consecutive days	Forty women who continue to experience fatigue more than 5 months after acute COVID-19 infection	A randomized double-blind, placebo-controlled trial	NCT04980573	Individuals who inhaled the essential oil blend for 2 weeks had significantly lower fatigue scores after controlling for baseline scores. This intervention improve energy levels and mental fatigue, as well as vigor significantly	Hawkins et al. (2022)