Echinacea as a Potential Weapon against Coronavirus Infections?: A Mini-Review of randomized controlled trials

Echinacea purpurea broadly inhibits coronaviruses and SARS-CoV-2 in vitro [1]. This review discusses the available evidence from human studies. A literature search on PubMed and EMBASE yielded two RCTs with results on coronavirus infections during prevention with Echinacea purpurea. Incidence and viral loads were measured by reversed transcriptase polymerase chain reaction (RT-PCR). Jawad (2012) collected nasopharyngeal swabs from N=755 adults over 4 months of prevention. Overall, 24 and 47 enveloped virus infections occurred, including 21 and 33 coronavirus detections [229E; HKU1; OC43] with Echinaforce [2’400mg daily] and placebo, respectively (p=0.0114). No significant difference was observed on symptom level. Ogal (2021) administered Echinaforce extract [1’200mg] or control for 4 months to N=203 children (4 – 12 years). Echinacea reduced the incidence from 47 to 29 enveloped virus infections (p=0.0038) and 11/13 coronavirus detections [229E, OC43, NL63] were counted (p>0.05). Viral loads in nasal secretions were significantly diminished by 98.5%, with Ct-values 31.1 [95% CI 26.3; 35.9] versus 25.0 [95% CI 20.5; 29.5] (p=0.0479). Finally, respiratory symptoms during coronavirus infections were significantly reduced with area-under-curve AUC=75.8 (+/-50.24) versus 21.1 (+/-21.27) score points (p=0.0036). Echinacea’s broad antiviral spectrum was confirmed in two clinical trials suggesting its potential for prevention of infections by respiratory pathogens, including coronavirus [2] [3].