RESUMO
Background/objective Cordyceps enhances animal survival against influenza by boosting the immune system. In animal studies, it also had anti-inflammatory and preventive properties. Cordyceps stimulates the immune system by increasing the activity and production of various immune cells. Some studies have shown the role of Cordyceps in the novel SARS-CoV-2 virus responsible for the COVID-19 pandemic, in addition to other respiratory diseases caused by the Picorna viruses, SARS-CoV, MERS-CoV, and Influenza viruses. However, it remains unknown whether this food supplement is safe and has anti-inflammatory effects in patients with COVID-19. Therefore, the objectives of this study were to evaluate the use and efficacy of Cordyceps capsules as an adjunct to standard treatment in patients with mild (symptomatic) to moderate COVID-19 infection. Methods A randomised, double-blind, placebo-controlled study was conducted to evaluate the efficacy and safety of Cordyceps capsules (a food supplement) 500 mg as adjuvant therapy in patients with COVID-19. The rationale for dose selection was as per the existing evidence from toxicity studies. The inclusion criteria were patients with either a mild or moderate COVID-19 infection. Clinical features suggestive of dyspnoea or hypoxia, fever, and cough, including SpO2 <94% (range 90-94%) on room air and a respiratory rate ≥24 per minute, were also included. Results Sixty-five patients were recruited for the study, with 33 in the Cordyceps group and 32 in the placebo group. Out of 58 evaluable patients, 33 recovered on day 5, 49 on day 10, and 58 on days 16 and 30. The recovery of patients steadily increased from 56.9% on day 5 to 100% on day 30. The time to clinical recovery was shorter in the Cordyceps group than in the placebo group (mean 6.6 vs. 7.3 days; p > 0.05) overall and for mild disease. However, there was no difference in the time to recovery (time from day 1 to the resolution of all symptoms) for moderate disease. A lower frequency of normal chest X-rays on day 1 and a higher number on day 16 in the treatment group than in the placebo group suggest an improvement in the number of normal chest X-rays with Cordyceps. Significant changes were seen in biomarkers MCPIP, CxCL10, and IL-1ß for overall (both mild and moderate patients) on days 5 and 10 as compared to baseline, and in biomarkers CRP and CxCL10 in moderate category patients on days 5 and 10, respectively. There were no statistically significant changes in IL-6, ferritin, lactate dehydrogenase (LDH), C-reactive protein (CRP), or D-dimer levels between baseline and day 5/10 in patients taking Cordyceps capsules and also between the treatment and placebo groups. Conclusion Cordyceps capsules administered at a dose of 500 mg three times a day along with supportive treatment showed effectiveness in patients with mild to moderate COVID-19 infection, as evidenced by the proportionately higher number of recoveries on day 5, the relatively shorter time for improvement of clinical symptoms, and the proportionately higher number of patients showing negative RT-PCR tests on day 10. Thus, Cordyceps appears to be a safe immunological adjuvant for the treatment of patients with mild-to-moderate COVID-19. Future studies with a larger sample size would shed more light on the evidence, as there are limitations in the generalizability of the results from the present study due to the small sample size.