Qingfei Paidu decoction (QFPD) is a Chinese herbal medicine newly formulated for the treatment of COVID-19. QFPD significantly enhances the therapeutic effects of stan- dard pharmacotherapy in mild to critically ill patients with COVID-19. However, limited information is available on the immunological mechanisms underlying the efficacy of QFPD. In addition, the feasibility of the prophylactic administration of QFPD to uninfected individuals remains unconfirmed. To obtain insight into these issues, an open-label, single-arm pilot study was conducted using 19 healthy uninfected individuals as subjects, and the effects of QFPD ingestion at a dose lower than that recommended for therapeutic use on hematological and immunological parameters were examined. QFPD was prepared according to the Chinese official clinical guideline, except that the dose of each herb was reduced to 1/30 and administered orally to the participants twice daily for 3 days. Low-dose QFPD ingestion significantly increased the plasma levels of pro-inflammatory cytokines, tumor necrosis factor (TNF)-α (P=0.000107), interleukin (IL)-1β (P=0.000982), IL-18 (P=0.00105), IL-2 (P=0.0483) and IL-8 (P=0.000191), key mediators of a broad spectrum of antiviral immunity. No apparent adverse effects were observed during the trial. These findings suggest that the clinical efficacy of QFPD against COVID-19 is, at least in part, associated with its immunological activity to mimic the blood cytokine environ- ment produced by early antiviral immune responses, which are shown to be profoundly suppressed during the early stages of COVID-19. The daily ingestion of low-dose QFPD may thus be a possible option for the prevention of COVID-19 during the epidemic. The present study was prospectively registered at the University Hospital Medical Information Network-Clinical Trials Registry (UMIN-CTR) under the trial no. UMIN000040341 on May 9, 2020. © 2021 Spandidos Publications. All rights reserved.
Qingfei Paidu decoction, a Chinese herbal medicine against COVID-19, elevates the blood levels of pro-inflammatory cytokines: An open-label, single-arm pilot study