Immunomodulatory effects of a mycelium extract of Cordyceps (Paecilomyces hepiali; CBG-CS-2): a randomized and double-blind clinical trial

BACKGROUND: Cordyceps is a traditional Chinese herb that produces various biopharmaceutical effects, including immune-enhancing effects. In this study, we prepared a Cordyceps mycelium culture extract (Paecilomyces hepiali, CBG-CS-2) to confirm its efficacy in enhancing the immune system and to evaluate its safety in healthy adults. METHODS: Healthy adults were divided into the intervention group (n = 39), who were given 1.68 g/day of CBG-CS-2 in capsules, and the control group (n = 40) for 8 weeks. The activities of natural killer (NK) cells and serum levels of monocyte-derived mediators were assessed initially for a baseline measurement and after 8 wks. RESULTS: The CBG-CS-2 group showed a significant 38.8 ± 17.6% enhancement from the baseline of NK cell cytotoxic activity relative to the placebo group after the administration of the capsules for 8 wks. (P < 0.019). CONCLUSION: The results suggest that the immune system functions well with CBG-CS-2 supplementation, perhaps with less accompanying inflammation. Thus, CBG-CS-2 is safe and effective for enhancing cell-mediated immunity in healthy adults. TRIAL REGISTRATION: This study was registered at Clinical Trials.gov (NCT 02814617). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12906-019-2483-y) contains supplementary material, which is available to authorized users.