Beneficial immune-stimulatory effect of chlorella supplementation : the enhancement of natural killer cell activity and early inflammatory response

Abstract

Background: in vitro and animal studies have demonstrated that Chlorella is potent biological response modifiers which modulate immune responses. However, no direct evidences for the effect of Chlorella supplementation on immune response in human subjects were reported. Objective: We investigated a beneficial effect of Chlorella supplementation on immune/inflammatory response in normal Koreans. Design: This study was designed for an 8-week randomized, double-blinded, placebo-controlled trial: Placebo (n=23) or 5g of Chlorella (CL, n=28) as form of tablets. Cytotoxic activities of Natural killer (NK) cells and serum concentrations of interleukin-12, interferon-γ and interleukin-1β were measured. Results: After the 8-week, serum concentrations of interferon-γ (p<0.05) and IL-1 (p<0.001) significantly increased and that of interleukin-12 (p<0.1) tended to increase in CL group. The differences in changed values of these cytokines between the two groups were statistically significant. NK cell activities (%) were significantly increased in CL group after the intervention, but not in Placebo group. The differences in changed values between the two groups were also statistically significant. Additionally, changed levels of NK cell activity were positively associated with those of serum interleukin-1b (r=0.280, p=0.047) and interferon-γ (r=0.271, p<0.005). Signficantly positive correlations were also observed among the changed levels of serum cytokines; betwwen interferon-γ and interleukin-1b (r=0.448, p<0.001), between interleukin-12 and interleukin-1b (r=0.416, p=0.003) and between interleukin-12 and interferon-γ (r=0.570, p<001). Conclusion: These results suggest a beneficial immunostimulatory effect of Chlorella supplementation by enhancing the NK cell activity and producing interferon-γ and interleukin-12 as well as interleukin-1, the Th-1 cell-induced cytokines.