Enhancement of Natural Killer Cell Activity in Healthy Subjects by Immulina®, a Spirulina Extract Enriched for Braun-Type Lipoproteins

Immulina (R), a commercial extract of Arthrospira (Spirulina) platensis is a potent activator of THP-1 monocytes and CD4+ T cells in vitro and enhances several immunological functions in mice. We further characterized Immulina (R) by determining that Braun-type lipoproteins are responsible for a major portion of the in vitro monocyte activation exhibited by this material. In order to understand the effect of Immulina (R) on NK cell activity, a pilot study was conducted on ten healthy North American individuals who supplemented their diet with Immulina (R) (400 mg/day) for seven days. We observed a 40% average increase in the killing of K562 tumor cells by NK cells (p < 0.01) after Immulina (R) supplementation. In a separate placebo-controlled, crossover study involving 11 healthy Danish subjects, we observed increased mRNA expression of the NK cell marker NKG2D by 37% (p = 0.02) and by 55% (p = 0.0003) after administration of Immulina (R) (200 mg and 400 mg per day, respectively) for seven days. The mRNA expression of the NK- and T-cell marker perforin increased by 75% (p = 0.008) after administration of 400 mg Immulina (R) per day. Both markers displayed significant dose-dependent effects (p = 0.0003 and p = 0.02, respectively). The ratio between CD56(bright) and CD56(dim) NK cells was not affected by Immulina (R) administration. In summary, two independent studies showed enhancement of NK cell activity following administration of Immulina (R) for seven days.