A Pilot Study: on in Vitro Maturation of CD56+ NK Cells Using the Human Umbilical Cord Blood, Among the Eleven Natural Health Substances Tested, Wheat Grass Extract Orchestrates and Enforces the Naïve Fate of CD56+ NK Cells

Objective: The immuno-modulating activity of natural substances was evaluated to assess their effects on human umbilical cord blood mononuclear cells (MNC). Most of the MNC might have been immunologically primed as they are exposed to immunological stressors, while MNC from the human umbilical cord blood (hUCB) are not. During pregnancy, MNC of hUCB is isolated from bio-stressors by virtue of the trophoblast stratum between the placenta and its neighboring maternal endometrium. Hence, the MNC is well protected from bio-stresses. The trophoblastic layer prevents MNCs of the hUBC from being affected by various factors circulating in the maternal blood, so that the exposure of MNC to those factors is reduced. Methods: After treatment with eleven different natural substances, including five herbal extracts and six pure compounds, the immunophenotypic expression of MNC subsets was analyzed via fluorescence activated cell sorting (FACS) analysis. Data reported here indicated that the extract of 79 wheat grass (Triticum aestivum L.) intensified the population of CD56^+ natural-killer (NK) cells, whereas the propagation of other MNC was insignificant. Results: NK cells separated with the positive magnetic bead cell isolation method (MACS) and treated with wheat grass extract showed marked cytotoxicity affecting the cells of Modal karyotype of human leukemia cell line, K562. Conclusions: This pilot study shows that wheat grass extracts likely orchestrates, enforces and promotes the in vitro maturation ofCD56^+ NK cells in the hUCB.