Dietary consumption of Echinacea by mice afflicted with autoimmune (type I) diabetes: effect of consuming the herb on hemopoietic and immune cell dynamics.

Epidemiological studies indicate that the incidence of Type 1 diabetes, an autoimmune disease, is rising rapidly. However, none of the current therapies produces life long remission, or can prevent the disease onset. The NOD (non-obese diabetic) mouse is currently regarded as an excellent animal model of human Type 1 diabetes. NKT cells are known to be fundamental in modulating the disease, yet they are numerically and functionally deficient in mammals bearing this disease. Indeed, the role of NK cells in inhibiting autoimmunity in general is well established. Immunoregulatory strategies are currently believed to be the way of the future with respect to modulating autoimmune diseases. Based on this hypothesis, and the fact that the herb, Echinacea, is a well demonstrated immunostimulant of NK cells in normal mice/humans, we aimed to investigate, in NOD mice, the effect of short term (days) and long term (months) daily dietary administration of Echinacea, on the absolute levels of NK cells, and five other classes of hemopoietic and immune cells, in the bone marrow and spleen. The results revealed that, in NOD mice, dietary Echinacea, resulted in a significant increase in the absolute numbers of NK cells, irrespective of feeding duration, in the spleen, and moreover, it actually stimulated NK cell production in their bone marrow birth site. We further found that there were transient, early (days), herb exposure-time-dependent, quantitative changes in several of the other hemopoietic and immune cells populations in both the bone marrow and spleen. We conclude that consumption of this herb by NOD mice, at least, has lead to no negative repercussions with respect to the hemopoietic and immune lineages, and secondly, the consistent, long-lasting immunostimulation only of NK cells, may lead to a possible new approach to the treatment of Type 1 diabetes.