Echinacea purpurea Alleviates Cyclophosphamide-Induced Immunosuppression in Mice

Echinacea purpurea (EP) has been widely used to treat upper respiratory infections, influenza, and the common cold. It can also exert various pharmacological activities, such as anti-inflammatory and anti-allergic effects. However, the potential of EP to modulate immune reactions remains unclear. Therefore, we evaluated the immunostimulatory effects of EP in cyclophosphamide (CP)-induced immunosuppressed mice. In this study, EP extract (12.5, 25, or 50 mg/kg) was orally administered to cyclophosphamide-induced immunosuppressed BALB/c mice. Then, indexes of immune organs, including the spleen and thymus, were recorded. Splenocyte proliferation and natural killer (NK) cell activities were measured by lactate dehydrogenase assay. Subsets of T cells, such as CD4+ and CD8+, were measured by flow cytometry, and immuno-cytokines, such as interleukin (IL)-2, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ, were measured by enzyme-linked immunosorbent assay and real-time polymerase chain reaction. The immunosuppressed mice showed decreased thymus and spleen indexes and immune cell activities. Treatment of EP elevated the indexes of immune organs, splenocyte proliferation, and NK cell activities in CP-induced immunosuppressed mice. Simultaneously, administration of EP reversed the CP-induced decrease in T-lymphocyte subsets (CD4+ and CD8+) and immunocytokines (IL-2, TNF-α, and IFN-γ). Taken together, these findings suggest that EP could be used to enhance health and immunity in immunosuppressed conditions.