Abstract
Flor·Essence (FE), a natural food grade herbal formula product manufactured by Flora Manufacturing & Distributing Ltd., has been used by patients with cancer in North America to stimulate immune cells in order to attenuate or reverse immune damage. To elucidate the mechanisms underlying the effects of FE on the immune system, spleen lymphocyte proliferation was analyzed by an MTT assay, and the phagocytic capacity of macrophages was measured via the neutral red phagocytosis method. The cytotoxicity of natural killer (NK) cells towards K562 cells was assessed via a CytoTox 96 assay. The production of the cytokines interleukin (IL)-12 and interferon (IFN)-γ in the peripheral blood was determined via ELISA and PCR analysis. The expression levels of caveolin-1 and NF-κB were measured via western blotting. In addition, cyclophosphamide was used to establish a mouse model of immunosuppression. It was found that the proliferation of splenocytes, the phagocytic capacity of macrophages and the cytotoxicity of NK cells against K562 cells were increased after oral administration of FE to mice. FE augmented the production of IL-12 and IFN-γ in the peripheral blood of mice. FE significantly increased the expression of proliferating cell nuclear antigen and caveolin-1, and decreased NF-κB expression. Finally, FE enhanced the viability of immune cells from cyclophosphamide-treated immunosuppressed mice. The results indicated that FE could activate immune responses and enhance natural immunity, suggesting that oral administration of FE can activate the body's immune response and resist damage caused by cyclophosphamide chemotherapy.