Categorization of traditional medicinal plants on inflammation-regulatory and anti-tumor activities by differenzial cytokine expression in dendritic cells

Traditional medicinal plants (TMP) are increasingly recognized for use in public health care throughout the world. However, systematic investigation of TMPs on specific and heath care-applicable immuno-regulatory activities is limited. Dendritic cells (DCs), a key type of professional antigen presenting cells are key mediators in human's immune systems. Therefore, DCs are considered by many as a viable pharmacological platform or target for evaluating TMP's immuno-regulatory activities. The objective of this study is to evaluate the regulatory activities of specific TMPs on cytokine regulation in DCs and anti-tumor activities in orthotopic mammary tumor model. Our results show that a number of extracts of test Taiwan specialty medicinal herbs exhibited an inhibitory activity on LPS-induced expression of IL-6 and IL-12 in mouse DCs. In addition, these herbal extracts were categorized into several functional sub-groups based on their capacities to regulate cytokine expression. In an orthotopic mammary tumor model, the extract of TMP1 effectively suppressed primary tumor growth. The extracts of both TMP1 and TMP2 suppressed mammary tumor metastasis, and the results were further confirmed by a mammary tumor resection model. Taken together, our results suggest that TMP1 and TMP2 may warrant further investigation for potential application as anti-tumor natural product agents.