FuFangChangTai Decoction Activates Macrophages via Inducing Autophagy

Abstract

The traditional Chinese medicine decoction FuFangChangTai (FFCT) has been used in the therapy of colon cancer clinically, yielding alleviated toxicity and enhanced immunity. In our previous study, FFCT exerted its antitumor activity not only by inducing apoptosis but also by activating autophagy to eliminate tumor cells. However, its mechanism is not well understood. The purpose of this study was to investigate the relationship between macrophages activation and FFCT-induced autophagy. Results showed that FFCT could induce autophagy in colon cancer, as demonstrated by increased level of intracellular autophagy marker LC3 II in CT26.WT cells by fluorescence microscope and western blot assay. FFCT also facilitated numbers of vesicular bodies with bilayer membrane in CT26.WT cells, which were indicative of autophagosomes formation. Autophagosomes secreted by FFCT-treated CT26.WT cells can activate M1 type macrophages, accompanied with increased expression of costimulatory molecules CD86 and CD40 on the surface of RAW264.7 cells, and more inflammatory cytokines secretion, such as TNF-α, IL-6, MCP-1, and IL-1β. mRNA expressions of M2 macrophages markers, such as IL-10, CD206, Arg-1, and FIZZ-1, were downregulated. And this process helps regulate the polarization of macrophages and promote the immune response. These findings support a mechanism of FFCT-induced autophagy and provide novel evidence demonstrating that macrophages are involved in FFCT-induced autophagy progression.