Pycnogenol® augments macrophage phagocytosis and cytokine secretion

Abstract

We previously reported that Pycnogenol®, procyanidins extracted from the bark of French maritime pine (Pinus maritima Aiton; the official botanical name is now Pinus pinaster Alton) is a potent free radical scavenger. It has been shown to inhibit macrophage oxidative burst. Macrophages carry out their microbicidal and tumoricidal activities via oxygen-dependent and oxygen-independent mechanisms. The present study investigated the effects of Pycnogenol® on oxygen-independent killing mechanisms of macrophages, with particular interest in phagocytosis and cytokine release. J774 cells, a murine macrophage cell line, were preincubated with Pycnogenol® and then exposed to fluorescein-conjugated Escherichia coli particles for phagocytosis. Pycnogenol® significantly enhanced the phagocytosis by J774 cells. Incubation with Pycnogenol® resulted in a significant increase in cell size indicating macrophage activation. J774 cells were treated with Pycnogenol® for 22 hr and the supernatants were tested for the release of tumor necrosis factor-alpha (TNF-'') and interleukin-1 beta (IL-1$). Pycnogenol® significantly increased the secretion of both TNF-'' and IL-1$. These results suggest that Pycnogenol® can enhance the macrophage function by increasing its ability to phagocytosis and secretion of TNF-'' and IL-1$. These two cytokines may provide costimulatory signals to enhance both the humoral and cellular immune responses to promote host defense. © Asian Network for Scientific Information 2002.