Anti-Inflammatory Potential of Pygeum africanum Bark Extract: An In Vitro Study of Cytokine Release by Lipopolysaccharide-Stimulated Human Peripheral Blood Mononuclear Cells

Abstract

Pygeum africanum bark has been shown to inhibit the production of pro-inflammatory prostaglandins in the prostate and reduces the production of leukotrienes and other 5-lipoxygenase (5-LO) metabolites. It has been suggested that inflammation plays an important role in the pathophysiology of benign prostatic hyperplasia (BPH). Data from clinical trials have shown that P. africanum improves the symptoms and objective measures of BPH. This in vitro study aimed to assess the anti-inflammatory potential of a proprietary Pygeum bark standardized extract (Prunera®) on cytokine release from lipopolysaccharide-stimulated human peripheral blood mononuclear cells (PBMCs). PBMCs were obtained from four donors, and a bead-based assay (ProcartaPlex™ panel) was used for the detection and quantitation of cytokines. Pygeum africanum bark standardized extract (PABE) induced a statistically significant decrease (p < 0.05) of IL-6 in three donors. Other effects were as follows: IL-2 was lowered in all donors in the absence of a clear dose–response relationship; IL-4, IL-5, IL-9, and IL-13 levels were decreased in most donors; IL-22 levels seemed to be suppressed only for donor 4 at lower and medium concentrations; and IL-27 and TNF-α levels decreased at all PABE concentrations in all donors. The anti-inflammatory effect of PABE, particularly the reduction in IL-6 as a marker of inflammation, supports the potential use of this natural compound in the management of BPH and other conditions in which pro-inflammatory cytokines are involved in their underlying pathophysiological mechanisms.