Honey used as conventional medicine has various pharmacological properties. In the honey and anti-inflammatory effect, Gelam honey and Manuka honey has been reported to exert anti-inflammatory activity. However, the anti-inflammatory effect and potential mechanisms of acacia honey (AH) are not well understood. In this study, we investigated anti-inflammatory activity and mechanism of action of AH in LPS-stimulated RAW264.7 cells. AH attenuated NO production through inhibition of iNOS expression in LPS-stimulated RAW264.7 cells. AH also decreased the expressions of IL-1β, IL-6 and TNF-α as pro-inflammatory cytokines, and MCP-1 expression as a pro-inflammatory chemokine. In the elucidation of the molecular mechanisms, AH decreased LPS-mediated IκB-α degradation and subsequent nuclear accumulation of p65, which resulted in the inhibition of NF-κB activation in RAW264.7 cells. AH dose-dependently suppressed LPS-mediated phosphorylation of ERK1/2 and p38 in RAW264.7 cells. In addition, AH significantly inhibited ATF2 phosphorylation and nuclear accumulation of ATF2 in LPS-stimulated RAW264.7 cells. These results suggest that AH has an anti-inflammatory effect, inhibiting the production of pro-inflammatory mediators such as NO, iNOS, TNF-α, IL-6, IL-1β and MCP-1 via interruption of the NF-κB and MAPK/ATF2 signaling pathways.

The initial segment (IS) in rodents is functionally and structurally distinct from other epididymal segments and plays an important role in sperm maturation. We previously showed that, in the mouse epididymis, basal cells (BCs) extend a narrow luminal-reaching projection only in the IS, while in all other regions, they mainly nestle at the base of the epithelium. We also found that BC projections are regulated by testicular luminal factors, and the present study was aimed at characterizing the signaling pathway involved in their formation and elongation. Previous studies reported that testicular luminal factors maintain the extracellular signal-regulated kinase (ERK) in a highly phosphorylated state in the IS. We report here that the BC projections, which we call axiopodia, periodically extend and retract over time. We found that axiopodia extensions and retractions follow an oscillatory pattern. This movement is controlled by MAPK/ERK signaling pathway. Our results suggest that ERK phosphorylation plays a key role in the formation and elongation of BC projections. Such unexpected cell motility may reflect a novel mechanism by which specialized epithelial cells sample the luminal environment.