LAUSR

An impaired intestinal barrier function results in aggravating inflammatory response at a systemic scale, eventually leading to rising risk for systemic diseases (e.g., muscle myopathy and vascular disorders). In the present study, the impact of intake polyphenol-rich red osier dogwood extracts (RWE) on the inflammation of endothelial cells was exploited. A strong anti-inflammatory activity of RWE was found to suppress the expression of pro-inflammatory mediators (e.g., IL-8, TNF-α, IL-6, and ICAM) in the inflamed intestinal epithelial cell model. Furthermore, the intestinal transported RWE derived phenolic compounds was shown to protect the endothelial cells against both oxidative and inflammatory damages in a Caco-2/EA.hy926 co-culture cell model. Their protective activities in EA.hy926 was found to be strongly associated with intestinal absorption efficiency. The accumulation of transported rutin and unknown monoglyceride quercetin from RWE were identified across the Caco-2 BBe1 monolayer by HPLC up to 24 h. The highest concentration of transported rutin and monoglyceride quercetin derived from RWE were detected as 2.0 ± 0.22 µg/mL and 0.5 ± 0.08 µg/mL in the basolateral compartment after 12 h and 24 h of incubation, respectively. Profound anti-inflammatory effects of RWE derived polyphenols was observed to suppress pro-inflammatory mediator expression, including IL-8, TNF-α, IL-6, ICAM, VCAM and Cox2, in the TNF-α or oxidized low-density lipoprotein (oxLDL)-induced basolateral EA.hy926 cells (co-culture model). Moreover, we observed a significant inhibitory effect of the transported RWE on oxLDL-induced inflammation after 6 h incubation rather than 24 h, indicating the potential health benefits of RWE is determined by its bioavailability. Results of this study demonstrated that phenolic compounds derived from RWE could be delivered into the circulation system to mitigate inflammatory responses thereby being a promising dietary agent for preventing systemic diseases (e.g., cardiovascular diseases in humans and white stripping/woody meat in broiler chickens).