Quercetin uptake and metabolism by murine peritoneal macrophages in vitro.

Quercetin (Q), a bioflavonoid ubiquitously distributed in vegetables, fruits, leaves, and grains, can be absorbed, transported, and excreted after oral intake. However, little is known about Q uptake and metabolism by macrophages. To clarify the puzzle, Q at its noncytotoxic concentration (44μM) was incubated without or with mouse peritoneal macrophages for different time periods.

Anti-inflammatory effects of phenolic extracts from strawberry and mulberry fruits on cytokine secretion profiles using mouse primary splenocytes and peritoneal macrophages.

This study isolated phenolic-rich extracts from strawberry (ES) and mulberry (EM) fruit juice using 70% ethanol, analyzed the individual phenolics including four flavonoid components using HPLC and assessed their cytokine secretion regulatory activities using murine primary splenocytes and peritoneal macrophages. The results showed that EM was rich in p-coumaric acid (20798±719μg/g dry weight), rutin (1992±26μg/g dry weight) and quercetin (81±5μg/g dry weight), but ES was relatively rich in p-coumaric acid (7475±1219μg/g dry weight), morin (101±68μg/g dry weight) and quercetin (72±42μg/g dry weight). ES and EM administration significantly decreased splenocytes' (IFN-γ+IL-2+IL-12)/IL-10 (Th1/Th2) cytokine secretion ratios in the absence or presence of lipopolysaccharide (LPS) and TNF-α/IL-10 (pro-/anti-inflammatory) cytokine secretion ratios in the presence of LPS in dose-dependent manners.

Anti-inflammatory and anti-apoptotic effects of strawberry and mulberry fruit polysaccharides on lipopolysaccharide-stimulated macrophages through modulating pro-/anti-inflammatory cytokines secretion and Bcl-2/Bak protein ratio.

This study is the first to isolate strawberry (SP) and mulberry fruit polysaccharides (MP) and assess their anti-inflammatory and anti-apoptotic activities using lipopolysaccharide (LPS)-stimulated mouse primary macrophages. Pro-/anti-inflammatory cytokine levels secreted by LPS-stimulated macrophages cultured with SP and MP for 48 h were determined using ELISA method to evaluate anti-inflammatory effects of SP and MP. The Bcl-2/Bak (anti-/pro-apoptotic) protein levels in the cells were determined using Western blotting method to evaluate anti-apoptotic effects of SP and MP.