(P03-027-23) Effects of Black Raspberry, Blueberry, and Blackberry Volatile Extracts on LPS-induced Intestinal Inflammation in a Caco-2/RAW264.7 Co-culture Model

Objectives: Berry volatiles are responsible for the aroma of berries. Berry volatiles were recently found to have an anti-inflammatory effect. However, their impacts on intestinal inflammation are unclear. Intestinal inflammation can alter gut microbiota composition, leading to gastrointestinal inflammatory diseases. The intestinal epithelial barrier is closely related to immune cells and their cytokine production. Thus, this study adapted an in vitro intestinal inflammation model using a co-culture of intestinal epithelial cells and macrophage cells to simulate the in vivo microenvironment. The objective of this study was to investigate the effects of black raspberry, blueberry, and blackberry volatile extracts (BVEs) on lipopolysaccharide (LPS)-induced intestinal inflammation in the Caco-2/RAW264.7 co-culture model.

Methods: Fully differentiated monolayer human intestinal epithelial Caco-2 cells (apical side) were cultured with macrophage RAW264.7 cells (basolateral side). BVEs with 25-fold dilution were pretreated to Caco-2 cells for 1 h, then 1 μg/mL of LPS was added to RAW264.7 cells to stimulate inflammation for 24 h. Cell culture supernatants from the basolateral side were collected to evaluate the production of nitric oxide (NO) and pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α).

Results: BVEs with 25-fold dilution showed no cytotoxicity to Caco-2 cells, showing more than 80% of cell viability. LPS stimulation significantly increased the production of NO, IL-6, and TNF-α compared to the control (p < 0.01). However, blueberry and blackberry volatile extract treatments significantly suppressed the LPS-induced overproduction of NO, IL-6, and TNF-α (p < 0.05). Black raspberry volatile extract did not suppress TNF-α level, but slightly reduced the level of NO and IL-6.

Conclusions: This study showed that BVEs from blueberries and blackberries have an intestinal anti-inflammatory effect on the LPS-induced co-culture model by suppressing pro-inflammatory mediators and cytokines. This suggests that blueberry and blackberry volatiles may have the potential as functional food components with gastrointestinal protective effects.

Funding Sources: Arkansas Biosciences Institute