Strawberry, loquat, mulberry, and bitter melon juices exhibit prophylactic effects on LPS-induced inflammation using murine peritoneal macrophages

We hypothesized the juices from strawberry, loquat, mulberry and bitter melon exhibit anti-inflammatory activities using lipopolysaccharide (LPS)-stimulated murine peritoneal macrophage cultures. Selected juices were administered as a prophylactic, postmortem or concurrent event relative to LPS stimulation to clarify the effective mechanisms. Selected fruits and vegetable juices were administered to macrophage cultures for 24 h prior to LPS stimulation (model A). Selected samples were administered to cell cultures at 24 h following LPS treatment (model B). Selected fruits and vegetable juices and LPS were simultaneously co-cultured with macrophages for 24 h (model C). The LPS-induced secretions of pro-inflammatory cytokines interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α and anti-inflammatory cytokine IL-10 were determined. The results showed that strawberry, loquat, mulberry and bitter melon administration increased IL-10 production by LPS-stimulated peritoneal macrophages in dose-dependent manners in experimental model A. Simultaneously, loquat, mulberry, and bitter melon administrations significantly (P < 0.05) decreased the levels of IL-1β, IL-6 and/or TNF-α. Administration with loquat and bitter melon to experimental model C significantly increased IL-10 production. This study suggests that strawberry, loquat, mulberry, and bitter melon juices exhibit a prophylactic effect on LPS-induced inflammation of peritoneal macrophages via increasing anti-inflammatory cytokine and/or decreasing pro-inflammatory cytokines secretions.