Methanol extract of the aerial parts of barley (Hordeum vulgare) suppresses lipopolysaccharide-induced inflammatory responses in vitro and in vivo.

CONTEXT: Recently, there has been renewed interest in barley (Hordeum vulgare L. Poaceae) as a functional food and for its medicinal properties. OBJECTIVE: This study examines the anti-inflammatory potential of the active fractions of barley and the mechanisms involved. MATERIALS AND METHODS: The macrophages were exposed to 100 µg/mL of each of the barley extracts in the presence of 1 µg/mL lipopolysaccharide (LPS) and after 24 or 48 h of incubation, cells or culture supernatants were analyzed by various assays. The anti-inflammatory potential of barley fractions was also investigated using the LPS-injected septic mouse model. The active constituents in the fractions were identified using gas chromatography-mass spectrometry (GC-MS). RESULTS: The active fractions, named F4, F7, F9 and F12, inhibited almost completely the LPS-induced production of nitric oxide (NO) and inducible NO synthase. Pre-treatment with these fractions at 100 µg/mL diminished the tumor necrosis factor-α (TNF-α) levels to 19.8, 3.5, 1.2 and 1.7 ng/mL, respectively, compared to LPS treatment alone (41.5 ng/mL). These fractions at 100 µg/mL also suppressed apparently the secretion of interleukin (IL)-6 and IL-1ß and the DNA-binding activity of nuclear factor-κB in LPS-stimulated cells. Mice injected intraperitoneally with LPS (30 mg/kg BW) showed 20% survival at 48 h after injection, whereas oral administration of the fractions improved the survival rates to 80%. GC-MS analysis revealed the presence of the derivatives of benzoic and cinnamic acids and fatty acids in the fractions. DISCUSSION AND CONCLUSION: The aerial parts of barley are useful as functional food to prevent acute inflammatory responses.

Chloroform extract of alfalfa (Medicago sativa) inhibits lipopolysaccharide-induced inflammation by downregulating ERK/NF-κB signaling and cytokine production.

Alfalfa (Medicago sativa L.) is commonly used as a traditional medicine and functional food. This study investigated the anti-inflammatory potential of alfalfa and the mechanisms involved. The chloroform extract of alfalfa aerial parts inhibited lipopolysaccharide (LPS)-stimulated immune responses more than ether, butanol, or water soluble extracts. Treatment with 1 µg/mL LPS increased nitrite concentrations to 44.3 µM in RAW267.4 macrophages, but it was reduced to 10.6 µM by adding 100 µg/mL chloroform extract. LPS treatment also increased the concentrations of tumor necrosis factor-α, interleukin (IL)-6, and IL-1ß to 41.3, 11.6, and 0.78 ng/mL in culture supernatants of the cells, but these cytokine levels decreased to 12.5, 3.1, and 0.19 ng/mL, respectively, by pretreating with 100 µg/mL of the extract. ICR mice injected with LPS (30 mg/kg body weight) alone showed a 0% survival rate after 48 h of the injection, but 48-h survival of the mice increased to 60% after oral administration of the extract. Subfractions of the chloroform extract markedly suppressed LPS-mediated activation of the extracellular signal-regulated kinase and nuclear factor kappa-B. Cinnamic acid derivatives and fatty acids were found to be active constituents of the extract. This research demonstrated that alfalfa aerial parts exert anti-inflammatory activity and may be useful as a functional food for the prevention of inflammatory disorders.