Antioxidant, anti-inflammatory and anti-septic potential of phenolic acids and flavonoid fractions isolated from Lolium multiflorum.

CONTEXT: Interest has recently renewed in using Lolium multiflorum Lam. (Poaceae) (called Italian ryegrass; IRG) silage as an antioxidant and anti-inflammatory diet. OBJECTIVE: This study investigated the antioxidant, anti-inflammatory and anti-septic potential of IRG silage and identified the primary components in IRG active fractions. MATERIALS AND METHODS: Total 16 fractions were separated from the chloroform-soluble extract of IRG aerial part using Sephadex LH-20 column before HPLC analysis. Antioxidant and anti-inflammatory activities of the fractions at doses of 0-100 µg/mL were investigated using various cell-free and cell-mediated assay systems. To explore anti-septic effect of IRG fractions, female ICR and BALB/c mice orally received 40 mg/kg of phenolic acid and flavonoid-rich active fractions F7 and F8 every other day for 10 days, respectively, followed by LPS challenge. RESULTS: The active fractions showed greater antioxidant and anti-inflammatory potential compared with other fractions. IC50 values of F7 and F8 to reduce LPS-stimulated NO and TNF-α production were around 15 and 30 µg/mL, respectively. Comparison of retention times with authentic compounds through HPLC analysis revealed the presence of caffeic acid, ferulic acid, myricetin and kaempferol in the fractions as primary components. These fractions inhibited LPS-stimulated MAPK and NF-κB activation. Supplementation with F7 or F8 improved the survival rates of mice to 70 and 60%, respectively, in LPS-injected mice and reduced near completely serum TNF-α and IL-6 levels. DISCUSSION AND CONCLUSION: This study highlights antioxidant, anti-inflammatory and anti-septic activities of IRG active fractions, eventually suggesting their usefulness in preventing oxidative damage and inflammatory disorders.

Improved production of phleichrome from the phytopathogenic fungus Cladosporium phlei using synthetic inducers and photodynamic ROS production by phleichrome.

Two different diketopiperazines, cyclo-(L-Pro-L-Leu) and cyclo-(L-Pro-L-Phe), which were isolated from the culture filtrate of Epichloe typhina and found to be inducers of phleichrome production, were chemically synthesized and evaluated for use in the improved production of phleichrome from wild-type and UV-mutagenized strains (M0035) of Cladosporium phlei. When supplemented with PDA and V8 juice agar media, both inducers showed significant increases in the production of phleichrome. Phleichrome production was increased in a dose-dependent manner up to a concentration of maximum yield for both inducers. No further significant induction was observed by supplementing inducers over the concentration of maximum yield. Among the two inducers, cyclo-(L-Pro-L-Phe) showed better inducing capability than cyclo-(L-Pro-L-Leu). The maximum yield was observed from the M0035 strain grown on V8 juice media supplemented with 150 µM cyclo-(L-Pro-L-Phe), which was estimated to be 232.6 mg of phleichrome per gram of mycelia and 10.2 mg of secreted phleichrome per 20 agar-plugs. Interestingly, growth inhibition was observed on V8 juice agar media with 100, 150, and 200 µM cyclo-(L-Pro-L-Phe) but not on PDA with the same amount of inducer, which suggests that the inhibitory effect might be through the overproduction of phleichrome rather than the toxic effect of the inducer itself. Superoxide production by purified phleichrome was dramatically stimulated upon illumination, thus demonstrating photodynamic production of superoxide in vitro by phleichrome.

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.