Identification and evaluation of flavone-glucosides isolated from barley sprouts and their inhibitory activity against bacterial neuraminidase.

Neuraminidase (NA) is one of the key enzymes responsible for bacterial infection and pathogenesis. This study aimed to gain deeper insights into the inhibitory effects of flavone-glucosides (1-9) isolated from barley sprouts (BS) on neuraminidase activity. The isolated compounds were identified as, lutonarin (1), saponarin (2), isoorientin (3), orientin (4), isovitexin (5), isoscoparin-7-O-[6-sinapoyl]-glucoside (6), isoscoparin-7-O-[6-feruloyl]-glucoside (7), isovitexin-7-O-[6-sinapoyl]-glucoside (8), and isovitexin-7-O-[6-feruloyl]-glucoside (9). Among them, compounds 1-5 exhibited neuraminidase-inhibitory activities in a dose-dependent manner, with IC50 values ranging from 20.1 to 32.7 µM, in a non-competitive inhibition mode according to kinetic studies. Moreover, the individual flavone-glucoside levels differed notably, in particular, lutonarin (1) and saponarin (2) were shown to be present in the greatest amounts, according to UPLC analysis. Consequently, our results suggest that BS may be utilized as an effective NA inhibitor in human health food, additives, and feed.

Toxicological evaluation and anti-inflammatory activity of a golden gelatinous sorghum bran extract.

Golden gelatinous sorghum (GGS) is rich in phytochemicals and anti-oxidants. We investigated the toxicity and anti-inflammatory properties of a GGS extract. We observed no toxic effects after a daily dose of up to 5000 mg/kg body weight of the GGS extract administered orally to rats for 14 d. The exposure of mice ears to 12-O-tetradecanoylphorbol-13-acetate (TPA) caused a marked increase in ear thickness, which was significantly inhibited by treating with the GGS extract; this inhibition of inflammatory response was clearly confirmed by a histological analysis. The TPA-induced mice ear edema model, indicated that treating with the GGS extract inhibited the expression levels of such inflammatory mediators as cyclooxygenase-2 and inducible nitric oxide synthase. The nitric oxide level in lipopolysaccharide (LPS)-induced Raw264.7 cells in vitro was lower in the GGS extract-treated group than in the LPS-only treated group. These results suggest that sorghum would be a safe, nontoxic product, and that the GGS extract possessed significant anti-inflammatory activity.

Effect of the growth stage and cultivar on policosanol profiles of barley sprouts and their adenosine 5'-monophosphate-activated protein kinase activation.

Adenosine 5'-monophosphate-activated protein kinase (AMPK) is an intracellular sensor that can regulate glucose levels within the cell. For this reason, it is well-known to be a target for drugs against diabetes and obesity. AMPK was activated significantly by the hexane extract of barley sprouts. This AMPK activation emerges across the growth stages of the sprout, becoming most significant (3 times above the initial stages) 10 days after sprouting. After this time, the activation decreased between 13 and 20 days post-sprouting. Analysis of the hexane extracts by gas chromatography-mass spectrometry showed that the amounts of policosanols (PCs, which are linear, primary aliphatic alcohols with 20-30 carbons) in the plant dramatically increased between 5 days (109.7 mg/100 g) and 10 days (343.7 mg/100 g) post-sprouting and then levels fell back down, reaching 76.4 mg/100 g at 20 days post-sprouting. This trend is consistent with PCs being the active ingredient in the barley plants. We validate this by showing that hexacosanol is an activator of AMPK. The richest cultivar for PCs was found to be the Daejin cultivar. Cultivars had a significant effect on the total PC content (113.2-183.5 mg/100 g) within the plant up to 5 days post-sprouting. However this dependence upon the cultivar was not so apparent at peak stages of PC production (10 days post-sprouting). The most abundant PC in barley sprout, hexacosanol, contributed 62-80% of the total PC content at every stage. These results are valuable to determine the optimal times of harvest to obtain the highest yield of PCs.