RESUMEN
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.
Asunto(s)
Proteínas Bacterianas/metabolismo , Inhibidores Enzimáticos/química , Inhibidores Enzimáticos/farmacología , Flavonas/química , Flavonas/farmacología , Glucósidos/química , Glucósidos/farmacología , Hordeum/química , Neuraminidasa/metabolismo , Activación Enzimática/efectos de los fármacosRESUMEN
Saponarin (SA), a natural flavonoid, is known for its antioxidant and hepatoprotective activities. SA is the predominant compound (1142.7 ± 0.9 mg per 100 g) in barley sprouts, constituting 72% of the total polyphenol content. We investigated, for the first time, the effects of SA from barley sprouts on cellular anti-inflammatory responses. In lipopolysaccharide (LPS)-induced RAW 264.7 macrophages, SA suppressed the activation of NF-κB, as evidenced by the inhibition of NF-κB DNA binding, nuclear translocation, IκBα phosphorylation, and reporter gene expression, and it downregulated the expression of the pro-inflammatory mediator IL-6. Furthermore, SA reduced the transcription of NF-κB target molecules COX2 and FLIP inhibited the phosphorylation of mitogen-activated protein kinases ERK and p38. These results suggest that SA isolated from barley sprouts exerts anti-inflammatory effects in LPS-induced RAW 264.7 macrophages via inhibition of NF-κB, ERK and p38 signaling. Thus, SA may be a promising natural anti-inflammatory agent.
Asunto(s)
Apigenina/farmacología , Glucósidos/farmacología , Hordeum/química , Lipopolisacáridos/efectos adversos , Proteínas Quinasas Activadas por Mitógenos/genética , FN-kappa B/genética , Extractos Vegetales/farmacología , Animales , Antiinflamatorios/farmacología , Apigenina/análisis , Línea Celular Tumoral , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/metabolismo , Regulación hacia Abajo , Glucósidos/análisis , Interleucina-6/genética , Interleucina-6/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Fosforilación , Espectrometría de Masas en Tándem , Proteínas Quinasas p38 Activadas por Mitógenos/genética , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismoRESUMEN
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.