Antioxidative Effect and Neuraminidase Inhibitory Activity of Polyphenols Isolated from a New Korean Red Waxy Sorghum (Sorghum bicolor L. cv. Hwanggeumchalsusu)

Abstract

To identify nutritional and therapeutic properties of the new Korean red waxy sorghum cultivar 'Hwanggeumchalsusu (HGC)', we assayed the antioxidative effects and neuraminidase inhibitory activity. A methanol and 70% ethanol extract of HGC exhibited strong antioxidative effects (IC50 values of 83.2±2.7 for DPPH) and 85.6±2.4 μg/ml for ABTS) and neuraminidase (ND) inhibitory activity (IC50 values of 1.8±0.1 from extracted with methanol and 3.4±0.1 μg/ml from extracted with 70% ethanol) compared with that of the control, noncolored sorghum cultivar 'Huinchalsusu (HC)' (IC50 > 200 μg/ml). We isolated nine polyphenols, Gallic acid (1), Protocatecuic acid (2), p-Hydroxy benzoic acid (3), Vanillic acid (4), Caffeic acid (5), Ferulic acid (6), Luteolinidin (7), Apigeninidin (8), Luteolin (9), from the HGC-methanol extract, to determine whether they were the active components Luteolinidin of one kind of polyphenols from the HGC, exhibited significant antioxidative effects (IC50 values of 10.9±0.5 μM for DPPH and 8.6 0.6 μM for ABTS) and neuraminidase (ND) inhibitory activity (IC50 values of 26.3±0.6) showed noncompetitive inhibition model. The binding affinity of the ND inhibitors in molecular docking experiments correlated with their ND inhibitory activities. These results suggest that HGC may be utilized to serve as a potential effective antioxidant and inhibitor of ND.Key words : Antioxidative effect, apigeninidin, luteolinidin, neuraminidase inhibitor, Sorghum bicolor L. † Authors contributed equally. *Corresponding author *Tel : +82-63-238-5333, Fax : +82-63-238-5305 *E-mail : swd2002@korea.kr This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. IntroductionSorghum is one of the most important staple foods in the semiarid tropics of Africa and Asia. It is primarily used as food in these regions and also used as feed for domestic animals. Recently, the number of studies that focus on the importance of sorghum as a food source has increased because of the beneficial effects of sorghum on human health [2]. For example, when consumed as part of the diet, sorghum or its components act as antiinflammatory agents [5], anticancer drugs [22], and as antimutagens [2]. Sorghum contains numerous compounds, particularly phenolic compounds such as phenolic acid and flavonoids. Among them, 3-deoxyanthocyanins, apigeninidin, and luteolinidin are components of pigments that impart grain color to sorghum [3]. These compounds mediate the beneficial effects of sorghum on health and contribute to the favorable characteristics of processed goods prepared using sorghum [7].Seasonal influenza kills hundreds of thousands of people because of the high infectivity of influenza virus and the emergence of strains with new antigenicity [2]. The surface of the influenza virus particle contains hem...

Inhibition of Human Respiratory Influenza A Virus and Human Betacoronavirus-1 by the Blend of Double-Standardized Extracts of Aronia melanocarpa (Michx.) Elliot and Sambucus nigra L.

“…The interaction of cyanidin-3-sambubiocid with neuraminidase was simulated [ 30 ], showing high sensitivity and potential antiviral activity for wild and mutant (H274Y) types of this peptide. Representatives of anthocyanidins, which are the sugar-free anthocyanins, such as luteolinidin, apigeninidin, or luteolin, were also found to inhibit neuraminidase [ 31 ]. The EAM-ESN blend is double-standardized to at least 25% of anthocyanins and 40% of polyphenols, which may be responsible for the main activity of the compound.…”