ABSTRACT
Vitis amurensis Rupr. "Beibinghong" is abundant in anthocyanins, including malvidin (Mv), malvidin-3-glucoside (Mv3G), and malvidin-3,5-diglucoside (Mv35 G). Anthocyanins offer nutritional and pharmacological effects, but their stability is poor. Interaction of malvid anthocyanins with caffeic acid through ultrahigh pressure technology produces stable anthocyanin derivatives. This study aims to identify the structure of stable mallow-like anthocyanins and to determine the effect of these stable anthocyanins on human umbilical vein endothelial cells (HUVECs) with H2O2-induced oxidative damage and the signaling pathway involved. The products of malvid anthocyanins and caffeic acid bonding were identified and analyzed using ultra-high performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UPLC-Q-Orbitrap MS/MS). The bonding products were malvidin-3-O-guaiacol (Mv3C), malvidin-3-O-(6â³-O-caffeoyl)-glucoside (Mv3CG), and malvidin-3-O-(6â³-O-caffeoyl)-5-diglucoside (Mv3C5G). An oxidative stress injury model in HUVECs was established using H2O2 and treated with Mv, Mv3G, Mv35 G, Mv3C, Mv3CG, and Mv3C5G at different concentrations (10, 50, and 100 µmol/L). Results showed that the above compound concentrations can significantly increase cell proliferation rate and reduce intracellular reactive oxygen species at 100 µmol/L. The effects of the most active products Mv and Mv3C on the AMP-activated protein (AMPK)/silencing information regulator-1 (SIRT1) pathway were analyzed. Results showed that Mv and Mv3C significantly increased SOD activity in the cells and significantly upregulated the expression of SIRT1 mRNA, SIRT1, and p-AMPK protein. However, they did not significantly change the expression of AMPK protein. After the silent intervention of siRNA in SIRT1 gene expression, the upregulation of SIRT1 and p-AMPK protein by Mv and Mv3C was significantly inhibited. These results indicate that stabilization malvid anthocyanins exerts an antioxidant activity via the AMPK/SIRT1 signaling pathway.
ABSTRACT
Two strains, 4G-K17T and 4G-K15, were isolated from forest soil from the Dinghushan Biosphere Reserve, Guangdong Province, PR China (112° 31' E 23° 10' N). The cells of the two strains were Gram-stain-negative, aerobic and non-motile short rods that multiplied by binary division. Strains 4G-K17T and 4G-K15 were obligately acidophilic, mesophilic bacteria capable of growth at pH 3.0-7.0 (optimum 4.0-5.5 and 3.5-5.5, respectively), temperature 12-42 °C (optimum 28 °C) and NaCl concentrations from 0~2.5â% and 0~3.0â% (w/v), respectively. They had a 16S rRNA gene sequence similarity of 99.2â% and showed the highest similarities of 97.1 and 97.4â% to Edaphobacter aggregans Wbg-1T, respectively, which indicated that these two isolates belonged to a novel species of the genus Edaphobacter in subdivision 1 in the family Acidobacteriaceae. The DNA G+C contents of strains 4G-K17T and 4G-K15 were 57.6 and 57.2â%, respectively. They had similar fatty acid profiles, with the major (>10â%) fatty acid profile comprising iso-C15â:â0, C16â:â0 and summed feature 3 (iso-C16â:â1ω7c and/or C16â:â1ω6c), and the major polar lipid profile comprising phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, unidentified aminophospholipids and unidentified phospholipids. All physiological, phylogenetic and chemotaxonomic data suggest that strains 4G-K17T and 4G-K15 belong to a new species of the genus Edaphobacter, for which the name Edaphobacter acidisoli sp. nov. is proposed, with 4G-K17T (=CGMCC 1.15447=LMG 29212) as the type strain.
