Antioxidant and Antiglycation Activities of Syzygium paniculatum Gaertn and Inhibition of Digestive Enzymes Relevant to Type 2 Diabetes Mellitus

Plant Foods for Human Nutrition - Advanced glycation end-products (AGEs) may be a contributing factor in the development of diabetes-specific vascular pathologies that affect the retina, glomerulus...     

Inhibitory Potential of Acroptilon repens against Key Enzymes involved in Alzheimer and Diabetes,Phytochemical Profile,Radical Scavenging,and Antibacterial Activity

Background:This study was devoted to assessing the inhibitory potential of acetone, methanol, and ethanol extracts of Acroptilon repens against disease-associated enzymes, as well as their antioxidant/antibacterial activity and phytochemical composition. Methods:Comparative assessment using various antioxidant evaluation methods, including FRAP, scavenging ability on DPPH radical and hydrogen peroxide, and RP, indicated that the acetone extract presented the highest antioxidant activity, due to its highest total antioxidant content. Results:The TPC and TFC of these extracts were 3.44 ± 0.32 mg GAE/g DW and 2.09 ± 0.2 mg QE/g DW, respectively. The hydrodistillation essential oil from A. repens was analyzed by GC/MS, and 17 compounds were identified. All extracts showed good inhibitory activities against disease-related enzyme acetylcholinesterase and α-amylase, with the lowest IC₅₀ for acetonic extract. Extracts of A. repens exhibited inhibiting activities against the Gram-positive bacteria, with the most effect of acetone extract. Conclusion:Our findings suggest A. repens as a promising source of natural antioxidant, antimicrobial, anti-cholinesterase and anti-amylase agents for the management of oxidative damage, and pharmaceutical, food, and cosmeceutical purposes. Key Words: Acroptilon repens, Antioxidants, Phytochemicals     

Influence of Extraction Solvents on Antioxidant Activity and the Content of Bioactive Compounds in Non-pungent Peppers

Bioactive compounds in foods have been shown to maintain human health. However, the relative amounts of bioactive compounds and the variation in the amounts are still poorly understood. In this study, the efficacy of different extraction solvents (hexane, ethyl acetate, acetone, methanol, and a methanol:water mixture), as well as the levels of certain bioactive compounds in non-pungent pepper cultivars (TMH, TMJ, PA137, and B58) were investigated using high-performance liquid chromatography (HPLC). Antioxidant activities were determined using 2,2,-diphenyl-1-picrylhydrazyl (DPPH), reducing power, and deoxyribose degradation. Hexane extracts had the highest level of carotenoids (47.2-628.8 μg/g), and methanol extracts contained maximum flavonoids (24.9-152.2 μg/g) in four different cultivars. Higher DPPH scavenging activity was found in the hexane extracts from TMH, TMJ, PA137, and B58 (IC?? value: 0.67, 0.74, 0.55, and 0.48 μg/ml, respectively), whereas the reducing power was high in ethyl acetate and acetone extracts. Inhibition of deoxyribose degradation was highest in methanolic extracts from TMH, TMJ, PA137, and B58 (51.2, 49.5, 52.6, and 47.4 %, respectively). These data demonstrate that solvent chemical properties such as polarity can differentially impact the efficiency with which different bioactive compounds are recovered from foods, and this could lead to differences in estimated biological activity such as antioxidant capacity.     

不同类型水稻品种Wx基因多态性位点的鉴定及其与直链淀粉含量的关系

利用Wx基因第1内含子第1位的G/T和第6外显子第1 132位的A/C碱基多态性,分别开发分子标记Wx-I和等位基因特异性分子标记Wx-a-F(Wx-b-F)/Wx-a-R,对76份水稻品种Wx基因多态性进行检测,并分析不同基因型与直链淀粉含量的关系。结果表明,供试品种中在Wx基因的这2个多态性位点上检测到了3种基因型(In1G-Ex6A、In1G-Ex6C和In1TEx6A),分别表现为高、中、低直链淀粉含量;籼稻中这3种基因型均存在,而供试爪哇稻和粳稻中分别只检测到In1G-Ex6C和In1T-Ex6A基因型;供试籼型杂交水稻亲本中,恢复系Wx基因以In1T为主,三系保持系均为In1G,而两系不育系同时含有这2种类型,说明两系不育系的Wx基因变异比三系不育系丰富。     

A Study of Glycemic Response to Corinthian Raisins in Healthy Subjects and in Type 2 Diabetes Mellitus Patients

This study was designed to evaluate the metabolic response to Corinthian raisins in healthy and in patients with type 2 diabetes mellitus. Healthy subjects (n?=?15) and diabetic patients (n?=?15) received 74 g raisins or 50 g glucose as reference food. Blood samples were collected at time 0 (before the consumption) and 30, 60, 90, 120, 150 and 180 min after raisin or glucose consumption. There was no significant difference in baseline glucose and insulin between raisins and reference in both groups. The difference at glucose peaks between raisins and reference was significant in healthy and in diabetics. Glycemic and insulinemic responses were decreased after raisin consumption compared to reference. An estimate of the glycemic index would be 66.3?±?3.4.     

高浓度CO2条件下水稻叶片氮含量下降与氮代谢关键酶活性的关系

利用FACE（Free Air Carbon Dioxide Enrichment）平台技术,研究了低氮（125 kg/hm2,以纯N计）和常氮（250 kg/hm2）水平下,高浓度CO2（周围大气CO2浓度+200 μmol/mol）对水稻不同生育期功能叶N代谢关键酶活性的影响。结果表明,高浓度CO2提高了叶片硝酸还原酶和蛋白水解酶的活性,两者在常N下的响应程度大于在低N下的响应程度;高浓度CO2降低了低N下叶片谷氨酰胺合成酶和谷氨酸脱氢酶（NADH GDH）活性,常N水平下酶活性的下降趋势得到改变或缓解。由此可见,高浓度CO2条件下NO3-转化为NH4+加速,而NH4+进一步同化为有机N却受阻,而且,由于后期蛋白水解加速,将进一步加剧叶片N含量的下降。这是水稻叶片N含量下降的内在因素。而增施N肥,有利于同化酶的表达,降低叶片蛋白水解酶活力,从而缓解叶片N含量的下降。     

Content Variations of the Secondary Compounds in Rice Plants and Their Influence on Rice Resistance to Brown Planthopper, Nilaparvata lugens

The brown planthopper (BPH), Nilaparvata lugens (St?l), is a monophagous pest that feeds only on rice, and sucks the juice from the phloem resulting in drying of the leaves and wilting of the tillers, causing ‘hopper burn’, as well as being an important…     

淡豆豉提取物对2型糖尿病大鼠主动脉iNOS,eNOS mRNA表达的影响

为观察淡豆豉提取物对NO/NOS系统的影响,探讨其对2型糖尿病大鼠大血管保护作用的机制。采用高糖高脂饲料喂养加小剂量链尿佐菌素腹腔注射的方法复制2型糖尿病大鼠模型,给药56 d后检测大鼠空腹血糖(FBG)、血清胰岛素(FIN),计算胰岛素敏感指数(ISI),放免法检测血清肿瘤坏死因子-α(TNF-α)及一氧化氮(NO)水平,RT-PCR法检测主动脉内皮型一氧化氮合酶(eNOS)和诱导型一氧化氮合酶(iNOS)mRNA表达。结果显示:淡豆豉提取物能显著降低T2DM大鼠FBG、FIN、TNF-α、NO水平,显著提高ISI,显著降低iNOS mRNA表达,对eNOS mRNA表达则无明显影响。淡豆豉提取物可影响2型糖尿病大鼠NO/NOS系统,并可能通过此途径对2型糖尿病大鼠大血管产生保护作用。     

Changes in Phenolic Compounds in Garlic (<Emphasis Type="Italic">Allium sativum</Emphasis> L.) Owing to the Cultivar and Location of Growth

The contents of total phenolic compounds, flavonoids, and phenolic acids were determined in selected garlic cultivars grown at four locations. The total phenolic content varied from 3.4 mg gallic acid equivalents (GAE)/g of dry matter (dm) to 10.8 mg GAE/g of dm with a mean value of 6.5 mg GAE/g of dm. The myricetin, quercetin, kaempferol, and apigenin flavonoids were not detected in any of the samples. Caffeic acid and ferulic acid were the major phenolic acids found with mean values of 2.9 mg/kg of dm and 2.6 mg/kg of dm, respectively. The mean contents of vanillic, p-hydroxybenzoic, and p-coumaric acids were comparable (0.4–0.8 mg/kg of dm), and the level of sinapic acid was negligible (< 0.1 mg/kg of dm). There was a significant effect of location but an insignificant effect of genotype on contents of caffeic, vanillic, p-hydroxybenzoic, and p-coumaric acids. However, genotype but not location affected the contents of total phenolics and ferulic acid. On average, the white garlic cultivars and Chinese garlic cultivars contained higher contents of total phenolics and ferulic acid than the purple garlic cultivars. However, the differences in the total phenolic content between the purple and white garlic cultivars were not significant.     

Digestibility of Quinoa (<Emphasis Type="Italic">Chenopodium quinoa</Emphasis> Willd.) Protein Concentrate and Its Potential to Inhibit Lipid Peroxidation in the Zebrafish Larvae Model

Quinoa protein concentrate (QPC) was extracted and digested under in vitro gastrointestinal conditions. The protein content of QPC was in the range between 52.40 and 65.01% depending on the assay used. Quinoa proteins were almost completely hydrolyzed by pepsin at pH of 1.2, 2.0, and 3.2. At high pH, only partial hydrolysis was observed. During the duodenal phase, no intact proteins were visible, indicating their susceptibility to the in vitro simulated digestive conditions. Zebrafish larvae model was used to evaluate the in vivo ability of gastrointestinal digests to inhibit lipid peroxidation. Gastric digestion at pH 1.2 showed the highest lipid peroxidation inhibition percentage (75.15%). The lipid peroxidation activity increased after the duodenal phase. The digest obtained at the end of the digestive process showed an inhibition percentage of 82.10%, comparable to that showed when using BHT as positive control (87.13%).