Jen-Fang Liu

Almond consumption improved glycemic control and lipid profiles in patients with type 2 diabetes mellitus.

Almond consumption is associated with ameliorations in obesity, hyperlipidemia, hypertension, and hyperglycemia. The hypothesis of this 12-week randomized crossover clinical trial was that almond consumption would improve glycemic control and decrease the risk for cardiovascular disease in 20 Chinese patients with type 2 diabetes mellitus (T2DM) (9 male, 11 female; 58 years old; body mass index, 26 kg/m²) with mild hyperlipidemia. After a 2-week run-in period, patients were assigned to either a control National Cholesterol Education Program step II diet (control diet) or an almond diet for 4 weeks, with a 2-week washout period between alternative diets. Almonds were added to the control diet to replace 20% of total daily calorie intake. Addition of approximately 60 g almonds per day increased dietary intakes of fiber, magnesium, polyunsaturated fatty acid, monounsaturated fatty acid, and vitamin E. Body fat determined with bioelectrical impedance analysis was significantly lower in patients consuming almonds (almonds vs control: 29.6% vs 30.4%). The almond diet enhanced plasma α-tocopherol level by a median 26.8% (95% confidence intervals, 15.1-36.6) compared with control diet. Furthermore, almond intake decreased total cholesterol, low-density lipoprotein cholesterol, and the ratio of low-density lipoprotein cholesterol to high-density lipoprotein cholesterol by 6.0% (1.6-9.4), 11.6% (2.8-19.1), and 9.7% (0.3-20.9), respectively. Plasma apolipoprotein (apo) B levels, apo B/apo A-1 ratio, and nonesterified fatty acid also decreased significantly by 15.6% (5.1-25.4), 17.4% (2.8-19.9), and 5.5% (3.0-14.4), respectively. Compared with subjects in the control diet, those in the almond diet had 4.1% (0.9-12.5), 0.8% (0.4-6.3), and 9.2% (4.4-13.2) lower levels of fasting insulin, fasting glucose, and homeostasis model assessment of insulin resistance index, respectively. Our results suggested that incorporation of almonds into a healthy diet has beneficial effects on adiposity, glycemic control, and the lipid profile, thereby potentially decreasing the risk for cardiovascular disease in patients with type 2 diabetes mellitus.

Effect of purple sweet potato leaves consumption on exercise-induced oxidative stress and IL-6 and HSP72 levels

The aim of this study was to evaluate the effects of purple sweet potato leaves (PSPL) consumption on oxidative stress markers in a healthy, nontrained, young male population after completing a running exercise protocol. A crossover design was applied, with 15 subjects participating in a two-step dietary intervention period. Each subject was given a high- (PSPL group) or low-polyphenol (control group) diet for 7 days with a 14-day washout period. After each dietary intervention period, all subjects performed 1 h of treadmill running at a speed corresponding to 70% of each subjects individual maximal oxygen uptake (Vo(2max)). Blood samples were taken before exercise and at 0, 1, and 3 h after exercise. Compared with the control group, PSPL consumption significantly increased plasma total polyphenols concentration and total antioxidant power (i.e., the ferric-reducing ability of plasma) in the PSPL group. The markers of oxidative damage, plasma TBARS and protein carbonyl, significantly decreased. Plasma IL-6 concentration also decreased. However, no significant difference was found in HSP72 levels between the two groups. These findings indicate that consuming a high-polyphenol diet for 7 days can modulate antioxidative status and decrease exercise-induced oxidative damage and pro-inflammatory cytokine secretion.

Constituents in purple sweet potato leaves inhibit in vitro angiogenesis with opposite effects ex vivo

OBJECTIVE The aim of this study was to investigate the in vitro effect of polyphenols in purple sweet potato leaves (PSPLs) on angiogenesis in human umbilical vascular endothelial cells (HUVECs). The ex vivo effect was test in human serum collected from the subjects who consumed 200 g of PSPL in a low polyphenol diet versus a low polyphenol diet. METHODS Methanolic extract from PSPLs and human sera from subjects were treated with HUVECs and the effects of cell proliferation, migration, tube formation, and matrix metalloproteinase activity were investigated. RESULTS The PSPL polyphenols at 0.2 to 0.6 mM gallic acid equivalents inhibited proliferation, migration, and tube formation of vascular endothelial growth factor-treated HUVECs. Further, the activity of secreted matrix metalloproteinase-2 was decreased by at least 13.8%. However, 5% PSPL serum increased migration and tube formation of HUVECs by 110% and 56.9%, respectively, compared with serum from subjects on the low polyphenol diet. Further, the activity of matrix metalloproteinase-9 was increased by 128% in the PSPL serum. CONCLUSION These results suggest that PSPL polyphenols inhibited in vitro angiogenesis, but PSPL constituents might shift serum biochemistries to be more proangiogenic.

Riboflavin protects mice against liposaccharide-induced shock through expression of heat shock protein 25.

Riboflavin (vitamin B2) is a water-soluble vitamin essential for normal cellular functions, growth and development. This study aimed to investigate the effects of vitamin B2 on the survival rate, and expressions of tissue heat shock protein 25 (HSP25) and heat shock factor 1 (HSF1) in mice undergoing lipopolysaccharide (LPS) induced shock. Mice were assigned to four groups, saline vehicle, LPS, LPS plus low dose of vitamin B2 (LB2) and LPS plus high dose of vitamin B2 (HB2). Vitamin B2 (1 and 10mg/kg BW) was administered intraperitoneally at 2 and 0 h before the i.p. administration of LPS. At the end of the experiment, the survival rate monitored was 10, 20, 60, and 100% for LPS, LB2, HB2, and saline mice, respectively. HSP25 expressions in the heart and lung were significantly enhanced in a time-dependent manner in the HB2 mice as compared to the saline mice (p < 0.05), but not altered in the LB2 mice. In the HB2 mice, plasma riboflavin concentrations reached 300 nM at 6h post LPS and returned to the 0 h level at 72 h. The results showed that high dose of riboflavin could decrease LPS-induced mortality through an increased expression of HSP25.