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Objective: To investigate the effect of Moringa oleifera leaf extract on angiogenesis and inflammatory process in a rat model of streptozotocin-induced diabetic nephropathy. Methods: Four weeks after a single injection of 50 mg/kg streptozotocin, rats were treated with 100 or 200 mg/kg/day Moringa oleifera leaf extract, 1 mg/kg/day dapagliflozin, or a combination of Moringa oleifera leaf extract and dapagliflozin for further eight weeks. Renal function, kidney histology, and gene expression were evaluated at the end of the experiment. Results: Renal function of diabetic rats was significantly impaired as evidenced by increased blood urea nitrogen, albuminuria, 24-h proteinuria, and high creatinine clearance which indicated glomerular hyperfiltration. In addition, diabetic rats showed an increase in gene expressions of vascular endothelial growth factor-A (VEGF-A), angiopoietin-2 (Ang2), the Ang2/Ang1 ratio, tumor necrosis factor-α, interleukin-1β and monocyte chemoattractant protein-1. Immunohistochemical staining demonstrated a significant increase in the density of glycoprotein CD34. Moringa oleifera leaf extract markedly improved all renal dysfunction markers and modulated the upregulated expression of angiogenic factors and inflammatory genes. Conclusions: Moringa oleifera leaf extract could suppress abnormal angiogenesis and inflammatory processes possibly by downregulating gene expression of angiogenesis factors and proinflammatory cytokines. [ABSTRACT FROM AUTHOR]

Objective: To examine the effect of water extract of Thunbergia laurifolia on hepatic insulin resistance in high-fat diet-induced obese mice. Methods: High-fat diet with 45 kcal% lard fat was used for obesity induction in ICR mice. The mice were fed with high-fat diet for 16 weeks, and during the last 8 weeks, they were treated with 200 mg/ kg/day of water extracts from Thunbergia laurifolia leaf, stem and flower. Serum biochemistry, liver histology, and protein expression were examined after the treatment. Results: Extracts from all of the three parts of Thunbergia laurifolia significantly alleviated hyperglycemia, hyperlipidemia, hyperinsulinemia, and hyperleptinemia. The stem and flower extracts improved glucose tolerance. All of the extracts significantly reduced serum TNFα and monocyte chemoattractant protein-1 levels. Liver weight, triglyceride levels, and lipid accumulation were also decreased. Moreover, hepatic glucose-6-phosphatase level was significantly decreased, while the levels of PPARα, phosphorylated AMPK, and phosphorylated Akt were significantly increased with treatment of Thunbergia laurifolia extracts. Conclusions: Thunbergia laurifolia extracts can ameliorate hepatic insulin resistance in high-fat diet-induced obese mice by improving glucose and lipid homeostasis, which may be associated with stimulating phosphorylation of AMPK and Akt pathways. [ABSTRACT FROM AUTHOR]

Background: Enhancing relaxation of resistance arteries and decreasing oxidative stress by using natural products are potential strategies for prevention and treatment of hypertension.Purpose: This study investigated whether aqueous extract of Moringa oleifera leaves (MOE) could alleviate Nω-nitro-L-arginine-methyl ester (L-NAME)-induced high blood pressure via modulation of vascular function and antioxidant properties.Methods: An experimental hypertensive model was established by administration of L-NAME (50 mg/kg/day) in drinking water to male Wistar rats for 3 weeks. Arterial pressure was measured indirectly by tail-cuff plethysmography and directly via femoral artery catheterization. Vasoreactivity of isolated rat mesenteric arterial bed was determined by the changes in perfusion pressure detected by a pressure transducer. Vascular superoxide anion (O2•-) production was determined by lucigenin-enhanced chemiluminescence. Other biochemical measurements including malondialdehyde (MDA) level, superoxide dismutase (SOD), and catalase (CAT) activities were measured by colorimetric assay.Results: L-NAME-treated rats developed significantly increased blood pressure and heart rate. Concurrent oral treatment with MOE (30 and 60 mg/kg/day) could decrease the high blood pressure and tachycardia in a dose-dependent manner. MOE reduced the impairment of acetylcholine-induced relaxation and decreased the hyperreactivity of adrenergic-mediated contraction in response to periarterial nerve stimulation and phenylephrine in isolated mesenteric arterial beds. In addition, MOE exhibited antioxidant effects in the hypertensive rats, as indicated by suppression of vascular O2•- production, decrease of plasma and thoracic aorta MDA levels, and increase of antioxidant activities of SOD and CAT. Moreover, MOE (0.001-0.3 mg) produced a dose-dependent relaxation in methoxamine pre-contracted arterial beds isolated from L-NAME hypertensive rats, which was abolished by endothelium denudation.Conclusion: These findings suggest that the antihypertensive effect of MOE in L-NAME-hypertensive rats may be mediated by alleviating vascular dysfunction and oxidative stress and promoting endothelium-dependent vasorelaxation. MOE may be potentially useful as a natural product against hypertension. [ABSTRACT FROM AUTHOR]

N ω -Nitro- l -arginine methyl ester ( l -NAME)-induced hypertension and cardiovascular remodeling are associated with oxidative stress and inflammation. Garcinia mangostana Linn., has been reported to have antioxidant and anti-inflammatory properties. This study investigated whether G. mangostana pericarp extract (GME) could prevent l -NAME-induced hemodynamic alterations, cardiovascular remodeling, oxidative stress and inflammation in rats. Male Sprague-Dawley rats were given 40 mg/kg/day of l -NAME in drinking water to induce hypertension, and were simultaneously treated with GME at a dose of 200 mg/kg/day. Rats that received l -NAME for five weeks had high blood pressure, left ventricular hypertrophy and thickening of aortic wall. Vascular superoxide production, plasma malondialdehyde (MDA), and plasma tumor necrosis factor alpha (TNF-α) were significantly increased in l -NAME-hypertensive rats ( p < 0.05). This was consistent with up-regulation of the p47 phox NADPH oxidase subunit and iNOS protein expression in aortic tissues ( p < 0.05). Low levels of plasma nitric oxide metabolites were observed in l -NAME hypertension. GME prevented the development of hypertension and cardiovascular remodeling induced by l -NAME with reduced oxidative stress and inflammation. These data suggest that GME had a protective effect against l -NAME-induced hypertension and cardiovascular remodeling via suppressing p47 phox NADPH oxidase subunit and iNOS protein expression resulting in enhancing NO bioavailability. [ABSTRACT FROM AUTHOR]

Morus alba Linn. (MA), mulberry leaves have been used as a beverage for prevention of various diseases including hyperlipidemia and hyperglycemia. Recently, the antioxidant activities of the MA leaf extract have been reported. The objective of this study was to investigate the effect of the MA leaf extract on free radical-induced cellular injury. In the in vitro models, the extract scavenged stable free radical (1, 1-diphenyl-2-picrylhydrazyl; DPPH) in a concentration-dependent manner with an IC50 of 20.10±0.78 µg/ml. The extract protected the erythrocytes from free radical (2, 2'-azobis (2-amidinopropane) dihydrochloride; AAPH)-induced hemolysis with an IC50 of 74.22±9.87 µg/ml. Additionally, the extract significantly prevented the gastric mucosal injury induced by ischemia-reperfusion (I/R) in rats when given orally at doses of 0.25 and 0.50 g/kg/day for 3 consecutive days (p<0.05; n=7). However, this effect was not found when the higher doses (1 and 2 g/kg/day) of the extract were tested. In conclusion, these results indicate that the MA leaf extract possesses the cytoprotective activity against free radical-induced cell injury. Therefore, when given at the appropriate dose range, the mulberry leaf may potentially be used as a food supplement in patients with certain diseases in which the oxidative stress-induced cellular injury is pathologically involved. [ABSTRACT FROM AUTHOR]