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Background: One of the biological activities of agar wood (Aquilaria sinensis Lour., Thymelaeaceae), is anti-hyperglycemic activity. The methanolic extract (ME) was proven to possess the fasting blood glucose activity in rat and glucose uptake transportation by rat adipocytes. Objective: To determine the decreasing fasting blood glucose level of constituents affordable for in vivo test. If the test was positive, the mechanism which is positive to the ME, glucose transportation, will be performed. Materials and Methods: The ME was separated by column chromatography and identified by spectroscopic methods. Mice was used as an animal model (in vivo), and rat adipocytes were used for the glucose transportation activity (in vitro). Result: Iriflophenone 3-C-β-glucoside (IPG) was the main constituent, 3.17%, and tested for the activities. Insulin and the ME were used as positive controls. The ME, IPG and insulin lowered blood glucose levels by 40.3, 46.4 and 41.5%, respectively, and enhanced glucose uptake by 152, 153, and 183%, respectively. Conclusion: These findings suggest that IPG is active in lowering fasting blood glucose with potency comparable to that of insulin. [ABSTRACT FROM AUTHOR]

Umbelliferone (UMB), a natural product of coumarin family, has been shown to reduce blood glucose and to improve lipid profiles in streptozotocin (STZ)-induced diabetic rats. Our objective was to examine the effect of UMB on adipogenesis by investigating its stimulatory effect on lipid accumulation and mRNA expression of adipogenic transcription factors and adipocyte-specific genes in 3 T3-L1 preadipocyte culture. An Oil Red O staining was used to monitor lipid accumulation, and we found that UMB treatment at concentration range of 10-100 μM significantly increased lipid accumulation of differentiating 3 T3-L1 cells. At the molecular level of adipogenesis, we examined the mRNA expression of adipogenic transcription factors, peroxisome proliferator-activated receptor γ, CCAAT/enhancer-binding protein α, and sterol regulatory element-binding protein 1c. Those transcription factors were increased by UMB at 10-100 μM. Interestingly, UMB also stimulated the mRNA expression of adipocyte-specific genes, adipocyte fatty acid-binding protein, lipoprotein lipase, fatty acid synthase, fatty acid translocase, and adiponectin. Our findings indicate that the stimulatory effect of UMB on adipocyte differentiation likely occurs through up-regulation of adipogenic transcription factors and downstream adipocyte-specific gene expression. [ABSTRACT FROM AUTHOR]

Background and Objective: Our recent study revealed the antihyperglycemic activity of an ethanolic extract of roselle calyxes (Hibiscus sabdariffa) in diabetic rats. The present study had, therefore, an objective to investigate the mechanism underlying this activity. Materials and Methods: Male Sprague Dawley rats were induced to be diabetes by intraperitoneal injection of 45 mg/kg streptozotocin (STZ). Normal rats as well as diabetic rats were administered with the ethanolic extract of H. sabdariffa calyxes (HS-EE) at 0.1 and 1.0 g/kg/day, respectively, for 6 weeks. Then, blood glucose and insulin levels, at basal and glucose-stimulated secretions, were measured. The pancreas was dissected to examine histologically. Results: HS-EE 1.0 g/kg/day significantly decreased the blood glucose level by 38 ± 12% in diabetic rats but not in normal rats. In normal rats, treatment with 1.0 g/kg HS-EE increased the basal insulin level significantly as compared with control normal rats (1.28 ± 0.25 and 0.55 ± 0.05 ng/ml, respectively). Interestingly, diabetic rats treated with 1.0 g/kg HS-EE also showed a significant increase in basal insulin level as compared with the control diabetic rats (0.30 ± 0.05 and 0.15 ± 0.01 ng/ml, respectively). Concerning microscopic histological examination, HS-EE 1.0 g/kg significantly increased the number of islets of Langerhans in both normal rats (1.2 ± 0.1 and 2.0 ± 0.1 islet number/10 low-power fields (LPF) for control and HS-EE treated group, respectively) and diabetic rats (1.0 ± 0.3 and 3.9 ± 0.6 islet number/10 LPF for control and HS-EE treated group, respectively). Conclusion: The antidiabetic activity of HS-EE may be partially mediated via the stimulating effect on insulin secretion. [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]

Agarwood leaf extract was found to possess antipyretic, laxative and antimicrobial activities. A trial of one diabetic patient taking long term agarwood leaf tea was found to have blood glucose returned to normal. In this work, the effects of methanol, water and hexane crude extracts of agarwood leaf on hyperglycemia in streptozotocin-induced diabetic rats were investigated. Only methanol and water extracts at the dose of 1 g/kg body weight lowered the fasting blood glucose levels, 54 and 40%, respectively. The results were comparable to 4 U/kg body weight of insulin (73%). In in vitro experiment, the effect of the methanol and water extracts at the concentration of 10 µg/mL enhanced glucose uptake activity on rat adipocytes by 172±10 and 176±21% of the control, respectively. The glucose uptake enhancement activity is comparable to 1.5 nM insulin (166±16%). The thin-layer chromatographic characteristics of all extracts were documented. The findings suggest that agarwood leaf is a promising potential antidiabetic agent. [ABSTRACT FROM AUTHOR]

Mali-Nil Surin rice bran hydrolysate (MRH) contains highly nutritional proteins and beneficial phenolic compounds. This study investigated an antihypertensive effect of MRH and evaluated the mechanisms mediating this action in N ω -nitro-L-arginine-methyl ester (L-NAME)-induced hypertensive rats. Antihypertensive activity was determined in male rats orally administered with MRH (100 or 300 mg/kg) or enalapril (15 mg/kg) daily together with L-NAME (50 mg/kg/day) in drinking water, for 21 days. Concurrent oral treatment with MRH lowered the high blood pressure in the L-NAME-induced hypertensive rats. MRH treatment improved endothelial function and increased the endothelium-derived hyperpolarizing factor-mediated vasorelaxation in L-NAME hypertensive rats. L-NAME rats treated with MRH had reduced adrenergic hypercontractility, which was associated with a decrease in L-type calcium channel-mediated vasoconstriction. In addition, MRH exhibited antioxidant activity in hypertensive rats, as indicated by suppression of vascular superoxide anion production and reduction of malondialdehyde levels, as well as magnification of superoxide dismutase and catalase activities in serum. This study demonstrated the nutraceutical potential of MRH to prevent oxidative stress-related vascular dysfunction in hypertension., (Copyright © 2022 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)