Judul: Study on antihyperglycemic mechanism of extract mixture of piper crocatum leaves and cinnamomum burmannii bark as potential functional drink
Abstrak: Piper crocatum, one of Indonesia’s medicinal plants, has antihyperglycemic activity despite its bitter taste. Considering that Indonesia was the 4th largest country whose population suffered from diabetes mellitus with a prevalence of 8.6% of the total population in 2005, the necessity to increase the potency of red piper betel is of great importance. This can be done by producing it as functional drink. For this reason, this research aimed to determine : (1) the formulation of a mixture of water extract of P. crocatum leaves and C. burmannii bark which have antioxidative activities by measuring their superoxide dismutase and catalase enzyme, and anti-hyperglycemic activity in vitro by measuring their a-glucosidase activity; (2) the evaluation of sub acute toxicity study on the selected formula using male and female Sprague dawley rats; (3) the functional effect of the chosen formula, especially its anti-hyperglycemic activity in streptozotocin-induced diabetics rats. P. crocatum leaves and C. burmannii bark powder were boiled in water separately for 15 minutes, and filtered. The filtrate was used in the formulation of mixing water extract of P.crocatum leaves and C. burmannii bark in a ratio of (5:0); (5:1); (5:3); (5:5); and (0:5). Each of this formula was then added with stevia (sweeteners) of 0.67% (v/v). In the evaluation of the sub acute toxicity, the chosen formula was administered orally into 4 groups of Sprague dawley rats with different doses (0, 630, 1260, 1890 mg/kg bw) for 28 days. In anti-hyperglycemic activity study, streptozotocin induced diabetics rats (50 mg/kg bw) were administered orally by a dosage of (0; 630; 1260 and 1890 mg/kg bw) for 14 days. During the treatment period, blood glucose level was recorded at 5 day-intervals, and at the end of treatment the rats were killed by chemical anesthesia. The blood was taken for further analysis, such as blood serum glucose, blood serum lipid, insulin, and red blood cell SOD; and catalase activities were also studied. The results showed that the formula with the ratio (5:3) was the chosen formula with the following characteristic parameters: activity of SOD at 3.32 ± 0.08 U/ml, catalase activity 0.18 ± 0.02 U/ml, and a- glucosidase inhibitor activity 61.00 ± 2.55%, and total phenolic compounds 1067.65 ± 0.90 ppm. In the sub acute toxicity, there were no significant differences in the body weight, food intake, hematological analysis, blood chemistry analysis (glucose, cholesterol, triglycerides, creatinine, SGPT, and SGOT), organ weights, and histopathological analysis among the control groups and treated animals. In vivo anti-hyperglycemic activity showed that 14 days of daily treatment of 1260 mg/kg bw dose of functional drink significantly (p<0.05) reduced blood glucose level (51%), and increased the amount of ß cell, Langerhans island of pancreas organ, and red blood cell SOD activity. There was no significant (p<0.05) increase in blood serum insulin level and catalase activity. In addition, extract mixtures of the chosen formula could prevent blood serum lipid level of diabetic rats from increasing.
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Judul: Antihyperglycemic activities of functional drink based on java tea (Orthosiphon aristatus BI. Miq) in streptozotocin induced diabetic mice
Abstrak: Diabetes is a group of diseases marked by high levels of blood glucose resulting from defects in insulin production, insulin action, or both. Diabetes can lead to serious complications and premature death. Antioxidant compounds in functional drinks such as flavonoid may offer some protection against the early stage of diabetic mellitus and the development of complications. The objective of this study was to investigate the antihyperglycemic effects of functional drinks based on java tea with different variety of java tea (white and purple flowers) and addition ginger extract in functional drink formulas on streptozotocin induced diabetic mice. These results indicated that the administration of functional drinks thats added java tea with white flowers and ginger extracts in diabetic mice can inhibit a more stable the increasing of blood glucose level and its can inhibited the rate of pancreatic beta cells damage. TLC profile and HPLC analysis show that the bioactive compounds in the extract ingredient are sinensetin, 6-gingerol, 8-gingerol, 10-gingerol, 6-shogaol, curcumin, desmethoxycurcumin, brazilin, hesperidin and naringin.
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Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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