Judul: Kapasitas Antioksidan Bawang Dayak (Eleutherine palmifolia) dalam Bentuk Segar,Simplisia dan Keripik, pada Pelarut Nonpolar, Semipolar dan Polar
Abstrak: Bawang dayak (Eleutherine palmifolia) is a red bulb plant from Central Kalimantan, which has bioactive compounds such as phenols, flavonoids, alkaloids, glycosides and tannins. The existence of bioactive compounds become parameter of antioxidant activity of this red bulb. The study showed antioxidant capacity of bawang dayak in fresh form, simplisia (dried) form and chips form, which were extracted by the solvent hexane, ethyl acetate, methanol, ethanol and water. Antioxidant capacity was measured by DPPH method and rancimat method. Phytochemical screening was conducted to determine the bioactive compounds of bawang dayak in each form for every solvent. Based on DPPH method, bawang dayak in fresh form was extracted with ethyl acetate had the highest antioxidant capacity value that is 227.0% equal to 1.02 mg AEAC/mg extract. Simplisia form which was extracted with ethanol had antioxidant capacity value 51.8% equal to 0.21 mg AEAC/mg extract. Chips form was extracted with ethylacetate and ethanol had the highest antioxidant capacity values 57.5% and 46.5% which were equal to 0.24 mg AEAC/ mg extract and 0.18 mg AEAC/ mg extract. The induction time of ethylacetate fresh extract, ethanol simplisia extract and ethylacetate chip extract based on measurement with rancimat method, were 3.7 hours, 2.8 hours and 2.6 hours. All of extract had higher induction time than tocoferol. Besides, the measurement of phenolic content resulted that methanol fresh extract, ethanol simplisia extract and methanol chip extract had 4.29 mg GAE/100 mg extract, 3.52 mg GAE/ 100 mg extract and 3.38 mg GAE/100 mg extract. Vitamin C (ascorbic acid) on fresh bawang dayak was quite high, reaching 61.5mg/100gram, whereas vitamin C on simplicia and chip were decreased, respectively 41.0 mg/100 gram and 22.0 mg/100gram due to the heating process. The Ethylacetate fresh extract contains of alkaloid , phenolic, flavonoids, triterpenoids, steroids and glycosides compounds, while the ethanol simplscia extract and ethylacetate chip extract contains of alkaloids, saponins, tannins, phenolics, flavonoids, triterpenoids, steroids and glycosides compounds.
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Judul: Antioxidants and Antidiabetic Potency of Aqueous and Ethanolic Extracts of Bawang Dayak Bulbs (Eleutherine palmifolia) in vitro and in vivo.
Abstrak: Eleutherine palmifolia is an indigenous plant from Kalimantan and is widely used by the Dayak tribes to cure several diseases including diabetes mellitus. The purpose of this research is to scientifically prove antioxidant and antidiabetic properties of bawang dayak bulbs and to evaluate its safety that can be used as a source of functional food. Bawang dayak bulbs (BDB) were extracted with water and ethanol solvents. The solutions which contain the aqueous and the ethanolic extracts then freeze dryed. Phytochemical screening that was conducted upon aqueous and ethanolic extracts showed that both of extracts contained alkaloids, tannins, phenolics, flavonoids, triterpenoids, and steroids. Prominent types of phytochemical compounds in aqueous extracts are alkaloids phenolic and triterpenoids, whereas in the ethanolic extract are alkaloid, tannin, phenolic, flavonoids and triterpenoids. Both types of extracts showed antioxidant activity and alpha glucosidase inhibition activity. The antioxidant activity of the ethanolic extract is very significantly higher (P<0.01) than that of the aqueous extract, with IC50 112 ppm for ethanolic extract and 526 ppm for aqueous extract. Alpha glucosidase inhibition activity of ethanolic extract was also very significantly greater (P<0.01) than that of the aqueous extract, with IC50 241 for ethanolic extract and 505 ppm for aqueous extract. The result of NMR (Nuclear Magnetic Spectroscopy) analysis showed that there were eleutherinoside A, eleutherol, and eleuthoside B in ethanolic extract of BDB, but there was not enough sinyal in NMR spectra of aqueous extract to conduct NMR-J resolved data analysis. According to Ieyama et al. (2011) those compounds showed alpha glucosidase inhibitory activity, and eleutherinoside has the biggest activity with IC50 0.5 mM. So it is suggested that eleutherinoside A, eleutherol and eleuthoside B are the active compounds of alpha glucosidase inhibitory activity in BDB ethanolic extract. It is also suggested that alphaglucosidase inhibitory capacity in BDB aqueous extract was presented by the activities of phenolic, alkaloid and triterpenes compounds. Oral glucose tolerance test (OGTT) was done to decide the dose of bawang dayak extracts for in vivo analysis in diabetic experimental rats. The chosen dose was 100 mg/kg BW to diabetic rats, whereas a higher dose was chosen for nondiabetic rats (500 mg/kg BW). The reason of higher dose implementation to non diabetic rats is to evaluate the safety of aqueous and ethanolic extracts to the function and morphology of liver and kidney organs. Sprague-Dawley (SD) male rats age ± 8 weeks old and weighs ± 180 grams were used in this experiment. Conditions of diabetes mellitus (DM) is obtained by induction of 110 mg/kg BW of alloxan monohydrate to SD rats intraperitoneally. BDB aqueous and ethanolic extracts were administered orally by gavage to diabetic and non-diabetic rats for 28 days. Termination was done by using ketamine on day 29 and followed by blood, liver, kidneys and pancreas collections. Observations and analysis were conducted on the body weight, blood glucose levels, serum insulin levels, blood lipid profile (total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides), serum catalase and superoxide dismutase (SOD) enzymes activities, liver malonaldehyde levels, serum creatinine levels, serum albumin levels, Serum Glutamic-Piruvic Transaminase (SGPT) and Serum Glutamic-Oxaloacetic Transaminase (SGOT)
Keyword: diabetes, bawang dayak, Eleutherine palmifolia, antioxidant, functional food

Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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