Judul: Aktivitas antihiperglikemik dari ekstrak buah mahkota dewa [Phaleria macrocarpa (Scheff.) Boerl.] sebagai inhibitor alfa-glukosidase in vitro dan in vivo pada tikus putih
Abstrak: Alpha-glucosidase inhibitor is an oral antidiabetes for use in the management of type 2 diabetes mellitus. The antihyperglycemic activity of alpha-glucosidase inhibitor resulted from a competitive, reversible inhibition of hydrolase enzymes, pancreatic alpha-amylase and intestinal digestion enzymes (i.e., isomaltase, sucrase and maltase) which hydrolyzed dietary carbohydrates to glucose and other monosaccharides. In diabetic patients, inhibition of these enzymes result in a delayed glucose absorption and a lowering of postprandial hyperglycemia. The purpose of this research is to study the antihyperglycemic activity of the fruit extracts of Phaleria macrocarpa (Scheff) Boerl. as alpha glucosidase inhibitor by in vitro and in vivo experiments. The research is performed in several steps: fractionation and extraction of the ripe and unripe fruits, phytochemistry test of the fruit extracts, alpha-glucosidase inhibition test by in vitro experiment, toxicity test of the fruit extracts by using BSLT method and antihyperglycemic activity test by in vivo experiment with Oral Glucose Tolerance Test (OGTT) in the white rats. The alpha-glucosidase inhibition test in vitro is performed by using alphaglucosidase enzyme and substrate p-nitrophenyl α-D-glucopyranosa. The result of these experiment showed that n-butanol fraction extract of the ripe and unripe fruits have the highest activity followed by ethyl acetate fraction extract, methanol extract and water extract from the boiled of the ripe and unripe fruits. The water fraction extract of ripe and unripe fruits do not have any significant inhibition activity. Brine Shrimp Lethality Test (BSLT) method used the shrimp larvas of Artemia salina Leach to study the mortality effect that caused by the fruit extracts of phaleria macrocarpa. The data obtained was analyzed by using Sam’s method. Based on the LC50 value from the result of BSLT method, the unripe fruit extracts are more toxic than the ripe fruit extracts, with the highest toxicity is methanol extract followed by ethyl acetate fraction extract, boiled water extract and n-butanol fraction extract. In the antihyperglycemic activity test by in vivo experiment is used fifteen rats which are divided into three treatment groups: the positive control group which is given Acarbose drug, the treatment group which is given the water extract from the boiled ripe fruit and the treatment group which is given the n-butanol fraction extract of ripe fruit. The result of this experiment indicated that giving the water extract from the boiled ripe fruit with dose of 6.20 x 10-4 mg/ g rat and 1.24 x 10-3 mg/ g rat and the n-butanol fraction extract of ripe fruit with dose of 1.81 x 10-3 mg/ g rat and 3.62 x 10-3 mg/ g rat decreased the blood glucose concentration of rats after giving 80% w/v sucrose solution treated rats, that were comparable to those of Acarbose with dose of 1.00 x 10-3 mg/ g rat as the positive control. The conclusion of this research is the n-butanol fraction extract of the ripe and unripe fruits of Phaleria macrocarpa (Scheff) Boerl. have the highest antihyperglycemic activity by in vitro experiment to inhibition of alpha-glucosidase enzyme and by in vivo experiment in the white rats showed that antihyperglycemic activity from the n-butanol fraction extract of
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Judul: Isolasi Fraksi Flavonoid sebagai Inhibitor Enzim α-Glukosidase dari Buah Mahkota Dewa
Abstrak: Mahkota dewa (Phaleria macrocarpa) empirically recognized as anti-diabetic. This claim requires further analysis, one of it by enzymatic inhibition assay using α-glucosidase enzyme. This intestinal enzyme produce in the jejunum catalyzed the breakdown of glycogen to glucose which increased blood sugar level therefore, elevating the risk of diabetes. Efforts to inhibit this enzyme could decrease postprandial blood sugar level. The aim of experiment was to determine the most active flavonoid subgroup which inhibited α-glucosidase enzyme of fruit etanol extract from mahkota dewa initiated with liquid partition and was continued with flash chromatography partition. Fruit pericarp is macerated using 3 different solvents (water, ethanol 96%, and n-hexane). Dry extract was analyzed for its water content, ash content, phytochemical content, and inhibition activity of α-glucosidase enzyme using modified Kawaniski method. The most active isolate is analyzed further using flash chromatography. Fruit pericarp water concentration was 9,42%. Phytochemical compound of the extracts were alkaloids, flavonoids, tannins. saponins, steroids, but do not contain triterpenoids. Amyl alcohol fraction has the highest inhibition to α-glucosidase of 40,04%, for the ethyl acetate fraction only 25,26%, and glucobay as positive control was 97,45%. Further analysis with flash chromatography using solvent of the best resolution was chlorofom:methanol with ratio of 9:1 which showed that amyl alcohol fraction contain flavonoid from several classes of isoflavon, flavon, flavonol, and flavanon. This result showed that the flash chromatography partition has not succeeded to separate the subgroup of flavonoid which was active to inhibit α-glucosidase enzyme.
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Judul: Pengaruh Pairing pada Isotop Sn dengan Menggunakan Pemodelan Sembilan Tingkat Energi
Abstrak: Formation of the neutron-rich tin isotopes (Sn isotopes) is the one of the interesting topics in the field of nuclear reaction, especially regarding the stability of the heavy nuclei. Calculations of total energy using the BCS approach using five energy levels can only calculate the total energy up to Sn50132. On the other hand, the experiment continues and has exceeded the formation of isotopes. Therefore, there is need for a new model to accomadate more neutrons. In this research, Sn isotopes is modelled using nine energy levels and constant interaction potential to explain the pairing phenomenon up to Sn50154. However, to obtain more accurate results, other methods to minimize the differences with the experimental results are clearly needed here.
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