Judul: Aktivitas Ekstrak Etil Asetat Daun Mimba sebagai Antihiperglikemik pada Tikus yang Diinduksi Aloksan
Abstrak: The aimed of this study to assess the potency of ethyl acetate extract of neem leaves which has the effect anti-hyperglycaemia in white rat as experimental animals. Eighteen male white rats age 4-5 months was divided into six groups: first as a normal control group (K1) which has given aquadest, second as a negative control group (K2) which has given aquadest, a third group as a positive control (K3) were have given glibenclamide; the treatment group (KP1, KP2, KP3) were have given ethyl acetate extract of neem leaves dose of 30, 60, 90 mg/kg BW. All groups except K1 were induced by alloxan dose 150 mg / kg BW. Phytochemical screening of neem leaves contained the active ingredients such as flavonoids, saponins, and tannins. Blood glucose concentrations in rats was examined before and after induction of alloxan and after treatment. The results showed that the ethyl acetate extract of neem leaves significantly affected the decrease blood glucose concentrations. The effective dose to decrease blood glucose concentrations are 60 and 90 mg / kg BW. The study concluded that the ethyl acetate extract of neem leaves can be recomended as anti-hyperglycaemia effect.
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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: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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