Judul: Potensi Antihiperkolesterolemia Ekstrak Seduhan Teh Herbal Lempuyang Gajah (Zingiber zerumbet L.)
Abstrak: The objective of this research was to study the effectivity of herbal tea compositions of lempuyang gajah as antihypercholesterolemic agent. Extracts were tested in Sprague-Dawley male rats. Forty six rats were divided into four experimental groups as follow: normal, hyperlipidemic, herbal tea extract 1, and herbal tea extract 2. Rats were made hiperlipidemic by oral administration of propil tiouracil (0.5 mg/Kg BW) and high cholesterol feeding (1.5 % cholesterol). Total blood cholesterol concentrations were measured by cholesterol oxidase enzymatic methods of ‘CHOD-PAP’ using spectrophotometer at wavelenght 500 nm. Results showed that cholesterol diet increased blood cholesterol concentration by 76.11 % (p=0.004). Following free cholesterol diet (washed out period), blood cholesterol concentration was decreased by 43.82 % (p=0.101). Similarly, extract 1 reduced cholesterol concentration by 43.20 % (p=0.005). Antihyperlipidemic potency of extract 2 is higher than extract 1 as shown by significant reduction of cholesterol by 51.70 % (p=0.000).
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Judul: Potensi Teh Herbal Lempuyang Gajah (Zingiber zerumbet L.) sebagai Antioksidan pada Tikus Sprague-Dawley Hiperkolesterolemia
Abstrak: Hypercholesterolemic conditions can increase lipid peroxidation and as an indicator of the presence of free radicals in the body. This research aimed to determine the efficacy of lempuyang gajah (Zingiber zerumbet L.) herbal tea as an antioxidant to prevent lipid peroxidation in hypercholesterolemic rats. Twenty six rats were divided into 4 following groups: normal, hypercholesterolemia, extract 1 (low dose), and extract 2 (high dose) groups. Hypercholesterolemia were induced in rats by high cholesterol diet (1.5% cholesterol) and oral administration of propil tiourasil (PTU) 0.5 mg/kg bw in six weeks. Before necropsied, rats were given standard diet for the last four weeks. Lipid peroxide concentrations in the liver were analyzed using thiobarbituric acid (TBA) assay with spectrofotometer UVVis at 532 nm. Results showed that feeding cholesterol free diet in the last four weeks normalized liver lipid peroxide concentration in the three treatment groups. The average of all groups were 40.88±13 nmol/g (p=0.317). Addition of extract reduced correlation between liver lipid peroxide concentration and blood cholesterol concentration on the extract groups (1 and 2). This observation suggest that components of lempuyang gajah herbal tea can prevent lipid peroxidation in liver.
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Judul: Transisi Fasa Materi Hadronik ke Materi Kuark pada Inti Bintang Neutron.
Abstrak: Bintang neutron terdiri dari beberapa lapisan yang disusun oleh materi nuklir yang berbeda dengan kerapatan yang semakin tinggi ketika mendekati pusat bintang. Inti luar bintang neutron disusun oleh materi hadronik (nukleon, lepton, dan hyperon), sedangkan inti dalam bintang neutron disusun oleh kuark-kuark bebas (up, down, strange) yang saling berinteraksi. Tujuan penelitian ini adalah mempelajari bagaimana transisi dari inti luar ke inti dalam bintang neutron dengan menggunakan pendekatan RMF (Relativistic Mean Field) untuk materi hadronik dan CIDDM (Confined Isospin Density Dependent Mass) untuk materi kuark. Tekanan transisi diperoleh ketika potensial kimia barion materi hadronik dan materi kuark bernilai sama. Nilai tekanan transisi dengan parameter SU6-TM1 sekitar 87 MeV/fm3 dan diperoleh massa maksimum bintang neutron yaitu 1.92M dengan jari-jari sekitar 8.62 km. Nilai tekanan transisi dengan parameter SU6-G2 sekitar 53 MeV/fm3 dan massa maksimum bintang neutron yaitu 1.88M dengan jari-jari sekitar 8.16 km. Jenis transisi fasa adalah orde satu ditandai dengan diskontinuitas dalam kerapatan energi (adanya mixed phase). Parameter-parameter pada model nuklir yang digunakan menyebabkan perbedaan kekakuan persamaan keadaan (EOS) dari materi hadronik dan materi kuark sehingga nilai tekanan transisi dari fasa hadronik ke fasa kuark juga berbeda.
Keyword: bintang neutron, persamaan keadaan, transisi fasa