Judul: Antihiperurisemia Ekstrak Sidaguri, Seledri, dan Tempuyung secara In Vitro dan In Vivo
Abstrak: Celery (Apium graveolens), sidaguri (Sida rhombifolia), and tempuyung (Sonchus arvensis) are an Indonesian native medicinal plants that can augment the production of urine (diuretic) and can inhibit xanthine oxidase enzyme activity in order to decrease the level of uric acid in blood. Inhibition of xanthine oxidase by in vitro was examined at the optimum condition (20 oC of incubation temperature, pH 7.5, 0.1 unit/ml of xanthine oxidase concentration, and 0.7 mM of xanthine concentration) was compared with allopurinol as positive control. The results of in vitro inhibition test of xanthine oxidase activity showed single extract of 400 ppm of sidaguri, 1400 ppm of celery, and 400 ppm of tempuyung that have greatest inhibition of 56.46, 80.95, and 83.02%, respectively. In addition, the combined extract of sidaguri, celery, and tempuyung of 4:14:4 ratio showed inhibition of 88.68%. The combination with dose of 2640 mg/300 g BB can decrease the concentration of uric acid in the blood of rat by 56.86% which exceeds the positive control (allopurinol) of 56.86%, and has xanthine oxidase activity of 179.05 mM/L min lower as compared with the normal group (501.12 mM / L min). These results proved that the combined extracts of sidaguri, celery, and tempuyung is potential as antigout medicine through xanthine oxidase enzyme inhibition.
Keyword: 

Judul: Kajian Potensi Beberapa Ekstrak Tanaman Herbal sebagai Anti Asam Urat dan Aktivitas Inhibisinya terhadap Xantina Oksidase
Abstrak: Artritis gout (asam urat) adalah penyakit gangguan sendi. Pencegahan gout dapat dilakukan dengan cara memberikan obat-obatan yang bekerja langsung pada enzim yang berperan meningkatkan kadar asam urat yaitu xantina oksidase. Penghambatan xantina oksidase terjadi oleh alopurinol. Penelitian bertujuan meninjau berbagai tulisan mengenai potensi beberapa ekstrak tanaman herbal sebagai inhibisi terhadap xantina oksidase untuk mengetahui potensinya sebagai anti gout (asam urat). Metode yang digunakan adalah menelaah pustaka primer berbagai tulisan, berupa jurnal, berita, makalah, skripsi, tesis, dan disertasi. Hasil penelitian menunjukan terdapat beberapa tanaman herbal yang memiliki senyawa aktif seperti flavonoid yang mampu menjadi inhibitor bagi xantina oksidase. Tanaman tersebut di antaranya, sidaguri, tempuyung, daun salam, daun alpukat, daun jarum tujuh bilah, dan keladi candik. Tanaman-tanaman tersebut memiliki potensi yang baik dalam menghambat xantina oksidase. Hal ini dapat dilihat dari nilai aktivitas inhibisinya yang lebih tinggi dari alopurinol, Gout artritis (uric acid) is a disease of joint disorders. Prevention of gout can be done by giving drugs that work directly on enzymes that play a role in increasing uric acid levels, is xanthine oxidase. Allopurinol is inhibited by xanthine oxidase. This study aims to review various articles on the potential of several herbal plant extracts as xanthine oxidase inhibitors to determine their potential as anti-gout. The method used is a literature review for the primary literature of various kinds of writings, in the form of journa ls, news, papers, theses, and dissertations. The results showed that there were several herbal plants that had active compounds such as flavonoids which were able to become inhibitors of xanthine oxidase. These plants include sidaguri, tempuyung, bay leaves, avocado leaves, jarum tujuh bilah leaves, and keladi taro. These plants have good potential in inhibiting xanthine oxidase. This can be seen from the value of its inhibitory activity which is better than alopurinol.
Keyword: gout, alopurinol, herbal plants, inhibition.

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.
Keyword: