Judul: Fraksi aktif ekstrak daun Sansevieria trifasciata Prain sebagai penghambat pertumbuhan sel lestari HeLa
Abstrak: Sansevieria trifasciata Prain is an ornamental plant which is also useful as a source of antibacterial and antioxidant agent. Studies of S. trifasciata Prain as anticancer have not been reported. Therefore, the objective of this study is to isolate bioactive compounds of S. trifasciata Prain leaves that shows in vitro proliferation inhibition of HeLa cell lines. The sample was macerated in 96% methanol and concentrated using a rotary evaporator. The crude extract was fractionated using chromatography column with silica gel as the stationary phase and gradient chloroform-ethyl acetate as the mobile phase. Qualitative phytochemical and inhibition activity using MTT assay (3- (4,5-dimethylthiazol- 2-yl)-diphenyltetrazolium-2,5-bromide) were performed on the crude extract and its fractions at concentrations between 200 and 1000 ppm. The crude extract contained flavonoids, alkaloids, and steroids, but the crude extract could not inhibit proliferation of HeLa cell lines. The chromatography resulted 10 fractions, however, there was only one fraction with the highest proliferation inhibition was 87.52% at concentration of 10000 ppm that. This fraction contained flavonoids and alkaloids.
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Judul: Fraksi aktif ekstrak daun sansevieria trifasciata lorentii sebagai penghambat proliferasi sel lestari HeLa
Abstrak: Daun lidah mertua (Sansevieria sp) telah banyak diteliti, terutama khasiatnya sebagai antioksidan dan antibakteri, sedangkan khasiat sebagai antikanker belum pernah dilaporkan. Oleh karena itu, tujuan penelitian ini adalah mengisolasi fraksi aktif ekstrak daun Sansevieria trifasciata yang dapat menghambat proliferasi sel lestari HeLa secara in vitro. Teknik ekstraksi dilakukan secara maserasi dalam metanol 96% dan dipekatkan menggunakan penguap putar. Ekstrak metanol difraksinasi menggunakan kolom kromatografi melalui proses elusi gradien dengan nisbah pelarut kloroform dan metanol. Uji fitokimia dan uji penghambatan proliferasi sel lestari HeLa dengan metode MTT [3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazolium bromida] dilakukan terhadap ekstrak kasar dan hasil fraksinasi pada konsentrasi antara 10-100 ppm. Rendemen ekstrak kasar daun lidah mertua diperoleh sebesar 18% dan mengandung flavonoid, saponin, dan steroid. Nilai daya hambat proliferasi sel lestari HeLa tertinggi untuk ekstrak kasar diperoleh sebesar 23% pada konsentrasi 10 ppm. Hasil uji hambat yang teraktif dari sepuluh fraksi adalah 41% pada konsentrasi 100 ppm dan mengandung metabolit golongan steroid.
Keyword: HeLa cell line, Kromatografi kolom, Bogor Agricultural University

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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