Judul: Activity of α-glucosidase inhibition and cytotoxicity effect from xanthorrhizol extract temulawak (curcuma xanthorriza roxb.) From different region
Abstrak: Temulawak (Curcuma xanthorrhiza Roxb.) sudah lama dijadikan sebagai obat herbal di Indonesia. Kualitas bahan baku obat herbal temulawak pada penelitian ini dilihat dari tingginya kadar xantorizol dan bioaktivitasnya. Penelitian ini bertujuan memilih temulawak terbaik dari daerah yang berbeda (Karanganyar, Ngawi, Wonogiri, Bogor, dan Ciemas-Sukabumi) berdasarkan kandungan bioaktif (xantorizol) dan bioaktivitasnya (sitotoksisitas dan inhibisi terhadap α-glukosidase). Ekstraksi xantorizol dilakukan dengan cara maserasi. Kadar xantorizol diukur dengan menggunakan HPLC (High Performance Liquid Chromatoghraphy). Kadar xantorizol tertinggi terdapat pada temulawak asal Wonogiri dan Karanganyar dengan konsentrasi masing-masing 479.82 mg/g dan 467.25 mg/g. Temulawak asal Karanganyar mempunyai nilai LC50 sebesar sebesar 52.02 μg/mL. Temulawak asal Karanganyar mempunyai aktivitas penghambatan α-glukosidase terbaik dengan nilai IC50 sebesar 362.20 μg/mL. Temulawak asal Karanganyar berpotensi untuk dikembangkan sebagai obat herbal dengan aktivitas antidiabetes., Temulawak (Curcuma xanthorrhiza Roxb.) has been widely used as herbal medication in Indonesian. The quality of temulawak herbal medication can be known from xanthorrhizol concentration and the bioactivity. The objectives of this research was to determine the best temulawak rhizomes from various regions (Karanganyar, Ngawi, Wonogiri, Bogor, and Ciemas-Sukabumi) based on xanthorrhizol concentration and its bioactivity (by BSLT method and its inhibitory against α-glucosidase). Extraction of xanthorrhizol was done by maceration. Xanthorrhizol concentration was measured with HPLC. The highest xanthorrhizol concentration was found at temulawak from Wonogiri and Karanganayar with values of 479.82 mg/g and 467.25 mg/g. Temulawak from Karanganyar has cytotoxicity activity with LC50 52.02 μg/mL. Temulawak from Karanganyar has the best inhibitory activity against α-glucosidase with IC50 values 362.20 μg/mL. Temulawak from Karanganyar has potential to be developed as a herbal medicine with bioactivity as antidiabetic.
Keyword: α-glukosidase, temulawak, xantorizol

Judul: Aktivitas Inhibisi Enzim α-Glukosidase dan Sitotoksisitas Ekstrak Kurkuminoid Rimpang Temulawak dari Berbagai Aksesi (In Vitro)
Abstrak: Temulawak (Curcuma xanthorriza Roxb.) is one of the Zingiberaceae family medicinal plants that grow in Indonesia. Temulawak rhizome contains curcuminoid which useful as an antidiabetic. This research aims to get temulawak accession with high capability of the inhibition activity of the α-glukosidase enzyme and it’s potential as a compound that toxic to shrimp’s larval Artemia salina Leach. Antidiabetic activity has been measured by formation of p-nitrophenol from enzymatc reaction of nitrophenil-α-D-glucopyranose (p-NPG) which is catalyze by α-glucosidase enzyme. The formation of p-nitrophenol was measured by spectrophotometer at λ=410 nm. The results of curcuminoid content and bioactivity assay (α-glukosidase enzyme inhibition and cytotoxicity) showed that the best accession of temulawak is Wonogiri’s accession. The value of curcuminoid content, IC50, LC50, from Wonogiri’s accession of temulawak rhizome extract, respectively for 85.19±4.64 mg/g, 333±22.52 μg/mL, and 82.78±7.70 μg/mL. Wonogiri’s accesion has the potential to be further researched and developed as a new variety.
Keyword: Bogor Agricultural University (IPB), cytotoxicity, curcuminoids, antidiabetic, Curcuma xanthooriza

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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