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 Terhadap Siklooksigenase, Kadar Pati dan Fenolik Temulawak (Curcuma xanthorriza Roxb.) Aksesi Sukabumi
Abstrak: Curcuma xanthorrhiza Roxb. known as temulawak is widely used as herbal medicinal plant that has many benefits, including antiinflammation. The objectives of this research were to evaluate inhibitory activity of temulawak Sukabumi accession toward cyclooxygenase-2 (COX-2) and to analyze its correlation with starch and phenolic level. The extraction method used maseration with ethanol 70%. The starch level was analyzed using Luff-scohrl’s method, and the phenolic level was determined using the Folin-Ciocalteu’s. The starch level is relatively higher (P>0.05) on temulawak Cursina variety were 23.05%±3.49, while the phenolic level is relatively higher (P>0.05) on temulawak Sukabumi accession were 81.16 mg/g±19.68. Both of temulawak extracts showed inhibitory activity against COX-2. The highest activity (P>0.05) on temulawak Sukabumi accession with inhibition value of 55.35%. Based on analysis of corelation, the phenolic compound has antiinflammation activity, while starch will reduce antiinflammation activity.
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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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