Judul: In Vitro Antioxidant and Antidiabetic Activity of Maja Leaf Extract and Trigona Honey
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh proporsi ekstrak daun maja terhadap inhibisi enzim α-glukosidase, aktivitas antioksidan, dan jenis fitokimia madu trigona. Penelitian ini menggunakan rancangan acak lengkap dengan bahan alam yang secara tradisional digunakan pada pengobatan diabetes masyarakat Sulawesi selatan. Penelitian dimulai dengan memetik daun maja segar lalu keringkan dan dijadikan ekstrak. Ekstrak yang dihasilkan kemudian dicampurkan dengan madu trigona raw dengan proporsi madu trigona saja (FI), madu trigona campur ekstrak daun maja proporsi sama (FII), ekstrak daun maja saja (FIII), madu trigona yang dua kali lebih besar dari ekstrak daun maja (FIV), dan ekstrak daun maja lebih besar dua kali dari madu trigona (FV). Setelah jadi kelima formulanya masing-masing diuji fitokimia secara kualitatif (flavonoid, alkaloid, tanin, triterpenoid, steroid, saponin, quinon), uji aktivitas antioksidan dengan metode DPPH, uji inhibisi enzim α-glukosidase. Hasil uji fitokimia menunjukkan madu trigona hanya mengandung flavonoid dan tanin, sedangkan ekstrak daun maja dan campurannya dengan madu trigona memiliki hasil positif pada flavonoid, tanin, steroid, dan saponin. Hasil uji aktivitas antioksidan FI (IC50 2.524 ppm) aktivitas antioksidan sangat lemah, FII (IC50 196 ppm) kategori antioksidan lemah, FIII (IC50 201 ppm) dan FIV (IC50 225 ppm) antioksidan yang sangat lemah, FV (IC50 147 ppm) kategori antioksidan sedang. Hasil uji inhibisi enzim α-glukosidase paling tinggi pada FV (IC50 300,74 ppm), lalu FIII (IC50 493,54 ppm), dan FIV (IC50 847,95) sedangkan untuk FI dan FII dianggap tidak dapat menginhibisi enzim α-glukosidase., This study aims to determine the effect of the maja leaves extract proportion to the α-glucosidase enzyme inhibition, the antioxidant activity and the phytochemical type of trigona honey. The design study applied a complete random design with natural ingredients which traditionally used in a diabetic treatment of people in South Sulawesi. The study process began by pick fresh maja leaves and drying them for making extracts. These extracts then mix with raw trigona honey under several proportions: F1 (only contains trigona honey), FII (trigona honey mixed with maja leaves extract under the same proportion), FIII (only contains of maja leaves extract), FIV (trigona honey and maja leaves extract under ratio of 2 :1) and FV (trigona honey and maja leaves extract under ratio of 1 :2). After the five formulas had been created, each formula was tested qualitatively for the phytochemical content (flavonoid, alkaloid, tannin, triterpenoid, steroid, saponin, and quinones). Next, a test for antioxidant activity by employing DPPH method was conducted which followed by α-glucosidase enzyme inhibition test. From the phytochemical test, it showed that trigona honey only contained flavonoid and tannin compounds, whereas maja leaves extract and its mixture (with trigona honey) obtained a positive result of flavonoid, tannin, steroid, and saponin contents. Meanwhile, the antioxidant activity results are categorizedas follow: FI (IC50 2,524 ppm) has a very weak antioxidant activity, FII (IC50 196 ppm) has a weak antioxidant activity, FIII (IC50 201 ppm) and FIV (IC50 225 ppm) have a very weak antioxidant activities, FV (IC50 147 ppm) has a moderate antioxidant activity. The results of the α-glucosidase inhibition test was found as the highest value in FV (IC50 300.74 ppm), then FIII (IC50 493.54 ppm), and FIV
Keyword: a-glukosidase, antioksidan, ekstrak, maja, madu trigona

Judul: α-Glucosidase Inhibition Activity and DPPH Free Radical Scavenging from Stratified Aqueous Extract of Red Ginger (Zingiber officinale Roxb. var Rubrum)
Abstrak: Jahe merah (Zingiber officinale Roxb. var. Rubrum) mengandung senyawa fenolik yang berpotensi menurunkan kadar glukosa darah (antihiperglikemik) pada pasien diabetes melitus. Penelitian ini bertujuan menentukan aktivitas inhibisi α-glukosidase, aktivitas antioksidan dalam meredam radikal bebas DPPH, dan kadar total fenolik ekstrak air jahe merah bertingkat (ekstrak ke-1, ekstrak residu ke-1, dan ekstrak residu ke-2). Metode penelitian yaitu ekstraksi jahe merah secara infundasi serta analisis dengan teknik uji spektronanometer yang meliputi analisis antidiabetes melalui aktivitas inhibisi α-glukosidase, aktivitas antioksidan metode DPPH, dan kadar total fenolik metode Folin-Ciocalteu. Aktivitas inhibisi α-glukosidase dan kadar total fenolik memiliki perbedaan nilai yang signifikan (p<0.05) dengan nilai tertinggi 97.729% (ekstrak ke-1) dan 27.624 mg GAE/g ekstrak (ekstrak residu ke-2). Aktivitas antioksidan dalam meredam radikal bebas DPPH memiliki perbedaan nilai yang tidak signifikan dengan nilai tertinggi 4.682 mg AAE/g ekstrak (ekstrak residu ke-1). Hasil analisis menunjukkan nilai aktivitas inhibisi α-glukosidase dan kadar fenolik total berbeda signifikan (p<0,05) dengan nilai tertinggi 97.729% (ekstrak ke-1) dan 27.624 mg GAE/g ekstrak (ekstrak residu ke-2). Hasil aktivitas antioksidan memiliki nilai yang tidak berbeda nyata (p>0,05) dengan nilai tertinggi 4.682 mg AAE/g ekstrak (ekstrak residu ke-1)., Red ginger (Zingiber officinale Roxb. var. Rubrum) contains phenolic compounds that have potential to reduce blood glucose levels (antihyperglycemic) in patients with diabetes mellitus. This study aimed to determine the inhibitory activity toward α-glucosidase, antioxidant activity in reducing DPPH free radicals, and total phenolic content from stratified aqueous extract of red ginger (1st extract, 1st residue extract, and 2nd residue extract). The red ginger was extracted by infundation and analyzed by spectronanometer test techniques which included analysis of antidiabetic through inhibitory activity of α-glucosidase, antioxidant activity using the DPPH method, and total phenolic content using the Folin-Ciocalteu method. The results of the analysis showed that the inhibitory activity of α-glucosidase and total phenolic content were significantly different (p<0.05) with the highest values 97.729% (1st extract) and 27.624 mg GAE/g extract (2nd residue extract). The result of antioxidant activity was not significantly different (p>0.05) with the highest value 4.682 mg AAE/g extract (1st residue extract).
Keyword: α-Glucosidase, Antioxidant, Diabetes Mellitus, Red Ginger

Judul: Asymptotic Distribution of Estimator for the Intensity Function of a Doubly Periodic Poisson Process
Abstrak: In this manuscript, estimation of the intensity function of a doubly periodic Poisson process is discussed. It is assumed that only a single realization of the Poisson process is observed in a bounded window [0,n]. It is also assumed that the period of the intensity function is known. The rate of consistency and asymptotic normality of the estimator are formulated. Finally, a confidence interval for the local intensity function is also formulated.
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