Judul: Antioxidants and Antidiabetic Potency of Aqueous and Ethanolic Extracts of Bawang Dayak Bulbs (Eleutherine palmifolia) in vitro and in vivo.
Abstrak: Eleutherine palmifolia is an indigenous plant from Kalimantan and is widely used by the Dayak tribes to cure several diseases including diabetes mellitus. The purpose of this research is to scientifically prove antioxidant and antidiabetic properties of bawang dayak bulbs and to evaluate its safety that can be used as a source of functional food. Bawang dayak bulbs (BDB) were extracted with water and ethanol solvents. The solutions which contain the aqueous and the ethanolic extracts then freeze dryed. Phytochemical screening that was conducted upon aqueous and ethanolic extracts showed that both of extracts contained alkaloids, tannins, phenolics, flavonoids, triterpenoids, and steroids. Prominent types of phytochemical compounds in aqueous extracts are alkaloids phenolic and triterpenoids, whereas in the ethanolic extract are alkaloid, tannin, phenolic, flavonoids and triterpenoids. Both types of extracts showed antioxidant activity and alpha glucosidase inhibition activity. The antioxidant activity of the ethanolic extract is very significantly higher (P<0.01) than that of the aqueous extract, with IC50 112 ppm for ethanolic extract and 526 ppm for aqueous extract. Alpha glucosidase inhibition activity of ethanolic extract was also very significantly greater (P<0.01) than that of the aqueous extract, with IC50 241 for ethanolic extract and 505 ppm for aqueous extract. The result of NMR (Nuclear Magnetic Spectroscopy) analysis showed that there were eleutherinoside A, eleutherol, and eleuthoside B in ethanolic extract of BDB, but there was not enough sinyal in NMR spectra of aqueous extract to conduct NMR-J resolved data analysis. According to Ieyama et al. (2011) those compounds showed alpha glucosidase inhibitory activity, and eleutherinoside has the biggest activity with IC50 0.5 mM. So it is suggested that eleutherinoside A, eleutherol and eleuthoside B are the active compounds of alpha glucosidase inhibitory activity in BDB ethanolic extract. It is also suggested that alphaglucosidase inhibitory capacity in BDB aqueous extract was presented by the activities of phenolic, alkaloid and triterpenes compounds. Oral glucose tolerance test (OGTT) was done to decide the dose of bawang dayak extracts for in vivo analysis in diabetic experimental rats. The chosen dose was 100 mg/kg BW to diabetic rats, whereas a higher dose was chosen for nondiabetic rats (500 mg/kg BW). The reason of higher dose implementation to non diabetic rats is to evaluate the safety of aqueous and ethanolic extracts to the function and morphology of liver and kidney organs. Sprague-Dawley (SD) male rats age ± 8 weeks old and weighs ± 180 grams were used in this experiment. Conditions of diabetes mellitus (DM) is obtained by induction of 110 mg/kg BW of alloxan monohydrate to SD rats intraperitoneally. BDB aqueous and ethanolic extracts were administered orally by gavage to diabetic and non-diabetic rats for 28 days. Termination was done by using ketamine on day 29 and followed by blood, liver, kidneys and pancreas collections. Observations and analysis were conducted on the body weight, blood glucose levels, serum insulin levels, blood lipid profile (total cholesterol, HDL-cholesterol, LDL-cholesterol, and triglycerides), serum catalase and superoxide dismutase (SOD) enzymes activities, liver malonaldehyde levels, serum creatinine levels, serum albumin levels, Serum Glutamic-Piruvic Transaminase (SGPT) and Serum Glutamic-Oxaloacetic Transaminase (SGOT)
Keyword: diabetes, bawang dayak, Eleutherine palmifolia, antioxidant, functional food

Judul: Isolation, Diversity, and Antioxidant Activity of Endophyte Actinobacteria from Dayak Onion (Eleutherine palmifolia L.Merr)
Abstrak: Bawang dayak merupakan tanaman khas Kalimantan yang berkhasiat sebagai antioksidan. Tanaman ini merupakan salah satu sumber potensial mikroorganisme endofit penghasil antioksidan. Penelitian ini bertujuan mengisolasi, mengkaji keragaman, dan menguji aktivitas antioksidan aktinobakteri bawang dayak. Tujuh isolat aktinobakteri telah berhasil diisolasi dari umbi bawang dayak menggunakan medium HVA. Berdasarkan karakter morfologi koloni, miselia aerial, dan penataan sporanya, isolat tersebut diduga termasuk kelompok Streptomyces sp. Uji aktivitas antioksidan menggunakan DPPH menunjukkan bahwa aktivitas antioksidan supernatan isolat-isolat tersebut memiliki aktivitas antioksidan dengan persen inhibisi berkisar antara 38,8% hingga 102,6%. Isolat EPB5 memiliki aktivitas antioksidan tertinggi sebesar 102,6%. Dengan demikian, tujuh isolat aktinobakteri tersebut berpotensi sebagai sumber antioksidan., Dayak onion (Eleutherine palmifolia L. Merr) is a typical Kalimantan herbaceous plant which is well known as a source of antioxidant. This plant could be a great source of endophytic microbes producing antioxidant compounds. The present study was aimed to isolate and analyze the morphological diversity of E. palmifolia endophytic actinobacteria as well as their antioxidant properties. Seven actinobacteria isolates have successfully been isolated from Dayak onion bulbs using HVA medium. Based on the morphological characteristics in different media and the type of their spore chains, it was assumed that these isolates belonged to the genus Streptomyces sp. As tested by DPPH analysis, supernatant derived from these isolates showed antioxidant activity with inhibition percentage ranging from 38,8% to 102,6%. The highest antioxidant activity exhibited by EPB5 isolate. In conclusion, all these isolates could be further studied and developed as the alternative source of antioxidant.
Keyword: morphology of colony, spore chains, supernatant, DPPH, inhibitory activity

Judul: Kajian frieze groups untuk klasifikasi dan konstruksi desain berdasarkan simetri pada pola
Abstrak: Frieze groups adalah konsep matematika untuk mengklasifikasikan desain pada dua dimensi permukaan yang berulang-ulang dalam satu arah berdasarkan simetri pada pola. Frieze groups merupakan grup yang mempertahankan bentuk pola. Pergerakan bentuk pola terdiri dari translasi, refleksi dan rotasi 180o. Tujuan dari karya ilmiah ini adalah mengkaji sifat Frieze group, mengkaji penggunaan Frieze group dalam mengklasifikasikan simetri pada pola dan mengkonstruksi pola dengan menggunakan software tesselmania. Hasil yang telah diperoleh, bahwa jenis Frieze groups merupakan subgroup dari grup pergerakan pola. Selain itu dapat dilihat dari sifat isomorfik berbagai jenis Frieze groups. Untuk mengkonstruksi sebuah bentuk pola dapat menggunakan salah satu software untuk membentuk sebuah pola bidang datar (dua dimensi) yaitu tesselmania.
Keyword: Frieze groups, Simetri, Pola