Sasangka Prasetyawan

Organophosphate Hydrolase in Conductometric Biosensor for the Detection of Organophosphate Pesticides.

The research has developed an enzyme biosensor for the detection organophosphate pesticide residues. The biosensor consists of a pair of screen-printed carbon electrode (SPCEs). One of electrodes contains immobilized organophosphate hydrolase (OPH) on a chitosan membrane by cross-linking it with glutaraldehyde. The area of the electrodes was optimized to 3, 5, and 7 mm2. The OPH was isolated from Pseudomonas putida, and was purified by the ammonium sulfate precipitation method, with 6444 ppm (A) and 7865 ppm (B). The organophosphate pesticide samples were 0–100 ppb in tris-acetate buffer 0.05 M, pH 8.5. The results showed that the best performance of the biosensor was achieved by the enzyme A with an electrode area of 5 mm2. The sensitivity of the biosensor was between 3 and 32 µS/ppb, and the detection limit for the organophosphate pesticides was 40 ppb (diazinon), 30 ppb (malathion), 20 ppb (chlorpyrifos), and 40 ppm (profenofos).

Optimization Of Elevating Blood Uric Acid Levels With High Purine Diet

Exploration of the use of medicinal plants to lower uric acid levels has been widely practiced. Stages of new drug development research is a preclinical test using experimental animals, therefore the manufacture of an animal model of hyperuricemia is necessary. This study aims to determine the optimal induction of uric acid to increase blood uric acid levels by administering high purine foods such as cow’s liver, cow’s spleen, Gnetum gnemon , emping and fried peanuts. Eighty male white rats were used individuals to be divided into 4 groups, they were: (I) cow’s liver, (II) cow’s liver and cow’s spleen, (III) cow’s liver, cow’s spleen and boiled gnetum gnemon beans, and (IV) cow’s liver, cow’s spleen, emping and fried peanuts. This study using easy touch GCU to measure blood uric acid level. The result of statistical analysis of uric acid level means with 5 times repetition using One Way ANOVA showed that there was a very significant difference between treatments ( p <0,01). The results concluded that high purine diet in group I, II and III had not been able to increase uric acid levels significantly. High purine diet group IV was able to increase blood uric acid levels significantly to make the rats experiencing hyperuricemia with the level of 6.54 mg/dL on day 7 and 13.79 mg/dL on day 14.

Molecular Docking of Isorhamnetin as CYP1A1 Inhibitor in Skin Photoaging

Skin aging is the aging process of skin tissue due to elastin and collagen breakdown. Collagen and elastin are protein of connective tissue in skin dermis that serves to regenerate the skin for firmness and flexibility maintained. Sunlight is composed by three main parts according to their wavelengths, namely UVA, UVB, and UVC where the intensity of UVB sunlight is most active. UVB generates the production superoxide anion (O 2) which is main free radical in the skin surface. It attacked the cell membrane and subsequently form a new ROS and decrease antioxidants enzymatic excesively. Excessive ROS production resulting overexpression of AP-1 which activated Matrix metalloproteinases lead to collagen breakdown and photoaging. This paper discusses the affinity and interaction of isorhamnetin to CYP1A1 causing inactivation of AP-1 using molecular docking program. CYP1A1 is protein member of cytochrome P450 superfamily of enzymes encoded by the CYP1A1 gene. Cytochrome P450 used as oxidazing catalist in metabolic pathways steroids, fatty acids, xenobiotics, including drugs, toxins and carcinogens. This study consist of two stages: (1) isorhamnetin-CYP1A1 docking and α-naphthoflavone-CYP1A1 redocking (2) ∆G scores, inhibitory constant, and bonding interaction between ligan-reseptor analysis. Gibbs energy and inhibitory (∆G) constant (Ki) showed stability interaction between isorhamnetin and CYP1A1. Based on the ∆G score isorhamnetin has higher potential as CYP1A1 inhibitor than-naphthoflavoneα. IsorhamnetinCYP1A1 get -10,3 kcal/mol and 11,34 μM and-naphthoflavoneα get -9,1 kcal/mol and 228,4 μM. Isorhamnetin-CYP1A1 binded by 4 π bondingand2hydrogen bonding. The result presented the potential of isorhamnetin to decreased AP-1 expressioan through CYP1A1 inhibition. Keyword: photoaging, AP-1, isorhamnetin, CYP1A1, molecular docking

Effect of Topical Aplication of Gel Aloe Vera Extract on The UVB-Induced Skin Photoaging in Hairless Rats

UVB generates the production of Reactive Oxygen Species (ROS) and decrease antioxidants enzymatic excessively. Both of these biological effects caused photo-aging. Excessive ROS production afforded overexpression of AP-1 as a major regulator of photoaging. This paper figured out the potential of Aloe vera extract as topical gel treatment on the UVB-induced skin photo-aging in twenty male wistar hairless rats (Rattus novergicus) divided into 2 groups. First group was induced by UVB and the second was induced by UVB and topical gel extract Aloe vera treatment. Each group was given treatment for 4 weeks. The expression of MDA and SOD were measured with immunohistochemistry. The result showed that the topical gel therapy decreased the MDA expression and increased SOD expression significantly (p < 0.01). The conclusion from this study was Aloe vera extract had potentially as an alternative topical treatment of photoaging.

Liquid Chromatography for Analysis of Metformin in Myrmeleon sp.

Myrmeleon sp is a typical of insect larva which has been used in Indonesia for diabetes treatment. However, there is no sufficient scientific report explaining the bioactive compounds in this insect. Based on our preliminary research, this insect contained metformin, i.e. one of bioactive compounds for the treatment of type-2 diabetes. Therefore, this study is focused on the development of separation technique using high performance liquid chromatography (HPLC) on a reverse phase C-18 column with UV detection to identify and quantify metformin in methanol extract of Myrmeleon sp. Several parameters of HPLC method were optimized with respect to high resolution of separation and accurate determination of metformin. Satisfied separation was obtained under gradient elution mode using aqueous methanol mobile phase varied from 50-90 % of methanol with flow rate of 0.5 mL/min and detection wavelength of 233 nm. The method performed total separation for all compounds in less than 11 minutes. Spiking technique was chosen for metformin identification and quantitation. Metformin in extract Myrmeleon sp was eluted at retention time (t R ) of 4.095 minutes, similarly with retention time of standard metformin of 4.092 minutes. The quantity of metformin in Myrmeleon sp can be simply determined by comparing the additional area of standard metformin with area of metformin from extract Myrmeleon sp . The results confirmed that methanol extract of Myrmeleon sp contained anti-diabetes compound of metformin of 0.58 mg/g Myrmeleon sp larvae with acceptable coefficient variation of 5.56 %.

Kinerja Biosensor Konduktometri Berbasis (Screen Printed Carbon Electrode) SPCE––Kitosan untuk Deteksi Diazinon, Malation, Klorpirifos dan Profenofos

The performance of biosensor is based on the hydrolysis reaction of organophosphorus compounds catalyzed by organophosphate hydrolase (OPH), produce H + and the other ionic species that increase conductance on the surface of electrode. In this research, OPH was immobilized by crosslinking on chitosan–glutaraldehyde membrane on the ( Screen Printed Carbon Electrode ) SPCE surface. Measurements were carried out at the range concentration 0 to 3.0 ppm of organophosphate, the range of pH 7.0 to 9.0 and 5–25 mL of enzyme. The result showed that optimum performances were obtained at 25 mL of OPH, pH 8.5, with the sensitivity for dizinon, malathion, chlorpirifos and profenofos is 1.353 mS/ppm, 1.270 mS/ppm, 1.230 mS/ppm dan 1.77 mS/ppm respectively and 0.97; 1.03; 0.98; 0.97 of LOD. DOI :http://dx.doi.org/10.15408/jkv.v0i0.3156 .

Effect of Metal Ions on Pectinase Activity from Aspergillus niger on Purifying Guava Fruit

Pectinase can be used on various fruit juices clarification; however, the activities can be affected by their metal ions content. The purpose of this study was to determine the type of metal ions inhibition i.e. Zn 2+ ; Mg 2+ and Ca 2+ on the pectinase activity of Aspergillus niger , and its potential application in guava juice clarification. Activity assays performed at pH 5, temperature 50°C during 55minutes and each ion concentration were 2-10 mM. Galacturonic acid concentration, as the product of pectin substrate hydrolysis, used as the basis for determining its activity and analyzed by visible spectrophotometry. The results showed that the ions concentration of Zn 2+ and Mg 2+ more than 4 mM were inhibitor for pectinase activity while Ca 2+ ion concentration was 6mM. K I values for the metal ions Zn 2+ ; Mg 2+ and Ca 2+ at concentrations of 6mM were 176.99; 326.09 and 280.37 mM respectively. Pectinase from Aspergillus niger were able to reduce 18% of pectin of guava juice.