High Glucose, But Not Testosterone, Increases Platelet Aggregation Mediated by Endothelial Cells

Endothelial cells inhibit platelet aggregation by releasing thromboregulators, such as prostacyclin and nitric oxide. Male subject is a traditional risk factor for cardiovascular diseases. Platelet hyperreactivity has been frequently found in patient with diabetes mellitus. To examine whether testosterone and high glucose modify platelet aggregation through endothelial cells, we did an in vitro study using endothelial cells culture from human umbilical vein (HUVEC). Treatments were performed in HUVEC sub culture as either normoglucose (5.6 mM) or high glucose (22.4 mM) medium, with or without testosterone (0, 1, 10, 100 nM), for 24 hours. HUVEC were trypsinized, resuspended, and then incubated with platelet rich plasma from healthy male donors with ratio 1:104 for 3 minutes. Platelet aggregation measured by turbidimetry methode. This study showed that testosterone did not significantly influence platelet aggregation through endothelial cells in normoglucose (p = 0.144) or high glucose (p = 0.916) medium. There was no main effect of testosterone (p = 0.73) as well as no interaction between testosterone and glucose (p = 0.69), but there was a main effect of glucose (p = 0.004), to platelet aggregation through endothelial cells. In conclusion, high glucose, but not testosterone, inhibits platelet aggregation mediated by endothelial cells

PENINGKATAN KADAR LOVASTATIN ANGKAK OLEH Monascuspurpureus KO-KULTUR DENGAN Endomycopsis Burtontt [Improvement of Lovastatin Angkak Production by Monascus Purpureus Strains Co-Cultured with Endomycopsis Burtonii]

Lovastatin is a bioactive material of statin groups and has been used to reduce cholesterol through inhibiting HMG Co-A reductase enzyme activities. Three indigenous strains of Monascus purpureus and three mutans were used in this study produced lovastatin at the range of 0,1 - 1,42%. The objectives of this study were to increase lovastatin productions by co-cultured with several concentrations of Endomycopsis burtonii. M. purpureus (10 cfu/ml) was co-cultured with various concentrations of E. burtonii (10M0 ) cfu/ral at three different feeding times (day 2, 4, and 6). Feeding times and concentrations of E. burtonii significantly increased production of lovastatin by four strains of M. purpureus (JMBA5K, AID, JMBA and TOS). The highest production of lovastatin was achieved by M. purpureus TOS co-cultured by E. burtonii at 10 cfu/ml added at day 6. Expression of the genes that responsible for lovastatin production were analyzed by PCR and RT-PCR method. The phenotypic character of M. purpureus TOS with high lovastatin production was conformed by the high intensity of its gene expression

ANTIMICROBIAL ACTIVITY OF BACTERIOCIN FROM INDIGENOUS Lactobacillus plantarum 2C12 AND ITS APPLICATION ON BEEF MEATBALL AS BIOPRESERVATIVE

One purpose of food preservation is to extend the shelf life of foods. Biological preservations can be conducted by adding antimicrobial substances, such as bacteriocin produced by lactic acid bacteria and has been characterized as biopreservatives. The aims of this research were to evaluate antimicrobial activity of bacteriocin produced by indigenous lactic acid bacteria Lactobacillus plantarum 2C12 isolated from local beef and to study the quality of beef meatball with 0.3% bacteriocin as biopreservative at different storage times (0, 3, and 6 days) in cold temperature (4oC), compared to 0.3% nitrite and control (without preservative). The results showed that bacteriocin from L. plantarum 2C12 could inhibit pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Salmonella Typhimurium. Bacteriocin was effective as well as nitrite as biopreservatives of meatballs by inhibiting the growth of total microbes and E. coli. The addition of bacteriocin did not lead the physical and nutritional changes in the meatballs. The quality of meatball with bacteriocin treatment conformed with Indonesia National Standard of meatball

Microcapsul Caracteristics of Probiotic Lactobacillus plantarum Encapsulated by Skim

KARAKTERISTIK MIKROKAPSUL PROBIOTIK Lactobacillus plantarum YANG DIENKAPSULASI DENGAN SUSU SKIM DAN GUM ARAB [Microcapsul Caracteristics of Probiotic Lactobacillus plantarum Encapsulated by Skim Milk and Arabic Gum] H. Rizqiati 1) , B.S.L. Jenie 2) , N. Nurhidayat 3) 1) Fakultas Peternakan UNDIP, Kampus Baru UNDIP Tembalang, Semarang 2) Sekolah Pasca Sarjana IPB, Kampus Darmaga, Bogor 3) Bidang Mikrobiologi Puslit Biologi – LIPI, Serpong Email: [email protected] Received April 15, 2009; Accepted May 25, 2009 ABSTRACT Probiotic Lactobacillus plantarum sa28k and Lactobacillus plantarum mar8 were encapsulated by skim milk, arabic gum, and mixture of skim milk - arabic gum. The probiotic culture was made by forming in biomass and suspension, encapsulating then was dried by spray drying method. microcapsule were in the range 7.4%-9.3%. Total yeast content in microcapsule were about 1.2-1.9 log cfu/ g. Screening result by Scanning Electron Microscope showed that in general has rounded form with unsmooth surfaces and some time had deep wrinkled at the surfaces. Microcapsule had various size, they were about 5-12 µm. Keywords: encapsulation, skim milk, arabic gu

Antibacterial Activity of Green Sirih (Piper betle L) Extract towards Food Pathogens

Green sirih (Piper betle L) extract were prepared using water, athanol and ethyl acetate extractionof the dried material. The extracts were tested for their antibacterial activities against Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillius cereus and Listeria monocytogenes. At concentrations10-50% the extracts effectively inhibited the growth of all tested bacteria as shown by the clear zones which varied from 7 to 24 mm, while the minimum inhibitory concentration (MIC) varied from 0.1 to 1 %. E. coli, S. Typhimumirum and S. aureus were more resistance to the green sirih extracts than other tested bacteria. The result showed that in general, ethanol extraction produced the best extract with strong antibacterial activities against E. coli and S. aureus. Analysis of the extract components with GC-MS revealed that sirih extract contained phenol, chavicol, eugenol, caryophylene, cylene, chalarene and others. Key words: Green Sirih (Piper betle L), bioactive compound, antibacterial

Antibacterial Activity of Green Sirih (Piper betle L) Extract towards Food Pathogens

Green sirih (Piper betle L) extract were prepared using water, athanol and ethyl acetate extractionof the dried material. The extracts were tested for their antibacterial activities against Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillius cereus and Listeria monocytogenes. At concentrations10-50% the extracts effectively inhibited the growth of all tested bacteria as shown by the clear zones which varied from 7 to 24 mm, while the minimum inhibitory concentration (MIC) varied from 0.1 to 1 %. E. coli, S. Typhimumirum and S. aureus were more resistance to the green sirih extracts than other tested bacteria. The result showed that in general, ethanol extraction produced the best extract with strong antibacterial activities against E. coli and S. aureus. Analysis of the extract components with GC-MS revealed that sirih extract contained phenol, chavicol, eugenol, caryophylene, cylene, chalarene and others. Key words: Green Sirih (Piper betle L), bioactive compound, antibacterial

Lanthanide luminescence enhancements in porous silicon resonant microcavities

In this paper, the covalent immobilization and luminescence enhancement of a europium (Eu(III)) complex in a porous silicon (pSi) layer with a microcavity (pSiMC) structure are demonstrated. The alkyne-pendant arm of the Eu(III) complex was covalently immobilized on the azide-modified surface via ligand-assisted "click" chemistry. The design parameters of the microcavity were optimized to obtain an efficient luminescence-enhancing device. Luminescence enhancements by a factor of 9.5 and 3.0 were observed for Eu(III) complex bound inside the pSiMC as compared to a single layer and Bragg reflector of identical thickness, respectively, confirming the increased interaction between the immobilized molecules and the electric field in the spacer of the microcavity. When comparing pSiMCs with different resonance wavelength position, luminescence was enhanced when the resonance wavelength overlapped with the maximum emission wavelength of the Eu(III) complex at 614 nm, allowing for effective coupling between the confined light and the emitting molecules. The pSiMC also improved the spectral color purity of the Eu(III) complex luminescence. The ability of a pSiMC to act as an efficient Eu(III) luminescence enhancer, combined with the resulting sharp linelike emission, can be exploited for the development of ultrasensitive optical biosensors.S. N. Aisyiyah Jenie, Stephanie Pace, Beniamino Sciacca, Robert D. Brooks, Sally E. Plush, and Nicolas H. Voelcke

Tunable particle size synthesis of nanoclay from Sidoarjo geothermal mud via ultrasonic method

Nanoclay has become a concern in the current industrial era, particularly in the sector of biomaterials, pharmaceuticals and cosmetics. Geothermal Mud from Sidoarjo, Central Java, Indonesia is an alternative source to produce nanoclay hence the value of Sidoarjo geothermal mud will increase leading to the development of inexpensive biomaterial products. The aim of this study is to synthesize nanoclay from geothermal mud using ultrasonic method as opposed to current methods such as solvothermal, ultrasonication does not require long periods or high temperature. The geothermal mud sample was dried at 105°C, followed by sieving 200 mesh to separate the clay fraction. The experiment was conducted by varying a suspension of clay in NaCl at concentrations 0.5, 1 and 2 M and ultrasonication time of 2 and 4 hours. The percent yield of nanoclay was obtained by gravimetry. In this experiment, the optimum conditions were obtained when the concentration of NaCl was 2 M and ultrasonication time 4 hours. From these conditions, the percent yield result was 63.4. The X-ray diffraction (XRD) data revealed that montmorillonite is a dominant mineral composition of nanoclay and the particle size of the nanoclay were performed using particle size analyzer (PSA) showed that ultrasonication reduce particle size of nanoclay. © 2022 AIP Publishing LLC