Syzygium Polyanthum Research Articles

Kombinasi Rebusan Daun Salam dan Kemangi dalam Menurunkan Kadar Asam Urat Mus musculus

Indonesia is one of the world�s largest of biodiversity. Especially bay leaves (Syzygium polyanthum) and basil leaves (Ocimum basilicum). These plants can be used to reduce blood uric acid. This study aimed to determine the optimum dose that could reduce uric acid levels by providing a combination of decoction of basil leaves and bay leaves and to knew the phytochemical compounds that could reduce uric acid levels in basil leaves and bay leaves. The antihiperuricemia activity of boiled bay leaves and basil leaves was tested on male sex mice (Mus musculus) Balb / C strain, aged 8-10 weeks to reveal the effectiveness of bay leaves and basil leaves as blood uric acid-lowering. The dosage of decoction used is 1.5 glasses, 1 glass, and 0.5 glass from the shrinking of the cooking water which was originally 2 glasses. Tests were carried out on mice that experienced hyperuricemia induced by potassium oxonate 250 mg / kg BW or 5 mg / 20 g BB in mice intraperitoneally and mixed chicken liver, sprouts and melinjo. Measuring the level of urate is done using the POCT (Point Of Care Tasting) method. The results showed that combination of boiled bay leaves and basil leaves could reduce blood uric acid levels in mice around 0.5 - 1.0 mg / dl. The activity was effective in both doses, 0.5 glass and 1.5 glasses, but to get a significant decrease in uric acid levels this cooking water had to be consumed regularly and for a longer time.

The effect of bay leaf extract Syzygium polyanthum (Wight) Walp. on C-reactive protein (CRP) and myeloperoxidase (MPO) level in the heart of rat model of myocardial infarction.

Aim To study the anti-inflammatory effect of bay leaf on C-reactive protein (CRP) and myeloperoxidase (MPO) level in the heart of rat model with myocardial infarction. Methods In the first phase, results of pathological examination and biochemical assay were compared between rats with and without induction of myocardial infarction. In the second phase, the effect of bay leaf extract on CRP and MPO of rats with myocardial infarction was studied. Results C-reactive protein and MPO were higher in rats which had myocardial infarction. Administration of bay leaf extract reduced levels of CRP and MPO in the rats started from day 4 after the induction of myocardial infarction. Conclusion Anti-inflammatory effect of bay leaf is confirmed, reflected by decreasing of CRP and MPO levels of rat model with myocardial infarction.

TOXICITY TEST OF BAY LEAF EXTRACT ON BHK-21 FIBROBLAST CELLS IN VITRO

Background: Denture stomatitis is an inflammatory reaction in the oral mucosa that support the denture. This lesion is caused by the fungus Candida albicans and can be avoided by always maintain the cleanliness of denture. Bay leaf (Syzygium polyanthum) has flavonoid as the highest content which has antifungal and antioxidant properties so that bay leaf can be used as alternative ingredient for denture cleanser. Toxicity test needs to be done to determine the safety of this material. Objective: to analyze the toxicity of bay leaf extract (Syzygium polyanthum) to BHK-21 fibroblast cells using the MTT assay method. Method: This study is a true experimental study, which using posttest-only with control group design. The group, treated with bay leaf extract, were 25%, 20%, 15%, 10% and 5% concentrations including 2 control groups which were media control and cell control. Absorbance was read using ELISA reader and cell viability was calculated. Results: The percentage of living cells in all groups which treated with bay leaf extract was 100%. The parametric analysis of One Way Annova showed that there was no significant difference. Conclusion: Bay leaf extract (Syzygium polyanthum) does not have any toxic effect to BHK-21 fibroblast cell using the MTT assay method because cell viability in all treatment groups was ≥ 60%.

Bactericidal Efficacy of Selected Medicinal Plant Crude Extracts and their Fractions against Common Fish Pathogens

The emergence of new diseases and the increased use of antibiotics have led to the development of resistant bacterial strains. Thus, there is greater attention to seek new antibacterial agents from the natural sources for combating fish diseases in the aquaculture industry. The present study evaluated the bactericidal efficacy of crude methanolic and aqueous extracts from Polygonum chinense, Syzygium polyanthum, Premna foetida, Pimenta dioica, Brucea javanica, Vitex negundo, Alpinia conchigera and Clinacanthus nutans against Vibrio harveyi, Vibrio alginolyticus, Vibrio parahaemolyticus and Aeromonas hydrophila using disc diffusion method. The results showed that methanolic extracts of P. dioica, P. foetida and P. chinense, and aqueous extracts of P. dioica and S. polyanthum showed moderate to strong activity (10.8 to 17.2 mm) against all the tested bacteria. These five potential crude extracts were fractionated using liquid-liquid extraction method to obtain the methanol, dichloromethane and ethyl acetate fractions. Among the fractions, ethyl acetate fraction showed the highest activity against all tested bacteria, with minimum inhibition concentration (MIC) values between 0.625 and 10.000 mg/mL. In addition, the five potential crude extracts had low to moderate toxicity with LC50 >100 μg/mL using brine shrimp cytotoxicity assays. The results of this study indicated that methanolic extracts of P. chinense and P. foetida that showed high bactericidal activity and low toxicity could be good potentials for use in fish culture.

Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Salam (Syzygium polyanthum) Sebagai Bioreduktor Dan Uji Aktivitasnya Sebagai Antioksidan

Silver nanoparticles have been synthesized by the reduction method using salam leaf extract (Syzygium polyanthum) as a reducing agent. The silver nanoparticles produced were then tested for their activity as antioxidants. The formation of silver nanoparticles was carried out by adding the leaf extract into the solution of AgNO3 and homogenized using a magnetic stirrer. A UV-Vis spectrophotometer was used to confirm the formation of silver nanoparticles. Particle Size Analyzer (PSA), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD) and Fourir Transform Infra Red (FTIR) spectrometers were used to characterize the nanoparticles produced before being tested for antioxidant activity. The results showed that the absorbance value increased with increasing reaction contact time. The maximum uptake was obtained at wavelengths of 432-446 nm using a UV-Vis spectrophotometer. The particle size was determined using a PSA with an average particle size distribution of 45.7 nm. The average diameter of silver nanoparticles was 10.06 – 13.97 nm and the silver nanoparticles had rod-shapes. Functional groups that play a role in the synthesis of nanoparticles were –OH, –C=O, and –C-O groups. Silver nanoparticles inhibited free radicals as antioxidants with the IC50 value of 582.7 ppm.

Sintesis Nanopartikel Perak Menggunakan Ekstrak Daun Salam (Syzygium polyanthum) Sebagai Bioreduktor Dan Uji Aktivitasnya Sebagai Antioksidan

Silver nanoparticles have been synthesized by the reduction method using salam leaf extract (Syzygium polyanthum) as a reducing agent. The silver nanoparticles produced were then tested for their activity as antioxidants. The formation of silver nanoparticles was carried out by adding the leaf extract into the solution of AgNO3 and homogenized using a magnetic stirrer. A UV-Vis spectrophotometer was used to confirm the formation of silver nanoparticles. Particle Size Analyzer (PSA), Scanning Electron Microscope (SEM), X-Ray Diffractometer (XRD) and Fourir Transform Infra Red (FTIR) spectrometers were used to characterize the nanoparticles produced before being tested for antioxidant activity. The results showed that the absorbance value increased with increasing reaction contact time. The maximum uptake was obtained at wavelengths of 432-446 nm using a UV-Vis spectrophotometer. The particle size was determined using a PSA with an average particle size distribution of 45.7 nm. The average diameter of silver nanoparticles was 10.06 – 13.97 nm and the silver nanoparticles had rod-shapes. Functional groups that play a role in the synthesis of nanoparticles were –OH, –C=O, and –C-O groups. Silver nanoparticles inhibited free radicals as antioxidants with the IC50 value of 582.7 ppm.

The Effect of Extraction Method on Total Phenolic Content and Antioxidant Activity of Salam Leaves (Syzygium polyanthum) using DPPH (1,1-Diphenyl-2-Picrylhidrazil)

Extraction is an important step in separating bioactive compounds from the plant. The selection of extraction technique is also important in the standardization of herbal products, for if not observed it can remove the desired soluble constituents. One of Indonesia’s endemic plants which have been proven to have an antioxidant activity is Salam leaves (Syzygium polyanthum). This study aims to determine the effect of extraction method on total phenolic content and antioxidant activity of S. polyanthum leaves by counteracting free radicals mechanism using DPPH. The S. polyanthum leaves were extracted by maceration, soxletation, and infusa methods, and tested for the total phenolic content and the antioxidant activity. The results showed that the total phenolic content of each method extration is different. The total of the phenolic content extraction by maceration, soxhlet, and infusa method respectively were 338.62±21.3; 227.72±21.6; and 144.48±8.2 mgGAE/g. The best antioxidant activity was maceration method with IC50 17.53±0.11 µg/mL followed by soxhlet and infusa which were 18.73±0.31 and 40.26±0.18 µg/mL. The research conclusion is that the extraction method has an effect on the total phenol and antioxidant activity of S. polyanthum leaves.

The effect of Leaf Salam Extracts (Syzygium polyanthum) in diabetes mellitus therapy on wistar albino rats

Diabetes mellitus (DM) is one of the chronic disease that caused the most complications and even death. Non-Insulin Dependent Diabetes Mellitus (NIDDM) is the most widely recognized. It is closely related with the incidence of insulin resistance. This research is an in vivo experimental study with post-test control group design located in laboratory of animal house and biomolecular laboratory Faculty of Medicine, Universitas Sriwijaya, Indonesia. The subjects of this study were albino rats (Rattus norvegicus), Wistar strain, divided into 5 groups are negative control, positive control (TZD), Leaf Salam Extract (LSE) 50 mg/kgBW, 100 mg/kgBW and 200 mg/kgBW. Rat was injected by Human Insulin (ip) 1,8 IU/kgBW and orally glucose for 14 days. In this study it was found that there was no distinction in blood sugar levels in the positive control group with LSE 200 mg/kgBW, LSE 100 mg/kgBW and LSE 50 mg/kgBW and there were no difference in insulin levels in the positive control group with LSE 200 mg/kgBW and LSE 100 mg/kgBW and LSE 50 mg/kgBW. So, it can be concluded that LSE (Syzygium polyanthum) was effective in lowering blood sugar and insulin levels of Wistar albino rat induced diabetes mellitus.

The Effect of Infusion of Syzygium polyanthum (Wight) Walp. Leaves as Natural Preservative Chicken Meats

Syzygium polyanthum (Wight) Walp. (Indonesian bay leaf) is known for possessing antimicrobial activity that might be applied for natural food preservative. In this study, we analyzed the constituents of infusion of S. polyanthum leaves and evaluated its potency as the preservative of fresh chicken meats. The infusions were prepared with the method described in Indonesian Pharmacopeia. Phytochemical content of infusion of S. polyanthum leaves was analyzed by qualitative phytochemical screening using colorimetric methods. Its application for preservative of fresh chicken meat was evaluated based on its activity in inhibiting the growth of bacteria on the meats as well as the physical observation of the preserved meats. The infusion of S. polyanthum leaves contained flavonoids, tannins, and saponins. The infusion at the optimum concentration of 10% was capable of inhibiting bacterial growth on chicken meats and extending their shelf life up to 3 days in temperature of 3-7ºC.

Subchronic Toxicity of Ethanol Extract of Syzygium polyanthum (Wight) Walp. Leaves on Wistar Rat

BACKGROUND: Previous works indicated various pharmacology activities of bay plant (Syzygium polyanthum (Wight) Walp.), however only few studies investigated its toxicity. This work was aimed to study the subchronic toxicity of ethanol extract of this plant.METHODS: White Wistar rats were divided into 4 groups and were treated with 2% of Arabic gum (PGA) suspension, 1000 mg/kg of body weight (BW), 400 mg/kg of BW and 100 mg/kg of BW, respectively. The animals were observed on their body weight, hematology, clinical biochemistry parameters, organ index and histopathology.RESULTS: Flavonoids, tannins, polyphenols, saponins, quinones, monoterpenes and sesquiterpenes were detected in dried leaves and ethanol extract of bay plant. An increase of body weight in male and female groups treated with dose 100 and 400 mg/kg BW compared to controls, was observed. Moreover, there was an increase of white blood cell (WBC) in male and female groups treated with S. polyanthum extracts compared to controls, whereas a decrease of red blood cell (RBC) was observed in male groups treated with S. polyanthum extracts in dose-dependent manner compared to control. No significant changes of RBC were seen in female groups, haemoglobin values were not altered by extract treatment. Photomicrographs of liver, kidney, lungs, heart and spleen histopathology of male and female S. polyanthum extract-treated groups showed no significant alteration compared to controls.CONCLUSION: Our study revealed that S. polyanthum extracts does not show toxicity on the body weight, hematology, creatinine and serum glutamic pyruvic transaminase (SGPT), but fatty liver and necrosis are observed in female rats. This result can be beneficial for plant-based drug discovery, particularly this study provides information about the safety of S. polyanthum to be further developed as candidate of phytopharmaceutics.KEYWORDS: bay plants, salam leaves, hepatotoxicity, necrosis, SGOT, SGPT

Comparative Evaluation of Protease Extraction from Leaves of <i>Syzygium polyanthum</i>

In this study, the comparison of four extraction methods for protease from the leaves of Syzygium polyanthum was evaluated. The methods include sodium phosphate buffer, 1-methyl-8-oxyquinolinium betaine (QB) solvent based extraction, hydrogen-bond acceptor (HBA) solvent based extraction and Trichloroacetic-acetone (TCA) precipitation. The effectiveness of these extraction methods was measured based on the specific activity demonstrated by the crude protease extracted in this experiment. The results indicated that QB solvent-based extraction method could extract the crude protease from the leaves of S. polyanthum with the highest specific activity of 10.204 ± 0.329 U/mg compared to other extraction methods.

Influence of extraction methods of bay leaves (Syzygium polyanthum) on antioxidant and HMG-CoA Reductase inhibitory activity

ObjectiveBay leaf, one of the plants in Indonesia that has been shown to have activities to reduce cholesterol in the blood. HMG-CoA Reductase inhibition is one of many mechanisms in lowering the level of cholesterol in the blood. Here, we reported the inhibitory activity of HMG-CoA Reductase of bay leaves ethanol extracts that we suspected to be the mechanism of action of bay leaves in reducing cholesterol in the blood. In this research we also investigated the correlation between the inhibitory activities, the total phenol content and antioxidant activities of bay leaves (Syzygium polianthum) ethanol extracts. MethodsThe inhibitory activity of HMG-CoA Reductase was determined kinetically at 340 nm using simvastatin as positive control. In vitro scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric ion reducing antioxidant power (FRAP), and beta-carotene method were used to determine the antioxidant activities. The total phenolic content was determined by Folin-Ciocalteu's method. ResultsThe IC50 of bay leaves ethanolic extract obtained by percolation and soxhlet extraction method towards HMG-CoA Reductase enzyme activity were 49.50 ± 0.700 μg/mL and 15.50 ± 0.707 μg/mL, respectively, while the IC50 of simvastatin was 0.00238 ± 0.00004 μg/mL. The antioxidant activity and total phenolic content of bay leaves ethanolic extract obtained by Soxhlet extraction method was higher compared to the percolation method (DPPH and beta-carotene assay results). The 3D linear analysis showed that there was a high correlation between the inhibition activities of HMG-CoA Reductase pattern of both extract types and the total phenol pattern and also the antioxidant pattern of these extracts. ConclusionThe result showed that the bay leaves ethanolic extract have a potent activity to reduce the cholesterol serum level by inhibition of HMG-CoA Reductase activity. The activity was due to the phenolic compounds in the extracts as well as the antioxidant activity of the extracts.

Penurunan Kadar Kolesterol Pada Kuning Telur Asin dengan Perendaman Seduhan Serbuk dan Ekstrak Daun Salam (Syzygium Polyanthum) dengan Variasi Lama Perendaman

Telur memiliki kandungan gizi yang baik, namun kuning pada telur memiliki kadar kolesterol yang sangat tinggi, sehingga apabila dikonsumsi secara berlebihan akan meningkatkan risiko penyakit jantung koroner (PJK). Oleh karena itu, diperlukan suatu inovasi dalam industri pengolahan pangan untuk mengolah makanan yang lebih sehat dan rendah kolesterol. Salah satunya dengan cara melakukan penurunan pada kadar kolesterol kuning telur asin menggunakan bahan alam yaitu daun salam (Syzygium polyanthum). Penurunan kadar kolesterol pada telur asin diawali dengan pembuatan sediaan daun salam (Syzygium polyanthum) dalam bentuk ekstrak dan juga serbuk. Selanjutnya dibuat seduhan ekstrak maupun serbuk daun salam dengan konsentrasi 2%. Telur yang masih mentah direndam dalam seduhan selama 12 dan 24 jam. Kemudian dikukus dan dilakukan pengujian kolesterol dengan metode “CHOD-PAP” serta uji organoleptis yang melibatkan 30 orang panelis. Hasil penelitian menunjukan perubahan kadar kolesterol dengan penurunan kadar kolesterol tertinggi dicapai pada perendaman dengan ekstrak daun salam (Syzygium polyanthum) selama 24 jam dengan kadar kolesterol sebesar 231 mg/100g. Kadar kolesterol telur sebelum dilakukan perendaman diketahui sebesar 621 mg/100g, sehingga diperoleh presentase penurunan sebesar 62,80%. Analisis statistik ANOVA dua jalan menunjukan adanya perbedaan kadar kolesterol yang nyata. Uji organoleptis menunjukkan rata-rata konsumen cukup suka.

Syzygium polyanthum (Wight) Walp: A Potential Phytomedicine

Ethnomedicinal plant is one of the important sources for drug discovery. Syzygium polyanthum (Wight) Walp is one of the ethnomedicinal plants that is currently gaining attention for its various pharmacological potentials. This review evaluates its traditional uses, chemical profiles, toxicological aspects, nutritional values, as well as its pharmacological properties. From our literature search in Science Direct, Scopus, and Google Scholar databases, it was found that S. polyanthum has valuable therapeutic potentials including antidiabetic, antihypertensive, antimicrobial, antioxidant, anticancer, antitumor, antidiarrheal, acetylcholinesterase inhibitory, and dental plaque inhibition properties. However, few research areas, especially its toxicological profiles, mechanism of actions, as well as identification of its bioactive compound, require more in-depth studies.

Antibacterial and cytotoxic activities of the Syzygium polyanthum leaf extract from Malaysia.

Background and Aim:The increasing prevalence of drug resistance eventually leads scientist to discover new drugs that could solve the problem. Since ancient immemorial times, medicinal plants generally known as herbs were widely used in every culture throughout the world. In fact, currently up to 70,000 plant species have been screened for biological activities and about 70% ends up for commercialization. Therefore, this study was aimed to evaluate the potential cytotoxic and antibacterial effect of Syzygium polyanthum leaves which are local Malaysia plants, against 4T1 and MCF-7 mammary carcinoma cells, respectively, and also against bacteria causing mastitis in cows.Materials and Methods:The cytotoxic effect of hydromethanolic extract of S. polyanthum against 4T1 and MCF-7 mammary carcinoma cells was evaluated using 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The cells were treated with the concentration of extracts ranging from 15.63 µg/mL to 1000 µg/ml for 72 h, and the percentage of cell survivability was determined based on minimum concentration that was able to allow at least 50% growth of cancer cells (IC50) after 72 h. The antibacterial activity was tested against common bacteria causing mastitis in cow. The bacteria were isolated from milk samples. The antibacterial activity of the extract was determined by disk diffusion method and susceptibility test based on minimum inhibitory concentration (MIC).Results:Staphylococcus aureus, Staphylococcus hyicus, and Staphylococcus intermedius were isolated from the milk samples that positive for mastitis. The MIC values range from 7.12 mm to 13.5 mm. The extract exhibits the widest zone of inhibition (13.5±0.20 mm) at 1000 mg/ml of concentrations. The extract relatively has low cytotoxicity effect against 4T1 and MCF-7 cells with IC50 values ranging from 672.57±59.42 and 126.05±50.89 µg/ml, respectively.Conclusion:S. polyanthum exerts weak antibacterial activity and cytotoxic effect to mammary carcinoma cells. The extract does not toxic to cells. However, further study is recommended, especially, this plant should be tested for in vivo.

The Efficacy of Combination Extract Andrographis peniculata and Syzygium polyanthum on Glucose Uptake in Skletal Muscle in Diabetic Rats

Insulin resistance is impaired insulin signaling cascade in target cells to respond normal or elevated circulating insulin to the final cellular effect, such as translocation of vesicles containing GLUT4 glucose transporters, which is the major mediator of glucose removal from the circulation and a key regulator of whole-body glucose homeostasis. Among the several plants, Andrographis peniculata (sambiloto) and Syzygium polyanthum (Daun salam). In the present study, a combination was made, Andrographis peniculata (sambiloto) and Syzygium polyanthum (Daun salam), and to determine the effects of combination on tretament insulin resistance. Male Wistar rats (weight, 200-300 g) were randomized into five groups (6 rats/group). Group 1: negative group. Group 2: positive group (metformin 63 mg/kgBW ). Group 3,4 and 5: treatment with extract combination, each group 250 mg/kgBW, 500 mg/kgBW and 1000 mg/kgBW. Rats were induced by high fat diet-glucocorticoid for insulin resistance. Insulin and GLUT-4 were assayed by ELISA. Treatment with extract combination (250, 500 and 1000 mg/kgBW) and metformin for 2 weeks showed a sigificant decrease in fasting plasma insulin compare with the negative control rats with a reduction of 11,2%, 33,6%, 20% and 19,4%, respectively. Two weeks treatment either extract combination or metformin in diabetic rats, significantly increased GLUT 4 level (p<0,05) with a percentage increase of 6,68%, 15,21%, 12,76% and 1,77%.

Amelioration of Aorta Morphology in Spontaneous Hypertensive Rat (SHR) by Syzygium Polyanthum

Background: Prolonged uncontrolled hypertension can lead to vessels damage; manifested as abnormal morphology changes. Sygyzium polyanthum has been shown to has blood pressure lowering effects in SHR rats. Objective: This study was designed to evaluate the improvement effects of S. polyanthum aqueous leave extracts (AESP) on the descending thoracic aorta morphology damaged secondary to hypertension. Material & Methods: Twenty-one rats were used in this study, with 7 rats in each group. Group 1: normotensive Wistar Kyoto (WKY) rat, Group 2: untreated SHR, Group 3: SHR on AESP (2250 mg/kg). AESP was orally administered daily for 3 months. The descending thoracic aorta was harvested at the end of the study. The aorta morphology was evaluated using Hematoxylin and Eosin stain (H&E stain) and Scanning Electron Microscope (SEM). Systolic blood pressure (SBP) were also recorded every 2 weeks during the study. Results: On HE stained, treatment with AESP increased the endothelial cell lining on the surface of aortic tunica intima. The endothelial lining also notably smoother. The elastic laminae were not discontinued and more regular pattern of vascular smooth muscle cells with elongated nuclei. The thickness ratio of tunica media to tunica intima was also reduced. Under SEM, the surface of the aorta was smoother and there were no crater-like defects as compared to untreated SHR. There were also no inflammatory cells or fibrinogen seen as on the aortic surface of untreated SHR. The SBP in AESP-treated SHR was significantly reduced (107.00 + 1.68 mmHg) as compared to untreated SHR (199.75 + 2.86 mmHg, p<0.001). Conclusion: S. polyanthum improves the morphology of aorta and also significantly reduces the blood pressure.

PENGARUH KOMPOSISI HERBAL DALAM MINUMAN TEH HIJAU GAMBUNG HERBAL TERHADAP HAMBATAN α-GLUKOSIDASE

The aim of this study is to make a formula of green tea that is enriched by other herbs. Green tea drinks are made using the basic ingredients of gambung (THG) green tea enriched with sapodilla leaves ( Manilkara zapota (Aw) bay leaves ( Syzygium polyanthum (Am), Artocarpus communis (Un) breadfruit leaves, and cinnamon leaves ( Cinnamomum verum (K)). The composition of gambung herbal green tea is made by reference to the antidiabetic activity of each herb. All the samples were tested for inhibition of α-glucosidase enzymes and toxicity using the lethality test method for brine shrimp. All samples showed good inhibition of the α-glucosidase enzyme barriers of gamboeng green tea (THG) 82.05%, sapodilla leaves (Aw) 97.81%, breadfruit leaves (Un) 73.34%, bay leaves (Am) 93.80%, cinnamon leaves (K) 91.24 %. The inhibition value of α-glucoside enzymes in the formulation of gamboeng herbal green tea drinks: 96.203% (GKUn) is higher when compared to the GKAm formula (94.78%) and GKAw (62.487%).

Magnetite Nanospheres as Carbon Paste Electrode Modifier for Xanthine Biosensor

Magnetite Nano spheres was prepared and used to fabricate a modified carbon paste electrode as xanthine biosensor and applied to determine inhibition kinetics of Syzygium polyanthum extract toward xanthine oxidase (XO). The magnetite Nano spheres was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical behaviour of xanthine was investigated by immobilizing the XO on the surface of carbon paste electrode (CPE), modified magnetite Nano spheres-CPE (MCPE), and modified 2,3-dimethoxy-5-metil-1,4-benzoquinone (Q0)-CPE (QCPE) employing cyclic voltammetry (CV) technique. The result showed that the MCPE was the best electrode to determine the analytical performance under optimum condition, based on lower limit of detection (0.005 mM), wider linearity range (0.01-1 mM with R2 = 99.24%), and higher sensitivity (5.16 µM-1) than the two other electrodes (CPE and QCPE). The MCPE successfully improve the analytical performance on xanthine biosensor and to be applied for determining inhibition kinetics of S. polyanthum extract. Inhibition kinetics of the extract has caused increase of KM and VMAX (IMAX) constant. Based on the result, the type of inhibition kinetics was a competitive inhibition.

Antibacterial and Sporicidal Activities of Syzygium polyanthum L. Extract against Bacillus cereus Isolated from Rice

Spore-forming bacteria, Bacillus sp., frequently been associated with the contamination of rice and other starchy products. Spores are more resistant to antimicrobial treatments than its vegetative cells. The extract of Indonesian bay leaf (Syzygium polyanthum L.) was assessed for its antibacterial and sporicidal activities against vegetative cells and spores of B. cereus isolated from rice (25 strains). The results showed that S. polyanthum L. extract was able to inhibit the growth of vegetative cells of all B. cereus isolates with MICs ranged from 0.16 to 0.63 mg/mL and can kill with MBCs ranged from 0.31 to 2.50 mg/mL. The bactericidal endpoint for B. cereus BC-NP.8 in time kill curve was at 1.25 mg/mL (8× MIC) after 4 h of incubation while for B. cereus ATCC 33019 was at 2.50 mg/mL (8× MIC). The sporicidal activity of S. polyanthum L. extract was not affected by different temperatures treatment and alteration of the pHs of extract. Therefore, this indicates that the extract was stable after exposed to pH3, 7 and 10 as well as temperature of 50, 80, and 121°C. Observation under on scanning electron microscope the structure of the B. cereus ATCC 33019 spores was ruptured after being treated with 1% (w/v) S. polyanthum L. extract for 1 h. In conclusion, S. polyanthum L. extract had antibacterial and sporicidal activity against vegetative cells and spores of B. cereus isolated from rice.