Diversity of Myxobacteria Isolated from Indonesian Mangroves and Their Potential for New Antimicrobial Sources.

Mangroves are unique intertidal ecosystems that provide ecological niches to different microbes, which play various roles in nutrient recycling and diverse environmental activities. The association between myxobacteria and mangroves are hitherto poorly understood. The aim of our study was to evaluate the myxobacterial community composition as well as isolate myxobacteria and to characterize the antimicrobial activity of myxobacteria isolates from Indonesian mangroves. Twenty-five cultivable myxobacteria were affiliated in six genera: Myxococcus, Corallococcus, Archangium, Chondromyces, Racemicystis and Nannocystis of the order Myxococcales based on partial 16S rRNA gene sequences. Thirteen crude extracts showed moderate activities against at least one of human pathogenic microorganisms. The crude extract of Racemicystis sp. strain 503MSO indicated a novel compound, which has not been reported in the database yet and the identification of this compound needs further study. The myxobacterial communities of three different sampling sites were analyzed using primers adapted for the myxobacteria group identification. The results showed that myxobacterial communities are more diverse than assumed. Therefore, our study has highlighted the importance of the mangrove habitat as promising harbor of myxobacteria as well as novel antimicrobial compounds with activity against pathogenic microorganisms.

Antidiabetic activity and acute toxicity of combined extract of Andrographis paniculata, Syzygium cumini, and Caesalpinia sappan.

Andrographis paniculata, Syzygium cumini, and Caesalpinia sappan are used as traditional medicines to treat diabetes mellitus. Therefore, this study aims to examine the antidiabetic effects and the acute toxicity of combined extract (1:1:1) of A. paniculata, S. cumini, and C. sappan (ASCE). The antidiabetic effect was tested using the rats model, induced by a high-fat diet and a double dose of streptozotocin injection of 35 mg/kg BW. Subsequently, diabetic rats in the experimental group were treated with 75 mg/kg BW and 150 mg/kg BW of ASCE, and those in the diabetic control group were treated with metformin 250 mg/kg BW. After seven days of treatment, fasting blood glucose (FBG), pancreatic ß-cells numbers, and lipid profiles were used to analyze the antidiabetic effect. The results showed that the administration of 150 mg/kg BW ASCE significantly reduced FBG (p < 0.01), cholesterol levels (p < 0.05), LDL levels (p < 0.05), but not triglycerides, compared to diabetic control, this effect was comparable to metformin treatment. In addition, the pancreatic ß-cells numbers were likely increased after ASCE treatment in a dose-dependent manner. The oral administration of a single dose of ASCE was safe up to 5000 mg/kg BW and did not result in any significant difference in body weight, relative organ weight, hematological and biochemical parameters compared with the control group. Therefore, it can be concluded that ASCE has a potential antidiabetic effect and can be safely developed as alternative medicine.

Amycolatomycins A and B, Cyclic Hexapeptides Isolated from an Amycolatopsis sp. 195334CR.

The rare actinobacterium Amycolatopsis sp. strain 195334CR was found to produce previously undescribed cyclic hexapeptides, which we named amycolatomycin A and B (1 and 2). Their planar structures were determined by high-resolution mass spectrometry as well as extensive 1D and 2D NMR spectroscopy, while the absolute stereochemistry of its amino acids were determined by Marfey's method. Moreover, 1 and 2 differ by the incorporation of l-Ile and l-allo-Ile, respectively, whose FDVA (Nα-(2,4-Dinitro-5-fluorphenyl)-L-valinamide) derivatives were separated on a C4 column. Their hallmark in common is a unique 2,6-dichloro-tryptophan amino acid unit. Amycolatomycin A (1) exhibited weak activity against Bacillus subtilis DSM 10 (minimum inhibitory concentration (MIC) = 33.4 µg/mL).

Hypoglycemic Effect of a Combined Andrographis paniculata and Caesalpinia sappan Extract in Streptozocin-Induced Diabetic Rats.

INTRODUCTION: Researchers usually use herbal combinations to explore and develop traditional medicine to obtain additional benefits in the treatment of diseases, including diabetes. This study aims to evaluate the hypoglycemic effect of the combination of Andrographis paniculata (Burm. f.) Wall ex Nees and Caesalpinia sappan Linn extract (APCSE) on diabetes-induced rats. There has not been sufficient research on this combination; however, single extract studies of these plants have been widely conducted. MATERIALS AND METHODS: Male Sprague Dawley rats (160-200 g) were induced by injecting a low dose of streptozotocin (35 mg/kg BW) twice and fed with a high-fat diet containing 25% fat, whereas control animals received only standard feed. Rats were treated with APCSE at doses of 100 mg and 200 mg/kg BW for seven days and compared to the APE and CSE groups treated with the extract at 100 mg, respectively. For the control group, rats were treated with metformin with a dose of 250 mg/kg. The antihyperglycemic and antihyperlipidemic effects were determined by measuring blood glucose levels and lipid profiles (cholesterol, triglycerides, HDL, and LDL). To assess the impact of the extract on pancreatic and adipose tissue, the number of pancreatic beta cells and adipocytes was evaluated through histopathological and immunohistochemical study. Results and Discussion. In a nonfasting state, the blood glucose change in APCSE 200 mg was 18.65% and was significantly lower from the DM group. However, a single extract of APE and CSE showed lower fasting blood glucose levels compared to the combined extract. Lipid profiles show no significant differences in cholesterol levels between groups; however, all treatment groups, including metformin, showed higher triglyceride levels. The APE-treated group showed significantly lower HDL and LDL, whereas CSE only showed lower LDL. The ß-cell number was significantly higher after treatment with single extract CSE. The CSE and the combined extract groups showed hyperplasia adipocytes. CONCLUSION: The combined extract of APCSE has a moderate antihyperglycemic effect; however, a single extract may have better potential than the combined extract.

Effect of interleukins (IL-2, IL-15, IL-18) on receptors activation and cytotoxic activity of natural killer cells in breast cancer cell.

INTRODUCTION: Breast cancer is one of the leading cause of cancer deaths in women. Metastasis in BC is caused by immunosurveillance deficiency, such NK cell maturation, low NK activity and decreasing cytotoxicity. This study was performed to improve activating receptors and cytotoxicity of NK cells using interleukins (ILs). METHODS: Human recombinant IL-2, -15, and -18 were used to induce NK cells. We measured the activating and inhibiting receptors, proliferation activity of NK cells, and the cytotoxicity of NK cells on BC cells (MCF7). The effects of ILs were tested on the NK cell receptors CD314, CD158a and CD107a with flowcytometry, proliferation at various incubation times with 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and concentrations of TNF-α and IFN-γ by NK cells with ELISA. RESULTS: ILs increased NK cell receptor levels (CD314, CD158a, and CD107a) at 24 hours of incubation. ILs increased NK cell viability, which increased with longer incubation. Moreover, ILs-induced NK cells inhibited proliferation in MCF7 cells, as well as increased TNF-α, IFN-γ, PRF1 and GzmB secretion. CONCLUSION: IL-2, IL-15, and IL-18 improved activating receptors and proliferation of NK cells. IL-induced NK cells increased TNF-α, IFN-γ, PRF1 and GzmB secretion and cytotoxic activity on BC cells. High NK cell numbers increased BC cell growth inhibition.

Nonocarbolines A-E, ß-Carboline Antibiotics Produced by the Rare Actinobacterium Nonomuraea sp. from Indonesia.

During the course of our ongoing screening for novel biologically active secondary metabolites, the rare Actinobacterium, Nonomuraea sp. 1808210CR was found to produce five unprecedented ß-carboline derivatives, nonocarbolines A-E (1-5). Their structures were elucidated from high-resolution mass spectrometry, 1D and 2D nuclear magnetic resonance spectroscopy, and the absolute configuration of 4 was determined by using the modified Mosher method. Nonocarboline B (2) displayed moderate antifungal activity against Mucor hiemalis, while nonocarboline D (4) exhibited significant cytotoxic activity against the human lung carcinoma cell line A-549 with the IC50 value of 1.7 µM.

Biosynthesis of Polyketides in Streptomyces.

Polyketides are a large group of secondary metabolites that have notable variety in their structure and function. Polyketides exhibit a wide range of bioactivities such as antibacterial, antifungal, anticancer, antiviral, immune-suppressing, anti-cholesterol, and anti-inflammatory activity. Naturally, they are found in bacteria, fungi, plants, protists, insects, mollusks, and sponges. Streptomyces is a genus of Gram-positive bacteria that has a filamentous form like fungi. This genus is best known as one of the polyketides producers. Some examples of polyketides produced by Streptomyces are rapamycin, oleandomycin, actinorhodin, daunorubicin, and caprazamycin. Biosynthesis of polyketides involves a group of enzyme activities called polyketide synthases (PKSs). There are three types of PKSs (type I, type II, and type III) in Streptomyces responsible for producing polyketides. This paper focuses on the biosynthesis of polyketides in Streptomyces with three structurally-different types of PKSs.

Effects of insulin-like growth factor-induced Wharton jelly mesenchymal stem cells toward chondrogenesis in an osteoarthritis model.

OBJECTIVES: This study aimed to determine the collagen type II (COL2) and SOX9 expression in interleukin growth factor (IGF-1)-induced Wharton's Jelly mesenchymal stem cells (WJMSCs) and the level of chondrogenic markers in co-culture IGF1-WJMSCs and IL1ß-CHON002 as osteoarthritis (OA) cells model. MATERIALS AND METHODS: WJMSCs were induced with IGF1 (75, 150, and 300 ng/ml) to enhance their chondrogenesis capability. The gene expression of SOX9 and COL2 was evaluated with quantitative RT-PCR. Furthermore, IGF1-WJMSCs were co-cultured with IL1ß-CHON002 cells in varied ratios (1:2, 1:1, 2:1). Chondrogenic markers ADAMTS1, ADAMTS5, MMP3, MMP1, and RANKL were measured with ELISA. RESULTS: The IGF1-WJMSCs had an increased expression of COL2 and SOX9. ADAMTS1, ADAMTS5, MMP1, MMP3, and RANKL levels were decreased in the co-culture IGF1-WJMSCs and IL1ß-CHON002. CONCLUSION: The IGF1-induced WJMSCs were capable to enhance chondrogenesis, indicated by increased expression of SOX9 and COL2 and decreased expression of ADAMTS1, ADAMTS5, MMP3, MMP1, and RANKL. These findings can be further used in the osteoarthritis treatment.

Fractionation using adsorptive macroporous resin HPD-600 enhances antioxidant activity of Gnetum gnemon L. seed hard shell extract.

In this study, antioxidant activities and identification of the bioactive substances in Gnetum gnemon L. (Gg) seed hard shell were evaluated. The seed of Gnetum gnemon L., an Indonesian native plant, is commonly consumed as a vegetable or further processed as cracker. Isolated substances from Gnetum gnemon seed are mainly stilbenoid derivatives which show potent antioxidant, tyrosinase inhibitor, and antimicrobial activities. Nevertheless, the antioxidant activity of its crude extract is still considered weak. In this study, an effort was made to improve antioxidant potency by fractionation using macroporous adsorptive resin (MAR). This fractionation successfully enhanced antioxidant activity of red Gg seed hard shell extract with efficient adsorption contact time within 30 min. Antioxidant activity of fractions 25-75% v/v ethanol increased three- to sevenfold as compared to crude extract and more importantly resulted in dry product which was easier for further processes. Identification of bioactive compounds in Gg seed hard shell extract with different degrees of ripeness was also performed by HPLC and confirmed the presence of Gnetin C, resveratrol, and other stilbenoid derivatives. These other stilbenoid derivatives could be the main substances contributing in antioxidant action with lower IC50 as compared to both Gnetin C and resveratrol. In summary, fractionation process using MAR HPD-600 reduced unnecessary sugar molecules from red Gg seed hard shell extract hence resulting to fraction with strong antioxidant activity.