Polycyclic Aromatic Hydrocarbons (PAHs) in Road Dust Collected from Myanmar, Japan, Taiwan, and Vietnam.

In this study, we determined the concentrations of polycyclic aromatic hydrocarbons (PAHs) in road dust from Myanmar, Japan, Taiwan, and Vietnam. PAHs were detected in urban and rural areas of Myanmar at mean concentrations of 630 ng/g dry weight and 200 ng/g dry weight, respectively. PAHs were also detected in road dust from Vietnam (mean 1700 ng/g) and Taiwan (2400 ng/g). PAH diagnostic ratios suggested that fossil fuel vehicular exhaust and biomass combustion are major sources of PAHs in road dust in Myanmar. Road dust samples from Japan, Taiwan, and Vietnam had similar PAH diagnostic ratios, implying that PAH sources are similar. We assessed the human health risks posed by PAHs in road dust using carcinogenic equivalents (CEQs) and incremental lifetime cancer risk (ILCR). Mean CEQs were decreased in the order Taiwan (173 ng/g) > Vietnam (162 ng/g for Hanoi) > Myanmar (42 and 31 ng/g for Yangon and Pathein, respectively) > Japan (30 ng/g for Kumamoto). Benz[a]pyrene, fluoranthene, and benzo[b]fluoranthene, the predominant PAHs, contributed > 70% of total CEQs. High ILCR values were found for Taiwan (5.9 × 10-4 and 9.9 × 10-4 for children and adults, respectively) and Vietnam (6.5 × 10-4 and 9.2 × 10-4 for children and adults, respectively, in Hanoi), indicating that PAHs in road dust pose cancer risks to the inhabitants of Taiwan and Hanoi. To our knowledge, this is the first report to identify PAH pollution in the environment and to evaluate the human health risks of these PAHs in Myanmar.

The Effect of Methanolic Valeriana officinalis Root Extract on Adipocyte Differentiation and Adiponectin Production in 3T3-L1 Adipocytes.

Adipose tissue is an endocrine organ and its endocrine function is closely associated with type 2 diabetes mellitus. Valeriana officinalis (Valerian) exerts some physiological effects; however, its influence on adipocytes remains unclear. We investigated the effect of methanolic Valerian root extract (Vale) on 3T3-L1 adipocytes. Vale (1, 10, and 100 µg/mL) dose-dependently promoted adipocyte differentiation with increasing lipid accumulation. In addition, Vale significantly increased the mRNA levels in genes associated with adipocyte differentiation, including peroxisome proliferator-activated receptor γ (PPARγ), CCAAT/enhancer-binding protein α , and adipocyte protein 2, in dose-dependent manner. Vale also significantly enhanced mRNA and protein levels in adiponectin. A PPARγ antagonist assay and a PPARγ binding assay revealed that Vale-induced increased adipocyte differentiation and adiponectin production were partly associated with direct binding to PPARγ. Valerenic acid, a characteristic component in Valerian, also demonstrated the ability to induce adipocyte differentiation and adiponectin secretion, suggesting that it is one of the functional components in Vale.

(-)-O-Methylcubebin from Vitex trifolia Enhanced Adipogenesis in 3T3-L1 Cells via the Inhibition of ERK1/2 and p38MAPK Phosphorylation.

In this study, for the purpose of elucidation for antidiabetic components, we isolated and identified compounds that could become lead compounds for the development of antidiabetic agents from the herbal medicine Vitex trifolia, which is used for liver protection in Myanmar. Three kinds of lignan, (-)-O-methylcubebin (MC), (-)-hinokinin, and (-)-cubebin, were isolated from the ethyl acetate extract of the leaves of V. trifolia, using various chromatography. Among the three isolated compounds, MC showed the strongest effects to increase intracellular lipid accumulation in 3T3-L1 cells. From the results of the elucidation of the MC's effects on the adipogenesis of 3T3-L1 cells, the downsizing of adipocytes and the promotion of the expression of adipogenesis-related proteins, as well as adiponectin, were observed. On the other hand, since the activity of MC was inhibited by antagonists of PPARγ and improved by inhibitors of the classical mitogen-activated protein kinase (MAPK) pathway and p38MAPK pathway, MC was considered to be an agonist of PPARγ, and furthermore promoted adipogenesis via the inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) and p38MAPK phosphorylation. Although MC showed similar effects to those of rosiglitazone (RO) used as a positive control, RO promoted the migration of GLUT4 from the cytoplasm to the cell membrane, whereas MC did not show such an effect. From the abovementioned results, it was considered that MC could be a lead compound for the development of antidiabetic drugs that does not show weight gain, which is a side effect of RO.

Mansonone E from Mansonia gagei Inhibited α-MSH-Induced Melanogenesis in B16 Cells by Inhibiting CREB Expression and Phosphorylation in the PI3K/Akt Pathway.

Many natural products that inhibit melanogenesis, freckles, and hyperpigmentation have been selectively used in cosmetics because melanogenesis is linked to the multiple biogenesis cascades of melanin synthesis. However, some of these compounds have side effects that may result in their restriction in the future. We report here the isolation and structural elucidation of compounds extracted from Mansonia gagei and evaluate their activity on melanogenesis inhibition. We isolated five known compounds from M. gagei and identified them as mansonone E (1), mansorin I (2), populene F (3), mansonone G (4), and mansorin B (5). After evaluating the five compounds for cytotoxicity against B16 cells and inhibitory activity on α-melanocyte-stimulating hormone (α-MSH) induced melanogenesis, we determined that the cytotoxicity and melanogenesis-inhibitory effect of 1 were relatively low and high, respectively. Next, the effect of 1 on the expression of melanogenesis-related proteins was assessed; it was confirmed that 1 dose-dependently inhibited the expression levels of tyrosinase, tyrosinase-related protein 1 (TRP-1), TRP-2, cAMP response element binding protein (CREB), and microphthalmia-associated transcription factor (MITF) which were increased after stimulation by α-MSH. Furthermore, the effects of 1 on the phosphorylation levels of intracellular signaling pathway-related proteins were evaluated, and it was found that 1 dose-dependently rescued the phosphorylation of Akt and p38 mitogen-activated protein kinases (MAPK), which were up- or down-regulated after stimulation by α-MSH. In contrast, treatment with the phosphoinositide 3-kinase (PI3K)/Akt inhibitor wortmannin enhanced melanogenesis inhibition by mansonone E. Cumulatively, the data suggest that 1 suppresses α-MSH-induced melanogenesis in B16 cells by inhibiting both phosphorylation in the PI3K/Akt pathway and the expression of melanogenesis-related proteins.

The Rosiglitazone-Like Effects of Vitexilactone, a Constituent from Vitex trifolia L. in 3T3-L1 Preadipocytes.

The increased number of patients with type 2 diabetes (T2D) has become a worldwide problem, and insulin sensitizers such as thiazolidinediones (TZDs) are used as therapeutic agents. We found that extracts of Vitex trifolia L. (V. trifolia), a medicinal plant from Myanmar, induced adipogenesis similar to rosiglitazone (ROS), which is a TZD, in 3T3-L1 preadipocytes. In the present study, we attempted to isolate from V. trifolia those compounds that showed ROS-like effects. Among the extracts of hexane, ethyl acetate, and methanol obtained from V. trifolia, the ethyl acetate extract with the strongest ROS-like effects was purified by various chromatographic methods to obtain three known compounds: vitexilactone (1), vitexicarpin (2) and oleanolic acid (3). Among the isolated compounds, the ROS-like action of 1 was the strongest. The effects of 1 on 3T3-L1 cells during adipogenesis were compared with those of ROS. Both 1 and ROS increased lipid accumulation, the expression of adiponectin and GLUT4 in the cell membrane and decreased both the size of adipocytes and the phosphorylation of IRS-1, ERK1/2 and JNK in 3T3-L1 cells. In contrast, unlike ROS, the induction of proteins involved in lipogenesis was partial. ROS-like effects of 1 in 3T3-L1 cells were suppressed by the addition of bisphenol A diglycidyl ether (BADGE), one of a peroxisome proliferator-activated receptor γ (PPARγ) antagonists, suggesting that the action of 1 on adipocytes is mediated by PPARγ. From the results of the present study, it can be concluded that 1 is a novel insulin sensitizer candidate.

Ubiquitous Detection of Artificial Sweeteners and Iodinated X-ray Contrast Media in Aquatic Environmental and Wastewater Treatment Plant Samples from Vietnam, The Philippines, and Myanmar.

Water samples from Vietnam, The Philippines, and Myanmar were analyzed for artificial sweeteners (ASs) and iodinated X-ray contrast media (ICMs). High concentrations (low micrograms per liter) of ASs, including aspartame, saccharin, and sucralose, were found in wastewater treatment plant (WWTP) influents from Vietnam. Three ICMs, iohexol, iopamidol, and iopromide were detected in Vietnamese WWTP influents and effluents, suggesting that these ICMs are frequently used in Vietnam. ASs and ICMs were found in river water from downtown Hanoi at concentrations comparable to or lower than the concentrations in WWTP influents. The ASs and ICMs concentrations in WWTP influents and adjacent surface water significantly correlated (r (2) = 0.99, p < 0.001), suggesting that household wastewater is discharged directly into rivers in Vietnam. Acesulfame was frequently detected in northern Vietnamese groundwater, but the concentrations varied spatially by one order of magnitude even though the sampling points were very close together. This implies that poorly performing domestic septic tanks sporadically leak household wastewater into groundwater. High acesulfame, cyclamate, saccharin, and sucralose concentrations were found in surface water from Manila, The Philippines. The sucralose concentrations were one order of magnitude higher in the Manila samples than in the Vietnamese samples, indicating that more sucralose is used in The Philippines than in Vietnam. Acesulfame and cyclamate were found in surface water from Pathein (rural) and Yangon (urban) in Myanmar, but no ICMs were found in the samples. The ASs concentrations were two-three orders of magnitude lower in the samples from Myanmar than in the samples from Vietnam and The Philippines, suggesting that different amounts of ASs are used in these countries. We believe this is the first report of persistent ASs and ICMs having ubiquitous distributions in economically emerging South Asian countries.

Evaluation of Myanmar medicinal plant extracts for antitrypanosomal and cytotoxic activities.

Current chemotherapeutic options for African trypanosomiasis in humans and livestock are very limited. In the present study, a total of 71 medicinal plant specimens from 60 plant species collected in Myanmar were screened for antitrypanosomal activity against trypomastigotes of Trypanosoma evansi and cytotoxicity against MRC-5 cells in vitro. The methanol extract of dried rootbark of Vitis repens showed the highest antitrypanosomal activity with IC(50) value of 8.6 +/- 1.5 microg/ml and the highest selectivity index of 24.4. The extracts of Brucea javanica, Vitex arborea, Eucalyptus globulus and Jatropha podagrica had also remarkable activity with IC(50) values and selectivity indices in the range of 27.2-52.6 microg/ml and 11.4-15.1 respectively.

Virgisporangium myanmarense sp. nov., a novel motile actinomycete isolated from an anthill soil in Myanmar.

An actinomycete strain, designated MM04-1133T, was isolated from an anthill soil sample collected in Bagan, Myanmar. To establish the taxonomic status of this strain, the isolate was subjected to a polyphasic approach. Strain MM04-1133T was Gram-staining positive, aerobic, motile and formed long and narrow sporangia directly above the surface of the substrate mycelium. Whole-cell hydrolysates of the strain contained 3-OH-diaminopimelic acid, arabinose, glucose, galactose, mannose, rhamnose and xylose. The predominant menaquinones were MK-10(H6) and MK-10(H8). The major cellular fatty acids were iso-C16:0 and anteiso-C17:0. The diagnostic phospholipid was phosphatidylethanolamine. The G+C content of the DNA was 69.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain MM04-1133T clustered within the genus Virgisporangium, with the sequence exhibiting highest similarity (98.5% identity) with Virgisporangium ochraceum NBRC 16418T. The strain grew in the presence of 0-1% (w/v) NaCl, at pH 5-8 and at 20-40 °C, with optimal growth at 30-37 °C. Based on phylogenetic analysis and chemotaxonomic and phenotypic data, we propose classifying this isolate as a novel species of the genus Virgisporangium, to be designated as Virgisporangium myanmarense sp. nov. The type strain is MM04-1133T (=NBRC 112733T=VTCC 910008T).