Gender-and Age-Group Specific Association of Persistent Organic Pollutants(POPs)Exposure with Diabetes Mellitus:Korean National Environmental Health Survey(KoNEHS)2015−2017

Exposure to persistent organic pollutants(POPs)has been reported as a potential risk factor for diabetes in adults.However,effect modifications by sex and age,especially among Asian populations,have seldom been investigated.In the present study,we assessed associations of major POPs exposure including organochlorine pesticides(OCPs),polychlorinated biphenyls(PCBs),and polybrominated diphenyl ethers(PBDEs),with diabetes in Korean adults(n=1,295),a subset of the Korean National Environmental Health Survey(KoNEHS)Cycle 3(2015−2017).In the adult population,serum levels of dichlorodiphenyltrichloroethanes(DDTs)and PCB167 showed an increased odds ratio(OR)for diabetes.When stratified by gender,associations became stronger and more consistent in women:In women,serum levels of OCPs including p,p′-DDT,p,p′-dichlorodiphenyldichloroethylene(p,p′-DDE),andΣOCPs and mono-ortho PCBs,such as PCB118 and PCB157,were significantly associated with diabetes.In the male participants,however,no significant positive associations were detected.When stratified by a cutoff age of 50 years,most studied POPs except PBDEs,i.e.,p,p′-DDT,p,p′-DDE,PCB118,PCB157,PCB167,PCB138,and PCB153,showed significant associations with diabetes,in the older adults.In the younger group,however,no measured POPs showed a significant positive association.Effects of endogenous sex hormones or interaction of POPs on aryl hydrocarbon receptors may partly explain the observed differences by gender and age,although further experimental confirmations should follow.Our findings show that POPs exposure at the current levels is associated with diabetes among general Korean adults,and such associations could be modified by gender and age.

Comparison of Accelerated Solvent Extraction, Soxhlet and Sonication Techniques for the Extraction of Estrogens, Androgens and Progestogens from Soils

Leaching of hormones from manure amended fields to receive surface water can lead to endocrine disruption in resident fish populations. In order to determine the concentrations of hormones present in manure amended soils, and thus the potential for soils to release hormones to aquatic environments, efficient extraction methods are needed. In this study, the efficacy of three techniques (accelerated solvent extraction [ASE], Soxhlet and sonication) for the extraction of estrogens, androgens and progestogens, as well as their metabolites, from various soil types were evaluated. The stability of hormones spiked into these soils and stored for 30, 90 and 210 days at -20°C was also investigated. Four experimental soil matrices (reagent sand, silt loam, clay and high organic) were spiked with 50 μL of 10 μg·mL-1 (in methanol;final conc. 100 ng·g-1) of a stock mix of hormones and isotopically-labeled standards (ISTDs). After equilibration, triplicate samples of the spiked soils were extracted by ASE, Soxhlet and sonication techniques and analysed, without post extraction cleanup, using HPLC-MS/MS. Sonication and ASE were effective at extracting hormones from all matrices with overall average apparent recoveries, for all 19 extracted analytes, of 71% ± 23% and 73% ± 16%, respectively. Soxhlet was significantly less efficient (p < 0.05) with overall average apparent recoveries of 58% ± 34%. Incorporation of ISTDs resulted in overall average process efficiencies of 108% ± 24%, 102% ± 24% and 180% ± 310% for ASE, Soxhlet and sonication, respectively. The hormones had variable stability in soils stored for at least 30 days, and therefore it recommended that soil samples be analysed within 30 days of sampling.

Induction of apoptosis in leukemic cells by the alkaloid extract of garden cress(Lepidium sativum L.)

Objective: Garden cress(Lepidium sativum L.) is an important herb in traditional medicine used to improve production of breast milk in women and semen in men. In the present research the authors evaluated its ability to destroy leukemic cancer(Jurkat E6-1) cells, using the alkaloid extract of this plant.Methods: Constituents of the alkaloid extract were analyzed by gas chromatography–mass spectrometry(GC–MS) and their cytotoxicity in leukemic cancer cells and healthy peripheral blood mononuclear cells(PBMCs) was assessed. Cell death via apoptosis was confirmed by DNA laddering, caspase-3 activity,annexin V-fluorescein isothiocyanate and mitochondrial toxicity assays. The specific course of gene activation in treated cells was determined through quantitative polymerase chain reaction(qPCR).Results: GC–MS analysis identified six alkaloids and proto-alkaloids, namely, benzyl isothiocyanate(1),2-ethoxy-4 H-3,1-benzoxazin-4-one(2),(4 R)-2-(2-aminophenyl)-4-phenyloxazoline(3), 5-acetyl-1,2-di hydro-6-methyl-2-oxo-4-phenyl-3-pyridinecarbonitrile(4), benzo[b][1,8]-naphthyridin-5(10 H)-on e,2,4,7-trimethyl(5) and 1,4-diaminoanthraquinone(6), in the alkaloid extract of L. sativum. Of these,compound 1 was previously identified in the seeds of L. sativum. Exposure to the alkaloid extract caused death of Jurkat E6-1 cells, with median lethal concentration(LC50) of 75.25 mg/mL. However, the alkaloid extract also showed a nontoxic and proliferative(1.6-fold) effect in healthy PBMCs. Further experiments performed with Jurkat cells at LC50 and sub-LC50 doses demonstrated DNA fragmentation, activation of caspase-3 and time-dependant phosphatidylserine translocation(apoptosis) from inner to outer cell membranes. Cell toxicity and assessment of adenosine triphosphate level, together with using qPCR to evaluate expression profile of major apoptosis genes, revealed that apoptosis may be induced by disruption in the mitochondrial outer membrane potential, through activation of extrinsic and intrinsic apoptosis pathways in Jurkat cells.Conclusion: The ability of the alkaloid extract of L. sativum seeds to induce apoptosis indicates a potential pharmacological use in cancer chemotherapy. The separation of individual active compounds and further in-depth exploration of the molecular mechanism of apoptosis may lead to novel chemotherapeutic compounds in our future antineoplastic research.

Cytochrome P450 BM3 of Bacillus megaterium-A possible endosulfan biotransforming gene

Computing chemistry was applied to understand biotransforrnation mechanism of an organochlorine pesticide, endosulfan. The stereo specific metabolic activity of human CYP-2B6 （cytochrome P450） on endosulfan has been well demonstrated. Sequence and structural similarity search revealed that the bacterium Bacillus megaterium encodes CYP-BM3, which is similar to CYP-2B6. The functional similarity was studied at organism level by batch-scale studies and it was proved that B. megaterium could metabolize endosulfan to endosulfan sulfate, as CYP-2B6 does in human system. The gene expression analyses also confirmed the possible role of CYP-BM3 in endosulfan metabolism. Thus, our results show that the protein structure based in-silico approach can help us to understand and identify microbes for remediation strategy development. To the best of our knowledge this is the first report which has extrapolated the bacterial gene for endosulfan biotransformation through in silico prediction approach for metabolic gene identification.