Effects of TmTak1 silencing on AMP production as an Imd pathway component in Tenebrio molitor.

Mealworms beetles, Tenebrio molitor, are the limelight next-generation food for humans due to their high nutrient contents. Since Tenebrio molitor is used as feed for pets and livestock in addition to their ability to decompose polystyrene and plastic waste, it is recognized as an insect with an industrial core value. Therefore, it is important to study the immune mechanism related to the development and infection of mealworms for mass breeding purposes. The immune deficiency (Imd) signaling is one of the main pathways with pivotal roles in the production of antimicrobial peptides (AMPs). Transforming growth factor-ß activated kinase (TAK1) is one of the Imd pathway components, forms a complex with TAK1 binding protein 2 (TAB2) to ultimately help activate the transcription factor Relish and eventually induce host to produce AMPs. Relatively, little has been revealed about TAK1 in insect models, especially in the T. molitor. Therefore, this study was conducted to elucidate the function of TmTak1 in T. molitor. Our results showed that the highest and lowest mRNA expression of TmTak1 were found in egg and young larvae respectively. The tissue-specific expression patterns were reported in the gut of T. molitor larvae and the fat bodies of adults. Systemic microbial challenge illustrated TmTak1 high expression following the fungal infection in all dissected tissues except for the whole body. However, silencing TmTak1 experiments showed that the survivability of T. molitor larvae affected significantly following Escherichia coli infection. Accordingly, AMP induction after TmTak1 knock down was mainly reported in the integument and the fat bodies.

A solvent-free headspace GC/MS method for sensitive screening of N-nitrosodimethylamine in drug products.

A solvent-free headspace gas chromatography-mass spectrometry (SF-HS-GC/MS) method was developed and validated for screening N-nitrosodimethylamine (NDMA) in various active pharmaceutical ingredients (APIs) and drug products. Experimental parameters such as incubation temperature, incubation time, and sample volume in solvent-free headspace conditions were optimized. The developed SF-HS-GC/MS method was validated in terms of linearity, limit of quantification (LOQ), precision, and accuracy. The results indicated excellent linearity from 5 to 500 ng g-1 with correlation coefficients higher than 0.9999. The LOQ of this method was 5 ng g-1 and matrix effects ranged from 0.97 to 1.11. The accuracy ranged from 92.77 to 106.54% and the precision RSDs were below 5.94%. No significant matrix effect was observed for any of the drug products. Also, artefactual NDMA formation in ranitidine, nizatidine, and metformin was investigated under HS conditions. Adjusted (mild) SF-HS conditions were suggested for precise quantification of NDMA in positive drug products by GC/MS. The present SF-HS-GC/MS method is a promising tool for the screening and determination of toxic NDMA in APIs and drug products.

Barley sprout extracts reduce hepatic lipid accumulation in ethanol-fed mice by activating hepatic AMP-activated protein kinase.

Chronic alcohol consumption leads to hepatic lipid accumulation and alcoholic fatty liver disease. Previously, we demonstrated that barley sprout extract, which contains saponarin as an active compound, reduces hepatic steatosis. In this study, we investigated the effect of barley sprout extracts (BSE) on hepatic lipid accumulation in a mouse model of alcoholic fatty liver disease. Seven-week-old C57BL/6 mice were fed an alcohol-containing diet (5% ethanol) and a low or high dose of BSE (100 or 200mg/kg body weight, respectively) for 10days. The high dose of BSE significantly decreased hepatic lipid accumulation compared with the ethanol-only control group. In the second animal study, mice were fed an alcohol-containing diet for 10days, followed by a 45% high-fat diet with oral administration of BSE (100 or 200mg/day/kg body weight) for 4weeks. Mice in both BSE-fed groups showed reduced hepatic steatosis. In the livers of mice fed BSE, phosphorylation of AMP-activated protein kinase (AMPK) was increased, and expression of hepatic autophagy markers was elevated. In cultured hepatocytes, BSE (200µg/mL) increased the rate of fatty acid oxidation and reduced that of fatty acid synthesis. Taken together, these findings suggest that BSE promotes degradation of lipid droplets and subsequent activation of fat oxidation by activating AMPK in the liver, thus protecting against development of hepatic steatosis in alcohol-fed mice. Saponarin, a major flavonoid in BSE and an activator of AMPK, increased the activity of microsomal triglyceride transfer protein, which suggests that the reduction in hepatic triglyceride levels was mediated by this component of BSE. In conclusion, BSE ameliorated hepatic steatosis in a mouse model of ethanol-induced fatty liver by activating AMPK, an effect possibly mediated by the saponarin component.

Olfactory receptor 544 reduces adiposity by steering fuel preference toward fats.

Olfactory receptors (ORs) are present in tissues outside the olfactory system; however, the function of these receptors remains relatively unknown. Here, we determined that olfactory receptor 544 (Olfr544) is highly expressed in the liver and adipose tissue of mice and regulates cellular energy metabolism and obesity. Azelaic acid (AzA), an Olfr544 ligand, specifically induced PKA-dependent lipolysis in adipocytes and promoted fatty acid oxidation (FAO) and ketogenesis in liver, thus shifting the fuel preference to fats. After 6 weeks of administration, mice fed a high-fat diet (HFD) exhibited a marked reduction in adiposity. AzA treatment induced expression of PPAR-α and genes required for FAO in the liver and induced the expression of PPAR-γ coactivator 1-α (Ppargc1a) and uncoupling protein-1 (Ucp1) genes in brown adipose tissue (BAT). Moreover, treatment with AzA increased insulin sensitivity and ketone body levels. This led to a reduction in the respiratory quotient and an increase in the FAO rate, as indicated by indirect calorimetry. AzA treatment had similar antiobesogenic effects in HFD-fed ob/ob mice. Importantly, AzA-associated metabolic changes were completely abrogated in HFD-fed Olfr544-/- mice. To our knowledge, this is the first report to show that Olfr544 orchestrates the metabolic interplay between the liver and adipose tissue, mobilizing stored fats from adipose tissue and shifting the fuel preference to fats in the liver and BAT.