Acylation of acylglycerols by acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1). Functional importance of DGAT1 in the intestinal fat absorption

Acyl coenzyme A:diacylglycerol acyltransferase 1 (DGAT1) is one of the four intestinal membrane bound acyltransferases implicated in dietary fat absorption. Recently, it was found that, in addition to acylating diacylglycerol (DAG), DGAT1 also possesses robust enzymatic activity for acylating monoacylglycerol (MAG) (Yen, C. L., Monetti, M., Burri, B. J., and Farese, R. V., Jr. (2005) J. Lipid Res. 46, 1502-1511). In the current paper, we have conducted a detailed characterization of this reaction in test tube, intact cell culture, and animal models. Enzymatically, we found that triacylglycerol (TAG) synthesis from MAG by DGAT1 does not behave according to classic Michaelis-Menten kinetics. At low concentrations of 2-MAG (<50 microm), the major acylation product by DGAT1 was TAG; however, increased concentrations of 2-MAG (50-200 microm) resulted in decreased TAG formation. This unique product/substrate relationship is similar to MGAT3 but distinct from DGAT2 and MGAT2. We have also found that XP620 is an inhibitor that selectively inhibits the acylation of MAG by DGAT1 (IC(50) of human DGAT1: 16.6+/-4.0 nM (MAG as substrate) and 1499+/-318 nM (DAG as substrate); IC(50) values of human DGAT2, MGAT2, and MGAT3 are >30,000 nM). Using this pharmacological tool, we have shown that approximately 76 and approximately 89% of the in vitro TAG synthesis initiated from MAG is mediated by DGAT1 in Caco-2 cell and rat intestinal mucosal membranes, respectively. When applied to intact cultured cells, XP620 substantially decreased but did not abolish apoB secretion in differentiated Caco-2 cells. It also decreased TAG and DAG syntheses in primary enterocytes. Last, when delivered orally to rats, XP620 decreased absorption of orally administered lipids by approximately 50%. Based on these data, we conclude that the acylation of acylglycerols by DGAT1 is important for dietary fat absorption in the intestine.     

Phytochemical and Biological Activities of Pseudocalymma elegans: A False Garlic

Evaluation of phytochemical constituents and antioxidant and antimicrobial activities of hexane (PELH), dichloromethane (PELDCM), ethyl acetate (PELEA), and MeOH (PELM) extracts of young leaves of Pseudocalymma elegans have been carried out. Moreover, extracts have also been explored for the presence of sulphur containing compounds, 1,2‐dithiolane ( 33 ), diallyl disulfide ( 35 ), 3‐vinyl‐1,2‐dithiacyclohex‐5‐ene ( 37 ), and diallyl trisulfide ( 38 ) responsible for the garlic like smell of P. elegans. All the extracts were found to be antioxidant and showed potent inhibition with IC₅₀ values of 0.168 ± 0.001, 0.128 ± 0.002, 0.221 ± 0.011, and 0.054 ± 0.001, respectively, as compared to standard drugs ascorbic acid (AA) and butylated hydroxytoluene (BHT). The ethyl acetate extract (PELE) showed excellent activities against few Gram‐positive and Gram‐negative bacteria and some fungi as compared with standard drug ceftriaxone (3rd generation cephalosporin) and nystatin, respectively. Chemical constituents of hexane, dichloromethane, and ethyl acetate extracts were identified by gas chromatography‐mass spectrometry and mass spectral library search. Over all 55 chemical constituents were first time identified from the leaves which included branched and n‐hydrocarbons, fatty acids, fatty acid methyl esters, fatty alcohols, terpenes, alkaloid, vitamins, glycosides, aromatic compounds, and sulfur containing compounds. Two known chemical constituents, ursolic acid ( 1 ) and β‐amyrin ( 2 ), were also purified for the first time from the MeOH extract. To elucidate the structures of these compounds, UV, IR, EI‐MS, ¹H‐ and ¹³C‐NMR spectroscopy were used.     

Benzo(a)pyrene-induced genotoxicity: attenuation by farnesol in a mouse model

In the present study we have evaluated the antigenotoxic effects of Farnesol (FL) a 15-carbon isoprenoid alcohol against benzo (a) pyrene [B(a)P] (125 mg kg(- 1).b.wt oral) induced toxicity. B(a)P administration lead to significant induction in Cytochrome P450 (CYP) content and aryl hydrocarbon hydrolase (AHH) activity (p < 0.001), DNA strand breaks and DNA adducts (p < 0.001) formation. FL was shown to suppress the activities of both CYP and AHH (p < 0.005) in modulator groups. FL pretreatment significantly (p < 0.001) restored depleted levels of reduced glutathione (GSH), quinone reductase (QR) and glutathione -S-transferase (GST). A simultaneous significant and at both the doses reduction was seen in DNA strand breaks and in in-vivo DNA adducts formation (p < 0.005), which gives some insight on restoration of DNA integrity. The results support the protective nature of FL. Hence present data supports FL as a future drug to preclude B (a) P induced toxicity.     

Cost of illness for severe and non-severe diarrhea borne by households in a low-income urban community of Bangladesh: A cross-sectional study

The illness cost borne by households, known as out-of-pocket expenditure, was 74% of the total health expenditure in Bangladesh in 2017. Calculating economic burden of diarrhea of low-income urban community is important to identify potential cost savings strategies and prioritize policy decision to improve the quality of life of this population. This study aimed to estimate cost of illness and monthly percent expenditure borne by households due diarrhea in a low-income urban settlement of Dhaka, Bangladesh. We conducted this study in East Arichpur area of Tongi township in Dhaka, Bangladesh from September 17, 2015 to July 26, 2016. We used the World Health Organization (WHO) definition of three or more loose stool in 24 hours to enroll patients and enrolled 106 severe patients and 158 non-severe patients from Tongi General Hospital, local pharmacy and study community. The team enrolled patients between the first to third day of the illness (≤ 72 hours) and continued daily follow-up by phone until recovery. We considered direct and indirect costs to calculate cost-per-episode. We applied the published incidence rate to estimate the annual cost of diarrhea. The estimated average cost of illness for patient with severe diarrhea was US$ 27.39 [95% CI: 24.55, 30.23] (2,147 BDT), 17% of the average monthly income of the households. The average cost of illness for patient with non-severe diarrhea was US$ 6.36 [95% CI: 5.19, 7.55] (499 BDT), 4% of the average monthly income of households. A single diarrheal episode substantially affects financial condition of low-income urban community residents: a severe episode can cost almost equivalent to 4.35 days (17%) and a non-severe episode can cost almost equivalent to 1 day (4%) of household’s income. Preventing diarrhea preserves health and supports financial livelihoods.     

Single-cell A3243G mitochondrial DNA mutation load assays for segregation analysis.

Segregation of mitochondrial DNA (mtDNA) is an important underlying pathogenic factor in mtDNA mutation accumulation in mitochondrial diseases and aging, but the molecular mechanisms of mtDNA segregation are elusive. Lack of high-throughput single-cell mutation load assays lies at the root of the paucity of studies in which, at the single-cell level, mitotic mtDNA segregation patterns have been analyzed. Here we describe development of a novel fluorescence-based, non-gel PCR restriction fragment length polymorphism method for single-cell A3243G mtDNA mutation load measurement. Results correlated very well with a quantitative in situ Padlock/rolling circle amplification-based genotyping method. In view of the throughput and accuracy of both methods for single-cell A3243G mtDNA mutation load determination, we conclude that they are well suited for segregation analysis.     

Environmental investigation of potentially pathogenic Vibrio parahaemolyticus in the Seto-Inland Sea, Japan

Seawater and organic material (live and/or dead matter deposited on any substratum submersed in seawater) were collected during the cool weather season from a coast of the Seto-Inland Sea, Japan, and analyzed to determine Vibrio parahaemolyticus densities and the occurrence of pathogenic strains, defined as those possessing tdh and/or trh genes by the polymerase chain reaction (PCR), using isolated DNA from enrichment culture of the samples. About 95% of the samples were positive for V. parahaemolyticus (with densities of 3 to >1400 cells per 100 ml water or 10 g organic samples) by the most-probable-number (MPN)-PCR technique with species-specific toxR primers, but only 40% were positive by the conventional MPN-culture technique (with densities ranging from 3 to 240 cells per 100 ml water or 10 g organics). Furthermore, the tdh and trh genes were positive in 55% and 20% of samples, respectively, by the MPN-PCR technique. No tdh and trh gene-positive strains were isolated by the conventional MPN-culture procedure. The difference in detection between the MPN-culture and the MPN-PCR techniques appeared to be significant and may be attributed to different detection sensitivities and other factors.