Characterization and discrimination of two varieties of eggplants using multi-element and metabolomics profiles coupled with chemometrics analysis.

The main purpose of the present study was to clarify the differences present in the multi-element and metabolite profiles between two varieties of eggplants. A total of 54 elements were identified by inductively coupled plasma mass spectrometry, 16 elements were significantly different between peel (n = 3) and flesh (n = 3). Besides, untargeted metabolomics combined with chemometrics was used to discriminate the peel (n = 4) and flesh (n = 4) of the two varieties of eggplants. A total of 178 metabolites were screened out with criteria of p < 0.05, fold change > 1.5 or < 0.67 and variable importance in projection score > 1 for the PLS-DA model. Maltitol and d-proline were the most important discriminants of the two varieties of eggplants. Kaempferol-3-O-rutinoside was the most important identification components between peel and flesh of the two varieties of eggplant. Results showed that the two varieties of eggplants could be distinguished based on their multi-element and metabolite profiles, which may provide new directions for eggplant function research.

Integrated network pharmacology and cellular assay for the investigation of an anti-obesity effect of 6-shogaol.

This study explored the anti-obesity effect of 6-shogaol and the underlying mechanisms by using Network pharmacology for the prediction and verification of molecular targets and pathways of 6-shogaol against obesity. Furthermore, the results were verified by molecular docking and cell experiments. A total of 86 core targets of 6-shogaol towards obesity were identified. Among them, AKT1 and PIK3CA were confirmed by using the molecular docking. In 3T3-L1 preadipocyte model, 6-shogaol significantly inhibited proliferation and differentiation, reducing the accumulation of lipid droplets. Compared with the control group, the inhibition rates of 6-shogaol on TG and TC were 90.8% and 40.0%, respectively. Additionally, 6-shogaol down-regulated the expression of PPAR-γ and C/EBP-α, while it decreased the phosphorylation of IRS-1, PI3K and AKT. This study, for the first time, confirmed the effect of 6-shogaol on improving obesity through PI3K/AKT pathway. An anti-obesity bioactivity study was further recommended for the development of novel anti-obesity products.

High sugar diet disrupts gut homeostasis though JNK and STAT pathways in Drosophila.

The incidence of diseases associated with a high sugar diet has increased in the past years, and numerous studies have focused on the effect of high sugar intake on obesity and metabolic syndrome. However, how a high sugar diet influences gut homeostasis is still poorly understood. In this study, we used Drosophila melanogaster as a model organism and supplemented a culture medium with 1 M sucrose to create a high sugar condition. Our results indicate that a high sugar diet promoted differentiation of intestinal stem cells through upregulation of the JNK pathway and downregulation of the JAK/STAT pathway. Moreover, the number of commensal bacteria decreased in the high sugar group. Our data suggests that the high caloric diet disrupts gut homeostasis and highlights Drosophila as an ideal model system to explore gastrointestinal disease.

Preparative and biosynthetic insights into pdA2E and isopdA2E, retinal-derived fluorophores of retinal pigment epithelial lipofuscin.

PURPOSE: Retinal-derived fluorophores that accumulate as RPE lipofuscin are implicated in pathological mechanisms of AMD. One component of RPE lipofuscin has been characterized as pdA2E, a pyridinium adduct derived from all-trans-retinal and excess ethanolamine. One-step preparation and biosynthetic studies of pdA2E and its novel isomer called isopdA2E are reported. METHODS: Biosynthetic reaction mixtures, RPE/choroids and neural retinas dissected from bovines, eyes harvested from Abca4(-/-)Rdh8(-/-) mice, irradiated samples, and enzyme-treated solutions were analyzed by HPLC, mass spectrometry, nuclear magnetic resonance spectroscopy, fluorescence spectrophotometry, and density functional theory (DFT). RESULTS: Optimization of the in vitro synthesis of pdA2E resulted in a biomimetic preparation of this pigment in a yield of 15%; this protocol also allowed the identification of isopdA2E, a double-bond isomer of pdA2E at the C13C14 position in bovine RPE lipofuscin. Interconversion between these two molecules occurs when either pdA2E or isopdA2E is exposed to light. A phospholipase D-based assay demonstrated the possibility of pdA2-PE being formed in neural retina and served as a precursor of pdA2E in the biosynthetic pathway. DFT calculations revealed that the 492-nm absorbance was assigned to the long arm of pdA2E/isopdA2E and the 340/342-nm absorbance to the short arm. Fluorescence efficiency of pdA2E and isopdA2E is very similar, but is much weaker in comparison with A2E, isoA2E, and iisoA2E. CONCLUSIONS: Our results facilitate the understanding of compositions and biosynthetic pathways of adverse RPE lipofuscin.

Effects of organic solvents on two retinal pigment epithelial lipofuscin fluorophores, A2E and all-trans-retinal dimer.

Gene and drug therapies are being developed to alleviate vision loss in patients with Stargardt's disease and age-related macular degeneration (AMD). To evaluate the therapeutic effects of these treatments, organic solvents are routinely used to extract and quantify bisretinoid lipofuscin constituents, such as N-retinylidene-N-retinyl-ethanolamine (A2E) and all-trans-retinal dimer (ATR-dimer). By high-performance liquid chromatography (HPLC), we found that A2E and ATR-dimer were both altered by tetrahydrofuran (THF) and chloroform, but were stable in dimethyl sulfoxide (DMSO) or methanol (MeOH). In addition, cyclohexane and ethanol (EtOH) did not alter ATR-dimer, whereas an alteration of A2E occurred in EtOH. On the basis of these findings, we designed processes II-IV, generated by modifications of process I, a routine method to measure bisretinoid compounds in vivo. Extra amounts of either ATR-dimer or A2E in mouse eyecups were released by processes II-IV versus process I. Efforts to clarify the effects of organic solvents on lipofuscin pigments are important because such studies can guide the handling of these fluorophores in related experiments.

Retinal metabolism in humans induces the formation of an unprecedented lipofuscin fluorophore 'pdA2E'.

Toxic lipofuscin in the RPE (retinal pigment epithelium) is implicated in blindness in AMD (age-related macular degeneration) or recessive Stargardt's disease patients. In the present study, we identified a novel fluorescent lipofuscin component in human and bovine RPEs. Using 1D and 2D NMR and MS, we confirmed the structure of this pigment and called it pdA2E. It exhibits absorbance maxima at 492 and 342 nm, and is susceptible to photocatalytic isomerization and oxidation. This fluorophore was also detected in the eyecup extracts of Abca4(-/-)Rdh8(-/-) (Abca4 encodes ATP-binding cassette transporter 4 and Rdh8 encodes retinol dehydrogenase 8) mice, an AMD/recessive Stargardt's disease model. Excess amassing of pdA2E within RPE cells caused significant cell viability loss and membrane damage. The formation of pdA2E occurred when atRAL (all-trans-retinal) reacted with excess ethanolamine in the absence of acetic acid, and the process is likely to involve the participation of three atRAL molecules. Our findings suggest that endogenous pdA2E may serve as a sensitizer for yielding singlet oxygen and a singlet oxygen quencher, as well as a by-product of retinal metabolism, and its complete characterization facilitates the understanding of biosynthetic pathways by which adverse RPE lipofuscin constituents form.