Selective inhibition of intestinal 5-HT improves neurobehavioral abnormalities caused by high-fat diet mice

Recent literature reported the adverse effects of high-fat diet (HFD) on animal's emotional and cognitive function. An HFD-induced obesity/hyperlipidemia is accompanied by hormonal and neurochemical changes that can lead to depression. The important roles of gut-derived serotonin (5-Hydroxytryptamine, 5-HT) during this processing have been increasingly focused. Hence, to determine the potential role of gut-derived serotonin, HFD model was established in C57BL/6 mice. At the 4th week of feeding, a pharmacologic inhibitor of gut-derived 5-HT synthesis LP533401 (12.5 mg/kg/day), simvastatin (SIM) (5 mg/kg/day) and benzafibrate (BZ) (75 mg/kg/day) were administered for two weeks by oral gavage. Then, intraperitoneal glucose tolerance test (IPGTT), open field test (OFT), tail suspension test (TST), forced swim test (FST), sucrose preference test (SPT) were used to evaluate metabolic and neurobehavioral performances. Immunohistochemical staining, real-time quantitative PCR and other methods were to explore possible mechanisms. It was found that HFD feeding and drug treatments had some significant effects on neurobehaviors and brain: (1) All administrations reduced the total cholesterol (TC) and triglyceride (TG) parametric abnormality caused by HFD. LP533401 and SIM could significantly improve the impaired glucose tolerance, while BZ had no significant effect. (2) LP533401, SIM and BZ alleviated depression-like behavior of HFD mice in OFT, TST, FST and SPT. (3) LP533401 and SIM reversed the inhibition of Tryptophan Hydroxylase 2, Tph2 gene expression and the activation of Indoleamine 2,3-dioxy-Genase, IDO expression in HFD-treated brain, whereas BZ did not. (4) LP533401, SIM and BZ restored the inhibitory expression of 5-HT_1A receptor in HFD hippocampus. Conclusions: Selective inhibition of intestinal 5-HT can attenuate depressive-like behavior, reduce 5-HT_1AR impairment in hippocampus and correct abnormal 5-HT pathway in brain while ameliorating HFD-induced glucose intolerance. Further experiments are warranted to define the adequate strategy of targeting peripheral 5-HT for the treatment of such co-morbidity.

HgS Inhibits Oxidative Stress Caused by Hypoxia through Regulation of 5-HT Metabolism Pathway

This study aims to reveal the potential relationship between 5-HT and oxidative stress in the organism. Our in vitro experiments in RIN-14B cells showed that anoxia leads the cells to the state of oxidative stress. Administration of exogenous 5-HT exacerbated this effect, whereas the inhibition of Tph1, LP533401 alleviated the oxidative stress. Several research articles reported that Cinnabar (consists of more than 96% mercury sulfide, HgS), which is widely used in both Chinese and Indian traditional medicine prescriptions, has been involved in the regulation of 5-HT. The present research revealed that HgS relieved the level of oxidative stress of RIN-14B cells. This pharmacological activity was also observed in the prescription drug Zuotai, in which HgS accounts for 54.5%, and these effects were found to be similar to LP533401, an experimental drug to treat pulmonary hypertension. Further, our in vivo experiments revealed that the administration of cinnabar or prescription drug Zuotai in zebrafish reduced the reactive oxygen species (ROS) induced by hypoxia and cured behavioral abnormalities. Taken together, in organisms with hypoxia induced oxidative stress 5-HT levels were found to be abnormally elevated, indicating that 5-HT could regulate oxidative stress, and the decrease in the 5-HT levels, behavioral abnormalities after treatment with cinnabar and Zuotai, we may conclude that the therapeutic and pharmacologic effect of cinnabar and Zuotai may be based on the regulation of 5-HT metabolism and relief of oxidative stress. Even though they aren't toxic at the present dosage in both cell lines and zebrafish, their dose dependent toxicities are yet to be evaluated.

Taxonomic profiling and populational patterns of bacterial bile salt hydrolase (BSH) genes based on worldwide human gut microbiome

BACKGROUND

Bile salt hydrolase plays an important role in bile acid-mediated signaling pathways, which regulate lipid absorption, glucose metabolism, and energy homeostasis. Several reports suggest that changes in the composition of bile acids are found in many diseases caused by dysbacteriosis.

RESULTS

Here, we present the taxonomic identification of bile salt hydrolase (BSH) in human microbiota and elucidate the abundance and activity differences of various bacterial BSH among 11 different populations from six continents. For the first time, we revealed that bile salt hydrolase protein sequences (BSHs) are distributed in 591 intestinal bacterial strains within 117 genera in human microbiota, and 27.52% of these bacterial strains containing BSH paralogs. Significant variations are observed in BSH distribution patterns among different populations. Based on phylogenetic analysis, we reclassified these BSHs into eight phylotypes and investigated the abundance patterns of these phylotypes among different populations. From the inspection of enzyme activity among different BSH phylotypes, BSH-T3 showed the highest enzyme activity and is only found in Lactobaclillus. The phylotypes of BSH-T5 and BSH-T6 mainly from Bacteroides with high percentage of paralogs exhibit different enzyme activity and deconjugation activity. Furthermore, we found that there were significant differences between healthy individuals and patients with atherosclerosis and diabetes in some phylotypes of BSHs though the correlations were pleiotropic.

CONCLUSION

This study revealed the taxonomic and abundance profiling of BSH in human gut microbiome and provided a phylogenetic-based system to assess BSHs activity by classifying the target sequence into specific phylotype. Furthermore, the present work disclosed the variation patterns of BSHs among different populations of geographical regions and health/disease cohorts, which is essential to understand the role of BSH in the development and progression of related diseases.

Simvastatin therapy in adolescent mice attenuates HFD-induced depression-like behavior by reducing hippocampal neuroinflammation

BACKGROUND

A high-fat diet (HFD)-induced obesity/hyperlipidemia is accompanied by hormonal and neurochemical changes that can be associated with depression. Emerging studies indicate that simvastatin (SMV, decreasing cholesterol levels) has therapeutic effects on neurological and neuropsychiatric diseases through hippocampal-dependent function. However, the studies on the HFD exposure in adolescent animals, which investigate the neuroprotective effects of SMV on the hippocampal morphology, serotonin (5-HT) system and inflammation, are limited. Hence, the aim of this study was to determine whether SMV attenuates HFD-induced major depressive disorders in adolescent animals and, more specifically, acts as an anti-neuroinflammatory response.

METHODS

Twenty-four male C57BL/6 mice were fed a control (n = 8), HFD (n = 8) and HFD + SMV (n = 8) for 14 weeks. In HFD + SMV group, SMV (10 mg/kg) was administrated from the 10th week of HFD feeding. The open field test (OFT) and the tail suspension test (TST) were used to examine the effect of SMV on behavioral performance. HE and Nissl staining were conducted to detect hippocampal morphology and neural survival. Expression of the inflammatory cytokine genes was assayed by quantitative polymerase chain reaction (Q-PCR).

RESULTS

Firstly, alterations in lipid parameters were minimized after SMV treatment. HFD-induced depression-like behavior, which was evidenced by an increase in immobility time in TST along with considerable decrease in locomotion activity, was significantly attenuated by SMV therapy for 4 weeks. Additionally, SMV could reduce HFD-induced structural abnormality, neuronal injury, serotonergic system disturbance and pro-inflammatory cytokine over-expression in the hippocampus. Neuroimmunological changes in central hippocampus displayed a similar characteristic (only IL-1β, IL-6, TNF-α) with that in periphery spleen, whereas they appeared in an entirely opposite trend with that in cerebral cortex.

CONCLUSION

Our results suggest that SMV may be a promising treatment for HFD-induced depression-like behavior during adolescent period through brain region-specific neuroninflammatory mechanisms.

Solvent-dependent regio- and stereo-selective reactions of 3-formylchromones with 2-aminobenzothiazoles and transacetalization efficiency of the product 3-((benzo[d]thiazol-2-ylimino)butyl)-4H-chromen-4-one

Using 2-propanol as the solvent, 3-formylchromones and 2-aminobenzothiaoles formed corresponding imines, while 1° and 2°-alcohols formed the corresponding 2-alkoxy-3-enamines with selectivity for the Z-isomer. Changing the substrates with similar molecules such as 3-formylchromone with quinoline-, quinolone- and indole-3-carbaldehydes sometimes resulted in the formation of the corresponding imines, whereas replacing 2-aminobenzothiazole with amides resulted in the formation of acetals. Considering the effect of the solvent, replacing alcohols with the aprotic solvents THF and CH₂Cl₂ resulted in the formation of imines and enamines, which are the characteristic reactions of 2-propanol and other 1° and 2°-alcohols, respectively. 2-Alkoxy-3-enamines were found to undergo transacetalization with both short and long chain alcohols. The novelty of these reactions is that they did not require an external catalyst, all the reactions were performed at the same temperature, and purification was achieved by filtration. The transacetalization we performed herein is a new concept, which has not been reported to date. In contrast, other similar reactions, such as transalkoxylation, transalkylation, and transetherification, are performed on a commercial scale using expensive catalysts such as Otera's catalyst. The highly sensitive nature of 3-formylchromones towards variations in the substrates and solvents to form different products and the reason behind the selective formation of the Z-isomer of 2-alkoxy-3-enamines and its transacetalization efficiency need further studies to understand the reaction mechanism and possibly other factors such as solvent effects.

2-Propanol forms lmine (4), other alcohols forms enamine (3) which can undergo transacetalization and replacing 2 with amides forms acetals (5).

Effects of six compounds with different chemical structures on melanogenesis

Several chemical compounds can restore pigmentation in vitiligo through mechanisms that vary according to disease etiology. In the present study, we investigated the melanogenic activity of six structurally distinct compounds, namely, scopoletin, kaempferol, chrysin, vitamin D₃, piperine, and 6-benzylaminopurine. We determined their effectiveness, toxicity, and mechanism of action for stimulating pigmentation in B16F10 melanoma cells and in a zebrafish model. The melanogenic activity of 6-benzylaminopurine, the compound identified as the most potent, was further verified by measuring green fluorescent protein concentration in tyrp1 a: eGFP (tyrosinase-related protein 1) zebrafish and mitfa: eGFP (microphthalmia associated transcription factor) zebrafish and antioxidative activity. All the tested compounds were found to enhance melanogenesis responses both in vivo and in vitro at their respective optimal concentration by increasing melanin content and expression of TYR and MITF. 6-Benzyamino-purine showed the strongest re-pigmentation action at a concentration of 20 μmol·L^-1in vivo and 100 μmol·L^-1in vitro, and up-regulated the strong fluorescence expression of green fluorescent protein in tyrp1a: eGFP and mitfa: eGFP zebrafish in vitro. However, its relative anti-oxidative activity was found to be very low. Overall, our results indicated that 6-benzylaminopurine stimulated pigmentation through a direct mechanism, by increasing melanin content via positive regulation of tyrosinase activity in vitro, as well as up-regulating the expression of the green fluorescent protein in transgenic zebrafish in vivo.

Normal diet Vs High fat diet - A comparative study: Behavioral and neuroimmunological changes in adolescent male mice

Recent evidence has established that consumption of High-fat diet (HFD)-induced obesity is associated with deficits in hippocampus-dependent memory/learning and mood states. Nevertheless the link between obesity and emotional disorders still remains to be elucidated. This issue is of particular interest during adolescence, which is important period for shaping learning/memory and mood regulation that can be sensitive to the detrimental effects of HFD. Our present study is focused to investigate behavioral and metabolic influences of short-term HFD intake in adolescent C57BL/6 mice. HFD caused weight gain, impaired glucose tolerance (IGT) and depression-like behavior as early as after 3 weeks which was clearly proved by a decrease in number of groomings in the open field test (OFT) and an increase in immobility time in the tail suspension test (TST). In the 4th week HFD induced obese model was fully developed and above behavioral symptoms were more dominant (decrease in number of crossings and groomings and increase in immobility time in both FST and TST). At the end of 6th week hippocampal analysis revealed the differences in morphology (reduced Nissl positive neurons and decreased the 5-HT_1A receptor expression), neuronal survival (increased cleaved caspase-3 expression), synaptic plasticity (down regulation of p-CREB and BDNF), and inflammatory responses (increase in expression of pro-inflammatory cytokines and decrease in expression of anti-inflammatory cyokines) in HFD mice. Our results demonstrate that, high-fat feeding of adolescent mice could provoke "depression-like" behavior as early as 3 weeks and modulate structure, neuron survival and neuroinflammation in hippocampus as early as 6 weeks proving that adolescent age is much prone to adverse effects of HFD, which causes obesity, behavioral differences, memory and learning deficiencies.

Identification of naphthol derivatives as novel antifeedants and insecticides. 1

A series of β-naphthol-derived 2-aminobenzothiazolomethylnaphthol derivatives (4a-4q) were synthesized and purified in excellent yields (86-94%) using green protocols and screened for their antifeedant and toxic activities against tobacco caterpillar (Spodoptera litura) and castor semilooper (Achaea janata) using no-choice leaf disk and topical bioassay methods. Four of them, 4d, 4f, 4i, and 4j, were identified to be potent antifeedants with ED50 values of 16.4, 19.3, 7.0, and 5.2 μg/cm(2) against S. litura and 13.9, 17.2, 10.2, and 7.7 μg/cm(2) against A. janata, respectively, and the mortality rate is >95% for 4i and 4j in the case of S. litura and 4j in case of A. janata at a dosage of 0.2 μg/insect. Compounds 4d, 4i, and 4m are moderately toxic to A. janata only. Overall, this study identified a novel class of synthetic compounds that do not belong to organochlorides, organophosphates, carbamates, or neonicotinoids as strong antifeedants as well as insecticides.