Optimized combination of Cervus nippon (Sika deer), Angelica (Dangui), and Rehmannia (Suk-jihwang) mitigates LPS-induced inflammation: exploring signaling pathways through plasma metabolomics.

This study aimed to determine the optimal combination of three anti-inflammatory materials [i.e., Cervus nippon Temminck (CT), Angelica gigas Nakai (AN), and Rehmannia glutinosa (RG)] for the strongest anti-inflammatory potential. Eighteen combinations of the three materials were tested in LPS-stimulated RAW264.7 cells via assessing nitric oxide (NO). The best combination from in vitro studies was administered to LPS-treated C57BL/6J mice for five days. Subsequently, plasma metabolites were profiled by bioinformatics analyses and validations. As results, 2, 20, and 50 µg/mL of CT, AN, and RG (TM) were the most effective combination suppressing inflammation. In mice, TM mitigated hepatic inflammatory markers. Similarly, the metabolomics indicated that TM may suppress NF-κB signaling pathway, thereby alleviating hepatic inflammation. TM also decreased systemic and hepatic pro-inflammatory cytokines. Collectively, we found the optimal combination of TM for mitigating inflammation; thus further studies on safety, mechanisms, and clinical models are warranted for human applications. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01476-x.

Sensitization of GSH synthesis by curcumin curtails acrolein-induced alveolar epithelial apoptosis via Keap1 cysteine conjugation: A randomized controlled trial and experimental animal model of pneumonitis.

INTRODUCTION: Epidemiological studies have reported an association between exposures to ambient air pollution and respiratory diseases, including chronic obstructive pulmonary disease (COPD). Pneumonitis is a critical driving factor of COPD and exposure to air pollutants (e.g., acrolein) is associated with increased incidence of pneumonitis. OBJECTIVES: Currently available anti-inflammatory therapies provide little benefit against respiratory diseases. To this end, we investigated the preventive role of curcumin against air pollutant-associated pneumonitis and its underlying mechanism. METHODS: A total of 40 subjects was recruited from Chengdu, China which is among the top three cities in terms of respiratory mortality related to air pollution. The participants were randomly provided either placebo or curcumin supplements for 2 weeks and blood samples were collected at the baseline and at the end of the intervention to monitor systemic markers. In our follow up mechanistic study, C57BL/6 mice (n = 40) were randomly allocated into 4 groups: Control group (saline + no acrolein), Curcumin only group (curcumin + no acrolein), Acrolein only group (saline + acrolein), and Acrolein + Curcumin group (curcumin + acrolein). Curcumin was orally administered at 100 mg/kg body weight once a day for 10 days, and then the mice were subjected to nasal instillation of acrolein (5 mg/kg body weight). Twelve hours after single acrolein exposure, all mice were euthanized. RESULTS: Curcumin supplementation, with no noticeable adverse responses, reduced circulating pro-inflammatory cytokines in association with clinical pneumonitis as positive predictive while improving those of anti-inflammatory cytokines. In the pre-clinical study, curcumin reduced pneumonitis manifestations by suppression of intrinsic and extrinsic apoptotic signaling, which is attributed to enhanced redox sensing of Nrf2 and thus sensitized synthesis and restoration of GSH, at least in part, through curcumin-Keap1 conjugation. CONCLUSIONS: Our study collectively suggests that curcumin could provide an effective preventive measure against air pollutant-enhanced pneumonitis and thus COPD.

Acrolein, an environmental toxicant and its applications to in vivo and in vitro atherosclerosis models: An update.

Cardiovascular disease, the foremost cause of death worldwide, is an overarching disease term that encompasses a number of disorders involving the heart and circulatory system, including atherosclerosis. Atherosclerosis is a primary cause of cardiovascular diseases and is caused by buildup of plaque and narrowing of blood vessels. Epidemiological studies have suggested that environmental pollutants are implicated in atherosclerosis disease progression. Among many environmental pollutants, acrolein (Acr) is an abundant reactive aldehyde and is ubiquitously present in cigarette smoke as well as food products (e.g., overheated oils and wine). Despite its ubiquitous presence and potential impact on the etiology of cardiovascular disease, a limited consensus has been made in regard to Acr exposure conditions to induce atherosclerosis in vivo. This mini-review summarizes in vivo atherosclerosis models using Acr to investigate biochemical and phenotypic changes related to atherosclerosis and in vitro mechanistic studies involving Acr and atherosclerosis.

Inhalation of low-dose basil (Ocimum basilicum) essential oil improved cardiovascular health and plasma lipid markers in high fat diet-induced obese rats.

This study investigated the antiobesogenic effects of the inhalation of volatile compounds derived from basil essential oil (BEO) in high fat diet-induced obese rats. A total of 47 volatile compounds were identified in BEO using gas chromatography-mass spectrometry. Major volatile compounds identified by olfactory testing include linalool oxide, linalool, 1-menthene, and carvone. White adipose tissue significantly decreased in the rats that inhaled 0.3% BEO (more than +10%) compared to the control. Plasma marker analysis showed increased high-density lipoprotein-cholesterol (ca. double fold) and decreased low-density lipoprotein-cholesterol (more than -30%) levels in inhaled 1% BEO group compared to the control. Leptin significantly decreased in the 0.3 and 1% BEO groups (more than -70 and -85%, respectively). Last, systolic blood pressure at week 12 was significantly lower in inhaled 1% BEO group (more than -15%) compared to the control. The results of this study suggest that BEO inhalation may be effective in managing plasma lipid markers (cholesterols and leptin) and possibly metabolic disorders such as obesity. Practical Application: Changes in metabolic health markers, which are effected by inhalation of volatiles in basil (Ocimum basilicum) essential oil, will provide physiological variations in vivo to the public. In this study, the opposite effects were identified between 0.3% and 1% inhalation, respectively. Therefore, our findings will provide optimized and useful guidance for inhalation of basil essential oil.

The role of microRNA-33 as a key regulator in hepatic lipogenesis signaling and a potential serological biomarker for NAFLD with excessive dietary fructose consumption in C57BL/6N mice.

Limited studies reported mechanisms by which microRNAs (miRNA) are interlinked in the etiology of fructose-induced non-alcoholic fatty liver disease (NAFLD). Here, we aimed to investigate the significance of miRNAs in fructose-induced NAFLD pathogenesis through unbiased approaches. In experiment I, C57BL/6N mice were fed either water or 34% fructose for six weeks ad libitum. In experiment II, time course effects of fructose intervention were monitored using the same conditions; mice were killed at the baseline, fourth, and sixth weeks. Bioinformatic analyses for hepatic proteomics revealed that SREBP1 is the most significant upstream regulator influenced by fructose; miR-33-5p (miR-33) was identified as the key miRNA responsible for SREBP1 regulation upon fructose intake, which was validated by in vitro transfection assay. In experiment II, we confirmed that the longer mice consumed fructose, the more severe liver injury markers (e.g., serum AST) appeared. Moreover, hepatic Srebp1 mRNA expression was increased depending upon the duration of fructose consumption. Hepatic miR-33 was time-dependently decreased by fructose while serum miR-33 expression was increased; these observations indicated that miR-33 from the liver might be released upon cell damage. Finally we observed that fructose-induced ferroptosis might be a cause of liver toxicity, resulting from oxidative damage. Collectively, our findings suggest that fructose-induced oxidative damage induces ferroptosis, and miR-33 could be used as a serological biomarker of fructose-induced NAFLD.

Colon Transcriptomics Reveals Sex-Dependent Metabolic Signatures in Response to 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine Treatment in C57BL/6N Mice.

Diets high in red meats, particularly meats cooked at high temperature, increase the risk of colon cancer due to a production of heterocyclic aromatic amines (HAAs). Of the identified HAAs, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is the most mass abundant colon carcinogen in charred meat or fish. Here, we comprehensively examined sex-dependent colon transcriptome signatures in response to PhIP treatment to identify biological discrepancies. Eight-week-old male and female C57BL/6N mice were intraperitoneally injected with PhIP (10 mg/kg of body weight) and colon tissues were harvested 24 h after PhIP injection, followed by colon transcriptomics analysis. A list of differentially expressed genes (DEGs) was utilized for computational bioinformatic analyses. Specifically, overrepresentation test using the Protein Analysis Through Evolutionary Relationships tool was carried out to annotate sex-dependent changes in transcriptome signatures after PhIP treatment. Additionally, the most significantly affected canonical pathways by PhIP treatment were predicted using the Ingenuity Pathway Analysis. As results, male and female mice presented different metabolic signatures in the colon transcriptome. In the male mice, oxidative phosphorylation in the mitochondrial respiratory chain was the pathway impacted the most; this might be due to a shortage of ATP for DNA repair. On the other hand, the female mice showed concurrent activation of lipolysis and adipogenesis. The present study provides the foundational information for future studies of PhIP effects on underlying sex-dependent mechanisms.

A postnatal peak in microglial development in the mouse hippocampus is correlated with heightened sensitivity to seizure triggers.

BACKGROUND: Explosive synaptogenesis and synaptic pruning occur in the hippocampus during the first two weeks of postnatal life, coincident with a heightened susceptibility to seizures in rodents. To determine the temporal correlation between microglial development and age-dependent susceptibility and response to seizures, we quantified developmental changes in basal microglia levels and seizure-induced microglial activation in the hippocampus of Cx3Cr1(GFP /+) transgenic mice. METHODS: Basal levels of microglia were quantified in the hippocampi of Cx3Cr1(GFP /+) mice at P0, P5, P10, P15, P20, P25, P30, P40, and P60. Seizure susceptibility and seizure-induced microglial activation were assessed in response to febrile seizures (lipopolysaccharide followed by hyperthermia) and kainic acid-induced status epilepticus. RESULTS: The density of microglia within the hippocampus increased rapidly after birth, reaching a peak during the second week of life - the age at which the animals became most vulnerable to seizure triggers. In addition, this peak of microglial development and seizure vulnerability during the second postnatal week represented the time of maximal seizure-induced microglia activation. CONCLUSIONS: Overreactive innate immunity mediated by activated microglia may exacerbate acute injury to neuronal synapses and contribute to the long-term epileptogenic effects of early-life seizures. Anti-inflammatory therapy targeting excessive production of inflammatory mediators by activated microglia, therefore, may be an effective age-specific therapeutic strategy to minimize neuronal dysfunction and prevent increases in susceptibility to subsequent seizures in developing animals.

CLC-3 chloride channels moderate long-term potentiation at Schaffer collateral-CA1 synapses.

The chloride channel CLC-3 is expressed in the brain on synaptic vesicles and postsynaptic membranes. Although CLC-3 is broadly expressed throughout the brain, the CLC-3 knockout mouse shows complete, selective postnatal neurodegeneration of the hippocampus, suggesting a crucial role for the channel in maintaining normal brain function. CLC-3 channels are functionally linked to NMDA receptors in the hippocampus; NMDA receptor-dependent Ca(2+) entry, activation of Ca(2+)/calmodulin kinase II and subsequent gating of CLC-3 link the channels via a Ca(2+)-mediated feedback loop. We demonstrate that loss of CLC-3 at mature synapses increases long-term potentiation from 135 ± 4% in the wild-type slice preparation to 154 ± 7% above baseline (P < 0.001) in the knockout; therefore, the contribution of CLC-3 is to reduce synaptic potentiation by ∼40%. Using a decoy peptide representing the Ca(2+)/calmodulin kinase II phosphorylation site on CLC-3, we show that phosphorylation of CLC-3 is required for its regulatory function in long-term potentiation. CLC-3 is also expressed on synaptic vesicles; however, our data suggest functionally separable pre- and postsynaptic roles. Thus, CLC-3 confers Cl(-) sensitivity to excitatory synapses, controls the magnitude of long-term potentiation and may provide a protective limit on Ca(2+) influx.

Presynaptic CLC-3 determines quantal size of inhibitory transmission in the hippocampus.

The absence of the chloride channel CLC-3 in Clcn3(-/-) mice results in hippocampal degeneration with a distinct temporal-spatial sequence that resembles neuronal loss in temporal lobe epilepsy. We examined how the loss of CLC-3 might affect GABAergic synaptic transmission in the hippocampus. An electrophysiological study of synaptic function in hippocampal slices taken from Clcn3(-/-) mice before the onset of neurodegeneration revealed a substantial decrease in the amplitude and frequency of miniature inhibitory postsynaptic currents compared with those in wild-type slices. We found that CLC-3 colocalized with the vesicular GABA transporter VGAT in the CA1 region of the hippocampus. Acidification of inhibitory synaptic vesicles induced by Cl(-) showed a marked dependence on CLC-3 expression. The decrease in inhibitory transmission in Clcn3(-/-) mice suggests that the neurotransmitter loading of synaptic vesicles was reduced, which we attribute to defective vesicular acidification. Our observations extend the role of Cl(-) in inhibitory transmission from that of a postsynaptic permeant species to a presynaptic regulatory element.