Essential oil from Citrus depressa peel exhibits antimicrobial, antioxidant and cancer chemopreventive effects.

BACKGROUND: Many diseases may be caused by pathogens and oxidative stress resulting from carcinogens. Earlier studies have highlighted the antimicrobial and antioxidant effects of plant essential oils (EO). It is crucial to effectively utilize agricultural waste to achieve a sustainable agricultural economy and protect the environment. The present study aimed to evaluate the potential benefits of EO extracted from the discarded peels of Citrus depressa Hayata (CD) and Citrus microcarpa Bunge (CM), synonyms of Citrus deliciosa Ten and Citrus japonica Thunb, respectively. RESULTS: Gas chromatography-mass spectrometry analysis revealed that the main compounds in CD-EO were (R)-(+)-limonene (38.97%), γ-terpinene (24.39%) and linalool (6.22%), whereas, in CM-EO, the main compounds were (R)-(+)-limonene (48.00%), ß-pinene (13.60%) and γ-terpinene (12.07%). CD-EO exhibited inhibitory effects on the growth of common microorganisms, including Candida albicans, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. However, CM-EO showed only inhibitory effects on E. coli. Furthermore, CD-EO exhibited superior antioxidant potential, as demonstrated by its ability to eliminate 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis-3-ethylbenzthiazoline-6-sulfonate free radicals. Furthermore, CD-EO at a concentration of 100 µg mL-1 significantly inhibited 12-O-tetradecanoylphorbol-13-acetate-induced cancer transformation in mouse epidermal JB6 P+ cells (P < 0.05), possibly by up-regulating protein expression of nuclear factor erythroid 2-related factor 2 and its downstream antioxidant enzymes, such as NAD(P)H:quinone oxidoreductase 1, heme oxygenase-1 and UGT1A. CONCLUSION: These findings suggest that CD-EO exhibits inhibitory effects on pathogenic microorganisms, possesses antioxidant properties and has cancer chemopreventive potential. © 2024 Society of Chemical Industry.

Conversational Agent Interventions for Mental Health Problems: Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Mental health problems are a crucial global public health concern. Owing to their cost-effectiveness and accessibility, conversational agent interventions (CAIs) are promising in the field of mental health care. OBJECTIVE: This study aims to present a thorough summary of the traits of CAIs available for a range of mental health problems, find evidence of efficacy, and analyze the statistically significant moderators of efficacy via a meta-analysis of randomized controlled trial. METHODS: Web-based databases (Embase, MEDLINE, PsycINFO, CINAHL, Web of Science, and Cochrane) were systematically searched dated from the establishment of the database to October 30, 2021, and updated to May 1, 2022. Randomized controlled trials comparing CAIs with any other type of control condition in improving depressive symptoms, generalized anxiety symptoms, specific anxiety symptoms, quality of life or well-being, general distress, stress, mental disorder symptoms, psychosomatic disease symptoms, and positive and negative affect were considered eligible. This study followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Data were extracted by 2 independent reviewers, checked by a third reviewer, and pooled using both random effect models and fixed effects models. Hedges g was chosen as the effect size. RESULTS: Of the 6900 identified records, a total of 32 studies were included, involving 6089 participants. CAIs showed statistically significant short-term effects compared with control conditions in improving depressive symptoms (g=0.29, 95% CI 0.20-0.38), generalized anxiety symptoms (g=0.29, 95% CI 0.21-0.36), specific anxiety symptoms (g=0.47, 95% CI 0.07-0.86), quality of life or well-being (g=0.27, 95% CI 0.16-0.39), general distress (g=0.33, 95% CI 0.20-0.45), stress (g=0.24, 95% CI 0.08-0.41), mental disorder symptoms (g=0.36, 95% CI 0.17-0.54), psychosomatic disease symptoms (g=0.62, 95% CI 0.14-1.11), and negative affect (g=0.28, 95% CI 0.05-0.51). However, the long-term effects of CAIs for the most mental health outcomes were not statistically significant (g=-0.04 to 0.39). Personalization and empathic response were 2 critical facilitators of efficacy. The longer duration of interaction with conversational agents was associated with the larger pooled effect sizes. CONCLUSIONS: The findings show that CAIs are research-proven interventions that ought to be implemented more widely in mental health care. CAIs are effective and easily acceptable for those with mental health problems. The clinical application of this novel digital technology will conserve human health resources and optimize the allocation of mental health services. TRIAL REGISTRATION: PROSPERO CRD42022350130; https://tinyurl.com/mvhk6w9p.

DNA methylome and transcriptome alterations and cancer prevention by curcumin in colitis-accelerated colon cancer in mice.

Inflammation is highly associated with colon carcinogenesis. Epigenetic mechanisms could play an important role in the initiation and progression of colon cancer. Curcumin, a dietary phytochemical, shows promising effects in suppressing colitis-associated colon cancer in azoxymethane-dextran sulfate sodium (AOM-DSS) mice. However, the potential epigenetic mechanisms of curcumin in colon cancer remain unknown. In this study, the anticancer effect of curcumin in suppressing colon cancer in an 18-week AOM-DSS colon cancer mouse model was confirmed. We identified lists of differentially expressed and differentially methylated genes in pairwise comparisons and several pathways involved in the potential anticancer effect of curcumin. These pathways include LPS/IL-1-mediated inhibition of RXR function, Nrf2-mediated oxidative stress response, production of NO and ROS in macrophages and IL-6 signaling. Among these genes, Tnf stood out with decreased DNA CpG methylation of Tnf in the AOM-DSS group and reversal of the AOM-DSS induced Tnf demethylation by curcumin. These observations in Tnf methylation correlated with increased and decreased Tnf expression in RNA-seq. The functional role of DNA methylation of Tnf was further confirmed by in vitro luciferase transcriptional activity assay. In addition, the DNA methylation level in a group of inflammatory genes was decreased in the AOM+DSS group but restored by curcumin and was validated by pyrosequencing. This study shows for the first time epigenomic changes in DNA CpG methylation in the inflammatory response from colitis-associated colon cancer and the reversal of their CpG methylation changes by curcumin. Future clinical epigenetic studies with curcumin in inflammation-associated colon cancer would be warranted.

Curcumin Derivative Epigenetically Reactivates Nrf2 Antioxidative Stress Signaling in Mouse Prostate Cancer TRAMP C1 Cells.

The carcinogenesis of prostate cancer (PCa) in TRAMP model is highly correlated with hypermethylation in the promoter region of Nrf2 and the accompanying reduced transcription of Nrf2 and its regulated detoxifying genes. We aimed to investigate the effects of (3E,5E)-3,5-bis-(3,4,5-trimethoxybenzylidene)-tetrahydro-thiopyran-4-one (F10) and (3E,5E)-3,5-bis-(3,4,5-trimethoxy-benzylidene)-tetrahydropyran-4-one (E10), two synthetic curcumin derivatives, on restoring Nrf2 activity in TRAMP C1 cells. HepG2-C8 cells transfected with an antioxidant-response element (ARE)-luciferase vector were treated with F10, E10, curcumin, and sulforaphane (SFN) to compare their effects on Nrf2-ARE pathways. We performed real-time quantitative PCR and Western blotting to investigate the effects of F10 and E10 on Nrf2, correlated phase II detoxification genes. We also measured expression and activity of DNMTand HDAC enzymes. Enrichment of H3K27me3 on the promoter region of Nrf2 was explored with a chromatin immunoprecipitation (ChIP) assay. Methylation of the CpG region in Nrf2 promoter was doubly examined by bisulfite genomic sequencing (BGS) and methylation DNA immunoprecipitation (MeDIP). Compared with curcumin and SFN, F10 is more potent in activating Nrf2-ARE pathways. Both F10 and E10 enhanced level of Nrf2 and the correlated phase II detoxifying genes. BGS and MeDIP assays indicated that F10 but not E10 hypomethylated the Nrf2 promoter. F10 also downregulated the protein level of DNMT1, DNMT3a, DNMT3b, HDAC1, HDAC4, and HDAC7 and the activity of DNMTs and HDACs. F10 but not E10 effectively reduced the accumulation of H3k27me3 on the promoter of Nrf2. F10 and E10 can activate the Nrf2-ARE pathway and increase the level of Nrf2 and correlated phase II detoxification genes. The reactivation effect on Nrf2 by F10 in TRAMP C1 may come from demethylation, decrease of HDACs, and inhibition of H3k27me3 accumulation.

Pharmacokinetics and Pharmacodynamics of Curcumin in regulating anti-inflammatory and epigenetic gene expression.

Chronic inflammation is a key driver of cancer development. Nitrite levels, which are regulated by inducible nitric oxide synthase (iNOS), play a critical role in inflammation. While the anti-oxidant and anti-inflammatory effects of curcumin, a natural product present in the roots of Curcuma longa have been studied widely, the acute pharmacokinetics (PK) and pharmacodynamics (PD) of curcumin in suppressing pro-inflammatory markers and epigenetic modulators remain unclear. This study evaluated the PK and PD of curcumin-induced suppression of lipopolysaccharide (LPS)-mediated inflammation in rat lymphocytes. LPS was administered intravenously either alone or with curcumin to female Sprague-Dawley rats. Plasma samples were analysed for curcumin concentration and mRNA expression was quantified in lymphocytes. The relative gene expression of several inflammatory and epigenetic modulators was analysed. To investigate the relationship between curcumin concentration and iNOS, TNF-α, and IL-6 gene expression, PK/PD modeling using Jusko's indirect response model (IDR) integrating transit compartments (TC) describing the delayed response was conducted. The concentration-time profile of curcumin exhibited a bi-exponential decline, which was well described by a two-compartmental pharmacokinetic model. Importantly the results demonstrate that LPS induced gene expression of pro-inflammatory markers in lymphocytes, with peak expression at approximately 3 h and curcumin suppressed the gene expression in animals administered with LPS. These effects were well captured using the IDR model and an IDR model with the transit compartments. In summary, the PK/PD modeling approach could potentially provide a robust quantitative framework for evaluating the acute anti-inflammatory and epigenetic effects of curcumin in future clinical trials.

The epigenetic effects of aspirin: the modification of histone H3 lysine 27 acetylation in the prevention of colon carcinogenesis in azoxymethane- and dextran sulfate sodium-treated CF-1 mice.

Colorectal cancer (CRC) is the third most common cancer worldwide. Chronic inflammation appears to enhance the risk of CRC. Emerging evidence has suggested that epigenetic mechanisms play an important role in CRC. Aspirin [acetylsalicylic acid (ASA)] has been shown to prevent CRC; however, the epigenetic mechanisms of its action remain unknown. This study investigated the protective role of ASA in azoxymethane (AOM)-initiated and dextran sulfate sodium (DSS)-promoted colitis-associated colon cancer (CAC) and examined the epigenetic effects, particularly on histone 3 lysine 27 acetylation (H3K27ac), underlying the preventive effect of ASA. CF-1 mice were fed with AIN-93M diet with or without 0.02% ASA from 1 week prior to AOM initiation until the mice were killed 20 weeks after AOM injection. Our results showed that AOM/DSS + ASA significantly suppressed inflammatory colitis symptoms and tumor multiplicity. AOM/DSS + ASA reduced AOM/DSS-induced protein expression and the activity of histone deacetylases (HDACs) and globally restored H3K27ac. Furthermore, AOM/DSS + ASA inhibited AOM/DSS-induced enrichment of H3K27ac in the promoters of inducible nitric oxide synthase (iNOS), tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) that corresponded to the dramatic suppression of the messenger RNA (mRNA) and protein levels. Surprisingly, no significant changes in the H3K27ac abundance in the prostaglandin-endoperoxide synthase 2 (Cox-2) promoters or in the Cox-2 mRNA and protein expression were observed. Collectively, our results suggest that a potential novel epigenetic mechanism underlies the chemopreventive effects of ASA, and this mechanism attenuates CAC in AOM/DSS-induced CF-1 mice via the inhibition of HDACs and the modification of H3K27ac marks that suppress iNOS, TNF-α and IL-6.

Epigenetics Reactivation of Nrf2 in Prostate TRAMP C1 Cells by Curcumin Analogue FN1.

It has previously been shown that curcumin can effectively inhibit prostate cancer proliferation and progression in TRAMP mice, potentially acting through the hypomethylation of the Nrf2 gene promoter and hence activation of the Nrf2 pathway to enhance cell antioxidative defense. FN1 is a synthetic curcumin analogue that shows stronger anticancer activity than curcumin in other reports. We aimed to explore the epigenetic modification of FN1 that restores Nrf2 expression in TRAMP-C1 cells. Stably transfected HepG2-C8 cells were used to investigate the effect of FN1 on the Nrf2- antioxidant response element (ARE) pathway. Real-time quantitative PCR and Western blotting were applied to study the influence of FN1 on endogenous Nrf2 and its downstream genes. Bisulfite genomic sequencing (BGS) and methylated DNA immunoprecipitation (MeDIP) were then performed to examine the methylation profile of the Nrf2 promoter. An anchorage-independent colony-formation analysis was conducted to examine the tumor inhibition activity of FN1. Epigenetic modification enzymes, including DNMTs and HDACs, were investigated by Western blotting. The luciferase reporter assay indicated that FN1 was more potent than curcumin in activating the Nrf2-ARE pathway. FN1 increased the expression of Nrf2 and its downstream detoxifying enzymes. FN1 significantly inhibited the colony formation of TRAMP-C1 cells. BGS and MeDIP assays revealed that FN1 treatment (250 nM for 3 days) reduced the percentage of CpG methylation of the Nrf2 promoter. FN1 also downregulated epigenetic modification enzymes. In conclusion, our results suggest that FN1 is a novel anticancer agent for prostate cancer. In the TRAMP-C1 cell line, FN1 can increase the level of Nrf2 and downstream genes via activating the Nrf2-ARE pathway and inhibit the colony formation potentially through the decreased expression of keap1 coupled with CpG demethylation of the Nrf2 promoter. This CpG demethylation effect may come from decreased epigenetic modification enzymes, such as DNMT1, DNMT3a, DNMT3b, and HDAC4.

Pharmacokinetics and pharmacodynamics of 3,3'-diindolylmethane (DIM) in regulating gene expression of phase II drug metabolizing enzymes.

3,3'-Diindolylmethane (DIM) has been investigated as a potential anti-cancer chemopreventive agent in many preclinical and clinical studies. In this study, we sought to characterize the pharmacokinetics of DIM and to build a pharmacokinetic (PK) and pharmacodynamic (PD) model of the DIM-induced gene expression of phase II drug metabolizing enzymes (DME), which potentially links DIM's molecular effects to its in vivo chemopreventive efficacy. DIM (10 mg/kg) was administered intravenously (i.v.) to male Sprague-Dawley rats and blood samples were collected at selected time points for 48 h. The plasma concentration of DIM was determined using a validated HPLC method. The mRNA expression of NQO1, GSTP1 and UGT1A1 in blood lymphocytes was measured using quantitative PCR. An indirect response model was employed to relate the concentration of DIM to the expression of the genes NQO1, GSTP1 and UGT1A1, which were chosen as PD markers for DIM. After i.v. administration, the plasma concentration of DIM declined quickly, and the expression of target genes increased significantly, peaking at 1-2 h and then returning to basal levels after 24 h. The parameters in the PK-PD model were estimated. The PK-PD model aptly described the time delay and magnitude of gene expression induced by DIM. Our results indicate that DIM is effective at inducing various phase II DME, which are capable of detoxify carcinogens. This PK-PD modeling approach provides a framework for evaluating the acute effects of DIM or other similar drugs in clinical trials.

Induction of NRF2-mediated gene expression by dietary phytochemical flavones apigenin and luteolin.

Apigenin (API) and luteolin (LUT) have been used as therapeutic agents in folk medicine for thousands of years. These compounds exert a variety of biological activities, including anticancer, antioxidant and antiinflammatory activities. This study investigated whether API and LUT could activate Nrf2-antioxidant response element (ARE)-mediated gene expression and induce antiinflammatory activities in human hepatoma HepG2 cells. The compounds did not exhibit any substantial toxicity at low doses (1.56-6.25 µm). The induction of ARE activity was assessed in HepG2-C8 cells after treatment with low doses of API and LUT for 6 and 12 h. It was found that the induction of ARE activity by these compounds at the higher doses was comparable to the effects of the positive control, SFN at a dose of 6.25 µm. Exposure to the PI3K inhibitor LY294002 abolished ARE activation by both API and LUT, whereas the ERK-1/2 inhibitor PD98059 only decreased ARE activity induced by API. Both compounds significantly increased the endogenous mRNA and protein levels of Nrf2 and Nrf2 target genes with important effects on heme oxygenase-1 (HO-1) expression. API and LUT significantly and dose-dependently decreased the production of nitric oxide (NO), nitric oxide synthase (iNOS) and cytosolic phospholipase A2 (cPLA2), which were induced by the treatment of HepG2 cells with 1 µg/ml of lipopolysaccharide (LPS) for 24 h. The results indicate that API and LUT significantly activate the PI3K/Nrf2/ARE system, and this activation may be responsible for their antiinflammatory effects, as demonstrated by the suppression of LPS-induced NO, iNOS and cPLA2.

In vitro and in vivo anti-inflammatory effects of a novel 4,6-bis ((E)-4-hydroxy-3-methoxystyryl)-1-phenethylpyrimidine-2(1H)-thione.

Inflammation plays a critical defensive role in the human body. However, uncontrolled or aberrant inflammatory responses contribute to various acute and chronic diseases. The Nrf2-ARE pathway plays a pivotal role in the regulation of inflammatory markers, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). On the basis of this concept, we synthesized a novel anti-inflammatory 4,6-bis ((E)-4-hydroxy-3-methoxystyryl)-1-phenethylpyrimidine-2(1H)-thione (HPT), and in vitro experiments using HepG2-C8 ARE-luciferase-transfected cells demonstrated the induction of Nrf2-ARE activity. In lipopolysaccharide (LPS)-induced RAW 264.7 cells, HPT treatment reduced the production of nitric oxide (NO) as well as the protein and mRNA expression levels of COX-2 and iNOS, in a dose-dependent manner. In addition, HPT suppressed the mRNA expression of inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, and IL-6. In LPS-induced macrophages, HPT inhibited COX-2 and iNOS by blocking the activation of p38 and c-Jun NH2-terminal kinase (JNK) but not extracellular signal-regulated kinase (ERK1/2). Furthermore, an in vivo anti-inflammatory study was performed using a TPA-induced skin inflammation mouse model, and the results showed that HPT reduced TPA-induced inflammation and attenuated the expression of COX-2 and iNOS in TPA-induced mouse skin tissue. Thus, HPT demonstrated anti-inflammatory activity both in LPS-induced RAW 264.7 cells and TPA-stimulated mouse skin and may therefore serve as a potential anti-inflammatory agent.

Pre-suicidal attempt: An intermediate type within ideation-to-action framework.

INTRODUCTION: Understanding the mechanisms of suicidal behavior is a prerequisite for suicide prevention and intervention. The current study aims to propose and verify the utility of pre-suicidal attempt as an intermediate type in the transition from suicidal ideation to suicidal attempt within the ideation-to-action framework. METHODS: A sample of 1084 college students completed a measurement package consisting of suicide history, suicide risk factors, and demographic information. Stratified stepwise multiple regression models and mediated moderation models were used to examine the relationship among the variables. RESULTS: Pre-suicidal attempts rather than suicidal ideation are predictive of suicide attempts. Age, depression, thwarted belongingness, fearlessness about death, perceived burdensomeness and suicidal ideation were predictors of pre-suicidal attempts. Supporting the interpersonal theory of suicide, pre-suicidal attempts mediated the relationship between suicidal ideation and suicidal attempts and were positively moderated by pain tolerance and fearlessness about death. The pre-suicidal attempters scored higher on fearlessness about death and suicide risk than the ideators, while pre-suicidal attempters scored significantly lower on suicide risk than suicide attempters. CONCLUSION: As an independent intermediate type within the ideation-to-action framework, pre-suicidal attempts contribute to deepen the understanding of the intermediate transition from suicidal ideation to suicidal attempts.

Citrus depressa peel extract acts as a prebiotic to reduce lipid accumulation and modulate gut microbiota in obese mice.

Citrus peels contain abundant polyphenols, particularly flavonoids, and have been shown to exert lipid accumulation decreasing ability. In this study, Citrus depressa peel applied to oven drying and extracted with ethanol extract as CDEE to analyze its flavonoids compositions and investigated its effects on a high-fat diet (HFD)-induced obese mice model. CDEE contained several flavonoids such as hesperidin, sinesentin, nobiletin, tangeretin, 5-demethylnobiletin, and 5-demethyltangeretin. The mice fed an HFD, and administration of 2% CDEE to could decrease weight gain, abdominal fat weight, inguinal fat weight, and the adipocyte size, and CDEE also reduced serum total cholesterol (TCHO), triacylglycerol (TG) compared with mice fed only on HFD. CDEE hindered lipid accumulation through a decreased fatty acid synthase (FAS) protein expression via upregulation of the protein expression of AMP-activated protein kinase α (AMPKα). Moreover, CDEE modulated gut microbiota that altered by HFD through an increased abundance of Lactobacillus reuteri compared with the HFD group. The results demonstrated that CDEE helps decrease lipid accumulation through the AMPK pathway, which also indicates a prebiotic-like effect on gut microbiota.

RNA viromes of Dermacentor nuttalli ticks reveal a novel uukuvirus in Qinghai Province, China.

Ticks are a major parasite on the Qinghai-Tibet Plateau, western China, and represent an economic burden to agriculture and animal husbandry. Despite research on tick-borne pathogens that threaten humans and animals, the viromes of dominant tick species in this area remain unknown. In this study, we collected Dermacentor nuttalli ticks near Qinghai Lake and identified 13 viruses belonging to at least six families through metagenomic sequencing. Four viruses were of high abundance in pools, including Xinjiang tick-associated virus 1 (XJTAV1), and three novel viruses: Qinghai Lake virus 1, Qinghai Lake virus 2 (QHLV1, and QHLV2, unclassified), and Qinghai Lake virus 3 (QHLV3, genus Uukuvirus of family Phenuiviridae in order Bunyavirales), which lacks the M segment. The minimum infection rates of the four viruses in the tick groups were 8.2%, 49.5%, 6.2%, and 24.7%, respectively, suggesting the prevalence of these viruses in D. â€‹nuttalli ticks. A putative M segment of QHLV3 was identified from the next-generation sequencing data and further characterized for its signal peptide cleavage site, N-glycosylation, and transmembrane region. Furthermore, we probed the L, M, and S segments of other viruses from sequencing data of other tick pools by â€‹using the putative M segment sequence of QHLV3. By revealing the viromes of D. nuttalli ticks, this study enhances our understanding of tick-borne viral communities in highland regions. The putative M segment identified in a novel uukuvirus suggests that previously identified uukuviruses without M segments should have had the same genome organization as typical bunyaviruses. These findings will facilitate virus discovery and our understanding of the phylogeny of tick-borne uukuviruses.

Viromes of Haemaphysalis longicornis reveal different viral abundance and diversity in free and engorged ticks.

Haemaphysalis longicornis ticks, commonly found in East Asia, can transmit various pathogenic viruses, including the severe fever with thrombocytopenia syndrome virus (SFTSV) that has caused febrile diseases among humans in Hubei Province. However, understanding of the viromes of H. longicornis was limited, and the prevalence of viruses among H. longicornis ticks in Hubei was not well clarified. This study investigates the viromes of both engorged (fed) and free (unfed) H. longicornis ticks across three mountainous regions in Hubei Province from 2019 to 2020. RNA-sequencing analysis identified viral sequences that were related to 39 reference viruses belonging to unclassified viruses and seven RNA viral families, namely Chuviridae, Nairoviridae, Orthomyxoviridae, Parvoviridae, Phenuiviridae, Rhabdoviridae, and Totiviridae. Viral abundance and diversity in these ticks were analysed, and phylogenetic characteristics of the Henan tick virus (HNTV), Dabieshan tick virus (DBSTV), Okutama tick virus (OKTV), and Jingmen tick virus (JMTV) were elucidated based on their full genomic sequences. Prevalence analysis demonstrated that DBSTV was the most common virus found in individual H. longicornis ticks (12.59%), followed by HNTV (0.35%), whereas JMTV and OKTV were not detected. These results improve our understanding of H. longicornis tick viromes in central China and highlight the role of tick feeding status and geography in shaping the viral community. The findings of new viral strains and their potential impact on public health raise the need to strengthen surveillance efforts for comprehensively assessing their spillover potentials.

A perspective on dietary phytochemicals and cancer chemoprevention: oxidative stress, nrf2, and epigenomics.

Oxidative stress is caused by an imbalance of reactive oxygen species (ROS)/reactive nitrogen species (RNS) and the antioxidative stress defense systems in cells. ROS/RNS or carcinogen metabolites can attack intracellular proteins, lipids, and nucleic acids, which can result in genetic mutations, carcinogenesis, and other diseases. Nrf2 plays a critical role in the regulation of many antioxidative stress/antioxidant and detoxification enzyme genes, such as glutathione S-transferases (GSTs), NAD(P)H:quinone oxidoreductase 1 (NQO1), UDP-glucuronyl transferases (UGTs), and heme oxygenase-1 (HO-1), directly via the antioxidant response element (ARE). Recently, many studies have shown that dietary phytochemicals possess cancer chemopreventive potential through the induction of Nrf2-mediated antioxidant/detoxification enzymes and anti-inflammatory signaling pathways to protect organisms against cellular damage caused by oxidative stress. In addition, carcinogenesis can be caused by epigenetic alterations such as DNA methylation and histone modifications in tumor-suppressor genes and oncogenes. Interestingly, recent studies have shown that several naturally occurring dietary phytochemicals can epigenetically modify the chromatin, including reactivating Nrf2 via demethylation of CpG islands and the inhibition of histone deacetylases (HDACs) and/or histone acetyltransferases (HATs). The advancement and development of dietary phytochemicals in cancer chemoprevention research requires the integration of the known, and as-yet-unknown, compounds with the Nrf2-mediated antioxidant, detoxification, and anti-inflammatory systems and their in vitro and in vivo epigenetic mechanisms; human clinical efficacy studies must also be performed.

Epigenetic reactivation of Nrf2 in murine prostate cancer TRAMP C1 cells by natural phytochemicals Z-ligustilide and Radix angelica sinensis via promoter CpG demethylation.

Cancer development has been linked to epigenetic modifications of cancer oncogenes and tumor suppressor genes; in advanced metastatic cancers, severe epigenetic modifications are present. We previously demonstrated that the progression of prostate tumors in TRAMP mice is associated with methylation silencing of the Nrf2 promoter and a reduced level of transcription of Nrf2 and Nrf2 target genes. Radix Angelicae Sinensis (RAS; Danggui) is a medicinal herb and health food supplement that has been widely used in Asia for centuries. Z-Ligustilide (Lig) is one of the bioactive components of RAS. We investigated the potential of Lig and RAS to restore Nrf2 gene expression through epigenetic modification in TRAMP C1 cells. Lig and RAS induced the mRNA and protein expression of endogenous Nrf2 and Nrf2 downstream target genes, such as HO-1, NQO1, and UGT1A1. Bisulfite genomic sequencing revealed that Lig and RAS treatment decreased the level of methylation of the first five CpGs of the Nrf2 promoter. A methylation DNA immunoprecipitation assay demonstrated that Lig and RAS significantly decreased the relative amount of methylated DNA in the Nrf2 gene promoter region. Lig and RAS also inhibited DNA methyltransferase activity in vitro. Collectively, these results suggest that Lig and RAS are able to demethylate the Nrf2 promoter CpGs, resulting in the re-expression of Nrf2 and Nrf2 target genes. Epigenetic modifications of genes, including Nrf2, may therefore contribute to the overall health benefits of RAS, including the anticancer effect of RAS and its bioactive component, Lig.

Effects of natural phytochemicals in Angelica sinensis (Danggui) on Nrf2-mediated gene expression of phase II drug metabolizing enzymes and anti-inflammation.

The root of Angelica sinensis (Oliv.) Diels (abbreviated as AS) (Danggui) has a long history in Asian herbal medicine. Recently, it was demonstrated that AS possesses anti-cancer and anti-oxidant activities. Because the transcription factor Nrf2 mediates the expression of many cellular anti-oxidative stress genes, including genes that are involved in phase II drug metabolism and anti-oxidative stress, this study sought to investigate whether pure compounds from AS or an AS extract could activate antioxidant response element (ARE)-mediated gene expression and induce anti-inflammatory activities. Z-Ligustilide (Ligu), 3-butylidenephthalide (Buty) and CO2 supercritical fluid-extracted lipophilic AS extract (SFE) were tested in HepG2-C8 cells stabilized with ARE luciferase reporter gene. Ligu and Buty caused significant toxicity only at 100 µm. All three samples induced ARE-luciferase activity; however, SFE at 8.5 µg/ml induced ARE-luciferase activity 2-3 fold more potently than did either of the pure compounds. SFE also significantly increased the endogenous mRNA of Nrf2 and the Nrf2 target anti-oxidative gene NAD(P)H dehydrogenase, quinone 1 (NQO1). The protein expression of NQO1 was also significantly induced by SFE. In RAW 264.7 cells, SFE suppressed lipopolysaccharide (LPS)-induced IL-1ß and TNF-α expression about 2 fold stronger than sulforaphane, whereas both pure compounds and SFE suppressed inflammatory nitric oxide (NO) production. In summary, this study demonstrates that AS has anti-inflammatory effects and activates the Nrf2 pathway, which protects against oxidative stress.

Chemoprevention of lotus leaf ethanolic extract through epigenetic activation of the NRF2-mediated pathway in murine skin JB6 P+ cell neoplastic transformation.

Background and aim: Skin is one barrier protecting from environmental risk factors that can make skin cells cancerous through DNA damage and oxidative stress. The nuclear factor erythroid 2-related factor 2 (NRF2) pathway is an anti-stress defense system that can be regulated by DNA methylation and histone modification. Dietary phytochemicals have chemopreventive properties that can inhibit or delay carcinogenesis. The lotus leaf is a traditional medicinal plant containing many polyphenols whose extracts show many biological activities, including antioxidant, anti-obesity, and anti-cancer. This study aim to investigate the effect of lotus leaves on neoplastic transformation in murine skin JB6 P+ cells. Experimental procedure: Lotus leaves were extracted with water (LL-WE) and ethanol (LL-EE), and the LL-WE residues were further extracted with ethanol (LL-WREE). JB6 P+ cells were treated with different extracts. The chemoprotective effect would be evaluated by heme oxygenase 1 (HO-1), NAD(P)H quinone oxidoreductase (NQO1), and UDP glucuronosyltransferase family 1 member A1 (UGT1A1) expression. Results and conclusion: LL-EE contained higher total phenolics and quercetin among extracts. In mouse skin JB6 P+ cells with 12-O-tetradecanoylphorbol-13-acetate treatment, LL-EE showed the greatest potential to suppress skin carcinogenesis. LL-EE activated the NRF2 pathway by upregulating antioxidant and detoxification enzymes upregulates antioxidant and detoxification enzymes, including HO-1, NQO1, and UGT1A1, and downregulates DNA methylation, which might be caused by lower DNA methyltransferase and histone deacetylase levels. Therefore, our results show that LL-EE reduces the neoplastic transformation of skin JB6 P+ cells, potentially by activating the NRF2 pathway and regulating epigenetic DNA methylation and histone acetylation.

Tangeretin and 4'-demethyltangeretin prevent damage to mouse hepatocytes from oxidative stress by activating the Nrf2-related antioxidant pathway via an epigenetic mechanism.

Polymethoxyflavones (PMFs) in citrus fruits have a variety of biological activities, including antioxidant, anti-inflammatory, anticancer, and anti-atherosclerotic effects. The liver is the major detoxifying organ of the human body; however, factors such as acetaminophen (APAP) overdose may increase oxidative stress in liver cells and lead to severe liver failure. In this study we examined the effects of tangeretin (TAN), a common citrus PMF, and its metabolite 4'-demethyltangeretin (4'-OH-TAN) on activation of the Nrf2 antioxidant system in mouse AML-12 hepatocytes through regulation by epigenetic mechanisms. The ability of TAN and 4'-OH-TAN to inhibit APAP-induced hepatotoxicity was also evaluated. The results showed that TAN and 4'-OH-TAN significantly increased the mRNA and protein levels of Nrf2 and Nrf2-mediated antioxidant and detoxifying enzymes (UGT1A, HO-1, and NQO1) in AML-12 cells. TAN and 4'-OH-TAN also suppressed protein expression of histone deacetylases (HDACs) and DNA methyltransferases (DMNTs) and reduced DNA methylation of the nrf2 promoter. Furthermore, TAN and 4'-OH-TAN prevented APAP-induced injury and inhibited APAP-induced ROS generation in AML-12 cells. Based on these results, we conclude that TAN and 4'-OH-TAN may increase the antioxidant capacity of liver cells by regulating epigenetic alteration to activate the Nrf2-related antioxidant system, thereby preventing liver cells from being damaged by APAP-induced oxidative stress.

Pharmacodynamics of ginsenosides: antioxidant activities, activation of Nrf2, and potential synergistic effects of combinations.

Ginseng has long been used in Asian countries for more than 2000 years. Currently, in the "Western World or Western Medicines", many reports have indicated that they have used herbal medicines, and ginseng is one of the most popular herbs. Several recent reports have indicated that the antioxidant/antioxidative stress activities of ginseng play a role in the benefits of ginseng; however, the precise mechanism is lacking. The antioxidant response element (ARE) is a critical regulatory element for the expression of many antioxidant enzymes and phase II/III drug metabolizing/transporter genes, mediated by the transcription factor nuclear factor (erythroid-derived 2)-like 2 (Nrf2). The aim of this study was to examine the potential activation and synergism of Nrf2-ARE-mediated transcriptional activity between three common ginsenosides present in ginseng, ginsenoside Rb1 (Rb1), ginsenoside Rg1 (Rg1), and ginsenoside 20(S)-protopanaxatriol (20S). We tested whether these ginsenosides and their combinations could induce Nrf2-ARE activities in HepG2-C8 cells with stably transfected ARE luciferase reporter gene. Cell proliferation, antioxidant and ARE activities, Western blotting of Nrf2 protein, and qPCR of mRNA of Nrf2 were conducted for Rb1, Rg1, and 20S as well as the combinations of 20S with Rb1 or Rg1. To determine the combination effects, the combination index (CI) was calculated. Rb1 and Rg1 are relatively nontoxic to the cells, while 20S at 50 µM or above significantly inhibited the cell proliferation. Rb1, Rg1, or 20S induced total antioxidant activity and ARE activity in a concentration-dependent manner. Furthermore, combinations of 20S with either Rb1 or Rg1 induced total antioxidant and ARE activity synergistically. The induction of Nrf2 protein and mRNA was also found to be synergistic with the combination treatments. In summary, in this study, we show that ginsenosides Rb1, Rg1, and 20S possess antioxidant activity, transcriptionally activating ARE as well as the potential of synergistic activities. The Nrf2-ARE-mediated antioxidant pathway could play a role for the overall antioxidative stress activities, which could be important for ginseng's health beneficial effects such as cancer chemopreventive activities.