Polycyclic aromatic hydrocarbons content of food, water and vegetables and associated cancer risk assessment in Southern Nigeria.

The polycyclic aromatic hydrocarbon content of water (four surface water, six underground water (borehole water), seven sachet water), barbecued food and their fresh equivalents (barbecued beef, fish, plantain, pork, yam, chicken, chevon, potato, corn), oil (three palm oil, nine vegetable oil), and fresh vegetable samples (water leaf, bitter leaf, cabbage, carrot, cucumber, pumpkin, garlic, ginger, green leaf, Gnetum Africana, onion, pepper) were determined by GC-MS analysis. The current study also determined the estimated lifetime cancer risk from ingesting polycyclic aromatic hydrocarbon-contaminated food. The polycyclic aromatic hydrocarbon content of water, oil, vegetable, and food samples were within the United States Environmental Protection Agency/World Health Organization safe limits. The naphthalene, benzo(b)fluoranthene, and benzo(k)fluoranthene levels in surface water were significantly higher than in borehole samples (P = 0.000, 0.047, 0.047). Vegetable oils had higher anthracene and chrysene compared to palm oil (P = 0.023 and 0.032). Significant variations were observed in levels of naphthalene, acenaphthylene, phenanthrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, and dibenzo(a,h)anthracene among the barbecued and fresh food samples (P <0.05). Barbecued pork, potato, and corn had significantly higher naphthalene compared to their fresh equivalents (P = 0.002, 0.017, and <0.001). Consumption of barbecued food and surface water may be associated with higher exposure risk to polycyclic aromatic hydrocarbons which may predispose to increased cancer health risk. The current work explores in depth the concentration of polycyclic aromatic hydrocarbons in different dietary categories that pose direct risk to humans via direct consumption. These findings add knowledge to support future considerations for human health.

Mechanism of non-phenolic substrate oxidation by the fungal laccase Type 1 copper site from Trametes versicolor: the case of benzo[a]pyrene and anthracene.

Laccases (EC 1.10.3.2) are multicopper oxidases with the capability to oxidize diverse phenolic and non-phenolic substrates. While the molecular mechanism of their activity towards phenolic substrates is well-established, their reactivity towards non-phenolic substrates, such as polycyclic aromatic hydrocarbons (PAHs), remains unclear. To elucidate the oxidation mechanism of PAHs, particularly the activation mechanism of the sp2 aromatic C-H bond, we conducted a density functional theory investigation on the oxidation of two PAHs (anthracene and benzo[a]pyrene) using an extensive model of the T1 copper catalytic site of the fungal laccase from Trametes versicolor.

Hypericin-mediated photodynamic therapy inhibits metastasis and EMT of colorectal cancer cells by regulating RhoA-ROCK1 signaling pathway.

Colorectal cancer (CRC) is significantly contributed to global cancer mortality rates. Treating CRC is particularly challenging due to metastasis and drug resistance. There is a pressing need for new treatment strategies against metastatic CRC. Photodynamic therapy (PDT) offers a well-established, minimally invasive treatment option for cancer with limited side effects. Hypericin (HYP), a potent photosensitizer for PDT, has been documented to induce cytotoxicity and apoptosis in various types of cancers. However, there are few reports on the inhibitory effects of HYP-mediated PDT on the metastatic ability of CRC cells. Here, we evaluate the inhibitory effects of HYP-mediated PDT against metastatic CRC cells and define its underlying mechanisms. Wound-healing and Transwell assays show that HYP-mediated PDT suppresses migration and invasion of CRC cells. F-actin visualization assays indicate HYP-mediated PDT decreases F-actin formation in CRC cells. TEM assays reveal HYP-mediated PDT disrupts pseudopodia formation of CRC cells. Mechanistically, immunofluorescence and western blotting results show that HYP-mediated PDT upregulates E-cadherin and downregulates N-cadherin and Vimentin. HYP-mediated PDT also suppresses key EMT regulators, including Snail, MMP9, ZEB1 and α-SMA. Additionally, the expressions of RhoA and ROCK1 are downregulated by HYP-mediated PDT. Together, these findings suggest that HYP-mediated PDT inhibits the migration and invasion of HCT116 and SW620 cells by modulating EMT and RhoA-ROCK1 signaling pathway. Thus, HYP-mediated PDT presents a potential therapeutic option for CRC.

Fluorescence lifetime nanothermometer based on the equilibrium formation of anthracene AIE-excimers in living cells.

The effective measurement of temperature in living systems at the nano and microscopic scales continues to be a challenge to this day. Here, we study the use of 2-(anthracen-2-yl)-1,3-diisopropylguanidine, 1, as a nanothermometer based on fluorescence lifetime measurements and its bioimaging applications. In aqueous solution, 1 is shown in aggregated form and the equilibrium between the two main aggregate types (T-shaped and π-π) is highly sensitive to the temperature. The heating of the medium shifts the equilibrium toward the formation of highly emissive T-shaped aggregates. This species shows a high fluorescence emission and a long lifetime in comparison with the π-π aggregates and the freé monomer. A linear relationship between the fluorescence lifetime and the temperature both in aqueous solution and in a synthetic intracellular buffer was found. Fluorescence lifetime imaging microscopy (FLIM) also showed a linear relationship between lifetime and temperature with an excellent sensitivity in MCF7 breast cancer cells, which opens the door for its potential use as FLIM nanothermometer in the biomedical field.

Dual inhibition of P38 MAPK and JNK pathways preserves stemness markers and alleviates premature activation of muscle stem cells during isolation.

BACKGROUND: Adult skeletal muscle contains resident muscle stem cells (MuSC) with high myogenic and engraftment potentials, making them suitable for cell therapy and regenerative medicine approaches. However, purification process of MuSC remains a major hurdle to their use in the clinic. Indeed, muscle tissue enzymatic dissociation triggers a massive activation of stress signaling pathways, among which P38 and JNK MAPK, associated with a premature loss of MuSC quiescence. While the role of these pathways in the myogenic progression of MuSC is well established, the extent to which their dissociation-induced activation affects the functionality of these cells remains unexplored. METHODS: We assessed the effect of P38 and JNK MAPK induction on stemness marker expression and MuSC activation state during isolation by pharmacological approaches. MuSC functionality was evaluated by in vitro assays and in vivo transplantation experiments. We performed a comparative analysis of the transcriptome of human MuSC purified with pharmacological inhibitors of P38 and JNK MAPK (SB202190 and SP600125, respectively) versus available RNAseq resources. RESULTS: We monitored PAX7 protein levels in murine MuSC during muscle dissociation and demonstrated a two-step decline partly dependent on P38 and JNK MAPK activities. We showed that simultaneous inhibition of these pathways throughout the MuSC isolation process preserves the expression of stemness markers and limits their premature activation, leading to improved survival and amplification in vitro as well as increased engraftment in vivo. Through a comparative RNAseq analysis of freshly isolated human MuSC, we provide evidence that our findings in murine MuSC could be relevant to human MuSC. Based on these findings, we implemented a purification strategy, significantly improving the recovery yields of human MuSC. CONCLUSION: Our study highlights the pharmacological limitation of P38 and JNK MAPK activities as a suitable strategy to qualitatively and quantitatively ameliorate human MuSC purification process, which could be of great interest for cell-based therapies.

In silico prediction of polyketide biosynthetic gene clusters in the genomes of Hypericum-borne endophytic fungi.

BACKGROUND: The search for new bioactive natural compounds with anticancer activity is still of great importance. Even though their potential for diagnostics and treatment of cancer has already been proved, the availability is still limited. Hypericin, a naphthodianthrone isolated essentially from plant source Hypericum perforatum L. along with other related anthraquinones and bisanthraquinones belongs to this group of compounds. Although it has been proven that hypericin is synthesized by the polyketide pathway in plants, none of the candidate genes coding for key enzymes has been experimentally validated yet. Despite the rare occurrence of anthraquinones in plants, their presence in microorganisms, including endophytic fungi, is quite common. Unlike plants, several biosynthetic genes grouped into clusters (BGCs) in fungal endophytes have already been characterized. RESULTS: The aim of this work was to predict, identify and characterize the anthraquinone BGCs in de novo assembled and functionally annotated genomes of selected endophytic fungal isolates (Fusarium oxysporum, Plectosphaerella cucumerina, Scedosporium apiospermum, Diaporthe eres, Canariomyces subthermophilus) obtained from different tissues of Hypericum spp. The number of predicted type I polyketide synthase (PKS) BGCs in the studied genomes varied. The non-reducing type I PKS lacking thioesterase domain and adjacent discrete gene encoding protein with product release function were identified only in the genomes of C. subthermophilus and D. eres. A candidate bisanthraquinone BGC was predicted in C. subthermophilus genome and comprised genes coding the enzymes that catalyze formation of the basic anthraquinone skeleton (PKS, metallo-beta-lactamase, decarboxylase, anthrone oxygenase), putative dimerization enzyme (cytochrome P450 monooxygenase), other tailoring enzymes (oxidoreductase, dehydrogenase/reductase), and non-catalytic proteins (fungal transcription factor, transporter protein). CONCLUSIONS: The results provide an insight into genetic background of anthraquinone biosynthesis in Hypericum-borne endophytes. The predicted bisanthraquinone gene cluster represents a basis for functional validation of the candidate biosynthetic genes in a simple eukaryotic system as a prospective biotechnological alternative for production of hypericin and related bioactive anthraquinones.

Novel 9-Methylanthracene Derivatives as p53 Activators for the Treatment of Glioblastoma Multiforme.

Glioblastoma multiforme, a highly aggressive and lethal brain tumor, is a substantial clinical challenge and a focus of increasing concern globally. Hematological toxicity and drug resistance of first-line drugs underscore the necessity for new anti-glioma drug development. Here, 43 anthracenyl skeleton compounds as p53 activator XI-011 analogs were designed, synthesized, and evaluated for their cytotoxic effects. Five compounds (13d, 13e, 14a, 14b, and 14n) exhibited good anti-glioma activity against U87 cells, with IC50 values lower than 2 µM. Notably, 13e showed the best anti-glioma activity, with an IC50 value up to 0.53 µM, providing a promising lead compound for new anti-glioma drug development. Mechanistic analyses showed that 13e suppressed the MDM4 protein expression, upregulated the p53 protein level, and induced cell cycle arrest at G2/M phase and apoptosis based on Western blot and flow cytometry assays.

Photodynamic treatment increases the lifespan and oxidative stress resistance of Caenorhabditis elegans.

Photodynamic therapy is a noninvasive treatment in which specific photosensitizers and light are used to produce high amounts of reactive oxygen species (ROS), which can be employed for targeted tissue destruction in cancer treatment or antimicrobial therapy. However, it remains unknown whether lower amounts of ROS produced by mild photodynamic therapy increase lifespan and stress resistance at the organism level. Here, we introduce a novel photodynamic treatment (PDTr) that uses 20 µM hypericin, a photosensitizer that originates from Hypericum perforatum, and orange light (590 nm, 5.4 W/m2, 1 min) to induce intracellular ROS formation (ROS), thereby resulting in lifespan extension and improved stress resistance in C. elegans. The PDTr-induced increase in longevity was abrogated by N-acetyl cysteine, suggesting the hormetic response was driven by prooxidative mechanisms. PDTr activated the translocation of SKN-1/NRF-2 and DAF-16/FOXO, leading to elevated expression of downstream oxidative stress-responsive genes, including ctl-1, gst-4, and sod-3. In summary, our findings suggest a novel PDTr method that extends the lifespan of C. elegans under both normal and oxidative stress conditions through the activation of SKN-1 and DAF-16 via the involvement of many antioxidant genes.

Carbohydrate-Functionalized Anthracene Carboximides as Multivalent Ligands and Bio-Imaging Agents.

Anthracene carboximides (ACIs) conjugated with gluco-, galacto- and mannopyranosides are synthesized, by glycosylation of N-hydroxyethylanthracene carboximide acceptor with glycosyl donors. Glycoconjugation of anthracene carboximide increases the aq. solubility by more than 3-fold. The glycoconjugates display red-shifted absorption and emission, as compared to anthracene. Large Stokes shift (λabs/λem=445/525 nm) and high fluorescence quantum yields (Φ) of 0.86 and 0.5 occur in THF and water, respectively. The ACI-glycosides undergo facile photodimerization in aqueous solutions, leading to the formation of the head-to-tail dimer, as a mixture of syn and anti-isomers. Solution phase and solid-state characterizations by dynamic light scattering (DLS), microscopic imaging by atomic force (AFM) and transmission electron (TEM) microscopies reveal self-assembled vesicle structures of ACI glycosides. These self-assembled structures act as multivalent glycoclusters for ligand-specific lectin binding, as evidenced by the binding of Man-ACI to Con A, by fluorescence and turbidity assays. The conjugates do not show cellular cytotoxicity (IC50) till concentrations of 50 µM with HeLa and HepG2 cell lines and are cell-permeable, showing strong fluorescence inside the cells. These properties enable the glycoconjugates to be used in cell imaging. The non-selective cellular uptake of the glycoconjugates suggests a passive diffusion through the membrane.

The contradictory role of febuxostat in ABCG2 expression and potentiating hypericin-mediated photodynamic therapy in colorectal cancers.

Photodynamic Therapy (PDT) is an emerging method to treat colorectal cancers (CRC). Hypericin (HYP) is an effective mediator of PDT and the ABCG2 inhibitor, Febuxostat (FBX) could augment PDT. HT29 and HEK293 cells showed light dependant cytotoxic response to PDT in both 2D and 3D cell models. FBX co-treatment was not found to improve PDT cytotoxicity. Next, ABCG2 protein expression was observed in HT29 but not in HEK293 cells. However, ABCG2 gene expression analysis did not support protein expression results as ABCG2 gene expression results were found to be higher in HEK293 cells. Although HYP treatment was found to significantly reduce ABCG2 gene expression levels in both cell lines, FBX treatment partially restored ABCG2 gene expression. Our findings indicate that FBX co-treatment may not be suitable for augmenting HYP-mediated PDT in CRC but could potentially be useful for other applications.

[The role of ROS/JNK/caspase 3 axis in apoptosis induction by menthol-favored electronic cigarette liquid in human periodontal ligament stem cells].

PURPOSE: To explore the cytotoxic effect of a menthol-favored E-liquid on human periodontal ligament stem cells (hPDLSCs), as well as the underlying mechanism of electronic cigarette (E-cig)-induced cell apoptosis. METHODS: PDLSCs were isolated and cultured from periodontal ligament tissues of healthy premolars extracted for orthodontic reasons. Cells in passage 3 were used to detect the surface markers of stem cells by flow cytometry. Then the cells were exposed to different doses of menthol-favored E-liquid (at 59 mg/L nicotine concentration) in the culture median (the final nicotine concentrations were 0.1 µg/mL, 1.0 µg/mL, 10 µg/mL, 50 µg/mL, 0.1 mg/mL, 0.2 mg/mL and 0.5 mg/mL, respectively) for different period of times (24, 48 and 72 h). The cell viability was analyzed by CCK-8 assay. Cell apoptosis was evaluated by flow cytometry (7-AAD and Annexin V staining) and TUNEL assay. Reactive oxygen species (ROS) production was detected with fluorescence probe DCFH-DA by confocal microscopy and flow cytometry. The protein expression levels associated with ROS/JNK/caspase 3 axis(p-JNK, JNK, c-Jun, p-c-Jun, Bcl-2, Bax and cleaved-caspase 3) were analyzed by Western blot. Immunocytofluorescense staining was applied to evaluate the expression level of p-JNK. After addition of NAC, a ROS scavenger, and MAPK/JNK specific blocker SP600125, their effects on E-cig-induced cell apoptosis were evaluated. Statistical analysis was performed with Graph Pad 5.0 software package. RESULTS: Human PDLSCs were successfully isolated and cultured and flow cytometry assay showed the mesenchymal stem cell surface biomarkers (CD73, CD90 and CD105) were positively expressed. CCK8 assay indicated cell viability was significantly(P＜0.001) different among all concentration groups at various time points (24, 48 or 72 h), and the difference in apoptosis rate among all concentration groups was also statistically significant (P＜0.001). After exposure to E-liquid with nicotine concentration ≥50 µg/mL, cell viability was significantly reduced, and the proportion of apoptotic cells and the cellular ROS level was significantly increased in a dose-dependent manner as compared with the control group(0.0 mg/mL). Western blot assay showed E-cig exposure could promote MAPK/JNK phosphorylation in a dose-dependent and time-dependent manner. Either NAC or SP600125 could partially rescue the E-cig-induced cell apoptosis via reversing up-regulation of p-JNK and cleaved caspase 3. CONCLUSIONS: ROS/JNK/caspase 3 axis is involved in menthol-favored E-liquid-induced apoptosis of hPDLSCs.

Surface active dicationic ionic liquids as green oil spill dispersants.

The utilization of chemical dispersants as a way of mitigating of oil spills in marine eco-system has been extensively documented worldwide. Hence, in this research we have successfully synthesized two amphiphilic asymmetric Dicaionic Ionic Liquids (DILs). The efficacy of these synthesized DILs as dispersants was assessed using the baffled flask test (BFT). The results indicated a dispersant effectiveness ranging from 47.98 % to 79.76 % for the dispersion of heavy crude oil across various temperature ranges (10-30 °C). These dispersant-to-oil ratios (DOR) were maintained at 3: 100 (V%), showcasing promising dispersant capabilities for mitigating heavy crude oil spills. Additionally, acute toxicity tests conducted on Nile tilapia and Oreochromis niloticus have demonstrated the relatively low toxicity of the IL-dispersants, with Lethal Concentration 50 (LC50) values exceeding 100 ppm after 96 h. This suggests a practically slight toxic effect on the tested fish. In summary, the newly developed IL-dispersants are considered to be conducive to environmentally benign oil spill remediation.

Prednisone and ibuprofen conjugate Janus dendrimers and their anticancer activity.

Drug release from hyperbranched Janus dendrimer-drug conjugates and their subsequent activity are influenced by the different drugs in each dendron and the linker. To understand these effects, we synthetized new Janus-type dendrimers of first and second generation. One dendron with 2,2-Bis(hydroxymethyl)propionic acid functionalized with ibuprofen and the second dendron was obtained with 3-aminopropanol-amidoamine and prednisone. The dendrimers were obtained by copper(I)-catalyzed Click azide-alkyne cycloaddition for the formation of a triazole as a dendrimeric nucleus of Janus dendrimer conjugates are reported. The influence of ibuprofen, prednisone, and spacer on cancer activity of Janus dendrimers conjugates is reported. The IC50 values of the anticancer activity on cancer cell lines the Janus dendrimer of second generation was higher in comparison to the first generation dendrimer. Similarly, the anticancer activity was higher compared to the dendron conjugates. Also, no cytotoxic effects of dendrons and dendrimers on non-cancerous kidney COS-7 cell line was observed. The interesting anticancer activity of the prepared prednisone-ibuprofen Janus dendrimer conjugates suggest that the dendrimers could be of potential use as new anticancer drug.

Enhancing Fractionated Cancer Therapy: A Triple-Anthracene Photosensitizer Unleashes Long-Persistent Photodynamic and Luminous Efficacy.

Conventional photodynamic therapy (PDT) is often limited in treating solid tumors due to hypoxic conditions that impede the generation of reactive oxygen species (ROS), which are critical for therapeutic efficacy. To address this issue, a fractionated PDT protocol has been suggested, wherein light irradiation is administered in stages separated by dark intervals to permit oxygen recovery during these breaks. However, the current photosensitizers used in fractionated PDT are incapable of sustaining ROS production during the dark intervals, leading to suboptimal therapeutic outcomes (Table S1). To circumvent this drawback, we have synthesized a novel photosensitizer based on a triple-anthracene derivative that is designed for prolonged ROS generation, even after the cessation of light exposure. Our study reveals a unique photodynamic action of these derivatives, facilitating the direct and effective disruption of biomolecules and significantly improving the efficacy of fractionated PDT (Table S2). Moreover, the existing photosensitizers lack imaging capabilities for monitoring, which constraints the fine-tuning of irradiation parameters (Table S1). Our triple-anthracene derivative also serves as an afterglow imaging agent, emitting sustained luminescence postirradiation. This imaging function allows for the precise optimization of intervals between PDT sessions and aids in determining the timing for subsequent irradiation, thus enabling meticulous control over therapy parameters. Utilizing our novel triple-anthracene photosensitizer, we have formulated a fractionated PDT regimen that effectively eliminates orthotopic pancreatic tumors. This investigation highlights the promise of employing long-persistent photodynamic activity in advanced fractionated PDT approaches to overcome the current limitations of PDT in solid tumor treatment.

Melatonin protects TEGDMA-induced preodontoblast mitochondrial apoptosis via the JNK/MAPK signaling pathway.

Resin monomer-induced dental pulp injury presents a pathology related to mitochondrial dysfunction. Melatonin has been regarded as a strong mitochondrial protective bioactive compound from the pineal gland. However, it remains unknown whether melatonin can prevent dental pulp from resin monomer-induced injury. The aim of this study is to investigate the effects of melatonin on apoptosis of mouse preodontoblast cells (mDPC6T) induced by triethylene glycol dimethacrylate (TEGDMA), a major component in dental resin, and to determine whether the JNK/MAPK signaling pathway mediates the protective effect of melatonin. A well-established TEGDMA-induced mDPC6T apoptosis model is adopted to investigate the preventive function of melatonin by detecting cell viability, apoptosis rate, expressions of apoptosis-related proteins, mitochondrial ROS (mtROS) production, mitochondrial membrane potential (MMP) and adenosine triphosphate (ATP) level. Inhibitors of MAPKs are used to explore which pathway is involved in TEGDMA-induced apoptosis. Finally, the role of the JNK/MAPK pathway is verified using JNK agonists and antagonists. Our results show that melatonin attenuates TEGDMA-induced mDPC6T apoptosis by reducing mtROS production and rescuing MMP and ATP levels. Furthermore, mitochondrial dysfunction and apoptosis are alleviated only by the JNK/MAPK inhibitor SP600125 but not by other MAPK inhibitors. Additionally, melatonin downregulates the expression of phosphorylated JNK and counteractes the activating effects of anisomycin on the JNK/MAPK pathway, mimicking the effects of SP600125. Our findings demonstrate that melatonin protects mDPC6T cells against TEGDMA-induced apoptosis partly through JNK/MAPK and the maintenance of mitochondrial function, offering a novel therapeutic strategy for the prevention of resin monomer-induced dental pulp injury.

Enhanced photocatalytic degradation of polycyclic aromatic hydrocarbons (PAHs) Using NiO nanoparticles.

The oncogenic and genetic properties of anthracene, a member of the polycyclic aromatic hydrocarbons (PAHs) family, pose a significant health threat to humans. This study aims to investigate the photocatalytic decomposition of anthracene under various conditions, such as different concentrations of PAHs, varying amounts of NiO (nickel oxide) nanoparticles, and different pH levels under ultraviolet light and sunlight. The synthesized NiO nanoparticles showed surface plasma resonance at 230 and 360 nm, while XRD and SEM analysis confirmed the nanoparticles were cubic crystalline in structure with sizes ranging between 37 and 126 nm. NiO nanoparticles exhibited 79% degradation of pyrene at 2 µg/mL of anthracene within 60 min of treatment. NiO at 10 µg/mL concentration showed significant adsorption of 57%, while the adsorption method worked efficiently (72%) at 5 pH. Photocatalytic degradation was confirmed by isotherm and kinetic studies through monolayer adsorption and pseudo-first-order kinetics. Further, the absorption process was confirmed by performing GC-MS analysis of the NiO nanoparticles. On the other hand, NiO nanoparticles showed antimicrobial activity against Gram negative and Gram-positive bacteria. Therefore, the present work is one of its kind proving the dual application of NiO nanoparticles, which makes them suitable candidates for bioremediation by treating PAHs and killing pathogenic bacteria.

Measurement constrained emission estimates of alkylated polycyclic aromatic hydrocarbons in the Canadian Athabasca oil sands region.

Alkylated polycyclic aromatic hydrocarbons (APAH) are important contaminants of crude oil production and exhibit similar toxicity to their parent compounds. This study developed an emission inventory of APAH in a major oil sands development region of Alberta, Canada, and validated the inventory with ambient concentration measurements through dispersion modeling. The initial estimate of regional total annual emissions of 21 APAH species was 362 tonnes/year in the last decade, of which 309 and 53 tonnes/year were in particle-bound and gas-phase APAH, respectively. Fugitive dust from oil sands mining activities is the primary source of particle-bound APAH, emitting 274 tonnes/year. Other major sources of APAH include point sources (31), tailings ponds (21), anthropogenic fuel consumption from mine fleet (17), and local transportation (13). The group of species with highest emissions was C1-C4 alkylnaphthalenes (53%), followed by C1-C4 alkylphenanthrenes/anthracenes (19%), C1-C4 fluorenes (13%), and C1-C4 fluoranthenes/pyrenes and C1-C4 benz[a]anthracenes/chrysene/triphenylenes (7% each). CALPUFF dispersion modeling was performed using the APAH emissions as model input. The model-predicted annual average ambient APAH concentrations at 17 monitoring sites were 1%-52% (19% on average) lower than the measurements. Inverse dispersion modeling was then applied to adjust APAH emissions higher by 19% for each of the 21 APAH species, which resulted in a revised estimate of APAH emissions to 431 tonnes/year. With the revised emissions as model input, model bias in the predicted ambient concentration was reduced from -19% to -8%. The model results showed the highest concentrations of APAH were near tailings ponds and open mining faces and downwind areas, with total APAH concentrations being higher than 50 ng/m3.

Isolation and Identification of a Tibetan Pig Porcine Epidemic Diarrhoea Virus Strain and Its Biological Effects on IPEC-J2 Cells.

Porcine epidemic diarrhoea virus (PEDV) is a coronavirus that can cause severe watery diarrhoea in piglets, with high morbidity and mortality rates, seriously hindering the healthy development of the global swine industry. In this study, we isolated a strain of PEDV from Tibetan pigs and named it CH/GS/2022. Subsequently, we screened the apoptosis signals of PEDV-infected IPEC-J2 cells and studied the correlation between apoptosis signals and cell apoptosis. The results showed that different infections of PEDV induced different degrees of apoptosis in cells, and PEDV-induced cell apoptosis was dose-dependent. We then detected the expression of the p53, p38, JNK, Bax, and Bcl-2 genes in the apoptosis signal pathway. The results showed that 24 h after PEDV infection, the expression of the p53, p38, JNK, and Bax genes in IPEC-J2 cells increased significantly, while the expression of the Bcl-2 gene decreased significantly (p < 0.05). Subsequently, we used Western blot to detect the protein levels of these five genes, and the results showed that PEDV infection upregulated the expression of p53, p38, JNK, and Bax proteins (p < 0.05) while downregulating the expression of Bcl-2 protein (p < 0.05). Thus, it was initially inferred that PEDV infection could regulate cell apoptosis by activating the p53, p38, and JNK signalling pathways. Finally, we further investigated the apoptosis of the cells through the use of inhibitors. The results indicated that the p53 inhibitor Pifithrin-α has a significant inhibitory effect on the expression of the p53 protein after PEDV infection and can reverse the expression levels of Bax and Bcl-2 proteins. This suggested that p53 is involved in PEDV-induced cell apoptosis. Similarly, the p38 MAPK inhibitor SB203580 has an inhibitory effect on the expression of the p38 protein and can reverse the expression levels of Bax and Bcl-2 proteins. This suggested that p38 is also involved in PEDV-induced cell apoptosis. On the other hand, the JNK inhibitor SP600125 has no inhibitory effect on the expression of the JNK protein after PEDV infection, but the expression levels of Bax and Bcl-2 proteins have changed. Furthermore, it is noteworthy that SP600125 can inhibit the activity of apoptotic proteins but not their levels, resulting in reduced cell apoptosis. These preliminary results indicated that JNK may be involved in PEDV-induced IPEC-J2 cell apoptosis.

The changes and correlation of IL-6 and oxidative stress levels in RAW264.7 macrophage cells induced by PAHs in PM2.5.

The objective of this study was to investigate the effects of anthracene (Ant) with 3 rings, benzo[a]anthracene (BaA) with 4 rings and benzo[b]fluoranthene (BbF) with 5 rings in fine particulate matter (PM2.5) at different exposure times (4 h and 24 h) and low exposure levels (0 pg/mL, 0.1 pg/mL, 1 pg/mL, 100 pg/mL and 10,000 pg/mL) on RAW264.7 cells. The changes of interleukin-6 (IL-6) and oxidative stress levels in RAW264.7 cells were investigated by methyl-thiazolyl-tetrazolium (MTT) and enzyme-linked immunosorbent assay (ELISA). Pearson correlation analysis was used to analyze the correlation between variables. Ant, BaA and BbF induced the secretion of IL-6 and the occurrence of oxidative stress in RAW264.7 cells. The inflammatory effect and oxidative damage were exacerbated with prolonged exposure time, increasing exposure concentration and increasing number of PAH rings. At the same time, IL-6 was found to have a certain correlation with the levels of ROS, MDA and SOD. Exposure to atmospheric PAHs at low concentrations can also produce toxic effects on cells, IL-6 and oxidative stress work together in cell damage. The study is expected to provide a theoretical and experimental basis for air pollution control and human health promotion.

Mechanisms of hepatocellular toxicity associated with the components of St. John's Wort extract hypericin and hyperforin in HepG2 and HepaRG cells.

St. John's Wort preparations are used for the treatment of mild to moderate depression. They are usually well tolerated but can cause adverse reactions including liver toxicity in rare cases. To date, the mechanism(s) underlying the hepatotoxicity of St. John's Wort extracts are poorly investigated. We studied the hepatocellular toxicity of hypericin and hyperforin as the two main ingredients of St. John's Wort extracts in HepG2 and HepaRG cells and compared the effects to citalopram (a synthetic serotonin uptake inhibitor) with a special focus on mitochondrial toxicity and oxidative stress. In HepG2 cells, hypericin was membrane-toxic at 100 µM and depleted ATP at 20 µM. In HepaRG cells, ATP depletion started at 5 µM. In comparison, hyperforin and citalopram were not toxic up to 100 µM. In HepG2 cells, hypericin decreased maximal respiration starting at 2 µM and mitochondrial ATP formation starting at 10 µM but did not affect glycolytic ATP production. Hypericin inhibited the activity of complex I, II and IV of the electron transfer system and caused mitochondrial superoxide accumulation in cells. The protein expression of mitochondrial superoxide dismutase 2 (SOD2) and thioredoxin 2 (TRX2) and total and reduced glutathione decreased in cells exposed to hypericin. Finally, hypericin diminished the mitochondrial DNA copy number and caused cell necrosis but not apoptosis. In conclusion, hypericin, but not hyperforin or citalopram, is a mitochondrial toxicant at low micromolar concentrations. This mechanism may contribute to the hepatotoxicity occasionally observed in susceptible patients treated with St. John's Wort preparations.