Preparation of Dihydromyricetin-Loaded Self-Emulsifying Drug Delivery System and Its Anti-Alcoholism Effect.

Intraperitoneal injection of dihydromyricetin (DMY) has shown promising potential in the treatment of alcoholism. However, its therapeutic effect is limited due to its low solubility, poor stability, and high gut-liver first-pass metabolism, resulting in very low oral bioavailability. In this study, we developed a DMY-loaded self-emulsifying drug delivery system (DMY-SEDDS) to enhance the oral bioavailability and anti-alcoholism effect of DMY. DMY-SEDDS improved the oral absorption of DMY by facilitating lymphatic transport. The area under the concentration-time curve (AUC) of DMY in the DMY-SEDDS group was 4.13-fold higher than in the DMY suspension group. Furthermore, treatment with DMY-SEDDS significantly enhanced the activities of alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) in the liver of mice (p < 0.05). Interestingly, DMY-SEDDS also increased ADH activity in the stomach of mice with alcoholism (p < 0.01), thereby enhancing ethanol metabolism in the gastrointestinal tract and reducing ethanol absorption into the bloodstream. As a result, the blood alcohol concentration of mice with alcoholism was significantly decreased after DMY-SEDDS treatment (p < 0.01). In the acute alcoholism mice model, compared to saline treatment, DMY-SEDDS prolonged the onset of LORR (loss of righting reflex) (p < 0.05) and significantly shortened the duration of LORR (p < 0.01). Additionally, DMY-SEDDS treatment significantly reduced gastric injury in acute alcoholism mice. Collectively, these findings demonstrate the potential of DMY-SEDDS as a treatment in the treatment of alcoholism.

Insufficiency of collagenases in establishment of primary chondrocyte culture from cartilage of elderly patients receiving total joint replacement.

Background Collagenases are frequently used in chondrocyte isolation from articular cartilage. However, the sufficiency of this enzyme in establishing primary human chondrocyte culture remains unknown. Methods Cartilage slices shaved from femoral head or tibial plateau of patients receiving total joint replacement surgery (16 hips, 8 knees) were subjected to 0.02% collagenase IA digestion for 16 h with (N = 19) or without (N = 5) the pre-treatment of 0.4% pronase E for 1.5 h. Chondrocyte yield and viability were compared between two groups. Chondrocyte phenotype was determined by the expression ratio of collagen type II to I. The morphology of cultured chondrocytes was monitored with a light microscope.Results Cartilage with pronase E pre-treatment yielded significantly higher chondrocytes than that without the pre-treatment (3,399 ± 1,637 cells/mg wet cartilage vs. 1,895 ± 688 cells/mg wet cartilage; P = 0.0067). Cell viability in the former group was also significantly higher than that in the latter (94% ± 2% vs. 86% ± 6%; P = 0.03). When cultured in monolayers, cells from cartilage with pronase E pre-treatment grew in a single plane showing rounded shape while cells from the other group grew in multi-planes and exhibited irregular shape. The mRNA expression ratio of collagen type II to I was 13.2 ± 7.5 in cells isolated from cartilage pre-treated with pronase E, indicating a typical chondrocyte phenotype. Conclusions Collagenase IA was not sufficient in establishing primary human chondrocyte culture. Cartilage must be treated with pronase E prior to collagenase IA application.

The effect of information overload and perceived risk on tourists' intention to travel in the post-COVID-19 pandemic.

Since the COVID-19 pandemic, the tourism economy has been seriously affected. China has implemented a direct traveling management mechanism and recovered from the pandemic faster than the rest of the world. However, the COVID-19 situation is complicated and uncontrollable because of the available unclear information including difficult medical terminologies. This study attempts to find the determinants of the travel intention of China's tourists in the post-COVID-19 epidemic. Along with information overload and perception risk, an expanded research model of the Theory of Planned Behavior (TPB) was employed to propose the theoretical framework of this study. A survey was conducted among 518 tourists who spend their holiday in Hainan, which is a popular tourist destination in China. The empirical results show that information overload positively and significantly impacted perceived risk. Furthermore, perceived risk negatively affects the intention to travel. Perceived risk also negatively affected the attitude toward traveling. However, response self-efficacy did not have a significant effect on the intention to travel. Finally, based on the analysis results, this study proposes relevant research contributions and practical recommendations with management implications for the travel industries.

Antihyperuricemic efficacy of Scopoletin-loaded Soluplus micelles in yeast extract/potassium oxonate-induced hyperuricemic mice.

Scopoletin (Sco) has great potential for hyperuricemia therapy. However, the relatively low oral bioavailability of Sco limits its further applications. Soluplus-based Sco micelles (Sco-Ms) were successfully prepared in our previous work. The oral bioavailability of Sco-Ms was increased by 438% compared with free Sco. In this study, we aimed to compare the biodistribution and antihyperuricemic efficacy of Sco and Sco-Ms, and explore their therapeutic mechanisms as well. We studied the tissue biodistribution of Sco and Sco-Ms after they were orally administered to mice. The antihyperuricemic effect and the therapeutic mechanisms of Sco and Sco-Ms were evaluated using yeast extract/potassium oxonate-induced hyperuricemia model in mice. The Sco concentration in each tissue was significantly higher than that of Sco suspension after orally administrating Sco-Ms to mice. Oral delivery of Sco-Ms exhibited significantly stronger hypouricemic efficacy in hyperuricemic mice than Sco. Meanwhile, Sco-Ms showed a better protective effect on mice kidney injury. The hypouricemic efficacy of Sco was due to promoting the excretion of uric acid via modulating the alteration of gene expression levels of renal uric acid transporter (URAT1), glucose transporter (GLUT9), and organic anion transporter 1 (OAT1). Sco-Ms could not only restore the dysregulation of URAT1, GLUT9, and OAT1 more effectively, but also down-regulate the activity of hepatic xanthine oxidase (XOD) to inhibit the production of uric acid. In conclusion, taken together, Sco-Ms represents a potential oral strategy for the treatment of hyperuricemia.

Perfluorooctanesulfonate induces neuroinflammation through the secretion of TNF-α mediated by the JAK2/STAT3 pathway.

Perfluorooctanesulfonate (PFOS)-containing compounds are widely used in all aspects of industrial and consumer products. Recent studies indicated that PFOS is ubiquitous in environments and is considered to be a new type of persistent organic pollutant (POP). This has raised concerns regarding its adverse effects on human health. The nervous system is regarded as a sensitive target of environmental contaminants, including PFOS. Previous findings showed that PFOS can induce neurobehavioral deficits. However, the molecular mechanism underlying PFOS neurotoxicity remains obscure. Astrocyte activation and the resulting pro-inflammatory cytokine release play an integral role in protecting neurons from neurotoxin-mediated damage. If uncontrolled, sustained astrocyte activation may cause the secretion of excessive levels of pro-inflammatory cytokines that exacerbate the initial damage. In this study, we showed that PFOS could promote excessive secretion of tumor necrosis factor-α (TNF-α) in dose- and time-dependent manners in astrocytes. Furthermore, PFOS exposure could induce the phosphorylation of Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3). This suggests that the JAK2/STAT3 signal transduction pathway is involved in PFOS-mediated astrocyte activation and secretion of TNF-α. Indeed, targeted blockage of the JAK2/STAT3 pathway prevented the phosphorylation of JAK and STAT3, and it also caused abnormal expression of TNF-α. Finally, we demonstrated that SH-SY5Y neuronal cells underwent rapid apoptosis via a TNF-α-dependent mechanism after exposure to PFOS-treated astrocyte-conditioned medium. In summary, our findings reveal that PFOS mediates a rapid activation of JAK2/STAT3 signal transduction in C6 astrocytes, which plays a pivotal role in the initiation of PFOS-mediated neurotoxicity.

Perfluorooctane sulfonate mediates secretion of IL-1ß through PI3K/AKT NF-кB pathway in astrocytes.

Perfluorooctane sulfonate (PFOS) is a persistent and bioaccumulative compound that has been widely used in various fields of life and industrial productions, because of its special chemical and physical properties. Numerous studies have indicated significant neurotoxic effect of PFOS, especially on neurons and microglia. However, the influence of PFOS on astrocyte physiology remains unclear. In this study, we showed that PFOS triggered reactive astrocytosis in time- and dose-dependent manners. The low-doses of PFOS increased the cell number and the expression of glial fibrillary acidic protein (GFAP), a well-known hallmark of reactive astrocytes, in C6 astrocyte cells. ELISA and RT-PCR analysis showed that PFOS promoted the expression and secretion of Interleukin-1 beta (IL-1ß) in dose- and time-dependent manners. Furthermore, PFOS exposure could induce the phosphorylation and degradation of IκBα, and the translocation of NF-κB p65 from the cytoplasm to the nucleus in C6 glioma cell line. Thus, the NF-кB signaling pathway can be activated after PFOS exposure. In addition, pretreatment with AKT inhibitor LY294002 could obviously attenuate PFOS-induced NF-κB activation and IL-1ß secretion. Taken together, these results indicated that PFOS could facilitate reactive astrocytosis and the secretion of pro-inflammatory cytokines through AKT-dependent NF-κB signaling pathway.

Arsenic trioxide mediates HAPI microglia inflammatory response and the secretion of inflammatory cytokine IL-6 via Akt/NF-κB signaling pathway.

Arsenic is a widely distributed toxic metalloid in around the world. Inorganic arsenic species are deemed to affect astrocytes functions and to cause neuron apoptosis. Microglia are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA and reverse transcriptase PCR (RT-PCR), we showed that Arsenic trioxide up-regulated the expression and secretion of IL-6 in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. These pro-inflammatory responses were inhibited by the Akt blocker, LY294002. Further, Arsenic trioxide exposure could induce phospho rylationand degradation of IкBα, and the translocation of NF-κB p65 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the NF-кB signaling pathway can be activated after Arsenic trioxide treatment. Besides, Akt blocker LY294002 also obviously attenuated NF-кB activation and transnuclear induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of pro-inflammatory cytokine and NF-кB activation induced by Arsenic trioxide can be mediated by elevation of p-Akt in HAPI microglia cells.

ROS-mediated apoptosis of HAPI microglia through p53 signaling following PFOS exposure.

Perfluorooctane sulfonate (PFOS), the most extensively studied member of perfluoroalkyl and polyfluoroalkyl substances (PFASs), has been thought to be toxic to the central nervous system (CNS) of mammals. However, the neurotoxic effects of PFOS remain largely unknown. In this study, the effect of PFOS on microglial apoptosis was examined. The results showed that PFOS could significantly reduce the cell viability and mediate cell apoptosis in HAPI microglia, which was closely accompanied with ROS production and p53 overexpression. Moreover, p53 interference significantly ameliorated PFOS-triggered cytotoxic effects in HAPI microglia, including the downregulation of cleaved PARP and cleaved caspase 3. Interestingly, NAC, a ROS inhibitor, inhibited p53 expression, and decreased the apoptosis of HAPI microglia. Taken together, these findings suggest that upregulated production of ROS plays a vital role in PFOS-mediated apoptosis in HAPI microglia via the modulation of p53 signaling.

Arsenic trioxide mediates HAPI microglia inflammatory response and subsequent neuron apoptosis through p38/JNK MAPK/STAT3 pathway.

Arsenic is a widely distributed toxic metalloid all over the world. Inorganic arsenic species are supposed to affect astrocytic functions and to cause neuron apoptosis in CNS. Microglias are the key cell type involved in innate immune responses in CNS, and microglia activation has been linked to inflammation and neurotoxicity. In this study, using ELISA, we showed that Arsenic trioxide up-regulated the expression and secretion of IL-1ß in a dose-dependent manner and a time-dependent manner in cultured HAPI microglia cells. The secretion of IL-1ß caused the apoptosis of SH-SY5Y. These pro-inflammatory responses were inhibited by the STAT3 blocker, AG490 and P38/JNK MAPK blockers SB202190, SP600125. Further, Arsenic trioxide exposure could induce phosphorylation and activation of STAT3, and the translocation of STAT3 from the cytosol to the nucleus in this HAPI microglia cell line. Thus, the STAT3 signaling pathway can be activated after Arsenic trioxide treatment. However, P38/JNK MAPK blockers SB202190, SP600125 also obviously attenuated STAT3 activation and transnuclear transport induced by Arsenic trioxide. In concert with these results, we highlighted that the secretion of IL-1ß and STAT3 activation induced by Arsenic trioxide can be mediated by elevation of P38/JNK MAPK in HAPI microglia cells and then induced the toxicity of neurons.

Particulate Matter Facilitates C6 Glioma Cells Activation and the Release of Inflammatory Factors Through MAPK and JAK2/STAT3 Pathways.

It has been widely accepted that astrocytes, play a role in regulating almost every physiological system. In the present study, we investigated the role of particulate matter (PM) in regulating activation of astrocytes. The glial cell strain C6 was cloned from a rat glioma which was induced by N-nitrosomethylurea. The C6 cells were plated at a density of 5 × 10(6) cells/10 cm diameter dish and incubated with different concentrations (0, 12, 25, 50, 100, 200, and 400 µg/mL) of PM for 24 h and different time (0, 1, 3, 6, 8,12, and 24 h) with 100 µg/mL at 37 °C. The study revealed that PM stimulated the expression of inducible nitric oxide synthase (iNOS) as well as the production of IL-1ß in a dose- and time-dependent manner. Furthermore, activation of JAK2/STAT3 and p38/JNK/ERK MAPKs was found in astrocytes following PM treatment. Blockage of JAK and p38/JNK/ERK MAPKs with their specific inhibitors, AG490, SB202190, SP600125 and U0126 significantly reduced PM-induced iNOS expression and IL-1ß production. In addition, it was demonstrated that inhibition of p38, JNK and JAK prevented STAT3 tyrosine phosphorylation induced by PM, while blocking ERK did not. MAPKs (p38 and JNK) could regulate tyrosine STAT3 phosphorylation, which suggested that the JAK2/STAT3 pathway might be the downstream of p38/JNK MAPK pathways.

2,3,7,8-tetrachlorodibenzo-p-dioxin exposure influence the expression of glutamate transporter GLT-1 in C6 glioma cells via the Ca(2+) /protein kinase C pathway.

The widespread environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), is considered one of the most toxic dioxin-like compounds. Although epidemiological studies have shown that TCDD exposure is linked to some neurological and neurophysiological disorders, the underlying mechanism of TCDD-mediated neurotoxicity has remained unclear. Astrocytes are the most abundant cells in the nervous systems, and are recognized as the important mediators of normal brain functions as well as neurological, neurodevelopmental and neurodegenerative brain diseases. In this study, we investigated the role of TCDD in regulating the expression of glutamate transporter GLT-1 in astrocytes. TCDD, at concentrations of 0.1-100 nm, had no significantly harmful effect on the viability of C6 glioma cells. However, the expression of GLT-1 in C6 glioma cells was downregulated in a dose- and time-dependent manner. TCDD also caused activation of protein kinase C (PKC), as TCDD induced translocation of the PKC from the cytoplasm or perinuclear to the membrane. The translocation of PKC was inhibited by one Ca(2+) blocker, nifedipine, suggesting that the effects are triggered by the initial elevated intracellular concentration of free Ca(2+) . Finally, we showed that inhibition of the PKC activity reverses the TCDD-triggered reduction of GLT-1. In summary, our results suggested that TCDD exposure could downregulate the expression of GLT-1 in C6 via Ca(2+) /PKC pathway. The downregulation of GLT-1 might participate in TCDD-mediated neurotoxicity. Copyright © 2016 John Wiley & Sons, Ltd.

Reactive oxygen species mediate nitric oxide production through ERK/JNK MAPK signaling in HAPI microglia after PFOS exposure.

Perfluorooctane sulfonate (PFOS), an emerging persistent contaminant that is commonly encountered during daily life, has been shown to exert toxic effects on the central nervous system (CNS). However, the molecular mechanisms underlying the neurotoxicity of PFOS remain largely unknown. It has been widely acknowledged that the inflammatory mediators released by hyper-activated microglia play vital roles in the pathogenesis of various neurological diseases. In the present study, we examined the impact of PFOS exposure on microglial activation and the release of proinflammatory mediators, including nitric oxide (NO) and reactive oxidative species (ROS). We found that PFOS exposure led to concentration-dependent NO and ROS production by rat HAPI microglia. We also discovered that there was rapid activation of the ERK/JNK MAPK signaling pathway in the HAPI microglia following PFOS treatment. Moreover, the PFOS-induced iNOS expression and NO production were attenuated after the inhibition of ERK or JNK MAPK by their corresponding inhibitors, PD98059 and SP600125. Interestingly, NAC, a ROS inhibitor, blocked iNOS expression, NO production, and activation of ERK and JNK MAPKs, which suggested that PFOS-mediated microglial NO production occurs via a ROS/ERK/JNK MAPK signaling pathway. Finally, by exposing SH-SY5Y cells to PFOS-treated microglia-conditioned medium, we demonstrated that NO was responsible for PFOS-mediated neuronal apoptosis.

Perfluorooctane sulfonate mediates microglial activation and secretion of TNF-α through Ca²âº-dependent PKC-NF-кB signaling.

Perfluorooctane sulfonate (PFOS), a ubiquitous pollutant widely found in the environment and biota, can cause numerous adverse effects on human health. In recent years, PFOS's toxic effects on the central nervous system (CNS) have been shown. However, we still have a lot to study in the underlying molecular mechanism of PFOS's neurotoxicity. Microglia, the innate immune cells of CNS, are critically implicated in various neurological diseases caused by pro-inflammatory mediators. In our research, we found that HAPI microglia secreted tumor necrosis factor-alpha (TNF-α) after PFOS exposure in time-dependent and dose-dependent way. We also discovered that intracellular concentration of free Ca(2+) ([Ca(2+)]i) significantly increased after PFOS treatments. It was noteworthy here the secretion of TNF-α mediated by PFOS was blocked by Ca(2+) inhibitor and protein kinase C (PKC) inhibitor. Besides these, we had learned as well that PFOS brought about the up-regulation of phosphorylated nuclear factor kappa B (NF-кB) p65 expression and accelerated degradation of NF-κB inhibitor alpha (IкBα), however, these effects could be attenuated or blocked by Ca(2+) inhibitor and PKC inhibitor. Finally, through treating SH-SY5Y cells with PFOS-treated microglial conditioned medium, we demonstrated that TNF-α mediated neuronal apoptosis. To sum up, our research had shown, for the first time, that the distinct TNF-α secretion brought by PFOS in HAPI microglia, was achieved through the Ca(2+)-dependent PKC-NF-кB signaling, subsequently participating in neuronal loss.