Fentanyl Induces Novel Conditioned Place Preference in Adult Zebrafish, Disrupts Neurotransmitter Homeostasis, and Triggers Behavioral Changes.

Abuse of new psychoactive substances increases risk of addiction, which can lead to serious brain disorders. Fentanyl is a synthetic opioid commonly used in clinical practice, and behavioral changes resulting from fentanyl addiction have rarely been studied with zebrafish models. In this study, we evaluated the rewarding effects of intraperitoneal injections of fentanyl at concentrations of 10, 100, and 1000 mg/L on the group shoaling behavior in adult zebrafish. Additional behavioral tests on individual zebrafish, including novel tank, novel object exploration, mirror attack, social preference, and T-maze memory, were utilized to evaluate fentanyl-induced neuro-behavioral toxicity. The high doses of 1000 mg/L fentanyl produced significant reward effects in zebrafish and altered the neuro-behavioral profiles: reduced cohesion in shoaling behavior, decreased anxiety levels, reduced exploratory behavior, increased aggression behavior, affected social preference, and suppressed memory in an appetitive associative learning task. Behavioral changes in zebrafish were shown to be associated with altered neurotransmitters, such as elevated glutamine (Gln), gamma-aminobutyric acid (GABA), dopamine hydrochloride (DA), and 5-hydroxytryptamine (5-HT). This study identified potential fentanyl-induced neurotoxicity through multiple neurobehavioral assessments, which provided a method for assessing risk of addiction to new psychoactive substances.

Caffeine-induced neurotoxicity mediated by Nrf2 pathway in PC12 cells and zebrafish larvae.

Caffeine is one of the most widely used psychostimulants in the world and possesses central excitative, anti-depressive, and neuroprotective properties. However, excessive ingestion or abuse of caffeine can lead to intoxication. Many toxic effects are attributed to oxidative damage, and nuclear factor erythroid 2-related factor 2 (Nrf2) is a critical intracellular regulator of the oxidative stress response. Here, we investigated the neurotoxicity of caffeine in rat pheochromocytoma PC12 cells and zebrafish larvae. It was found that caffeine inhibited the viability of PC12 cells in a dose- and time-dependent manner. Furthermore, it induced PC12 cell apoptosis and elevated reactive oxygen species (ROS) production. Quantitative polymerase chain reaction (qPCR) and western blotting revealed that caffeine also inhibited the expression levels of Nrf2 mRNA and protein and its target genes (e.g., NADPH quinone oxidoreductase 1 [NQO1]). Furthermore, Nrf2 silencing attenuated the toxic effects of caffeine. In addition, zebrafish larvae were treated with different doses of caffeine. Behavioral experiments showed that a low dose of caffeine (0.05 to 0.3 mM) increased the average distance of movement and promoted excitation. Survivorship curves showed that caffeine (0.2 to 1.5 mM) caused lethality. Finally, qPCR revealed that a higher dose of caffeine inhibited mRNA levels in the Nrf2 pathway. Based on these results, this study identified for the first time that overuse of caffeine can induce neurotoxicity by inhibiting the Nrf2 pathway. These results will provide a new perspective for studies on caffeine toxicity.

Ginsenoside Rd reverses cisplatin resistance in non-small-cell lung cancer A549 cells by downregulating the nuclear factor erythroid 2-related factor 2 pathway.

Clinical drug resistance to platinum-based chemotherapy is considered a major impediment in the successful treatment of non-small-cell lung cancer (NSCLC). The nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway regulates the oxidative stress response, and in many cancer types, the high constitutive expression of NRF2 leads to proliferation and chemoresistance. Ginsenoside Rd (GS-Rd) is the main active component of ginsenosides. Here, GS-Rd was found to inhibit the proliferation of A549 lung cancer cells and induce G0/G1 phase arrest. We established cisplatin (DDP)-resistant A549 cell lines (A549/DDP). The half maximal inhibitory concentrations of DDP, gemcitabine, and adriamycin were much higher in A549/DDP cells than in A549 cells. The A549/DDP cell lines developed multidrug resistance, accompanied by activation of multidrug resistance protein 1 and multidrug resistance-associated protein 1, as well as NRF2 and its target genes. Treatment with GS-Rd inhibited the NRF2 pathway and significantly sensitized A549/DDP cells to therapeutic drugs. In addition, NRF2 knockdown attenuated the synergistic effects of GS-Rd in both A549 and A54/DDP cells. Taken together, these data show that NRF2 plays an important role in acquired drug resistance in NSCLC, and GS-Rd may ameliorate this chemoresistance by downregulating the NRF2 pathway. This study demonstrates that the NRF2 pathway may serve as a therapeutic target in NSCLC, and ginseng compounds may be effective for the treatment of this disease.

H∞ output-feedback fuzzy proportional-integral control of fully delayed input/output systems.

This paper presents the output-feedback fuzzy proportional-integral (PI) controller design for uncertain nonlinear systems with both fully delayed input and output. Based on the Takagi-Sugeno (T-S) fuzzy model representation, the output-feedback PI control is realized via parallel distributed PI compensation and novel LMI gain design. Although the T-S fuzzy PI controller is simple, asymptotic output regulation is assured to overcome the effect of uncertainty, state delay, and full input/output delays. When considering disturbance and measurement noise, the control performance is achieved by robust gain design. Furthermore, state observers and bilinear matrix inequality conditions are removed in this paper. Finally, time-delay Chua׳s circuit system and a continuous-time stirred tank reactor are taken as applications to show the expected performance.

Grey anti-inflammation analysis of phenolic acid phenethyl esters in human neutrophils.

This paper presents grey structure activity relationship analysis for anti-inflammation of phenolic acid phenethyl esters in human neutrophils. To study the anti-inflammation effect, 14 compounds of phenolic acid phenethyl esters are synthesised, while the inhibition on superoxide anion generation (which is linked to an inflammation effect) induced by PMA and fMLP stimulants is detected. Next, the relationship weighting of each functional group of phenolic acid phenethyl esters is found by applying the grey system theory on the measured data. Moreover, evident structure activity relationships are established to regulate the anti-inflammation effect of such compounds, e.g. the most important functional group affecting the anti-inflammation in human neutrophils is revealed. In addition, some extending results are obtained based on the grey analysis. It is interesting that the analysed result is consistent with the actual circumstance. In comparison with traditional methods, this paper applying the grey theory indicates more characteristic information about the structure activity relationships of phenolic acid phenethyl esters while fewer data samples are required.

Luteolin sensitizes two oxaliplatin-resistant colorectal cancer cell lines to chemotherapeutic drugs via inhibition of the Nrf2 pathway.

Oxaliplatin is a first-line therapy for colorectal cancer, but cancer cell resistance to the drug compromises its efficacy. To explore mechanisms of drug resistance, we treated colorectal cancer cells (HCT116 and SW620) long-term with oxaliplatin and established stable oxaliplatin-resistant lines (HCT116-OX and SW620-OX). Compared with parental cell lines, IC50s for various chemotherapeutic agents (oxaliplatin, cisplatin and doxorubicin) were increased in oxaliplatin-resistant cell lines and this was accompanied by activation of nuclear factor erythroid-2 p45-related factor 2 (Nrf2) and NADPH quinone oxidoreductase 1 (NQO1). Furthermore, luteolin inhibited the Nrf2 pathway in oxaliplatin-resistant cell lines in a dose-dependent manner. Luteolin also inhibited Nrf2 target gene [NQO1, heme oxygenase-1 (HO-1) and GSTα1/2] expression and decreased reduced glutathione in wild type mouse small intestinal cells. There was no apparent effect in Nrf2-/- mice. Luteolin combined with other chemotherapeutics had greater anti-cancer activity in resistant cell lines (combined index values below 1), indicating a synergistic effect. Therefore, adaptive activation of Nrf2 may contribute to the development of acquired drug-resistance and luteolin could restore sensitivity of oxaliplatin-resistant cell lines to chemotherapeutic drugs. Inhibition of the Nrf2 pathway may be the mechanism for this restored therapeutic response.

Luteolin inhibits the Nrf2 signaling pathway and tumor growth in vivo.

Nuclear factor erythroid 2-related factor 2 (Nrf2) is over-expressed in many types of tumor, promotes tumor growth, and confers resistance to anticancer therapy. Hence, Nrf2 is regarded as a novel therapeutic target in cancer. Previously, we reported that luteolin is a strong inhibitor of Nrf2 in vitro. Here, we showed that luteolin reduced the constitutive expression of NAD(P)H quinone oxidoreductase 1 in mouse liver in a time- and dose-dependent manner. Further, luteolin inhibited the expression of antioxidant enzymes and glutathione transferases, decreasing the reduced glutathione in the liver of wild-type mice under both constitutive and butylated hydroxyanisole-induced conditions. In contrast, such distinct responses were not detected in Nrf2(-/-) mice. In addition, oral administration of luteolin, either alone or combined with intraperitoneal injection of the cytotoxic drug cisplatin, greatly inhibited the growth of xenograft tumors from non-small-cell lung cancer (NSCLC) cell line A549 cells grown subcutaneously in athymic nude mice. Cell proliferation, the expression of Nrf2, and antioxidant enzymes were all reduced in tumor xenograft tissues. Furthermore, luteolin enhanced the anti-cancer effect of cisplatin. Together, our findings demonstrated that luteolin inhibits the Nrf2 pathway in vivo and can serve as an adjuvant in the chemotherapy of NSCLC.

Semi-decentralized adaptive fuzzy control for cooperative multirobot systems with H(infinity) motion/internal force tracking performance.

We present a semi-decentralized adaptive fuzzy control scheme for cooperative multirobot systems to achieve H(infinity) performance in motion and internal force tracking. First, we reformulate the overall system dynamics into a fully actuated system with constraints. To cope with both parametric and nonparametric uncertainties, the controller for each robot consists of two parts: 1) model-based adaptive controller; and 2) adaptive fuzzy logic controller (FLC). The model-based adaptive controller handles the nominal dynamics which results in both zero motion and internal force errors for a pure parametric uncertain system. The FLC part handles the unstructured dynamics and external disturbances. An H(infinity) tracking problem defined by a novel performance criterion is given and solved in the sequel. Hence, a robust controller satisfying the disturbance attenuation is derived being simple and singularity-free. Asymptotic convergence is obtained when the fuzzy approximation error is bounded with finite energy. Maintaining the same results, the proposed controller is further simplified for easier implementation. Finally, the numerical simulation results for two cooperative planar robots transporting an object illustrate the expected performance.