Toxicology and applied pharmacology最新文献

Opioids are potent analgesics in clinical pain management but exert variable analgesia in different pain types. Opioid-induced constipation is a common side effect of opioid therapy, and whether opioids induce different gastrointestinal motility inhibitions in different pain types is unknown. In this study, we evaluated the antinociceptive effects and inhibition of upper gastrointestinal transit and colonic bead expulsion of morphine, DAMGO, and Deltorphin in mouse CFA chronic inflammatory pain, SNI chronic neuropathic pain, and carrageenan chronic inflammatory pain models. Furthermore, quantitative PCR and immunofluorescence were used to investigate the mechanisms underlying the altered inhibition. Results showed that intrathecal administration of morphine, DAMGO, and Deltorphin produced higher antinociceptive effects in the CFA and carrageenan groups than in the SNI group. Upper gastrointestinal transit inhibition was significantly enhanced in the carrageenan group by morphine and DAMGO; colonic bead expulsion inhibition was also enhanced in the CFA and carrageenan groups by morphine and DAMGO, but not in Deltorphin treatment. Additionally, mu (MOR) opioid receptor mRNA and MOR-expressing cell density in the lumbar spinal cord of CFA and carrageenan mice were increased, whereas delta opioid receptor expression remained unchanged in these groups. Finally, the pharmacological blockade of MOR completely prevented the enhanced upper gastrointestinal transit inhibition in the carrageenan group by morphine and DAMGO. Altogether, our results indicate that gastrointestinal motility inhibition induced by MOR agonists can be enhanced with upregulated spinal MOR expression in chronic inflammatory pain.

Clozapine (CLZ) is an antipsychotic which is particularly used in treatment resistant schizophrenia patients who do not respond to other agents. It is preferred because it reduces suicidal behaviours and attempts, reducing aggression and violent behaviour. The aim of the study is to evaluate the effects of ABCB1 rs1045642 and UGT1A4 rs2011425 polymorphisms on CLZ and its major metabolite N- desmethly clozapine (DCLZ) plasma concentrations in patients with schizophrenia. A total 109 of Turkish patients with schizophrenia on continually administered CLZ monotherapy were included. The plasma concentrations of CLZ and DCLZ were measured using an HPLC after liquid-liquid extraction while, transporter gene ABCB1 and phase two enzyme UGT1A4 polymorphisms were identified using PCR- RFLP method. Results showed that UGT1A4*3 polymorphism has statistically significant effects on CLZ C/D and DCLZ C/D levels in patients with sub/supra therapeutic levels while ABCB1 C3435T polymorphism has a significant effect on CLZ/DCLZ ratio among patients who have subtherapeutic levels. This study indicates the influence of genetic differences on plasma levels and highlights the importance of pharmacogenetic studies in clinic. Using the obtained results as pharmacogenetic biomarkers will help clinicians provide effective treatment in individual patients and reduce the undesirable side effects.

Breast cancer (BC) is a leading cause of cancer-related mortality among women worldwide, with incidence rates rising globally. Urolithin B (UB), a bioactive metabolite of ellagic acid, has demonstrated promising anticancer effects in various cancer models. This study aimed to evaluate the effects of UB on the growth, angiogenesis, and metastasis of BC cells using both in vivo and in vitro approaches. Cytotoxic effects of UB were assessed on MDA-MB-231 cells and normal HFF cells using the MTT assay. Scratch assays and gelatin zymography demonstrated UB's suppression of cell migration and reduced enzymatic activities of MMP-2 and MMP-9. In a xenograft mouse model, UB significantly reduced tumor growth, enhanced necrosis, and decreased vascularity in tumor tissues. It downregulated mRNA expression levels of VEGF, VEGFR, MMP-2, and MMP-9, indicating potent anti-angiogenic and anti-metastatic properties. Additionally, UB exhibited antioxidant effects by increasing total thiol content and the activities of superoxide dismutase (SOD) and catalase (CAT) while reducing malondialdehyde (MDA) levels in tumor tissues. In conclusion, our results highlight the anticancer potential of UB, through its ability to suppress the proliferation, angiogenesis, and metastatic properties of BC both in vitro and in vivo. Coupled with its antioxidant properties, UB emerges as a promising and safe candidate for further pre-clinical and clinical research and therapeutic applications in BC management.

Liver damage caused by acetaminophen (APAP) overdose remains a worldwide medical problem. New therapeutic medicines for APAP poisoning are needed as the efficacy of the only antidote, N-acetyl-cysteine (NAC), significantly decreases if administered after 8 h of APAP intake and massive APAP overdose remains to induce hepatotoxicity despite the timely administration of NAC. Peroxisome proliferator-activated receptor β/δ (PPARβ/δ) possesses versatile roles including regulation of lipid homeostasis and anti-inflammation in the liver. This study aimed to investigate the effects of GW0742, one specific PPARβ/δ agonist, on APAP-caused liver damage in mice. We found that GW0742 (40 mg/kg, i.p.) pretreatment completely blocked the increase of serum aminotransferase activities, hepatocyte necrosis, oxidative stress, and liver inflammation in mice exposed to 300 mg/kg APAP (i.p.). Mechanistically, GW0742 pretreatment significantly suppressed the M1 polarization of liver Kupffer cells and activation of NLRP3 inflammasome. Interestingly, GW0742 remained effective when administered 6 h after APAP exposure, although its efficacy was less pronounced than that administered 6 h before the APAP challenge. Notably, GW0742 exhibited a more profound effect than NAC evidenced by the lower serum alanine transaminase (ALT) level and the improved histopathological manifestation. Furthermore, exposure to APAP for 6 h had resulted in dramatic liver inflammation, while pretreatment with GW0742 prior to APAP exposure did not influence the increase in serum aminotransferase activity and oxidative stress at 2 h after APAP exposure. These results highlight that PPARβ/δ may be a promising therapeutic target for treating APAP-caused acute liver damage probably acting on liver macrophages.

Salidroside, a glucoside of tyrosol, is a powerful active ingredient extracted from the Chinese herb medicine Rhodiola rosea L.. As a neuroprotective agent, the application of salidroside in combination with neural tissue engineering has recently attracted much attention in peripheral nerve repair and reconstruction. However, the cellular and molecular mechanisms by which salidroside promotes nerve regeneration remain to be elucidated. We aim to evaluate the long-term neuroprotective potential of salidroside in an experimental rat model of neonatal sciatic nerve crush injury, with a focus on target-deprived neuronal death and the mechanisms involved. Behavioral analysis showed that salidroside dose-dependently improved voluntary hindlimb behavior and rod rotation ability following neonatal axotomy during an 8-week observation period. According to electrophysiology, Fluoro-Gold retrograde tracing, histological and immunohistochemical analyses, salidroside significantly improved nerve regeneration and reinnervation. Nissle and TUNEL staining, as well as caspase-3 activation assay indicated a beneficial effect of salidroside on retrograde loss and apoptosis of motoneurons within 2 weeks after axotomy. qPCR, ELISA and oxidative stress experiments revealed that salidroside improved the imbalance of spinal microenvironment, including oxidative stress and down-regulation of neurotrophic factors. Western blotting analysis showed that salidroside enhanced the activation of PI3K/Akt and inhibited the p38 MAPK signaling pathway following axotomy. The oxidative stress and axonal disconnection/regeneration models of primary motoneurons in vitro further confirmed the involvement of these two pathways in the neuroprotective effects of salidroside. These data provide a theoretical basis for the application of salidroside in peripheral nerve repair and reconstruction.

Centromere protein K (CENPK) is a newly identified malignancy-related gene that exhibits differential expression in various cancers and plays a crucial role in carcinogenesis. However, it remains uncertain whether CENPK is involved in clear cell renal cell carcinoma (ccRCC). This work aimed to unveil the expression, clinical significance, biological functions, and regulatory mechanisms of CENPK in ccRCC. Through analysis of RNA-seq data obtained from TCGA, a high expression pattern of CENPK was identified in ccRCC, which was found to be associated with pathologic stage, histologic grade, and clinical outcome. The enrichment of CENPK in ccRCC was further verified through the analysis of clinical samples. By conducting cellular functional experiments, we showed an inhibitory effect of CENPK knockdown on the malignant behavior of ccRCC cells. GSEA revealed a close relationship between CENPK and the Hippo-YAP1/TAZ signal cascade. The following experiments demonstrated that the activation of YAP1/TAZ was strongly inhibited by CENPK knockdown, and this change was accompanied by a decrease in the levels of CTGF and CYR61. Blockade of the MST1/2-LATS1/2 axis reversed the suppressive impact of CENPK knockdown on YAP1/TAZ. The tumor-promoting impact observed upon CENPK overexpression was diminished in YAP1 knockout cells. Notably, ccRCC cells with reduced CENPK expression exhibited a diminished capability to form tumors in nude mice. This report highlights the importance of CENPK in ccRCC and sheds new light on the underlying mechanism of this cancer type. Therefore, CENPK has the potential to serve as a viable candidate target for treating ccRCC.

Methomyl (MET), a universally used insecticide, has many adverse effects on various organs in both humans and animals including the liver, kidneys, and heart. Betaine (BET), a natural antioxidant, has a protective role against many toxicants-induced cardiovascular disorders. The present study was designed to elucidate the molecular mechanistic way underlying the mitigating effect of BET against MET-induced cardiopulmonary injury and inflammation in rats. Four groups of rats were used and orally administered the consequent materials daily for 28 days: normal saline, BET (250 mg/kg bwt), MET (2 mg/kg bwt), MET + BET. Blood and tissue (heart & lungs) samples were collected to assess the oxidative stress markers, lipid profile, biochemical markers, microscopic appearance, and inflammatory gene regulations. The results proved that MET induced oxidant/antioxidant imbalance, elevation of serum creatine kinase (CK) and lactate dehydrogenase (LDH) levels, and deterioration in lipid profile. The histopathological inspection showed severe myocardial necrosis and interstitial pneumonia along with bronchitis and alveolar damage. There was a marked increase in the intensity of cyclooxygenase-2 (Cox-2) and inducible nitric oxide synthase (iNOS) immunostaining with marked upregulation of the transcriptase levels of keap-1gene and downregulation of nuclear factor erythroid 2-related factor-2 (Nrf-2) and heme oxygenase-1 (HO-1) genes in both heart and lung tissues of MET group. Otherwise, the coadministration of BET with MET markedly alleviated the abovementioned toxicological parameters. We can conclude that BET was able to reduce the MET-induced oxidative stress-mediated cardiovascular injury and pulmonary inflammation by modulating Keap-1/Nrf-2 signaling pathway and inactivating Cox-2 and iNOS expression which therefore reduced further cellular damage and inflammatory response.

Introduction: Accurate staging of malignancies often requires comprehensive evaluation of lymph nodes. However, finding these lymph nodes during oncological surgery is a daunting and time-consuming task, which increases the risk of missed lymph nodes and complications. Near-infrared (NIR) fluorescence imaging with the experimental fluorescent contrast agent PanLN800(-Forte) could provide real-time identification of lymph nodes and may solve this longstanding problem. In the current study we performed the preclinical toxicology evaluation of PanLN800(-Forte) towards its clinical translation for intraoperative pan lymph node imaging in thoracic surgery.

Methods: A single extended dose toxicology study was conducted to determine the safety and potential toxicity of PanLN800(-Forte) after administration of a single intravenous dose to Wistar Han rats. The study included a control group and two treatment groups (5.0 mg/kg and 15.0 mg/kg PanLN800(-Forte)), each consisting of 10 male and 10 female rats. Experimental endpoints included moribundity/mortality, clinical signs, body weights, body weight gains, clinical pathology, toxicity, and gross necropsy observations.

Results: Unexpected acute mortality was observed after administration of 5.0 mg/kg PanLN800(-Forte) to rats. No clear cause of sudden death was found after gross necropsy and pathology observations. To understand the mechanism of toxicity of PanLN800(-Forte), several additional tests were performed. By elimination, acute cardiac toxicity appears to be the cause of acute mortality in rats, in which PanLN800(-Forte) was found to be a potent inotrope acting as a cardiac calcium sensitizer.

Conclusion: PanLN800(-Forte) is not a viable fluorescent contrast agent for lymph node imaging in surgery because of cardiac calcium sensitization but may be a novel treatment for heart failure.

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Due to the poor therapeutic efficacy of CRC treatments and poor prognosis of the disease, effective treatment strategies are urgently needed. As long-term proteotoxic stress is a major cause of cell death, agents that induce proteotoxic stress offer a promising strategy for cancer intervention. Thiostrepton is a natural antibiotic derived from the Streptomyces genus. In the present study, we found that thiostrepton triggered apoptosis, reduced the migration of CRC cells, and inhibited xenograft tumour growth in vivo. Mechanistically, thiostrepton reduced proteasome activity; induced the aggregation of ubiquitinated proteins; caused endoplasmic reticulum (ER) stress, which was characterized by increased protein levels of GRP78, ATF4, P-eIF2α, and CHOP and cytosolic calcium release; and ultimately resulted in cell death. Thiostrepton-related changes in cell survival and cell migration, as well as mechanistical processes, were almost completely reversed by treatment with the antioxidant N-acetylcysteine (NAC), suggesting that the mechanism is dependent on reactive oxygen species (ROS). These results demonstrated that thiostrepton induced apoptosis and inhibited migration through ROS-induced ER stress and proteotoxic stress in colorectal cancer.

The elevated risk of cardiovascular disease (CVD) associated with inflammatory rheumatic diseases has long been recognized. Patients with established rheumatoid arthritis (RA) have a higher mortality rate compared to the general population due to abnormal platelet activation. Thymidine phosphorylase (TYMP) plays a crucial role in platelet activation and thrombosis, following bridging the link between RA and CVD. Data from Gene Expression Omnibus (GEO) database exhibited that TYMP levels were highly expressed in synovial tissues, immune cells, and whole blood of RA patients especially those with high levels of inflammation. Platelet count (PLT) and plateletcrit (PCT) were positively correlated with the severity of inflammation in rheumatoid arthritis while platelet distribution width (PDW) and mean platelet volume (MPV) were adverse. Levels of CD62P and TYMP in platelets of patients with active RA were significantly elevated compared to patients in the inactive phase. In vivo experiments showed that reducing TYMP expression levels of platelets could relieve inflammation in Adjuvant-Induced Arthritis (AIA) mice. Platelet activation was significantly elevated in AIA model mice, along with increased levels of intracellular calcium (Ca²⁺), reactive oxygen species (ROS), and decreased Mitochondrial Membrane Potential (ΔΨm). However, treatment with Tipiracil hydrochloride (TPI) or the utilization of Tymp^-/- mice reversed these effects. In vitro stimulation of wild type (WT) mouse platelets with tumor necrosis factor-alpha (TNF-α) promoted platelet activation, elevated levels of intracellular Ca²⁺as well as ROS while decreased ΔΨm. Platelets of WT mice treated with TPI or platelets of Tymp^-/- mice exhibited the adverse results. Our study illustrates the vital role of TYMP in promoting RA inflammation and platelet activation, suggesting that TYMP may be a potential therapeutic target for RA.