Showing papers in "Fundamental & Clinical Pharmacology in 2020"

Melatonin as a potential modulator of Nrf2.

Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) is considered as the sensor of oxidative stress, and the main aim of this signaling pathway is to maintain physiological condition by induction of redox balance. Also, this pathway exerts anti-inflammatory effects via antioxidant response element. Oxidative stress is a key factor in a variety of pathological conditions and high level of oxidative stress is associated with damages in lipids, proteins, genetic material, and cell membrane. Multiple drugs have been developed in order to diminish oxidative stress. However, synthetic drugs suffer from various drawbacks such as high cost and side effects. On the other hand, naturally occurring compounds are of interest due to their minimal side effects and valuable biological activities. Melatonin is a hormone of pineal gland which is found in different plants. This compound has a variety of favorable biological and therapeutic activities such as antioxidant, anti-inflammatory, anti-tumor, anti-diabetic, and cardioprotection. At the present review, we demonstrate that Nrf2 signaling pathway explains some of the therapeutic and biological effects of melatonin.

Empagliflozin attenuates transient cerebral ischemia/reperfusion injury in hyperglycemic rats via repressing oxidative–inflammatory–apoptotic pathway

Abstract: Hyperglycemia is one of the ischemic neuronal damage triggers that exacerbate the response to oxidative stress, inflammation, and apoptosis induced by cerebral ischemia/reperfusion (I/R) injury. Empagliflozin, a sodium-glucose cotransporter 2 (SGLT 2) inhibitor, was shown to effectively reduce hyperglycemia and glucotoxicity besides improving glycemic control in diabetics. Therefore, the present study was conducted to investigate the neuroprotective effect of empagliflozin against cerebral I/R injury in hyperglycemic rats. Hyperglycemia was induced by streptozotocin (55 mg/kg), and transient cerebral I/R was induced by bilateral common carotid occlusion for 30 min followed by 24-h reperfusion. Either empagliflozin (10 mg/kg; i.p.) or gliclazide (2 mg/kg, p.o.) was administered at 1 and 24 h after reperfusion. Treatment with empagliflozin showed a significant amelioration of behavioral/neurological functions and histopathological changes observed in brain tissues of hyperglycemic rats subjected to cerebral I/R injury. Comparable to gliclazide, empagliflozin decreased cerebral infarct volume along with suppression of cerebral oxidative stress, inflammatory, and apoptotic markers in brain tissues of hyperglycemic I/R-injured rats. These findings suggested that empagliflozin can significantly alleviate neuronal damage resulting from global I/R injury induced in hyperglycemic rats. The proposed neuroprotective effect of empagliflozin may be attributed to its glycemic control effect and related antioxidant, anti-inflammatory, and antiapoptotic effects.

Potential drug-drug interactions associated with drugs currently proposed for COVID-19 treatment in patients receiving other treatments.

Abstract: Patients with COVID-19 are sometimes already being treated for one or more other chronic conditions, especially if they are elderly. Introducing a treatment against COVID-19, either on an outpatient basis or during hospitalization for more severe cases, raises the question of potential drug-drug interactions. Here, we analyzed the potential or proven risk of the co-administration of drugs used for the most common chronic diseases and those currently offered as treatment or undergoing therapeutic trials for COVID-19. Practical recommendations are offered, where possible.

Chronic prostatitis/chronic pelvic pain syndrome and prostate cancer: study of immune cells and cytokines.

Abstract: Prostate cancer and prostatitis are both significant health concerns. A large number of studies have established that the occurrence of the two is closely related. However, the most common prostatitis, type III chronic prostatitis/chronic pelvic pain syndromes (CP/CPPS), is reported to not correlate with the occurrence of prostate cancer. Although the etiology of CP/CPPS is unknown, it may be related to the autoimmune mechanism favored by most studies. Manipulating the immune system and targeting tumor microenvironment are promising new methods for the treatment of prostate cancer. Therefore, this review focuses on the immune cells and cytokines of CP/CPPS and prostate cancer from the perspective of biological immunology and immune microenvironment. We discuss T-regulatory (Treg) and T helper 17 (Th17) cells dysfunction, the abnormal regulation of T helper 1(Th1) and T helper 2 (Th2) cells, macrophages, and their related cytokines as key activators in CP/CPPS. In addition, we discuss the roles of Treg and Th17 cells, Th1 and Th2 cells, and related cytokines in modulating prostate cancer progression. This review highlights the concept that immune cells and cytokines provide a research strategy for the etiology of CP/CPPS and offer potentially promising targets for the treatment of prostate cancer.

Genesis of an emergency public drug information website by the French Society of Pharmacology and Therapeutics during the COVID-19 pandemic.

Abstract: On March 16, 2020, the French Society of Pharmacology and Therapeutics put online a national Question and Answer (Q&A) website, https://sfpt-fr.org/covid19 on the proper use of drugs during the COVID-19 pandemic. The working group 'Drugs and COVID-19' was composed of a scientific council, an editorial team, and experts in the field. The first questions were posted online during the first evening of home-confinement in France, March 17, 2020. Six weeks later, 140 Q&As have been posted. Questions on the controversial use of hydroxychloroquine and to a lesser extent concerning azithromycin have been the most consulted Q&As. Q&As have been consulted 226 014 times in 41 days. This large visibility was obtained through an early communication on Twitter, Facebook, traditional print, and web media. In addition, an early communication through the French Ministry of Health and the French National Agency for Medicines and Health Products Safety ANSM had a large impact in terms of daily number of views. There is a pressing need to sustain a public drug information service combining the expertise of scholarly pharmacology societies, pharmacovigilance network, and the Ministry of Health to quickly provide understandable, clear, expert answers to the general population's concerns regarding COVID-19 and drug use and to counter fake news.

Targeting MDR‐1 gene expression, BAX/BCL2, caspase‐3, and Ki‐67 by nanoencapsulated imatinib and hesperidin to enhance anticancer activity and ameliorate cardiotoxicity

Abstract: There is a great demand to introduce new approaches into cancer treatment field due to incidence of increased breast cancer all over the world. The current study was designed to evaluate the role of imatinib mesylate (IM) and/or hesperidin (HES) nanoparticles alone or in combination in enhancing the anticancer activity and to investigate the ability of nanoencapsulation to reduce cardiotoxicity of IM in solid Ehrlich carcinoma (SEC)-bearing mice. IM and HES were loaded into PLGA (poly(lactic-co-glycolic acid) polymer. SEC was induced in female albino mice as a model for experimentally induced breast cancer. Mice were randomly divided into eight groups (n = 10). On day 28 from tumor inoculation, mice were sacrificed and blood samples were collected in heparinized tubes for hematological studies, biochemical determination of lactate dehydrogenase (LDH), and glutamic oxaloacetic transaminase (SGOT) levels. In addition, tumor and cardiac tissues were utilized for histopathological examination as well as determination of MDR-1 gene expression. Immunohistochemical staining of BAX and BCL-2 was done. Nano IM- and/or Nano HES-treated groups showed a significant reduction in tumor volume, weight, hematological, cardiac markers, and tumor MDR-1 gene downregulation compared to free conventional treated groups. In conclusion, the use of HES as an adjuvant therapy with IM could improve its cytotoxic effects and limit its cardiac toxicity. Furthermore, nanoencapsulation of IM and/or HES with PLGA polymer showed a remarkable anticancer activity.

Effects of hippocampal histone acetylation and HDAC inhibition on spatial learning and memory in the Morris water maze in rats

Abstract: In recent years, it has been pointed out that epigenetic changes affect learning and memory formation. Particularly, it has been shown that histone acetylation and DNA methylation work in concert to regulate learning and memory formation. We aimed to examine whether acetylation of H2B within the rat hippocampus alters by trainings in the Morris water maze test. Male, 2-3 months old, Sprague Dawley rats were trained in Morris water maze task. Animals were given four trials per day for five consecutive days to locate a hidden platform. On the sixth day, the platform was removed and the animals were swum for 60 s. The effects of sodium butyrate, histone deacetylase inhibitor, were tested on normal and scopolamine-induced memory-impaired rats. The histone deacetylase inhibitor, sodium butyrate, increased histone H2B acetylation in normal rats. Sodium butyrate had no effect on learning and memory performance of normal rats; however, it partially ameliorated learning and memory disruption induced by scopolamine. So, the histone deacetylase inhibitors can be new treatment agent for cognitive disorders.

In vitro interactions of abiraterone, erythromycin, and CYP3A4: implications for drug-drug interactions

Abstract: Potential drug-drug interactions of the antitumor drug abiraterone and the macrolide antibiotic erythromycin were studied at the stage of cytochrome P450 3A4 (CYP3A4) biotransformation. Using differential spectroscopy, we have shown that abiraterone is a type II ligand of CYP3A4. The dependence of CYP3A4 spectral changes on the concentration of abiraterone is sigmoidal, which indicates cooperative interactions of CYP3A4 with abiraterone; these interactions were confirmed by molecular docking. The dissociation constant (Kd ) and Hill coefficient (h) values for the CYP3A4-abiraterone complex were calculated as 3.8 ± 0.1 μM and 2.3 ± 0.2, respectively. An electrochemical enzymatic system based on CYP3A4 immobilized on a screen-printed electrode was used to show that abiraterone acts as a competitive inhibitor toward erythromycin N-demethylase activity of CYP3A4 (apparent Ki = 8.1 ± 1.2 μM), while erythromycin and its products of enzymatic metabolism do not affect abiraterone N-oxidation by CYP3A4. In conclusion, the inhibition properties of abiraterone toward CYP3A4-dependent N-demethylation of erythromycin and the biologically inert behavior of erythromycin toward abiraterone hydroxylation were demonstrated.

In vitro assessment of P-gp and BCRP transporter-mediated drug–drug interactions of riociguat with direct oral anticoagulants

Abstract: As an alternative to vitamin K antagonists (VKAs), direct oral anticoagulants (DOACs) are increasingly prescribed in combination with riociguat in the treatment of chronic thromboembolic pulmonary hypertension (CTEPH). Pharmacokinetics of riociguat and DOACs are influenced by efflux transporters, such as P-glycoprotein (P-gp) and Breast Cancer Resistance Protein (BCRP). This work aimed to assess P-gp and BCRP-mediated drug-drug interactions of riociguat with DOACs using in vitro models. Bidirectional permeabilities of apixaban and rivaroxaban were investigated across MDCK-MDR1 and MDCK-BCRP models, in the absence and in the presence of increasing concentrations of riociguat (0.5-100 μm). Calculated efflux ratios were subsequently used to determine riociguat inhibition percentages and half maximal inhibitory concentration (IC50). P-gp-mediated efflux of apixaban and rivaroxaban was inhibited by 8% and 21%, respectively, in the presence of 100 μm riociguat. BCRP-mediated transport of apixaban and rivaroxaban was inhibited by 36% and 77%, respectively. IC50s of riociguat on MDCK-MDR1 and MDCK-BCRP models were higher than 100 μm for apixaban and higher than 100 μm and 46.5 μm for rivaroxaban, respectively. This work showed an in vitro inhibition of BCRP-mediated DOACs transport by riociguat. In vivo studies may be required to determine the clinical relevance of these transporter-mediated interactions.

Evaluation of antitumor effects of aspirin and LGK974 drugs on cellular signaling pathways, cell cycle and apoptosis in colorectal cancer cell lines compared to oxaliplatin drug

Abstract: Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies. Despite recent advances in the treatment for CRC, resistance to chemotherapy drugs and recurrence of the tumor are among the main problems for treatment in this cancer. The MTT assay was performed to assess the cytotoxic effects of drugs on CRC cell lines (SW742 and SW480) and normal colon cells. Three-dimensional culture (spheroid) was also used to evaluate the effect of drugs on tumor cell masses. The rate of expression of genes was also evaluated using Real-Time PCR. The analysis of the results demonstrated that aspirin and LGK974 have cytotoxic effects on CRC cell lines, and in the IC50 dose, they disintegrate the cancerous cell masses. These drugs reduce the invasion and increase apoptosis in SW742 and SW480 cell lines. A decrease in the expression of WNT, AXIN, TCF and APC genes and an increase in the expression of β-catenin gene in the WNT signaling pathway were revealed. The genes involved in the MAPK signaling pathway such as ERK, JNK, KRAS and MEK showed a decrease in expression and a increase in expression of RAF gene. In the apoptotic pathway, increased expression of BAX and decreased expression of BCL-2 were reported. Also, decreased expression of P53, cyclin D1 and COX-2 was observed. This study demonstrates that aspirin and LGK974 could be effective in inhibiting the signaling pathways of WNT and MAPK, arresting cell cycle and inducing apoptosis in CRC cell lines.

Novel potential of metformin on valproic acid-induced autism spectrum disorder in rats: involvement of antioxidant defence system.

Abstract: Prenatal exposure to valproic acid (VPA) has been shown to increase the risk of autism in children. This study examined the effect of metformin on VPA-induced autism spectrum disorders in rats. Pregnant albino rats administered VPA (500 mg/kg, i.p.) or normal saline (10 mL/kg, i.p.; vehicle-control) on gestational day 12.5. The pups were given metformin (5, 50 or 500 mg/kg, p.o.) or vehicle (10 mL/kg, p.o.) daily from postnatal day (PND) 21-50. Social behaviour, spatial learning/reference memory, repetitive behaviour and anxiety were assessed using the three-chamber social assay, Morris water maze (MWM), Y maze and elevated plus maze tests (EPM), respectively. On PND 51, the animals were euthanized and brains removed for biochemical assay. In utero VPA exposure caused significant reduction in sociability index, social novelty preference index in three-chambered apparatus and spatial learning and reference memory deficits in the MWM task as well as increase in repetitive/anxiety-like behaviour in Y maze and EPM tests, respectively, which were ameliorated by post-treatment with metformin in a dose-dependent manner. Moreover, prenatal VPA increased malondialdehyde (MDA) and nitrite levels as well as deficits in antioxidant enzymes activities in the hippocampus and prefrontal cortex (PFC) which were attenuated by metformin administration. Similarly, VPA-induced increase in acetylcholinesterase activity in the hippocampus and PFC were attenuated by postnatal treatment with metformin. Findings from this study showed that postnatal administration of metformin prevented valproic acid-induced autistic-like behaviour. Hence, metformin could be a potential adjunct in the management of autism spectrum disorders.

Differential effects of alliin and allicin on apoptosis and senescence in luminal A and triple-negative breast cancer: Caspase, ΔΨm, and pro-apoptotic gene involvement.

Abstract: Breast cancer is the most frequent cancer in women worldwide, and drug resistance is common in all breast cancer types. The combination of natural products with chemotherapies has attracted attention, as it was found that natural compounds enhance the effects of standard cancer chemotherapeutic drugs and protect from side effects. Into the different natural products, garlic has been recognized for its antitumor properties. It is suggested that its anticancer effects are associated with its organo-sulfur compounds, especially alliin and allicin. Here, we evaluated the effects of both molecules on cell death, senescence, and their senolytic potential in luminal A and triple-negative breast cancer cells. MCF-7 (luminal A) and HCC-70 (triple-negative) cells were cultured and treated with different concentrations of alliin or allicin. Then, cell viability was determined using the WST-1 reagent. Apoptosis and caspase activity were evaluated by flow cytometry; ΔΨm was assessed using a JC-10 fluorometric assay kit. Apoptosis-related genes were evaluated by RT-PCR. Proliferation was measured using bromodeoxyuridine incorporation. We also evaluated clonogenicity, senescence (β-Galactosidase Staining), and the senolytic effect of the compounds. Our results showed that allicin has antiproliferative, anticlonogenic, and senolytic effects. In addition, allicin decreased cell viability and induced apoptosis by loss of ΔΨm, caspase-3, caspase-8, and caspase-9 activation, upregulation of NOXA, P21, and BAK, as well as downregulation of BCL-XL expression. Contrary to allicin, alliin promoted clonogenicity, induced senescence, and did not exhibit pro-apoptotic effects in breast cancer cells.

Ketamine inhibits LPS‐mediated BV2 microglial inflammation via NMDA receptor blockage

Abstract: Microglial inflammation leads to the upregulation of proinflammatory cytokine and proinflammatory enzyme expression, resulting in inflammation-induced neuronal cell apoptosis. Ketamine, an anesthetic mostly used in critical patients, has been reported to possess neuroprotective effects. However, the potential mechanism is still not well understood. In the present study, we investigated how ketamine attenuates lipopolysaccharide (LPS)-mediated BV2 cell inflammation. LPS upregulated proinflammatory cytokine and proinflammatory enzyme expression, increased NF-κB phosphorylation and nuclear translocation, and augmented calcium (Ca2+ )/calmodulin-dependent protein kinase II (CaMK II) phosphorylation and Ca2+ levels in BV2 cells. Ketamine could reverse these LPS-induced effects. Furthermore, AP5, an inhibitor of NMDA receptors, inhibited LPS-induced inflammatory effects in BV2 cells, which was similar to the effects of ketamine. Moreover, these effects of ketamine against LPS-mediated inflammation in BV2 cells could be reversed by D-serine, an activator of NMDA receptors. The present study suggests that ketamine, by inhibiting NMDA receptors, attenuating Ca2+ levels, and inhibiting CaMK II phosphorylation, NF-κB phosphorylation and nuclear translocation, may ameliorate LPS-mediated inflammation in BV2 cells.

Effect of antimicrobial peptides HNP-1 and hBD-1 on Staphylococcus aureus strains in vitro and in vivo.

Abstract: The aims of this study were: (i) To investigate the activity of recombinant AMPs HNP-1 and hBD-1 in combination with cefotaxime against Staphylococcus aureus strains (MSSA and MRSA) in vitro using checkerboard method; (ii) To investigate the activity of HNP-1 and hBD-1 encapsulated in silicon nanoparticles (niosomes) in the treatment of MRSA-infected wound in rats. For this S. aureus strains (MSSA and MRSA) were isolated from patients with diabetic foot infection. Cefotaxime, recombinant HNP-1 and hBD-1 (in all possible combinations with each other) were used for testing by the checkerboard method. Two niosomal topical gels with HNP-1/hBD-1 were prepared to treat MRSA-infected wounds in rats. Gels were administered once a day, the control group-without treatment. Wound healing rate was calculated on the 4th, 9th and 16th days of the experiment and compared using one-way ANOVA with Bonferroni correction. MIC of HNP-1 for MSSA and MRSA was the same-1 mg/L. MIC of hBD-1 for MSSA and MRSA was also the same-0.5 mg/L. Topical gels with niosomal HNP-1 (or hBD-1) showed a significantly faster wound healing in comparison with the control. The data obtained open up prospects for use of AMPs encapsulated in silica nanoparticles for the development of new antibiotics.

Endogenous hydrogen sulfide alleviates methotrexate-induced cognitive impairment by attenuating endoplasmic reticulum stress-induced apoptosis via CHOP and caspase-12.

Abstract: The aim of this study was to estimate whether methotrexate (MTX) promotes cognitive impairment via increased ER stress and disrupted H2 S signaling in the hippocampus and whether H2 S may alleviate MTX-induced cognitive impairment by inhibiting ER stress through CHOP and caspase-12. Cognitive impairment behaviors were observed by Morris water maze test, and the apoptosis of neurons was assessed by TUNEL assay. The production of neurons was analyzed by DCX and Ki67 immunohistochemistry. The expressions of CHOP and caspase-12 in the hippocampus were determined by Western blot and immunohistochemistry. MTX increased the expression of CHOP and caspase-12 and the number of TUNEL-positive cells in the hippocampus by inhibiting endogenous H2 S-induced neuronal pyknosis in the hippocampal CA1 region. MTX decreased the number of DCX- and Ki67-positive cells in the hippocampal DG region. The results of Morris water maze showed that MTX could damage the spatial memory of rats. The changes of MTX-induced Morris water maze test in mice and H2 S levels in serum and hippocampus, as well as the expression of CHOP and caspase-12 and the number of CHOP and caspase-12-positive neurons in the hippocampus, indicated that H2 S could alleviate the cognitive impairment induced by methotrexate through CHOP and caspase-12.

Omentin-1 attenuates adipose tissue inflammation via restoration of TXNIP/NLRP3 signaling in high-fat diet-induced obese mice.

Abstract: Omentin-1 is an adipokine expressed by the adipose tissue and is reduced in obesity. This study was designed to calculate the protective efficiency and mechanism of omentin-1 against inflammation of the adipose tissue in obese mice. A transgenic mouse model with omentin-1 protein overexpression was established by crossing omentin-1 transgenic mice with Fabp4-Cre mice. Obesity was induced in the mice by feeding them a high-fat diet for 10 weeks. Fabp4-Cre-mediated overexpression of omentin-1 significantly increased serum omentin-1 level, serum anti-inflammatory factor levels, and expression of M2-specific mRNAs; inhibited body weight and adipose tissue weight gain; improved glucose tolerance, insulin tolerance, and insulin sensitivity; decreased serum levels of insulin and proinflammatory factors, adipocyte size, and expression of M1-specific mRNAs; suppressed macrophage infiltration; downregulated expression of proinflammatory factors; upregulated expression of anti-inflammatory factors; and inhibited thioredoxin-interacting protein (TXNIP)/NOD-like receptor 3 (NLRP3) signaling in the adipose tissue of obese mice. An NLRP3 inhibitor (20 mg/kg MCC950) exhibited the same effects as overexpression of omentin-1. Pretreatment with omentin-1 inhibited lipopolysaccharide-induced inflammation via TXNIP/NLRP3 signaling in RAW 264.7 macrophages. These findings suggest that omentin-1 suppresses adipose tissue inflammation in obese mice, at least partly, via inhibiting the TXNIP/NLRP3 signaling pathway.

NRF2/ABCB1‐mediated efflux and PARP1‐mediated dampening of DNA damage contribute to doxorubicin resistance in chronic hypoxic HepG2 cells

Abstract: Transarterial chemoembolization (TACE)-induced hypoxia can trigger residual liver cancer cells to present a more aggressive phenotype associated with chemoresistance, but the underlying mechanisms are still unknown. In this study, the human liver cancer cell line HepG2 was pre-cultured in different oxygen environments to examine the possible mechanisms of hypoxia-induced doxorubicin resistance. Our study showed that HepG2 cells pre-cultured in a chronic intermittent hypoxic environment exhibited significant resistance to doxorubicin, evidenced by increased intracellular doxorubicin efflux, relatively higher cell proliferation, lower apoptosis, and decreased DNA damage. These changes were accompanied by high levels of NRF2 and ABCB1 under conditions of both chronic and acute hypoxia and PARP1 gene expression only under conditions of chronic hypoxia. SiRNA-mediated silencing of NRF2 gene expression downregulated the expression of ABCB1 and increased the intracellular doxorubicin accumulation and cell apoptosis both in acute and chronic hypoxic HepG2 cells. Moreover, silencing of PARP1 gene expression increased the doxorubicin-induced DNA damage and cell apoptosis in chronic hypoxic cells. On the basis of these findings, we concluded that NRF2/ABCB1-mediated efflux and PARP1-mediated DNA repair contribute to doxorubicin resistance in chronic hypoxic HepG2 cells.

GPER-mediated, oestrogen-dependent visceral hypersensitivity in stressed rats is associated with mast cell tryptase and histamine expression.

Abstract: Visceral hypersensitivity (VH) is common in irritable bowel syndrome (IBS), and female patients are more likely to seek healthcare services for IBS-related abdominal pain. Oestrogen has been reported to mediate pain modulation via its receptor, and mast cells are known to participate in the development of visceral hypersensitivity. Our previous studies showed that the G-protein-coupled oestrogen receptor (GPER, also known as GPR30) was expressed by mast cells in human colonic tissues and was associated with IBS type and severity of visceral pain. However, whether GPER is involved in oestrogen-dependent visceral hypersensitivity via mast cell degranulation is still unknown. Rats were subjected to wrap partial restraint stress to induce visceral hypersensitivity and were ovariectomized (OVX) to eliminate the effects of oestrogen on visceral hypersensitivity. OVX rats were treated with oestrogen, an oestrogen receptor α and β antagonist (ICI 182.780), a GPER antagonist (G15) or a GPER agonist (G1), to evaluate the effects of oestrogen via its receptor. The colorectal distention test was performed to assess visceral sensitivity. Immunofluorescence studies were performed to evaluate GPER and mast cell tryptase co-expression. Mast cell number with degranulation was detected by specific staining. Mast cell tryptase expression in rat colon was also investigated by Western blot and immunohistochemistry. Substance P and histamine expression were examined by ELISA. GPER was expressed by the majority of tryptase-positive mast cells in the colonic mucosa. Stressed rats showed increased visceral sensitivity, increased mast cell degranulation, mast cell tryptase expression, and increased colon histamine levels. Ovariectomy reduced stress-induced VH in female rats and decreased mast cell degranulation, mast cell tryptase expression, and histamine levels, whereas oestrogen replacement reversed these effects. In OVX rats, the GPER antagonist G15 counteracted the enhancing effects of oestrogen on stress-induced VH, mast cell degranulation, mast cell tryptase, and histamine expression, whereas VH was preserved after treatment with ICI 182.780. On the other hand, pretreatment with the selective GPER agonist G1 at doses between 1 and 20 μg/kg significantly increased VH, mast cell tryptase, and histamine expression in OVX-stressed rats, mimicking the effects of oestrogen. GPER plays a pivotal role in the regulation of mast cell degranulation, mast cell tryptase expression, and histamine levels and contributes to the development of colonic hypersensitivity in a female rat model of IBS.

Dexmedetomidine attenuates LPS-mediated BV2 microglia cells inflammation via inhibition of glycolysis.

Abstract: Microglia inflammation induces pro-inflammatory cytokines and pro-inflammatory enzymes expression, thus leading to inflammation-mediated neuronal cell death. Increased intracellular glycolysis participates in LPS-mediated microglia inflammation. Dexmedetomidine exhibits neuroprotective effects in some situations. In this study, we mainly focused on whether and how dexmedetomidine inhibits LPS-mediated cellular glycolysis and inflammation in BV2 cells. LPS induced pro-inflammatory cytokines and pro-inflammatory enzymes expression, and increased glycolysis capacity in BV2 cells. Moreover, inhibition of glycolysis by 2DG attenuated LPS-induced pro-inflammatory cytokines and pro-inflammatory enzymes expression. Moreover, LPS upregulated hypoxia-inducible factor 1α (HIF1α) expression and decreased sirt1 expression. Dexmedetomidine counteracted these effects induced by LPS. Further, 2-methoxyestradiol, a HIF1α inhibitor, could inhibit LPS-mediated glycolysis and inflammation in BV2 cells, which was similar to the effects of dexmedetomidine. In addition, these effects of dexmedetomidine could be reversed by EX527, a sirt1 inhibitor. The present study indicated that dexmedetomidine, via upregulation of sirt1 expression, inhibited HIF-1α expression and glycolysis, thus reducing LPS-mediated inflammation in BV2 cells.

Cancer stem cells as therapeutic targets of pancreatic cancer.

Abstract: The discovery of stem cells and their potential abilities in self-renewal and differentiation has opened a new horizon in medicine. Scientists have found a small population of stem cells in some types of cancers with the same functions as normal stem cells. There are two models for tumor progression: clonal (stochastic) and cancer stem cell (CSCs) models. According to the first model, all transformed cells in the tumor have carcinogenic potential and are able to proliferate and produce the same cells. The latter model, which has received more attention recently, considers the role of CSCs in drug resistance and tumor metastasis. Following the model, researchers have found that targeting CSCs may be a promising way in cancer therapy. This review describes CSC characteristics in general, while also focusing on CSC properties in the context of pancreatic cancer.

Cannabidiol alleviates hemorrhagic shock-induced neural apoptosis in rats by inducing autophagy through activation of the PI3K/AKT pathway.

Abstract: Recently, several studies have reported that the pharmacological effects exerted by cannabidiol (CBD) are partially related to the regulation of autophagy. Increasing evidence indicates that autophagy provides protection against ischemia-induced brain injury. However, the protective effect of CBD against mitochondrial-dependent apoptosis in hemorrhagic shock (HS)-induced brain injury has not been studied. In the present study, we observed the protective effects of CBD against neural mitochondrial-dependent apoptosis in a rat model of HS. In addition, CBD increased Beclin-1 and LC3II expression and reduced P62 expression, which were indicative of autophagy. CBD treatment attenuated the neural apoptosis induced by HS, as reflected by restoring mitochondrial dysfunction, downregulation of BAX, neuro-apoptosis ratio and NF-κB signaling activation, and upregulation of BCL2 in the cerebral cortex. Such protective effects were reversed by 3-Methyladenine, a specific autophagy inhibitor, indicating that the protective effects of CBD treatment involved autophagy. LY294002, a PI3K inhibitor, significantly inhibited CBD-induced autophagy, demonstrating that PI3K/AKT signaling is involved in the CBD's regulation of autophagy. Furthermore, we found that CBD treatment upregulated PI3K/AKT signaling via cannabinoid receptor 1. Therefore, these findings suggested that CBD treatment protects against cerebral injury induced by HS-mediated mitochondrial-dependent apoptosis by activating the PI3K/AKT signaling pathway to reinforce autophagy.

The effects of melatonin on signaling pathways and molecules involved in glioma

Abstract: Glioblastoma is one of the most common brain tumors with high invasion and malignancy. Despite extensive research in this area and the use of new and advanced therapies, the survival rate in this disease is very low. In addition, resistance to treatment has also been observed in this disease. One of the reasons for rapid progression and failure in treatment for this disease is the presence of a class of cells with high proliferation and high differentiation, a class called glioblastoma stem-like cells shown as being the source of glioblastoma tumors. It has been reported that several oncogenes are expressed in this disease. One important issue in recognizing the pathogenesis of this disease, and which could improve the treatment process, is the identification of involved oncogenes as well as molecules that affect the reduction of the expression of these oncogenes. Melatonin regulates the biological rhythm and inhibits the proliferation of malignant glioma cells due to antioxidant and anti-apoptotic effects. Melatonin has been considered in biological processes and in signaling pathways involved in the development of glioma. The aim of this review is to investigate the effects of melatonin on signaling pathways and molecules involved in the progression of glioma.

Acetyl-11-keto-β-boswellic acid triggers premature senescence via induction of DNA damage accompanied by impairment of DNA repair genes in hepatocellular carcinoma cells in vitro and in vivo.

Abstract: Cellular senescence, a state of irreversible growth arrest, occurs in all somatic cells and causes the cells to exhaust replicative capacity. Recently, cellular senescence has been emerging as one of the principal mechanisms of tumor suppression, which can be induced by low doses of therapeutic drugs in cancer cells. Acetyl-11-keto-β-boswellic acid (AKBA), an active ingredient isolated from the plant Boswellia serrata, has been identified to induce apoptosis in hepatocellular carcinoma (HCC) cells. In this study, we found that low concentrations of AKBA treatment triggered cell growth arrest at G0/G1 phase with features of premature cellular senescence phenotype in both HCC cell lines HepG2 and SMMC7721, as observed by enlarged and flattened morphology, significant increase in cells with senescence-associated β-galactosidase staining, and decrease in cell proliferation and DNA synthesis. Furthermore, cellular senescence induced by AKBA occurred via activation of DNA damage response and impairment of DNA repair, as evidenced by strong induction of γH2AX and p53, and downregulated expressions of multiple DNA repair associated genes. Induction of p53 by AKBA caused a significant increase in p21CIP1 , which had a critical involvement in the induction of cellular senescence. Additionally, in vivo study demonstrated that induction of senescence contributed to the anticancer efficacy of AKBA. Therefore, our findings suggested that induction of premature senescence by AKBA through DNA damage response accompanied by impairment of DNA repair genes defines a novel mechanism contributing to its growth suppression in HCC cells.

Adeno-associated virus (AAV)-mediated neuroprotective effects on the degenerative retina: the therapeutic potential of erythropoietin.

Abstract: Retinal degeneration (RD) results in photoreceptor loss and irreversible visual impairments. This study sought to alleviate the photoreceptor degeneration via the adeno-associated virus (AAV)-mediated erythropoietin (EPO) therapy. AAV-2/2-mCMV-EPO vectors were constructed and delivered into the subretinal space of a RD model. The retinal morphology, optokinetic behaviour and electrophysiological function of the treated animals were analysed. The subretinal delivery of AAV-2/2 vectors induced robust EPO gene expressions in the retinas. AAV2/2-mediated EPO therapy ameliorated the photoreceptor degeneration and visual impairments of the RD animal model. Furthermore, the multi-electrodes array (MEA) was used to detect the firing activities of retinal ganglion cells. MEA recording showed that the EPO therapy could restrain the spontaneous firing response, enhance the light-induced firing response and preserve the basic configurations of visual signal pathway in RD model. Our MEA assay provided an example to evaluate the potency of pharmacological compounds on retinal plasticity. In conclusion, AAV2/2-mediated EPO therapy can ameliorate the photoreceptor degeneration and rectify the abnormities in visual signal transmission. These beneficial results suggest the AAV vector is a viable therapeutic option for retinopathies with rapidly degenerating kinetics and lay the groundwork for future development of EPO gene therapy.

Anticonvulsant effect of melatonin through ATP-sensitive channels in mice.

Abstract: Melatonin is a neurohormone secreted principally by the pineal gland. This molecule has various pharmacological properties including improving immune system, prevent cancer, anti-aging, and anti-oxidant effects. The anticonvulsant effects of melatonin have been proved by previous studies. Adenosine triphosphate (ATP)-sensitive potassium (KATP ) channels are considered as an important target in the seizure modulation. The aim of the present study was to investigate the anticonvulsant effect of melatonin in pentylenetetrazole (PTZ)-induced seizures in mice, focusing on its ability to regulate KATP channels. Acute intraperitoneal administration of melatonin (40 and 80 mg/kg) increased clonic seizure threshold induced by intravenous administration of PTZ. Melatonin (40 and 80 mg/kg) increased the latency of clonic seizure and reduced its frequency in mice receiving an intraperitoneal injection of PTZ. Administration of glibenclamide, a KATP channels blocker, before intravenous injection of PTZ reduced melatonin anticonvulsant effect. Diazoxide and cromakalim, as KATP channels openers, increased antiseizure effect of melatonin in PTZ model of seizures. These findings suggest that the antiseizure effect of melatonin probably is gained through increasing the opening of KATP channels.

Fraxin inhibits lipopolysaccharide‐induced inflammatory cytokines and protects against endotoxic shock in mice

Abstract: Fraxin, the effective component isolated from Cortex Fraxini, has been reported to have anti-inflammation effects. The aim of this study was to explore the effect of fraxin on lipopolysaccharide (LPS)-induced endotoxic shock in mice. We used Kunming male mice to establish the model, and we found that fraxin could improve the survival rate of the LPS-induced mice. Histopathological study showed that fraxin could mitigate the injuries in LPS-induced lung and liver tissues. The levels of tumour necrosis factor-α and interleukin-6 both in serum and lung, liver tissues, and the productions of nitric oxide (NO), aspartate transaminase and alanine transaminase in serum were decreased by fraxin. Western blot assay demonstrated that the pretreatment with fraxin could downregulate LPS-induced protein expressions of nuclear factor-kappa B (NF-κB) and NLRP3 inflammatory corpuscle signalling pathways. Overall, fraxin had protective effects on LPS-induced endotoxic shock mice and the possible mechanisms might activate through NF-κB and NLRP3 inflammatory corpuscle signalling pathways.

Simvastatin enhances chemotherapy in cervical cancer via inhibition of multiple prenylation-dependent GTPases-regulated pathways.

Abstract: Aberrant activation of GTPases is common in cervical cancer, and their proper biological functions largely depend on a post-translational modification termed prenylation. Simvastatin is a cholesterol-lowering drug via inhibiting HMG-CoA reductase, thereby inhibiting protein prenylation. In this study, we show that simvastatin selectively inhibits proliferation and induces apoptosis in cervical cancer cells while sparing normal cervical epithelial cells. This is achieved by depleting geranylgeranyl pyrophosphate, inhibiting prenylation, decreasing GTPases activities and suppressing the activation of downstream Ras and RhoA signaling. The combination of simvastatin and paclitaxel remarkably augments in vitro as well as in vivo efficacy of either drug alone in cellular system and xenograft mouse model. Importantly, we show that cervical cancer cells have higher level of HMG-CoA reductase and elevated activities of GTPases, suggesting that cervical cancer cells may be more dependent on prenylation than normal cervical epithelial cells. This might explain the selective inhibitory effects of simvastatin in cervical cancer. Since simvastatin is already available for clinic use, these results suggest that simvastatin is a promising drug candidate in combination with chemotherapy for the treatment of cervical cancer. Our findings also emphasize the therapeutic value of prenylation inhibition and provide preclinical evidence to evaluate prenylation-targeted drugs in cervical cancer.

Key roles of Rho GTPases, YAP, and Mutant P53 in anti-neoplastic effects of statins.

Abstract: Emerging epidemiological and preclinical studies have focused on statins and mevalonate pathway to identify potential therapeutic target and clarify the underlying mechanism of the anti-neoplastic effects. Reductions of mevalonate or isoprenoids, caused by statins, would further decrease the isoprenylation of Rho GTPases which is the crucial step for Rho GTPases to anchor on inner cellular membrane. Following anchoring, activated Rho GTPases can mediate a series of cellular activities such as cytoskeleton reprogramming, front-rear polarity, and cell-ECM adhesion. These changes not only facilitate tumor cell detachment and migration but also bring great mechanical changes to directly activate YAP, the major nuclear mechanotransducer, to translocate into nucleus. Recently, statins have been identified as potent inhibitors of YAP. Once entering nucleus, YAP would combine TEADs to promote the transcription of about 100 genes, which are involved in cell proliferation, cell cycle regulation, stemness, invasion, and metastasis. Besides, statins are able to promote the degradation of misfolded mutant p53 (mutp53), which is an oncogene in a variety of human malignancies. Reduction in mevalonate-5-phosphate (MVP), also induced by statins, would impair the stability of DNAJA1-mutp53 complex; then, elevated C terminus of Hsc70-interacting protein (CHIP) mediates the nuclear export and degradation of misfolded mutp53 through ubiquitin-proteasome pathway. It is worth noted that YAP, mutp53, and mevalonate pathway form two positive feedback loops. It is reasonable to believe that Rho GTPases, YAP, and mutp53 are determinants for statins as anti-cancer agents: tumor cells harboring mutp53 and nuclear-located YAP would be more sensitive to statins.

Tanshinone IIA reduces palmitate‐induced apoptosis via inhibition of endoplasmic reticulum stress in HepG2 liver cells

Abstract: Research has indicated that stress on the endoplasmic reticulum (ER) of a cell affects the pathogenesis of metabolic disorders such as obesity, type 2 diabetes mellitus, and non-alcoholic fatty liver disease (NAFLD). Palmitate, a saturated fatty acid, is known to induce toxicity and cell death in various types of cells. Tanshinone IIA (Tan IIA), one of the effective components of the traditional Chinese medicine Danshen, was reported to exhibit a variety of biochemical activities, including amelioration of ER stress-mediated apoptosis in renal preservation. To address the hypothesis that tan IIA attenuates apoptosis and triglycerides (TG) accumulation via reducing ER stress, we studied the effect of tan IIA on experimentally induced ER stress using palmitate in HepG2 cells. Palmitate led to cytotoxicity, TG accumulation, and apoptosis in HepG2 cells and also strongly induced ER stress indicated by increased GRP78, phosphorylation of eIF2α, ATF6, and CHOP. Pretreatment with tan IIA (10 μm) significantly increased cell viability, decreased apoptotic cell death, and reduced the activity of caspase-3. Meanwhile, tan IIA significantly decreased palmitate-induced TG accumulation. Moreover, tan IIA significantly suppressed the phosphorylation of eIF2α, and inhibited GRP78, ATF6, and CHOP expression. In conclusion, tan IIA protects the HepG2 cells exposed to palmitate partially by inhibiting excessive ER stress, ER stress-induced apoptosis, and hepatic steatosis. Therefore, tan IIA has therapeutic potential in the treatment of NAFLD.

SGLT1 Inhibition Boon or Bane for Diabetes Associated Cardiomyopathy

Abstract: Chronic hyperglycaemia is a peculiar feature of diabetes mellitus (DM). Sequential metabolic abnormalities accompanying glucotoxicity are some of its implications. Glucotoxicity most likely corresponds to the vascular intricacy and metabolic alterations, such as increased oxidation of free fatty acids and reduced glucose oxidation. More than half of those with diabetes also develop cardiac abnormalities due to unknown causes, posing a major threat to the currently available marketed preparations which are being used for treating these cardiac complications. Even though impairment in cardiac functioning is the principal cause of death in individuals with type 2 diabetes (T2D), reducing plasma glucose levels has little effect on cardiovascular disease (CVD) risk. In vitro and in vivo studies have demonstrated that inhibitors of sodium glucose transporter (SGLT) represent a putative therapeutic intervention for these pathological conditions. Several clinical trials have reported the efficacy of SGLT inhibitors as a novel and potent antidiabetic agent which along with its antihyperglycaemic activity possesses the potential of effectively treating its associated cardiac abnormalities. Thus, hereby, the present review highlights the role of SGLT inhibitors as a successful drug candidate for correcting the shifts in deregulation of cardiac energy substrate metabolism together with its role in treating diabetes-related cardiac perturbations.