2-(2-benzofuranyl)-2-imidazoline and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Our group previously showed that 2-(-2-benzofuranyl)-2-imidazoline (2-BFI) is a potent neuroprotective agent in the treatment of ischemic stroke in rats. As its mode of action was not well defined, we determined if its therapeutic effect includes altering an immune response to experimental ischemic stroke in rats. In the current study, 2-BFI significantly reduced stroke-induced brain infarct volume and it also decreased neurological deficits. Its anti-immune effects were determined based on flow cytometry measurements of both the 2-BFI-induced changes in the Th17/ Treg cell balance ratio and ELISA measurements of proinflammatory IL-17A and anti-inflammatory IL-10 cytokine expression levels in the brain and peripheral blood following ischemic strokes. 2-BFI blunted the stroke-induced increases in this ratio, which resulted from suppression of the rises in the Th17 cell number whereas the proportion of Treg cells increased. Stroke also induced increases in IL-17A expression levels whereas the IL-10 expression levels declined. 2-BFI treatment inhibited the rises in IL-17A expression levels whereas the corresponding declines in IL-10 were suppressed by this agent. Therefore, one of the neuroprotective effects of 2-BFI in the treatment of cerebral strokes stems from its suppression of rises in the Th17/Treg balance along with corresponding changes in related cytokines modulating development of this condition.

Topics: Animals; Benzofurans; Cytokines; Disease Models, Animal; Imidazoles; Interleukin-17; Ischemic Stroke; Male; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; T-Lymphocytes, Regulatory; Th17 Cells

Pharmacotherapies for fibromyalgia treatment are lacking. This study examined the antinociceptive and antidepressant-like effects of imidazoline I2 receptor (I2R) agonists in a reserpine-induced model of fibromyalgia in rats. Rats were treated for 3 days with vehicle or reserpine. The von Frey filament test was used to assess the antinociceptive effects of I2 receptor agonists, and the forced swim test was used to assess the antidepressant-like effects of these drugs. 2-BFI (3.2-10 mg/kg, intraperitoneally), phenyzoline (17.8-56 mg/kg, intraperitoneally), and CR4056 (3.2-10 mg/kg, intraperitoneally) all dose-dependently produced significant antinociceptive effects, which were attenuated by the I2R antagonist idazoxan. Only CR4056 significantly reduced the immobility time in the forced swim test in both vehicle-treated and reserpine-treated rats. These data suggest that I2R agonists may be useful to treat fibromyalgia-related pain and comorbid depression.

Topics: Analgesics; Animals; Benzofurans; Depression; Disease Models, Animal; Fibromyalgia; Hyperalgesia; Idazoxan; Imidazoles; Imidazoline Receptors; Imidazolines; Male; Pain; Pain Measurement; Quinazolines; Rats; Rats, Sprague-Dawley; Reserpine

We showed previously that 2-(2-benzofuranyl)-2-imidazoline (2-BFI), a ligand to type 2 imidazoline receptor (I2R) exerts neuroprotective effects in ischemia stroke via an unknown mechanism. The present study was to investigate whether 2-BFI can protect the neurovascular unit (NVU) using a rat model of 90 min focal cerebral ischemia.. Rats were randomly divided into three groups: thesham-operated group; the vehicle control group and the 2-BFI group which received 2-BFI (3 mg/kg) immediately after the start of middle cerebralartery occlusion (MCAO). Neurological deficit score, infarct size, apoptosis level, brain water content and Evans Blue extravasation were assessed at 24 h after stroke. Expressions of occludin and zonula occludens 1 (ZO-1), collagen IV, aquaporin-4 (AQP-4), matrix metalloproteinase-9 (MMP-9) and MMP-2 were assessed by Western blotting.. 2-BFI treatment was associated with significant improvement of neurological performance and decreased infarct volume at 24 h after stroke. Apoptosis level reduced significantly by 2-BFI compared to the vehicle group (34.3 ± 5.4% vs 56.1 ± 7.9%, p < 0.05). Significant decreased of brain water content (79.5 ± 2.6% vs 84.62 ± 2%, p < 0.05) and Evans Blue extravasation (1.2 ± 0.5 vs 2.5 ± 0.41 µg/g, p < 0.05) of ipsilateral hemisphere was observed in 2-BFI group compared to vehicle group. Expressions of occludin, ZO-1 and collagen IV were significantly higher while MMP-9 level significantly lower in 2-BFI group. AQP-4 and MMP-2 showed no difference between 2-BFI and the vehicle groups.. These results suggest that the neuroprotective effects of 2-BFI in acute ischemic brain damage are at least partly due to the drug's ability to improve the functions of NVU.

Topics: Animals; Apoptosis; Benzofurans; Brain; Brain Edema; Brain Ischemia; Capillary Permeability; Disease Models, Animal; Imidazoles; Male; Motor Activity; Neurons; Neuroprotection; Neuroprotective Agents; Random Allocation; Rats, Sprague-Dawley

Stroke is the third leading cause of death and disability in developing countries. The effective therapy for acute ischemic stroke is thrombolysis with recombinant tissue plasminogen activator (rt-PA) within 4.5 h of stroke onset. An effective post-ischemic neuroprotectant would extend the advantages of rt-PA, and protect against complications of thrombolysis. We previously reported that 2-(2-benzofuranyl)-2-imidazoline (2-BFI), a newly discovered ligand for high-affinity type 2 imidazoline receptor (I2R), provides neuroprotection against ischemic stroke in rats. Here we investigated the protective effects of 2-BFI in combination with delayed intravenous rt-PA after stroke induced by embolic middle cerebral artery occlusion (eMCAO) in rats. Infarct size was determined using 2,3,5-triphenyltrazolium chloride staining, while neurological deficit was assessed based on neurological score. Numbers of apoptotic cells in vivo were estimated using TUNEL stain, and expression of the pro-apoptotic protein BAX and anti-apoptotic protein BCL-2 were quantified by Western blotting. The results showed that 2-BFI (3 mg/kg) administered at 0.5 h after embolic MCAO combined with rt-PA (10 mg/kg) administered at 6 h reduced brain infarct size, mitigated neurological deficit, decreased the number of TUNEL-positive cells, down-regulated BAX expression, and up-regulated BCL-2 expression. These findings suggest that 2-BFI may extend the therapeutic window of rt-PA to 6 h after embolic stroke onset in rats.

Topics: Animals; Apoptosis; Benzofurans; Brain; Disease Models, Animal; Drug Therapy, Combination; Embolism; Imidazoles; Male; Neuroprotective Agents; Random Allocation; Rats, Sprague-Dawley; Stroke; Tissue Plasminogen Activator

Alzheimer's Disease (AD) is one of the commonest neural degeneration in aging population, and has become a global health challenge. 2-(2-benzofuranyl)-2-imidazoline (2-BFI) was reported to effectively improved the damage of patients with neuropathological disorders. In the present study, we investigated the effect of 2-BFI on the improvement of antioxidative, inflammation, and apoptosis in AD rats. Sprague-Dawley rats (2 months old, n=40) were used in this study and after injection of Aβ1-42 into hippocampal CA1 (Cornu Ammonis) region, the rats were given high, moderate and low dose of 2-BFI though intraperitoneal (i.p.) injection. Then spatial memory and navigation ability were analyzed by Morrize Water Maze. For the molecular testing, chemical colorimetry, ELISA and immunoblotting were performed to measure the activities of antioxidative enzymes, the abundance of immune cytokines and expression of apoptotic proteins, respectively. Hematoxylin and Eosin staining was used to analyze the pathological changes. We observed that 2-BFI significantly ameliorated the learning and memory abilities in rat models with AD by dosage treatment, as demonstrated by the shorten learning latency and greater times of travel across the platform quadrant. Additionally, reactive oxygen species (ROS) and malondialdehyde (MDA), were decreased after treatment of 2-BFI with dosage dependency, while the activities of superoxidase dismutase (SOD) and (GPX) Glutathione peroxidase were in turn enhanced, suggesting that 2-BFI could protect the antioxidative enzymes and reduce the oxidative stress in the hippocampus. Moreover, the expression of inflammatory factors including TNF-a and IL-1β were decreased after 2-BFI treatment. Additionally, the neuronal apoptosis was also attenuated, as shown by Western blot results. Taken together, the cognitive impairment in AD rats could be significantly improved by 2-BFI in a dose-dependent manner through suppressing oxidants accumulation, inhibiting of inflammatory response, as well as enhancing the neural viability.

Topics: Alzheimer Disease; Amyloid beta-Peptides; Animals; Anti-Inflammatory Agents, Non-Steroidal; Apoptosis; Benzofurans; Disease Models, Animal; Dose-Response Relationship, Drug; Hippocampus; Imidazoles; Inflammation; Maze Learning; Neuroprotective Agents; Nootropic Agents; Oxidative Stress; Peptide Fragments; Random Allocation; Rats, Sprague-Dawley; Spatial Memory; Spatial Navigation

The imidazoline I2 receptor is an emerging drug target for analgesics. This study extended previous studies by examining the antinociceptive effects of three I2 receptor agonists (2-BFI, BU224, and CR4056) in the formalin test. The receptor mechanisms and anatomical mediation of I2 receptor agonist-induced antinociception were also examined. Formalin-induced flinching responses (2%, 50 μl) were quantified after treatment with I2 receptor agonists alone or in combination with the I2 receptor antagonist idazoxan. Anatomical mediation was studied by locally administering 2-BFI into the plantar surface or into the right lateral ventricle through cannulae (intracerebroventricular). The locomotor activity was also examined after central (intracerebroventricular) administration of 2-BFI. 2-BFI (1-10 mg/kg, intraperitoneal) and BU224 (1-10 mg/kg, intraperitoneal) attenuated the spontaneous flinching response observed during 10 min (phase 1) and 20-60 min (phase 2) following formalin treatment, whereas CR4056 (1-32 mg/kg, intraperitoneal) decreased only phase 2 flinching response. The I2 receptor antagonist idazoxan attenuated the antinociceptive effects of 2-BFI and BU224 during phase 1, but not phase 2. Peripheral administration of 2-BFI (1-10 mg/kg, intraplantar) to the hind paw of rats had no antinociceptive effect. In contrast, centrally delivered 2-BFI (10-100 µg, intracerebroventricular) dose-dependently attenuated phase 1 and phase 2 flinching at doses that did not reduce the locomotor activity. Together, these data revealed the differential antinociceptive effects of I2 receptor agonists and the differential antagonism profiles by idazoxan, suggesting the involvement of different I2 receptor subtypes in reducing different phases of formalin-induced pain-like behaviors. In addition, the results also suggest the central mediation of I2 receptor agonist-induced antinociceptive actions.

Topics: Analgesics; Animals; Behavior, Animal; Benzofurans; Disease Models, Animal; Dose-Response Relationship, Drug; Imidazoles; Imidazoline Receptors; Injections, Intraperitoneal; Injections, Intraventricular; Locomotion; Male; Pain; Pain Measurement; Quinazolines; Rats; Rats, Sprague-Dawley; Time Factors

Emerging preclinical evidence suggests that imidazoline I2 receptor ligands may be effective analgesics. Quantitative analysis of the combined I2 receptor ligands and opioids is needed for the justification of combination therapy.. This study systematically examined the anti-hyperalgesic and response rate-suppressing effects of selective I2 receptor ligands (2-BFI and phenyzoline) alone and in combination with oxycodone in rats.. Von Frey filament test was used to examine the anti-hyperalgesic effects of drugs in a rat model of complete Freund's adjuvant (CFA)-induced inflammatory pain. Schedule-controlled responding was used to assess the rate-altering effects of study drugs. Duration of actions of individual drugs (2-BFI, phenyzoline, and oxycodone) alone or in combination was studied. Dose-addition analysis was employed to assess the anti-hyperalgesic interactions between drugs.. Oxycodone (0.1-3.2 mg/kg, i.p.), 2-BFI (1-17.8 mg/kg, i.p.), and phenyzoline (17.8-56 mg/kg, i.p.) all dose-dependently produced significant antinociceptive effects. When studied as combinations, 2-BFI and oxycodone produced additive interactions while phenyzoline and oxycodone produced supra-additive interactions under all fixed ratios. The same drug combinations did not alter or significantly reduced the operant responding depending on the ratios of the drug combinations.. Quantitative analysis of the anti-hyperalgesic effects of I2 receptor ligands strongly supports the therapeutic potential of I2 receptor ligands against inflammatory pain. In addition, the data reveal that phenyzoline is superior to the prototypic I2 receptor ligand 2-BFI for the management of pain and warrants further consideration as a novel analgesic.

Topics: Analgesics, Opioid; Animals; Behavior, Animal; Benzofurans; Disease Models, Animal; Drug Synergism; Hyperalgesia; Imidazoles; Imidazoline Receptors; Imidazolines; Inflammation; Ligands; Male; Nociception; Oxycodone; Pain; Protein Binding; Rats; Rats, Sprague-Dawley

Our previous studies showed that ligands to type 2 imidazoline receptors (I₂R), including 2-(2-Benzofuranyl)-2-imidazoline (2-BFI) and Idazoxan, were effective in reducing spinal cord inflammation caused by experimental autoimmune encephalomyelitis (EAE). In the present study, we determined the effective therapeutic time window of 2-BFI and found that administration of 2-BFI in mice before the appearance of ascending flaccid paralysis (1-10 days post immunization), but not during the period when neurological deficits occurred (11-20 days post immunization), significantly ameliorated EAE-induced neurobehavioral deficits, reduced the infiltration of inflammatory cells into the spinal cord, and reduced the level of demyelination. More interestingly, giving 2-BFI during 1-10 days post immunization selectively suppressed IL-17 levels in the peripheral blood, which strongly suggests that IL-17 may be a good early marker to indicate EAE progression and that 2-BFI may target CD4⁺ T lymphocytes, especially Th17 cells to reduce IL-17 expression. Collectively, these studies led us to envisage that 2-BFI can be a useful drug to treat multiple sclerosis (MS) when used in combination with an early indicator of MS progression, such as IL-17.

Topics: Analysis of Variance; Animals; Benzofurans; Calcium-Binding Proteins; Cytokines; Disease Models, Animal; Encephalomyelitis, Autoimmune, Experimental; Enzyme-Linked Immunosorbent Assay; Freund's Adjuvant; Imidazoles; Indoles; Mice; Mice, Inbred C57BL; Microfilament Proteins; Myelin Sheath; Myelin-Oligodendrocyte Glycoprotein; Nervous System Diseases; Peptide Fragments; Spinal Cord Injuries; Time Factors

Pain remains a significant clinical challenge and currently available analgesics are not adequate to meet clinical needs. Emerging evidence suggests the role of imidazoline I(2) receptors in pain modulation primarily from studies of the non-selective imidazoline receptor ligand, agmatine. However, little is known of the generality of the effect to selective I(2) receptor ligands. This study examined the antinociceptive effects of two selective I(2) receptor ligands 2-BFI and BU224 (>2000-fold selectivity for I(2) receptors over α(2) adrenoceptors) in a hypertonic (5%) saline-induced writhing test and analyzed their interaction with morphine using a dose-addition analysis. Morphine, 2-BFI and BU224 but not agmatine produced a dose-dependent antinociceptive effect. Both composite additive curve analyses and isobolographical plots revealed a supra-additive interaction between morphine and 2-BFI or BU224, whereas the interaction between 2-BFI and BU224 was additive. The antinociceptive effect of 2-BFI and BU224 was attenuated by the I(2) receptor antagonist/α(2) adrenoceptor antagonist idazoxan but not by the selective α(2) adrenoceptor antagonist yohimbine, suggesting an I(2) receptor-mediated mechanism. Agmatine enhanced the antinociceptive effect of morphine, 2-BFI and BU224 and the enhancement was prevented by yohimbine, suggesting that the effect was mediated by α(2) adrenoceptors. Taken together, these data represent the first report that selective I(2) receptor ligands have substantial antinociceptive activity and produce antinociceptive synergy with opioids in a rat model of acute pain. These data suggest that drugs acting on imidazoline I(2) receptors may be useful either alone or in combination with opioids for the treatment of pain.

Topics: Adrenergic alpha-2 Receptor Antagonists; Agmatine; Analgesics; Analgesics, Opioid; Animals; Benzofurans; Disease Models, Animal; Drug Synergism; Idazoxan; Imidazoles; Imidazoline Receptors; Ligands; Male; Morphine; Pain; Rats; Rats, Sprague-Dawley; Saline Solution, Hypertonic; Yohimbine

Stroke is the third leading cause of death and disability in North America and is becoming the most frequent cause of death in the rapid developing China. Protecting neurons in order to minimize brain damage represents an effective approach towards stroke therapeutics. Our recent study demonstrated that 2-(-2-benzofuranyl)-2-imidazoline (2-BFI), a ligand for imidazoline I(2) receptors, is potently neuroprotective against stroke, possibly through transiently antagonizing NMDA receptor activities. In this study, we further investigated the characteristics and mechanisms of 2-BFI-mediated neuroprotection using a rat stroke model of transient occlusion of the middle cerebral artery. Here, we show that 2-BFI was most effective at the dose of 3mg/kg in vivo, with significantly reduced brain infarct size and improved neurological deficits. Lower doses of 2-BFI at 1.5mg/kg, or higher dose of 2-BFI at 6 mg/kg, were either not effective, or toxic to the brain, respectively. Treating stroke rats with 3mg/kg 2-BFI significantly reduced the number of TUNEL positive cells and preserved the integrity of subcellular structures such as nuclear membranes and mitochondria as shown under the electron microscope, confirming neuroprotection. Most interestingly, 2-BFI-treated brains exhibited significant expression of Bcl-2, a gene with a known function in neuroprotection. Taken together, these studies not only demonstrated that 2-BFI at 3mg/kg was effective in neuroprotection, but also, for the first time, showed that 2-BFI provided neuroprotection through up-regulating the neuroprotective gene Bcl-2. 2-BFI can be further developed as a therapeutic drug for stroke treatment.

Topics: Animals; Apoptosis; Benzofurans; Brain; Cell Death; Consciousness; Disease Models, Animal; Dose-Response Relationship, Drug; Imidazoles; Imidazoline Receptors; Immunohistochemistry; In Situ Nick-End Labeling; Infarction, Middle Cerebral Artery; Ischemic Attack, Transient; Male; Microscopy, Electron; Motor Activity; Neuroprotective Agents; Proto-Oncogene Proteins c-bcl-2; Random Allocation; Rats; Rats, Sprague-Dawley; Treatment Outcome; Up-Regulation; Walking

The aim of this study was to determine whether 2-(2-benzofuranyl)-2-imidazoline, an imidazoline I(2) receptor ligand, could protect against cell death from brain injury and improve the functional outcome after focal cerebral ischemia in rats.. Transient focal ischemia was induced by suture occlusion of the middle cerebral artery. Rats were intraperitoneally treated with a vehicle, 2-(2-benzofuranyl)-2-imidazoline or idazoxan immediately after focal ischemia. Infarct volume was assessed by 2,3,5-triphenyltrazolium chloride staining and neurobehavioral deficits were monitored. The volume of cell death in the penumbra after ischemia was determined by immunostaining using anti-cleaved caspase-3 antibody and terminal deoxynucleotidyl transferase biotin-dUTP nick end labeling (TUNEL).. Both 2-(2-benzofuranyl)-2-imidazoline and idazoxan significantly improved the neurological score compared with the vehicle at 24 hours after focal ischemia. Treatment with 2-(2-benzofuranyl)-2-imidazoline or idazoxan also significantly reduced infarct volume and the number of both caspase-3- and TUNEL-positive cells in the penumbra compared with vehicle-treated rats (p<0.01 and p<0.05, respectively).. The results suggest the neuroprotective role of 2-(2-benzofuranyl)-2-imidazoline and idazoxan in focal cerebral ischemia, and may therefore represent useful targets for developing new treatments for stroke.

Topics: Animals; Benzofurans; Brain Injuries; Brain Ischemia; Caspase 3; Disease Models, Animal; Idazoxan; Imidazoles; Imidazoline Receptors; In Situ Nick-End Labeling; Male; Neurologic Examination; Neuroprotective Agents; Rats; Rats, Sprague-Dawley; Tetrazolium Salts