retinol-acetate 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

In overactive bladder (OAB) therapy several herbal medicines presented promising effects, however the results are sparse to provide their efficacy. Herbals may become a popular alternative for OAB therapy. Therefore, we investigated whether Potentilla chinensis extract (PCE) would reverse retinyl acetate (RA)-induced detrusor overactivity (DO).. 60 rats were divided into 4 groups, as follows: I - control, II - rats with RA-induced DO, III - rats received PCE in dose of 500 mg/kg, and IV - rats with RA-induced DO which received PCE. PCE or vehicle were administered orally for 14 days. The cystometry and bladder blood flow assessment were performed 3 days after the last dose of the PCE. Then the rats were put into the metabolic cages for 24 h. Next, urothelium thickness measurement and biochemical analyses were performed. < /p>

Results. Intravesical infusion of RA solution induced DO. PCE had no influence on the urinary bladder function and  micturition cycles in normal rats. PCE diminished the severity of RA-induced DO. In the urothelium the RA induced the elevation of ATP, CGRP, substance P, VEGF-A, OTC3, and ERK1/2. The concentration of NOS2, CDH1, and ZO1 decreased. Moreover, RA affected the concentration of SNARE proteins (increased concentration of SNAP23, SNAP25, and SV2A). Also in detrusor the elevated level of ROCK1 and VAChT were observed. In turn, PCE in RA-induced DO caused a reversal of the described biochemical changes within urothelium, detrusor muscle and urine. < /p>

Conclusions. PCE attenuates detrusor overactivity. The potential mechanisms of action of PCE in the urinary bladder seem to be multifactorial and complex. PCE seems to become a reasonable novel OAB therapy.

Topics: Animals; Disease Models, Animal; Diterpenes; Female; Plant Extracts; Potentilla; Rats; Rats, Wistar; Retinyl Esters; Treatment Outcome; Urinary Bladder; Urinary Bladder, Overactive; Urination

The aims of the study were to determine the effectiveness of blebbistatin (BLEB) on detrusor overactivity (DO) in an animal model induced by retinyl acetate (RA) and, because of potential urothelial permeability, to evaluate the degenerative impact of BLEB on the urothelium. Three days after RA instillation into the urinary bladder, BLEB was administered into the bladder and immediately after cystometric assessment was performed. Furthermore, Evans Blue extravasation into bladder tissue and urothelium thickness were measured. Sixty female Wistar rats were used and randomly assigned to one of four groups (n = 15 in each group): (1) control, (2) RA, (3) BLEB, and (4) RA + BLEB. RA administration induced changes in cystometric parameters reflecting DO, as previously reported. Treatment with BLEB did not significantly alter cystometric parameters in rats which did not receive RA. Administration of BLEB to rats pretreated with RA reversed changes in cystometric parameters induced by RA in basal pressure, threshold pressure, detrusor overactivity index, amplitude of nonvoiding contractions, frequency of nonvoiding contractions, voided volume, volume threshold, intercontraction interval, bladder compliance, and volume threshold to elicit nonvoiding contractions. There were no significant differences in Evans Blue extravasation into bladder tissue or urothelium thickness between the groups. The current research provides new data on the possible utility of blebbistatin in the pharmacotherapy of DO, which is an important feature of overactive bladder (OAB). Further studies in human patients with DO/OAB are warranted to confirm these preclinical results.

Topics: Administration, Intravesical; Animals; Disease Models, Animal; Diterpenes; Female; Heterocyclic Compounds, 4 or More Rings; Rats, Wistar; Retinyl Esters; Urinary Bladder, Overactive; Urination; Urodynamics; Vitamin A

Provitamin A biofortification of staple crops may decrease the prevalence of vitamin A (VA) deficiency if widely adopted in target countries. To assess the impact of processing methods on the VA value of plant foods, the unique bioefficacies of cis-βC isomers (formed during cooking) compared with all-trans (at) β-carotene (βC) must be determined. The bioefficacies of 9-cis (9c)- and 13-cis (13c)-βC isomers were compared with those of the at-βC isomer and VA positive (VA+) and negative (VA - ) controls in VA-depleted Mongolian gerbils (Meriones unguiculatus) in two experimental studies (study 1, n 56; study 2, n 57). A 3- or 4-week depletion period was followed by a 3- or 4-week treatment period in which the groups received oral doses of the 9c-, 13c- or at-βC isomers in cottonseed oil (study 1, 15 nmol/d; study 2, 30 nmol/d). In study 1, the βC isomers did not maintain baseline liver VA stores in all groups (0.69 (SD 0.20) μmol/liver) except in the VA+group (0.56 (SD 0.10) μmol/liver) (P= 0.0026). The βC groups were similar to the VA+group, but the 9c- and 13c-βC groups did not differ from the VA - group (0.39 (SD 0.09) μmol/liver). In study 2, the βC isomers maintained baseline liver VA stores in all the βC groups (0.35 (SD 0.13) μmol/liver), and in the VA+group, the VA supplement (0.54 (SD 0.19) μmol/liver) exceeded the baseline VA status (0.38 (SD 0.15) μmol/liver) (P< 0.0001); however, the 9c-βC group did not differ from the VA - group (0.20 (SD 0.07) μmol/liver). In vivo isomerisation of βC was confirmed in both experimental studies. Lower VA bioconversion factor values were obtained for the cis-βC isomers in study 2 when compared with study 1, but higher values were obtained for the at-βC isomer. Dose and VA status clearly affect bioconversion factors. In conclusion, the cis-βC isomers yielded similar liver VA stores to the at-βC isomer in Mongolian gerbils, and liver VA stores of the 9c- and 13c-βC groups did not differ when the doses were provided at physiological levels over time in two studies.

Topics: Animals; beta Carotene; Biotransformation; Chromatography, High Pressure Liquid; Dietary Supplements; Disease Models, Animal; Diterpenes; Gerbillinae; Liver; Male; Molecular Structure; Retinyl Esters; Stereoisomerism; Vitamin A; Vitamin A Deficiency

Analysis of the effects of retinol acetate on LPO processes in vivo revealed antioxidant effects under normal conditions and during experimental free-radical pathology (toxic hepatosis-hepatitis). The concentration inversion of antioxidant effects of retinol acetate into prooxidant effects were observed only under normal conditions.

Topics: Animals; Antioxidants; Disease Models, Animal; Diterpenes; Free Radicals; Glutathione Peroxidase; Glutathione Transferase; Hepatitis; Lipid Peroxides; Male; Malondialdehyde; Rats; Reactive Oxygen Species; Retinyl Esters; Vitamin A

Chronic lung disease (CLD) is a major cause of long-term morbidity in extremely LBW infants with respiratory distress syndrome. Parenteral vitamin A administration decreases the risk of CLD. We tested the hypothesis that intratracheal vitamin A administration with surfactant is systemically bioavailable without interfering with the functional properties of exogenous surfactant. Newborn piglets were ventilated with 100% FiO2 and sequential saline lavage induced respiratory distress syndrome. During lung injury induction, ventilator changes were allowed, but none were made following treatment allocation. Animals were assigned by chance in a blinded control trial to three groups: I=control; II=surfactant; III=surfactant+vitamin A. Hemodynamics, lung mechanics, and blood gases were measured following instrumentation, pre- and posttreatment for 4 h, at which time the liver was sampled for retinol determination. All parameters improved in animals receiving surfactant. A significant interaction existed between time and group for PaO2 and alveolar-arterial oxygen difference (A-aDO2). Hepatic levels of retinol were higher (p<0.001) in animals receiving retinyl acetate. Intratracheal administration of surfactant+vitamin A did not alter the beneficial effects of surfactant on lung compliance and gas exchange. Intratracheal Vitamin A was associated with rapid hepatic uptake. Further studies are warranted.

Topics: Administration, Inhalation; Animals; Animals, Newborn; Biological Availability; Disease Models, Animal; Diterpenes; Drug Combinations; Hemodynamics; Humans; Infant, Newborn; Intubation, Intratracheal; Liver; Lung; Lung Compliance; Oxygen; Pulmonary Gas Exchange; Pulmonary Surfactants; Respiratory Distress Syndrome, Newborn; Retinyl Esters; Swine; Time Factors; Vitamin A; Vitamins

Leber congenital amaurosis (LCA), a heterogeneous early-onset retinal dystrophy, accounts for approximately 15% of inherited congenital blindness. One cause of LCA is loss of the enzyme lecithin:retinol acyl transferase (LRAT), which is required for regeneration of the visual photopigment in the retina.. An animal model of LCA, the Lrat-/- mouse, recapitulates clinical features of the human disease. Here, we report that two interventions--intraocular gene therapy and oral pharmacologic treatment with novel retinoid compounds--each restore retinal function to Lrat-/- mice. Gene therapy using intraocular injection of recombinant adeno-associated virus carrying the Lrat gene successfully restored electroretinographic responses to approximately 50% of wild-type levels (p < 0.05 versus wild-type and knockout controls), and pupillary light responses (PLRs) of Lrat-/- mice increased approximately 2.5 log units (p < 0.05). Pharmacological intervention with orally administered pro-drugs 9-cis-retinyl acetate and 9-cis-retinyl succinate (which chemically bypass the LRAT-catalyzed step in chromophore regeneration) also caused long-lasting restoration of retinal function in LRAT-deficient mice and increased ERG response from approximately 5% of wild-type levels in Lrat-/- mice to approximately 50% of wild-type levels in treated Lrat-/- mice (p < 0.05 versus wild-type and knockout controls). The interventions produced markedly increased levels of visual pigment from undetectable levels to 600 pmoles per eye in retinoid treated mice, and approximately 1,000-fold improvements in PLR and electroretinogram sensitivity. The techniques were complementary when combined.. Intraocular gene therapy and pharmacologic bypass provide highly effective and complementary means for restoring retinal function in this animal model of human hereditary blindness. These complementary methods offer hope of developing treatment to restore vision in humans with certain forms of hereditary congenital blindness.

Topics: Acyltransferases; Adenoviridae; Administration, Oral; Animals; Blindness; Disease Models, Animal; Diterpenes; Genetic Therapy; Genetic Vectors; Mice; Mice, Knockout; Molecular Sequence Data; Optic Atrophy, Hereditary, Leber; Prodrugs; Pupil; Retinal Pigments; Retinyl Esters; Vitamin A

Decreased plasma concentrations of vitamin A (retinol) and retinol-binding protein have been previously identified in human subjects with type I diabetes mellitus. The present study was undertaken to investigate the effects of streptozotocin-induced diabetes in rats of three different strains including Wistar Furth, Sprague Dawley and Wistar, on plasma and liver concentrations of vitamin A. The diabetic animals gained less weight than nondiabetic controls even though they ate 50% more food. The hepatic vitamin A concentration was increased at three weeks after the onset of diabetes in all three strains of rats but the magnitude of increase was greater in Wistar than either Wistar Furth or Sprague Dawley rats. This increased storage of vitamin A in diabetic animals most likely is due to increased food intake. The plasma concentrations of vitamin A, on the other hand, remained unaffected in Wistar Furth and decreased moderately (P < 0.02) in Sprague Dawley but severely (P < 0.0001) in Wistar rats. The fact that the plasma vitamin A levels in diabetic Wistar and Sprague Dawley rats were markedly reduced despite their increased hepatic store suggest an impairment in the transport of vitamin A from the liver. The circulatory levels of vitamin A in Wistar rats are more sensitive to the diabetic state, which is in agreement with those observations seen in diabetic patients. Because of this similarity, it is reasonable to suggest that Wistar should be the choice of rat strain for future experimental studies involving vitamin A and diabetes relationships.

Topics: Animal Feed; Animals; Blood Glucose; Body Weight; Chromatography, High Pressure Liquid; Diabetes Mellitus, Experimental; Disease Models, Animal; Diterpenes; Eating; Glycosuria; Liver; Male; Rats; Rats, Inbred Strains; Rats, Inbred WF; Rats, Sprague-Dawley; Rats, Wistar; Retinyl Esters; Vitamin A

Both retinoic acid and retinyl acetate, administered in high doses on days 13--15 of gestation, are capable of causing a 90 per cent incidence of cleft palate in Charles River rats. However, an attempt to develop as in vivo rabbit model system for the induction of clefts via hypervitaminosis A was unsuccessful. In the rat, the retinoic acid form of vitamin A is the more potent teratogen, inducing clefts at less than half the dose required to produce them with retinyl acetate. Histologic examination of fetal rat heads confirmed the biochemical evidence that retinoic acid is the more potent teratogen. Both forms of vitamin A prevented palatal shelf reorientation from occurring at the correct gestational age. The retinyl acetate treatment delayed the rotation for approximately 12 hours, the retinoic acid for at least 48 hours.

Topics: Animals; Cleft Palate; Disease Models, Animal; Diterpenes; Palate; Rabbits; Rats; Retinaldehyde; Retinyl Esters; Teratogens; Tretinoin; Vitamin A