Elaboración de videos didácticos como alternativa a los ensayos in vivo en las prácticas de farmacología / Didactic video as an alternative to in vivo assays in practical lessons of pharmacology

La Farmacología es una ciencia eminentemente práctica, en la que tiene gran relevancia la investigación "in vivo" con animales de experimentación. Los conocimientos impartidos en las clases teóricas, seminarios y tutorías, se completan con la enseñanza en las sesiones prácticas. Sin embargo, algunos aspectos importantes de esta enseñanza práctica, que incluyen la realización de ensayos “in vivo”, resulta problemático impartirlos correctamente con la normativa actual sobre la utilización de animales de laboratorio. Por ello, nos planteamos la realización de unos vídeos demostrativos de las técnicas experimentales utilizadas en algunas de las sesiones prácticas de las asignaturasde Farmacologia I y II del Grado en Farmacia. En cada sesión el profesor realiza una breve introducción del modelo experimental, indicando los objetivos que se plantea el investigador asi como las posibilidades de dicha técnica. A continuación en los vídeos, los estudiantes ven el desarrollo completo del experimento, los materiales necesarios y las condiciones experimentales adecuadas para su realización, asi como los diferentes parámetros y variables que se pueden medir. Al finalizar la proyección del vídeo se plantean dos tipos de tareas a los estudiantes:- diseño de un protocolo de evaluación de un fármaco con la metodología descrita- análisis, presentación y discusión de resultados, tras proporcionarles ejemplos de datos obtenidos en el ensayo.El procedimiento seguido para la elaboración de los vídeos es: 1) Diseño del ensayo de laboratorio. 2) Preparación del material necesario y las condiciones para una correcta grabación. 3) Grabación. Montaje de las imágenes (incluye fotografías, esquemas) y del sonido. 4) Edición del material filmado (una versión para Video- DVD y otra para incluirla en el Servidor Multimedia de la plataforma de la Universitat de València)(AU)

Pharmacology is a primarily practical science, in which “in vivo” research using experimental animal models plays a relevant role. The topics covered in the theoretical classes, seminars and tutorials are complemented with learning in practical sessions. However, certain important aspects of the practical learning, which include performing “in vivo” assays, represents a challenge given the actual regulations regarding laboratory animal utilization. Therefore, we proposed to produce didactic videos for various practical sessions. The teacher gives a brief introduction of the selected experimental animal model, indicating the intended objectives to be achieved. The students can see in the video the complete experiment progression, necessary materials and the proper experimental conditions toperform the assay, as well as the different parameters and variables to be measured.- a protocol design to evaluate a drug with the described methodology- analysis, result presentation and discussion of given example data obtained with the assay.The procedure used for the video elaboration was: 1) Design of the laboratory assay. 2) Preparation of the necessary materials and conditions for a correct recording. 3) Recording. Image (including photographs, schemes, figures) and sound download. 4) Editing of the filmed material (one version for Video- DVD and another one to be included in the virtual platform Multimedia Server of the University of Valencia)(AU)

Inducers of heme oxygenase-1.

Heme oxygenase-1 (HO-1) is an inducible rate-limiting enzyme which catalyzes group heme into carbon monoxide, iron and bilirubin. In the recent years, HO-1 expression has been reported as an important protective endogenous mechanism against physical, chemical and biological stress. In this regard, induction of this enzyme has shown beneficial effects in several pathologic conditions, such as inflammatory processes, atherosclerosis, carcinogenesis, ischemia-reperfusion systems or degenerative diseases. Complex intracellular signalling cascades mediate the expression of HO-1 in response to external stimuli, Transcription factors, as nuclear factor E2-related factor-2, activator protein-1, and nuclear factor-kappa B, and some of their upstream kinases, mitogen-activated protein kinases, phosphatidylinositol 3-kinase, or protein kinases A, C are responsible of the HO-1 gene expression. The purpose of this article is to review the increasing number of natural and synthetic molecules reported to induce HO-1 as additive mechanism responsible for their therapeutic effects; experimental and pathological conditions as well as possible signalling mechanism involved in HO-1 expression by this compounds are described. Controlled upregulation of this enzyme, or its catalytic activity, has shown antioxidant, anti-proliferative, anti-apoptotic and anti-inflammatory properties. For this reason, pharmacologic modulation of HO-1 system may represent an effective and cooperative strategy to intervene in several pathologic conditions.

Treatment with a CO-releasing molecule (CORM-3) reduces joint inflammation and erosion in murine collagen-induced arthritis.

OBJECTIVE: CO-releasing molecules (CO-RMs) are a novel class of anti-inflammatory agents. We have examined the possible therapeutic effects of CORM-3 in collagen-induced arthritis (CIA). METHODS: Arthritis was induced in DBA-1/J mice by type II collagen. Animals were treated with CORM-3 (5 and 10 mg/kg/day, intraperitoneally) or the inactive compound iCORM-3 (10 mg/kg/day, intraperitoneally) unable to release CO, from days 22 to 31. Production of anti-type II collagen antibodies, cytokines and cartilage olimeric matrix protein (COMP) was evaluated by enzyme-linked immunosorbent assay, and prostaglandin E(2) (PGE(2)) by radioimmunoassay. Localisation of cyclooxygenase-2 (COX-2), haem oxygenase-1 (HO-1), intercellular adhesion molecule-1 (ICAM-1) and receptor activator of nuclear factor kappaB ligand (RANKL) was examined by immunohistochemistry. RESULTS: Therapeutic administration of CORM-3 suppressed clinical and histopathological manifestations of disease. The levels of PGE(2), interleukin (IL)1beta, IL2, IL6, IL10 and tumour necrosis factor (TNF)alpha in joint tissues were inhibited by CORM-3. By contrast, CORM-3 augmented IL4. Anti-type II collagen antibodies and COMP levels in serum were reduced by CORM-3. Treatment with CORM-3 decreased cellular infiltration, joint inflammation and destruction, as well as the expression of COX-2, ICAM-1 and RANKL, whereas HO-1 increased. These beneficial effects were due to CO release, as iCORM-3 was ineffective. CONCLUSION: This study reveals the antiarthritic properties of CORM-3 in the CIA model and supports the notion that CO-RMs could be developed as a novel strategy for the treatment of inflammatory and arthritic conditions.

Evaluation of the anti-inflammatory and analgesic activity of Me-UCH9, a dual cyclooxygenase-2/5-lipoxygenase inhibitor.

Recently, we reported the dual inhibition of cyclooxygenase-2 (COX-2) and 5-lipoxygenase (5-LO) activity by some phenylsulphonyl urenyl chalcone derivatives. 2,4-dichloro-4'N[N'(4''methylphenylsulphonyl)urenyl] chalcone (Me-UCH9), was selected in the present study to determine its potential anti-inflammatory and analgesic effect after oral administration in several animal models related to the activation of COX-2 and 5-LO pathways. In the zymosan stimulated mouse air pouch model, Me-UCH9, reduced in a dose-dependent manner leukotriene B(4) (LTB(4)) levels in pouch exudates obtained at 4 h, as well as prostaglandin E(2) (PGE(2)) generated through COX-2 activation at 24 h. Tumor necrosis factor alpha (TNF-alpha) and myeloperoxidase activity were also strongly inhibited in this model. Me-UCH9 significantly reduced granuloma size and vascular index determined in the murine air pouch granuloma model of angiogenesis. In the carrageenan-induced paw edema, this compound inhibited inflammatory response and pain, as well as PGE(2) and LTB(4) content in paw edematous fluid. Analgesic properties were corroborated in the murine phenyl-p-benzoquinone-induced writhing test. Finally, Me-UCH9 exerted anti-inflammatory effects in the chronic model of rat adjuvant-induced arthritis, both inhibiting paw swelling and reducing PGE(2) content. Our findings confirm that Me-UCH9 can modulate inflammatory and nociceptive responses in relation to the dual inhibition of COX-2 and 5-LO activities presented by this compound.

Phenylsulphonyl urenyl chalcone derivatives as dual inhibitors of cyclo-oxygenase-2 and 5-lipoxygenase.

Two series of phenylsulphonyl urenyl chalcone derivatives (UCH) with various patterns of substitution were tested for their effects on nitric oxide (NO) and prostaglandin E2 (PGE2) overproduction in RAW 264.7 macrophages. None of the tested compounds reduced NO production more than 50% at 10 microM but most of them inhibited the generation of PGE2 with IC50 values under the micromolar range. Me-UCH 1, Me-UCH 5, Me-UCH 9, Cl-UCH 1, and Cl-UCH 9 were selected to evaluate their influence on human leukocyte functions and eicosanoids generation. These derivatives selectively inhibited cyclo-oxygenase-2 (COX-2) activity in human monocytes being Me-UCH 5 the most potent (IC50 0.06 microM). Selected compounds also reduced leukotriene B4 synthesis in human neutrophils by a direct inhibition of 5-lipoxygenase (5-LO) activity, with IC50 values from 0.5 to 0.8 microM. In addition, lysosomal enzyme secretion, such as elastase or myeloperoxidase as well as superoxide generation in human neutrophils were also reduced in a similar range. Our findings indicate that UCH derivatives exert a dual inhibitory effect on COX-2/5-LO activity. The profile and potency of these compounds may have relevance for the modulation of the inflammatory and nociceptive responses with reduction of undesirable side-effects associated with NSAIDs.

Effects of heme oxygenase-1 inducers on established rat adjuvant arthritis.

Heme oxygenase-1 (HO-1) activity can inhibit inflammatory and immune responses. We have examined the influence of HO-1 induction on the established rat adjuvant arthritis model of chronic inflammation. Therapeutic administration of cobalt protoporphyrin IX (CoPP; 5 mg/kg/day i.p.) from day 17 to 23 significantly reduced the inflammatory response, with partial inhibition of hind paw edema and the production of some inflammatory mediators such as nitric oxide metabolites and tumor necrosis factor-alpha, although joint erosion was observed. Hemin administration (26 mg/kg/day i.p.) during the same time period was ineffective on these parameters. Western blot analysis of hind paw homogenates revealed a weaker induction of HO-1 by this compound in comparison with CoPP. Our data indicate that pharmacological HO-1 induction after the establishment of adjuvant arthritis partially reduced the inflammatory response but it was not sufficient to control joint erosion in our experimental conditions.

Effect of some hexahydroimidazo[1,2-c]pyrimidines in inflammatory responses involving leucocytes and macrophages.

We have studied the effects of some hexahydroimidazo[1,2-c]pyrimidine derivatives (HIPs) on leucocyte functions in-vitro and we have assayed the anti-inflammatory activity of these compounds in two models of inflammation. All HIPs inhibited the human neutrophil degranulation process and superoxide generation at concentrations in the microM range. In mouse peritoneal macrophages stimulated with lipopolysaccharide, HIP-4 and HIP-5 inhibited nitrite production without affecting prostaglandin E2 (PGE2) accumulation. HIP-4 was also active in the zymosan-injected mouse air pouch model (at 100 nmol/pouch), with significant reductions in leucocyte migration and PGE2 and leukotriene B4 levels in the air pouch exudate. To confirm the anti-inflammatory effects of this compound, we tested HIP-4 orally (10-40 mg kg(-1)) on carrageenan mouse-paw oedema where it exerted a dose-dependent inhibition of paw swelling with significant reductions of myeloperoxidase and elastase activity and PGE2 levels in paw homogenates. This study demonstrates that some HIPs inhibit leucocyte functions and one of these derivatives (HIP-4) shows anti-inflammatory activity when administered by the oral route, which can be related to inhibition of leucocyte migration.

Effect of imidazo[1,2-a]pyrimidine derivatives on leukocyte function.

OBJECTIVE AND DESIGN: A series of six imidazo[1,2-a]pyrimidine (IP) derivatives were evaluated for their effects on leukocyte functions in vitro as well as on the inflammatory response induced by zymosan in the mouse air pouch. MATERIALS AND SUBJECTS: Human neutrophils and murine peritoneal macrophages were used for in vitro assays. Mouse air pouch was performed in Swiss mice. TREATMENT: Test compounds were incubated with either human neutrophils or mouse peritoneal macrophages at concentrations not showing cytotoxic effects. For in vivo experiments, IPs were injected into the air pouch. METHODS: Elastase and myeloperoxidase release, superoxide generation and LTB4 production were assayed in human neutrophils treated with different stimuli. Mouse peritoneal macrophages were stimulated with lipopolysaccharide (LPS), followed by determination of nitrite and PGE2 levels in supernatants. Zymosan was injected into six days-old mouse air pouches. Dunnett's t-test was employed for statistical analysis. RESULTS: All IPs inhibited human neutrophil degranulation with IC50 values in the microM range. IP-1, IP-2 and IP-5 also decreased superoxide generation. In LPS-stimulated macrophages, IP-4 and IP-6 inhibited nitrite production with a moderate reduction in PGE2 generation. In addition, these two compounds at 100 nmol/pouch inhibited leukocyte migration and LTB4 levels in the exudate of the mouse air pouch. CONCLUSIONS: Imidazo[1,2-a]pyrimidines are a class of compounds with antiinflammatory potential.

Inhibition of 5-lipoxygenase activity by the natural anti-inflammatory compound aethiopinone.

OBJECTIVE AND DESIGN: We have investigated the mechanisms of action of aethiopinone, an anti-inflammatory compound from Salvia aethiopis L. roots. MATERIAL AND SUBJECTS: Human neutrophils from healthy volunteers and murine peritoneal macrophages. Swiss mice were randomly divided into groups of six animals. TREATMENT: Test compounds were applied topically in the mouse ear oedema test. In the air pouch, mice received aethiopinone (0.001-0.5 pmol/pouch or 12.5-50 mg/kg p.o.). METHODS: LTB4 production was assayed in human neutrophils and COX-2 and iNOS activities in murine macrophages. Air pouches were induced subcutaneously in mice and injected with zymosan on the day six. Mouse ear oedema was induced by arachidonic acid. Dunnett's t-test was employed for statistical analysis. RESULTS: We have observed potent inhibitory effects on human neutrophil LTB4 production without effects on COX or NOS activities. Aethiopinone is an in vitro inhibitor of 5-LO from human neutrophils (IC50 = 0.11 microM). In addition, aethiopinone reduced leukocyte accumulation and showed in vivo inhibitory activity on this enzyme. CONCLUSIONS: Our results indicate that inhibition of 5-LO could participate in the anti-inflammatory properties of this natural product.

4-dimethylamino-3',4'-dimethoxychalcone downregulates iNOS expression and exerts anti-inflammatory effects.

Reactive oxygen and nitrogen species contribute to the pathophysiology of inflammatory conditions. We have studied the effects of a novel superoxide scavenger, 4-dimethylamino-3', 4'-dimethoxychalcone (CH11) in macrophages and in vivo. CH11 has been shown to inhibit the chemiluminescence induced by zymosan in mouse peritoneal macrophages and the cytotoxic effects of superoxide. In the same cells, the modulation by superoxide of nitric oxide (NO) production in response to zymosan was investigated. CH11 was more effective than the membrane-permeable scavenger Tiron for inhibition of inducible nitric oxide synthase (iNOS) protein expression and nitrite production. We have shown that CH11 inhibited chemiluminescence in vivo, as well as cell migration, and eicosanoid and tumor necrosis factor-alpha (TNF-alpha) levels in the mouse air pouch injected with zymosan. This chalcone derivative also exerted anti-inflammatory effects in the carrageenan paw oedema.

Effects of some isoxazolpyrimidine derivatives on nitric oxide and eicosanoid biosynthesis.

The inhibitory effect of some isoxazolpyrimidine derivatives on iNOS and COX-2 endotoxin induction in mouse peritoneal macrophages has been studied. Three of these compounds inhibited nitrite and PGE2 accumulation in a concentration dependent-manner at microM range. None of these active compounds affected iNOS, COX-2, COX-1 or PLA2 activities, although some reduced iNOS or COX-2 expression. Besides, no effect was observed on human neutrophil inflammatory responses (LTB4 biosynthesis and superoxide or elastase release). Active compounds were assayed by oral administration in the mouse air pouch model, where they inhibited nitrite accumulation without affecting PGE2 levels or leukocyte migration.

Co-regulation between cyclo-oxygenase-2 and inducible nitric oxide synthase expression in the time-course of murine inflammation.

Many in vitro studies have used cell cultures to focus on the relationships between cyclo-oxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) isoforms. We have investigated the time-course of regulation and the role of COX-2 and iNOS in a model of experimental inflammation in mice, the air pouch injected with zymosan. This study demonstrates that there is an early acute phase (4 h) mediated mainly by eicosanoids, with high levels of prostaglandin E2 (PGE2) produced by cyclo-oxygenase-1. In addition, in the later phase (from 12 h) there is a participation of nitric oxide (NO) and PGE2 accompanied by co-induction of both iNOS and COX-2. These enzymes were detected in migrating leukocytes as well as in macrophages lining the air pouch. Administration of NS398 or indomethacin inhibited PGE2 levels and COX activity, but also nitrite levels and iNOS activity, which was accompanied by a reduction in iNOS expression. Aminoguanidine inhibited nitrite levels and iNOS activity in addition to exerting inhibitory effects on the COX pathway. Treatment of animals with dexamethasone reduced nitrite and PGE2 concentrations in air pouch exudates, as well as iNOS and COX-2 expression in migrating cells. Our results indicate that PGE2 and NO may play in vivo mutual modulatory roles in the inflammatory response caused by zymosan injection into the mouse air pouch, a suitable model to study drugs acting on those pathways.

Novel anti-inflammatory chalcone derivatives inhibit the induction of nitric oxide synthase and cyclooxygenase-2 in mouse peritoneal macrophages.

In a previous work, we tested a series of chalcone derivatives as possible anti-inflammatory compounds. We now investigate the effects of three of those compounds, CHI, CH8 and CH12, on nitric oxide and prostanoid generation in mouse peritoneal macrophages stimulated with lipopolysaccharide and in the mouse air pouch injected with zymosan, where they showed a dose-dependent inhibition with inhibitory concentration 50% values in the microM range. This effect was not the consequence of a direct inhibitory action on enzyme activities. Our results demonstrated that chalcone derivatives inhibited de novo inducible nitric oxide synthase and cyclooxygenase-2 synthesis, being a novel therapeutic approach for inflammatory diseases.

Inhibition of human sPLA2 and 5-lipoxygenase activities by two neo-clerodane diterpenoids.

The inhibitory effect of two neo-clerodane diterpenoids, E-isolinaridial (EI) and its methylketone derivative (EIM), isolated from Linaria saxatilis var. glutinosa, on PLA2 and other enzyme activities involved in the inflammatory process was studied. Both compounds inhibited human synovial sPLA2 in a concentration-dependent manner with IC50 values of 0.20 and 0.49 microM, respectively, similar to scalaradial. Besides, these compounds decreased the cell-free 5-lipoxygenase activity and A23187-induced neutrophil LTB4 biosynthesis. Another function of human neutrophils, such as receptor-mediated degranulation, was also significantly reduced. In contrast, none of the compounds affected superoxide generation in leukocytes, or cyclooxygenase-1, cyclooxygenase-2 and inducible nitric oxide synthase activities in cell-free assays.

Hypothesis: can N-acetylcysteine be beneficial in Parkinson's disease?

Based on the finding of decreased mitochondrial complex I activity in the substantia nigra of patients with Parkinson's disease, we propose that the consequent reduction of ATP synthesis and increased generation of reactive oxygen species may be a possible cause of nigrostriatal cell death. Since sulfhydryl groups are essential in oxidative phosphorylation, thiolic antioxidants may contribute to the preservation of these proteins against oxidative damage. In the present paper, we hypothesize that treatment with a sulfur-containing antioxidant such as N-acetylcysteine may provide a new neuroprotective therapeutic strategy for Parkinson's disease.

Suppression of leukotriene B4 and tumour necrosis factor alpha release in acute inflammatory responses by novel prenylated hydroquinone derivatives.

A series of prenyl hydroquinone derivatives synthesized as structural analogs of marine products were tested for their effects on inflammatory responses in vitro and in vivo. 2-Prenyl-1,4-hydroquinone (H1), 2-diprenyl-1,4-hydroquinone (H2), 2-triprenyl-1,4-hydroquinone (H3) and 2-tetraprenyl-1,4-hydroquinone (H4) scavenged reactive oxygen species and inhibited 5-lipoxygenase (5-LO) activity in human neutrophils. The inhibition of 5-LO activity was demonstrated in vivo in the mouse air pouch injected with zymosan and arachidonic acid-induced ear inflammation. The four compounds suppressed the production of tumour necrosis factor alpha (TNFalpha) in J774 cells stimulated with lipopolysaccharide (LPS) and also in vivo in the mouse air pouch injected with zymosan. In addition, all prenyl-hydroquinones inhibited the release of nitrite and PGE2 in LPS-stimulated J774 cells, without direct effects on cyclo-oxygenase-1 (COX-1), cyclo-oxygenase-2 (COX-2) or inducible nitric oxide synthase (iNOS) activities in several cell-free systems. The reduction in the length of the lateral chain in prenyl-hydroquinones (1-4 isoprene units) with respect to their marine analogs (7-8 isoprene units) has improved the anti-inflammatory activity of this class of compounds. Marine natural products may be a model to design new anti-inflammatory agents.

A new cacospongionolide inhibitor of human secretory phospholipase A2 from the Tyrrhenian sponge Fasciospongia cavernosa and absolute configuration of cacospongionolides.

A new inhibitor of human secretory phospholipase A2 (PLA2), cacospongionolide E (4a), has been isolated from the Tyrrhenian sponge Fasciospongia cavernosa. The structure was proposed on the basis of spectroscopic data and by chemical transformations. The absolute configuration of cacospongionolides 2a-4a was established using the modified Mosher's method. Cacospongionolide E was the most potent inhibitor toward human synovial PLA2, showing higher potency than the reference compound manoalide and exerting no signs of toxicity on human neutrophils. It showed high activity in the Artemia salina bioassay and moderate toxicity in the fish (Gambusia affinis) lethality assay.

Anti-inflammatory activity in mice of extracts from Mediterranean marine invertebrates.

The effects of dichloromethane and methanol extracts from the marine invertebrates Leptogorgia ceratophyta, Holothuria tubulosa, Coscinasterias tenuispina and Phallusia fumigata on carrageenan-induced paw oedema in mice were investigated. The dichloromethane extract of Coscinasterias tenuispina and the methanol extract of Holothuria tubulosa administered p.o. at 50, 100 and 150 mg/kg, inhibited oedema in a dose-dependent manner 3 h after administration of carrageenan. Both extracts partially decreased elastase activity and PGE2 levels measured in homogenates from inflamed paws, without affecting the levels of this prostanoid present in stomach homogenates. As observed with the selective inhibitor NS398, both extracts can decrease cyclo-oxygenase activity in inflamed tissues but do not modify the constitutive cyclo-oxygenase enzyme. Therefore, these extracts represent new marine resources for the isolation of novel agents active on inflammatory conditions.

Synthesis and anti-inflammatory activity of chalcone derivatives.

Chalcones and their derivatives were synthesized and evaluated for their anti-inflammatory activity. In vitro, chalcones 2, 4, 8, 10 and 13 inhibited degranulation and 5-lipoxygenase in human neutrophils, whereas 11 behaved as scavenger of superoxide. Only four compounds (4-7) inhibited cyclo-oxygenase-2 activity. The majority of these samples showed anti-inflammatory effects in the mouse air pouch model.

N-acetylcysteine protects against age-related increase in oxidized proteins in mouse synaptic mitochondria.

Since it has been proposed that oxidized protein accumulation plays a critical role in brain aging, we have investigated the effect of a thiolic antioxidant on protein carbonyl content in synaptic mitochondria from female OF-1 mice. At 48 weeks of age, a control group was fed standard food pellets and another group received pellets containing 0.3% (w/w) of N-acetylcysteine. A 24-week treatment resulted in a significant decrease in protein carbonyl content in synaptic mitochondria of the N-acetylcysteine-treated animals as compared to age-matched controls.