Phytochemical characterisation and in vivo antilithiatic activity of the stems of Caesalpinia bahamensis (Brasilete).

The aim of this work was to identify the main chemical constituents and to evaluate the antilithiatic activity of the aqueous and hydroalcoholic extracts of stems of Caesalpinia bahamensis Lam. Fractionation and isolation of constituents from the hydroalcoholic extract was carried out by flash chromatography and semi-preparative liquid chromatography. The antilithiatic activity of the aqueous and hydroalcoholic extracts was evaluated in Wistar rats, where kidney stones were induced by ethylene glycol and ammonium chloride. Creatinine, calcium, and oxalate levels were evaluated and histological analysis was carried out. The homoisoflavonoids protosappanin B, 10-methyl-protosappanin B and brazilin were isolated and the antilithiatic activity of the aqueous and hydroalcoholic extracts was demonstrated by the reduction of the concentration of calcium and oxalate in urine compared to the lithiasis group. It was corroborated by histological analysis. Brazilin and protosappanin B were proposed as chemical markers for this plant species.

Antiproliferative, Antiangiogenic, and Antimetastatic Therapy Response by Mangiferin in a Syngeneic Immunocompetent Colorectal Cancer Mouse Model Involves Changes in Mitochondrial Energy Metabolism.

In spite of the current advances and achievements in cancer treatments, colorectal cancer (CRC) persists as one of the most prevalent and deadly tumor types in both men and women worldwide. Drug resistance, adverse side effects and high rate of angiogenesis, metastasis and tumor relapse remain one of the greatest challenges in long-term management of CRC and urges need for new leads of anticancer drugs. We demonstrate that CRC treatment with the phytopharmaceutical mangiferin (MGF), a glucosylxanthone present in Mango tree stem bark and leaves (Mangifera Indica L.), induces dose-dependent tumor regression and decreases lung metastasis in a syngeneic immunocompetent allograft mouse model of murine CT26 colon carcinoma, which increases overall survival of mice. Antimetastatic and antiangiogenic MGF effects could be further validated in a wound healing in vitro model in human HT29 cells and in a matrigel plug implant mouse model. Interestingly, transcriptome pathway enrichment analysis demonstrates that MGF inhibits tumor growth, metastasis and angiogenesis by multi-targeting of mitochondrial oxidoreductase and fatty acid ß-oxidation metabolism, PPAR, SIRT, NFκB, Stat3, HIF, Wnt and GP6 signaling pathways. MGF effects on fatty acid ß-oxidation metabolism and carnitine palmitoyltransferase 1 (CPT1) protein expression could be further confirmed in vitro in human HT29 colon cells. In conclusion, antitumor, antiangiogenic and antimetastatic effects of MGF treatment hold promise to reduce adverse toxicity and to mitigate therapeutic outcome of colorectal cancer treatment by targeting mitochondrial energy metabolism in the tumor microenvironment.

Synergistic interaction between amitriptyline and paracetamol in persistent and neuropathic pain models: An isobolografic analysis.

The current study was designed to evaluate the transient antinociceptive interaction between amitriptyline and paracetamol in the formalin test. In addition, considering other long-term neuroprotective mechanisms of these drugs, we hypothesized that this combination might exert some synergistic effects on neuropathic pain linked with its possible ability to prevent Wallerian degeneration (WD). The effects of individual and fixed-ratio of 1:1 combinations of orally administered amitriptyline and paracetamol were assayed in the two phases of the formalin test and in the chronic constriction injury (CCI) model in rats. Isobolographic analysis was employed to characterize the synergism produced by the combinations. Amitriptyline, paracetamol, and fixed-ratio amitriptyline-paracetamol combinations produced dose-dependent antinociceptive effects mainly on the inflammatory tonic phase. Repeated doses of individual drugs and their combination decreased CCI-induced mechanical allodynia in a dose-dependent manner. ED30 (formalin) and ED50 (CCI) values were estimated for the individual drugs, and isobolograms were constructed. Theoretical ED30/50 values for the combination estimated from the isobolograms were 16.5 ± 3.9 mg/kg and 26.0 ± 7.2 mg/kg for the single and repeated doses in persistent and neuropathic pain models, respectively. These values were significantly higher than the actually observed ED30/50 values, which were 0.39 ± 0.1 mg/kg and 8.2 ± 0.8 mg/kg in each model, respectively, indicating a synergistic interaction. Remarkably, CCI-induced sciatic nerve WD-related histopathological changes were prevented by this combination compared to either drug administered alone.

Novel arylidene malonate derivative, KM-34, showed neuroprotective effects on in vitro and in vivo models of ischemia/reperfusion.

Cerebral ischemia constitutes the most frequent type of cerebrovascular disease. The reduction of blood supply to the brain initiates the ischemic cascade starting from ionic imbalance to subsequent glutamate excitotoxicity, neuroinflammation and oxidative stress, eventually causing neuronal death. Previously, the authors have demonstrated the in vitro cytoprotective and antioxidant effects of a new arylidene malonate derivative, KM-34, against oxidizing agents like hydrogen peroxide, glutamate or Fe3+/ascorbate. Here, we examined for the first time the neuroprotective effect of KM-34 on ischemia/reperfusion models. In vitro, treatment with 10 and 50 µM KM-34 reduced the cellular death (propidium iodide incorporation) induced by oxygen glucose deprivation (OGD) in rat organotypic hippocampal slices cultures. In vivo, stroke was induced in male Wistar rats through middle cerebral artery occlusion (MCAO), followed by 23 h of reperfusion. KM-34 was orally administered 105 min after MCAO onset. We noticed that 1 mg/kg KM-34 reduced infarct volume and neurological score, and increased the latency to fall in the Hanging Wire test compared to vehicle-treated ischemic animals. While ischemic and sham-operated groups showed similar horizontal locomotor activity, vertical counts decreased after MCAO, suggesting that vertical movements are more sensitive to the ischemic injury. Treatment with KM-34 also alleviated the mitochondrial impairment (ROS generation, swelling and membrane potential dissipation) induced by transient MCAO but not significant alterations were found in oxidative stress parameters. Overall, the study provides preclinical evidences confirming the neuroprotective effects of a novel synthetic molecule and paved the way for future investigations regarding its therapeutic potential against brain ischemia/reperfusion injury.

Marine Seagrass Extract of Thalassia testudinum Suppresses Colorectal Tumor Growth, Motility and Angiogenesis by Autophagic Stress and Immunogenic Cell Death Pathways.

Marine plants have become an inexhaustible reservoir of new phytopharmaceuticals for cancer treatment. We demonstrate in vitro/in vivo antitumor efficacy of a standardized polyphenol extract from the marine angiosperm Thalassia testudinum (TTE) in colon tumor cell lines (RKO, SW480, and CT26) and a syngeneic allograft murine colorectal cancer model. MTT assays revealed a dose-dependent decrease of cell viability of RKO, CT26, and SW480 cells upon TTE treatment with IC50 values of, respectively, 175, 115, and 60 µg/mL. Furthermore, TTE significantly prevented basal and bFGF-induced angiogenesis in the chicken chorioallantoic membrane angiogenesis assay. In addition, TTE suppressed bFGF-induced migration of endothelial cells in a wound closure assay. Finally, TTE treatment abrogated CT26 colorectal cancer growth and increased overall organism survival in a syngeneic murine allograft model. Corresponding transcriptome profiling and pathway analysis allowed for the identification of the mechanism of action for the antitumor effects of TTE. In line with our in vitro/in vivo results, TTE treatment triggers ATF4-P53-NFκB specific gene expression and autophagy stress pathways. This results in suppression of colon cancer cell growth, cell motility, and angiogenesis pathways in vitro and in addition promotes antitumor immunogenic cell death in vivo.

Anti-hypernociceptive and anti-inflammatory effects of JM-20: A novel hybrid neuroprotective compound.

The present study examines the possible effect of the novel hybrid molecule JM-20 (3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-411-dihydro-1H-pyrido[2,3-b] [1,5] benzodiazepine) on pain-related behaviours in a persistent pain model (5% formalin test) and in the neutrophil migration events during the inflammatory process. It further introduces JM-20 in a chronic constriction injury (CCI) model to clarify the possible subjacent mechanisms with its consequent clinical relevance. A single administration of JM-20 (20 or 40 mg/kg, per os [p.o.]) decreased licking/biting exclusively in the tonic phase of the formalin test in a GABA/benzodiazepine (BZD) receptor antagonist flumazenil-sensitive manner. JM-20 reduced in vivo neutrophil migration, rolling and adhesion to the endothelium induced by intraperitoneal administration of carrageenan in mice. In addition, plasma extravasation and tumour necrosis factor alpha production in the peritoneal fluid were decreased. Treatment with JM-20 (20 mg/kg, p.o.) for 7 days after CCI reduced mechanical hypersensitivity in a NG-monomethyl-l-arginine (L-NMMA)/methylene blue/glibenclamide-sensitive manner. Histopathological signs of Wallerian degeneration (WD) of the sciatic nerve were also attenuated, as well as interleukin-1 beta release in the spinal cord. The nitrate/nitrite concentration was increased centrally and did not show differences at the peripheral nerve level. The findings of this study suggest JM-20 can decrease persistent pain. A transient activity of its BDZ portion on nociceptive pathways mediated by GABA/BDZ receptors in association with its anti-inflammatory properties could be at least partially involved in this effect. JM-20 decreased CCI-induced mechanical hypersensitivity via the l-arginine/nitric oxide (NO)/cyclic GMP-sensitive ATP-sensitive potassium channel pathway. Its neuroprotective ability by preventing WD could be implicated in its anti-neuropathic mechanisms.

Anti-angiogenic effects of mangiferin and mechanism of action in metastatic melanoma.

Advanced metastatic melanoma, one of the most aggressive skin malignancies, is currently without reliable therapy. The process of angiogenesis is crucial for progression and metastasis of the majority of solid tumors including melanomas. Therefore, new therapies are urgently needed. Mangiferin is a naturally occurring glucosylxanthone which exerts many pharmacological activities against cancer-inflammation. However, the effect of mangiferin on metastasis and tumor growth of metastatic melanoma remains unclear. In this study, we demonstrate that mangiferin interferes with inflammation, lipid and calcium signaling which selectively inhibits multiple NFkB target genes including interleukin-6, tumor necrosis factor, interferon gamma, vascular endothelial growth factor receptor 2, plasminogen activator urokinase, matrix metalloprotease 19, C-C Motif Chemokine Ligand 2 and placental growth factor. This abrogates angiogenic and invasive processes and capillary tube formation of metastatic melanoma cells as well as human placental blood vessel explants in-vitro and blocks angiogenesis characteristic of the chicken egg chorioallantoic membrane assay and in melanoma syngeneic studies in vivo. The results obtained in this research illustrate promising anti-angiogenic effects of the natural glucosylxanthone mangiferin for further (pre)clinical studies in melanoma cancer patients.

Emerging immune and cell death mechanisms in stroke: Saponins as therapeutic candidates.

The complexity of the ischemic cascade is based on the integrated crosstalk of every cell type in the neurovascular unit. Depending on the features of the ischemic insult, several cell death mechanisms are triggered, such as apoptosis, necroptosis, ferroptosis/oxytosis, ETosis or pyroptosis, leading to reactive astrogliosis. However, emerging evidence demonstrates a dual role for the immune system in stroke pathophysiology, where it exerts both detrimental and also beneficial functions. In this review, we discuss the relevance of several cell death modalities and the dual role of the immune system in stroke pathophysiology. We also provide an overview of some emerging immunomodulatory therapeutic strategies, amongst which saponins, which are promising candidates that exert multiple pharmacological effects.

Mangiferin: Possible uses in the prevention and treatment of mixed osteoarthritic pain.

Osteoarthritis (OA) pain has been proposed to be a mixed pain state, because in some patients, central nervous system factors are superimposed upon the more traditional peripheral factors. In addition, a considerable amount of preclinical and clinical evidence has shown that, accompanying the central neuroplasticity changes and partially driven by a peripheral nociceptive input, a real neuropathic component occurs that are particularly linked to disease severity and progression. Hence, innovative strategies targeting neuroprotection and particularly neuroinflammation to prevent and treat OA pain could be introduced. Mangiferin (MG) is a glucosylxanthone that is broadly distributed in higher plants, such as Mangifera indica L. Previous studies have documented its analgesic, anti-inflammatory, antioxidant, neuroprotective, and immunomodulatory properties. In this paper, we propose its potential utility as a multitargeted compound for mixed OA pain, even in the context of multimodal pharmacotherapy. This hypothesis is supported by three main aspects: the cumulus of preclinical evidence around this xanthone, some preliminary clinical results using formulations containing MG in clinical musculoskeletal or neuropathic pain, and by speculations regarding its possible mechanism of action according to recent advances in OA pain knowledge.

Dry amorphisation of mangiferin, a poorly water-soluble compound, using mesoporous silica.

Mangiferin, a poorly water soluble compound, was processed via a dry amorphisation technique (ball milling) in combination with mesoporous silica to enhance the solubility of mangiferin. The amorphous samples were prepared by mixing 1:1 (w/w) Syloid® XDP 3050 silica-mangiferin mixtures using a planetary mono mill at different milling speeds and milling times according to a 32 full factorial experimental design. The prepared samples were characterized for dissolution profile, particle size distribution using laser diffraction particle size analyzer, thermal characteristics using DSC, crystalline characteristics using XRD and molecular interactions using FTIR and ss-NMR. The samples were tested for stability at stress conditions (40 °C/75%RH) for up to 6 months in open and closed containers. To improve stability of the samples, mixtures of 1:1:2 mangiferin-polymer (Soluplus or HPMC)-silica samples were also prepared and analyzed. Amorphisation of mangiferin is possible using dry amorphisation by ball milling with mesoporous silica in a short amount of time. The amorphisation rate of the samples improved with the energy input of the milling process. The samples prepared with high energy input resulted in amorphous samples and showed a better stability at the stress conditions for up to 3 months. Solubility of these samples increased from 0.32 to 0.50 mg/ml and the particle size decreased from 35.5 µm to around 7 µm. The spectral analysis suggest presence of interactions between the silica material and the compound. The amorphous stability was improved with addition of polymer, even though the solubility of the samples was lower.

JM-20 Treatment After MCAO Reduced Astrocyte Reactivity and Neuronal Death on Peri-infarct Regions of the Rat Brain.

Stroke is frequently associated with severe neurological decline and mortality, and its incidence is expected to increase due to aging population. The only available pharmacological treatment for cerebral ischemia is thrombolysis, with narrow therapeutic windows. Efforts aimed to identify new therapeutics are crucial. In this study, we look into plausible molecular and cellular targets for JM-20, a new hybrid molecule, against ischemic stroke in vivo. Male Wistar rats were subjected to 90 min middle cerebral artery occlusion (MCAO) following 23 h of reperfusion. Animals treated with 8 mg/kg JM-20 (p.o., 1 h after reperfusion) showed minimal neurological impairment and lower GABA and IL-1ß levels in CSF when compared to damaged rats that received vehicle. Immunocontent of pro-survival, phosphorylated Akt protein decreased in the cortex after 24 h as result of the ischemic insult, accompanied by decreased number of NeuN+ cells in the peri-infarct cortex, cornu ammonis 1 (CA1) and dentate gyrus (DG) areas. Widespread reactive astrogliosis in both cortex and hippocampus (CA1, CA3, and DG areas) was observed 24 h post-ischemia. JM-20 prevented the activated Akt reduction, neuronal death, and astrocytes reactivity throughout the brain. Overall, the results reinforce the pharmacological potential of JM-20 as neuroprotective agent and provide important evidences about its molecular and cellular targets in this model of cerebral ischemia.

Anti-allodynic Effect of Mangiferin in Rats With Chronic Post-ischemia Pain: A Model of Complex Regional Pain Syndrome Type I.

The present study reproduces chronic post-ischemia pain (CPIP), a model of complex regional pain syndrome type I (CRPS-I), in rats to examine the possible transient and long-term anti-allodynic effect of mangiferin (MG); as well as its potential beneficial interactions with some standard analgesic drugs and sympathetic-mediated vasoconstriction and vasodilator agents during the earlier stage of the pathology. A single dose of MG (50 and 100 mg/kg, p.o.) decreased mechanical allodynia 72 h post-ischemia-reperfusion (I/R). MG 100 mg/kg, i.p. (pre- vs. post-drug) increased von Frey thresholds in a yohimbine and naloxone-sensitive manner. Sub-effective doses of morphine, amitriptyline, prazosin, clonidine and a NO donor, SIN-1, in the presence of MG were found to be significantly anti-allodynic. A long-term anti-allodynic effect at 7 and 13 days post-I/R after repeated oral doses of MG (50 and 100 mg/kg) was also observed. Further, MG decreased spinal and muscle interleukin-1ß concentration and restored muscle redox status. These results indicate that MG has a transient and long-term anti-allodynic effect in CPIP rats that appears to be at least partially attributable to the opioid and α2 adrenergic receptors. Additionally, its anti-inflammatory and antioxidant mechanisms could also be implicated in this effect. The association of MG with sub-effective doses of these drugs enhances the anti-allodynic effect; however, an isobolographic analysis should be performed to define a functional interaction between them. These findings suggest the possible clinical use of MG in the treatment of CRPS-I in both early sympathetically maintained pain and long-term sympathetically independent pain.

Antioxidant and Neuroprotective Effects of KM-34, A Novel Synthetic Catechol, Against Oxidative Stress-Induced Neurotoxicity.

Free radicals are important mediators in a number of neurodegenerative diseases and molecules capable of scavenging reactive oxygen species (ROS) may be a feasible strategy for protecting neuronal cells. In this sense, polyphenols have been studied for their antioxidant effects, KM-34 (5-(3, 4-dydroxyl-benzylidene)-2, 2-dimethyl-1, 3-dioxane-4, 6-Dione) is a novel synthetic catechol with potential neuroprotective and antioxidant properties. We have assessed the antioxidant (as scavenging and iron-chelating compound) and neuroprotectant in vitro (in PC12 cell injury induced by H2O2, glutamate or FeSO4/AA) of KM-34. KM-34 was found to be a potent antioxidant, as shown by (i) inhibition of iron induced-brain lipid peroxidation, (ii) inhibition of 2-deoxyribose degradation, (iii) inhibition of superoxide radicals generation (IC50=11.04 µM) and (iv) inhibition of 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical reduction (IC50=16.26 µM). The overall anti-oxidant action of KM-34 appears to be a combination of a direct reaction with free radicals and chelating the metal ions responsible for the production of ROS. Our work suggests that the antioxidant properties of KM-34 may provide future therapeutic approaches for neurodegenerative disorders.

Semi-synthetic sapogenin exerts neuroprotective effects by skewing the brain ischemia reperfusion transcriptome towards inflammatory resolution.

Stroke represents one of the first causes of mortality and morbidity worldwide. We evaluated the therapeutic potential of a novel semi-synthetic spirosteroid sapogenin derivative "S15" in a transient middle cerebral artery occlusion (tMCAO) focal ischemia model in rat. S15-treated rats had significantly reduced infarct volumes and improved neurological functions at 24h post-reperfusion, compared with ischemia. Corresponding gene expression changes in brain were characterized by mRNA sequencing and qPCR approaches. Next, we applied geneset, pathway and transcription factor motif enrichment analysis to identify relevant signaling networks responsible for neuronal damage upon ischemia-reperfusion or neuroprotection upon pretreatment with S15. As expected, ischemia-reperfusion brain damage strongly modulates transcriptional programs associated with immune responses, increased differentiation of immune cells as well as reduced (cat)ion transport and synaptic activity. Interestingly, S15-dependent neuroprotection regulates inflammation-associated genes involved in phagosome specific resolution of tissue damage, chemotaxis and anti-inflammatory alternative activation of microglia. Altogether our transcriptome wide RNA sequencing and integrated pathway analysis provides new clues in the neuroprotective properties of a novel spirosteroid S15 or neuronal damage in rat brains subjected to ischemia, which opens new perspectives for successful treatment of stroke.

In Vitro Neuroprotective and Anti-Inflammatory Activities of Natural and Semi-Synthetic Spirosteroid Analogues.

Two spirosteroid analogues were synthesized and evaluated for their in vitro neuroprotective activities in PC12 cells, against glutamate-induced excitotoxicity and mitochondrial damage in glucose deprivation conditions, as well as their anti-inflammatory potential in LPS/IFNγ-stimulated microglia primary cultures. We also evaluated the in vitro anti-excitotoxic and anti-inflammatory activities of natural and endogenous steroids. Our results show that the plant-derived steroid solasodine decreased PC12 glutamate-induced excitotoxicity, but not the cell death induced by mitochondrial damage and glucose deprivation. Among the two synthetic spirosteroid analogues, only the (25R)-5α-spirostan-3,6-one (S15) protected PC12 against ischemia-related in vitro models and inhibited NO production, as well as the release of IL-1ß by stimulated primary microglia. These findings provide further insights into the role of specific modifications of the A and B rings of sapogenins for their neuroprotective potential.

Neuroprotection by JM-20 against oxygen-glucose deprivation in rat hippocampal slices: Involvement of the Akt/GSK-3ß pathway.

Cerebral ischemia is the third most common cause of death and a major cause of disability worldwide. Beyond a shortage of essential metabolites, ischemia triggers many interconnected pathophysiological events, including excitotoxicity, oxidative stress, inflammation and apoptosis. Here, we investigated the neuroprotective mechanisms of JM-20, a novel synthetic molecule, focusing on the phosphoinositide-3-kinase (PI3K)/Akt survival pathway and glial cell response as potential targets of JM-20. For this purpose, we used organotypic hippocampal slice cultures exposed to oxygen-glucose deprivation (OGD) to achieve ischemic/reperfusion damage in vitro. Treatment with JM-20 at 0.1 and 10 µM reduced PI incorporation (indicative of cell death) after OGD. OGD decreased the phosphorylation of Akt (pro-survival) and GSK 3ß (pro-apoptotic), resulting in respective inhibition and activation of these proteins. Treatment with JM20 prevented the reduced phosphorylation of these proteins after OGD, representing a shift from pro-apoptotic to pro-survival signaling. The OGD-induced activation of caspase-3 was also attenuated by JM-20 treatment at 10 µM. Moreover, in cultures treated with JM-20 and exposed to OGD conditioning, we observed a decrease in activated microglia, as well as a decrease in interleukin (IL)-1ß, IL-6 and tumor necrosis factor (TNF)-α release into the culture medium, while the level of the anti-inflammatory IL-10 increased. GFAP immunostaining and IB4 labeling showed that JM-20 treatment significantly augmented GFAP immunoreactivity after OGD, when compared with cultures exposed to OGD only, suggesting the activation of astroglial cells. Our results confirm that JM-20 has a strong neuroprotective effect against ischemic injury and suggest that the mechanisms involved in this effect may include the modulation of reactive astrogliosis, as well as neuroinflammation and the anti-apoptotic cell signaling pathway.

The effects of JM-20 on the glutamatergic system in synaptic vesicles, synaptosomes and neural cells cultured from rat brain.

JM-20 (3-ethoxycarbonyl-2-methyl-4-(2-nitrophenyl)-4,11-dihydro-1H-pyrido[2,3-b][1,5]benzodiazepine) is a novel benzodiazepine dihydropyridine hybrid molecule, which has been shown to be a neuroprotective agent in brain disorders involving glutamate receptors. However, the effect of JM-20 on the functionality of the glutamatergic system has not been investigated. In this study, by using different in vitro preparations, we investigated the effects of JM-20 on (i) rat brain synaptic vesicles (L-[(3)H]-glutamate uptake, proton gradient built-up and bafilomycin-sensitive H(+)-ATPase activity), (ii) rat brain synaptosomes (glutamate release) and (iii) primary cultures of rat cortical neurons, astrocytes and astrocyte-neuron co-cultures (L-[(3)H]-glutamate uptake and glutamate release). We observed here that JM-20 impairs H(+)-ATPase activity and consequently reduces vesicular glutamate uptake. This molecule also inhibits glutamate release from brain synaptosomes and markedly increases glutamate uptake in astrocytes alone, and co-cultured neurons and astrocytes. The impairment of vesicular glutamate uptake by inhibition of the H(+)-ATPase caused by JM-20 could decrease the amount of the transmitter stored in synaptic vesicles, increase the cytosolic levels of glutamate, and will thus down-regulate neurotransmitter release. Together, these results contribute to explain the anti-excitotoxic effect of JM-20 and its strong neuroprotective effect observed in different in vitro and in vivo models of brain ischemia.

Evaluación del efecto del tratamiento combinado de mangiferina con cisplatino y 5-fluorouracilo en células CT26. WT y CHO-K1 / Evaluation of combination treatment effect of mangiferin with cisplatin and 5-fluorouracil in CT26. WT and CKO-K1 cells

Introducción: la mangiferina posee diferentes propiedades farmacológicas, y otras están por ser investigadas, tal como su actividad antitumoral como agente adyuvante a la quimioterapia antineoplásica convencional en la terapia combinada. Objetivo: evaluar el efecto antiproliferativo de la mangiferina sola y combinada con concentraciones bajas de agentes quimioterapéuticos. Métodos: las líneas celulares de carcinoma de colon de ratón CT26.WT y normal de ovario de hámster chino CHO-K1, se trataron con mangiferina en combinación con cisplatino y 5-fluorouracilo bajo diferentes esquemas de tratamiento (secuencial y simultáneo), a diferentes concentraciones y tiempos de incubación. La viabilidad celular se determinó por el ensayo de MTT. Resultados: la mangiferina (1-200 µg/mL) no fue citotóxica para ambas líneas celulares. El cotratamiento secuencial con mangiferina (1-200 µg/mL) por 3 h y cisplatino a concentraciones no citotóxicas (1 µM y 5 µM) durante 72 h, mostró un incremento significativo de la muerte celular en CT26.WT, sin inducir incremento significativo de la muerte en células CHO-K1, a concentraciones bajas de ambos compuestos. En el caso de los cotratamientos con mangiferina y 5-fluorouracilo (0,1 µM y 0,5 µM), se incrementó significativamente la muerte celular en los cotratamientos simultáneo por 72 h y secuencial 5-fluorouracilo 72 h y mangiferina 24 h en células CT26.WT; pero solo en este último, no se incrementó significativamente la muerte celular en CHO-K1. Conclusiones: la mangiferina en combinación con concentraciones bajas no citotóxicas de cisplatino y 5-fluorouracilo, promueve la muerte celular e incrementa la citotoxicidad de estos agentes quimioterapéuticos en las condiciones de experimentación realizadas(AU)

Introduction: mangiferin has several pharmacological properties, but others remain to be deeply explored, such as antitumor activity since it may serve as adjuvant agent in conventional antitumoral chemotherapy in a combined treatment. Objective: to evaluate the antiproliferative effect of the use of mangiferin alone and in combination with low concentrations of chemotherapeutic agents. Methods: the CT26.WT mouse colon carcinoma and the CHO-K1 hamster ovary normal cell lines were treated with mangiferin in combination with cisplatin and 5-fluorouracil in several treatment schedules (sequential and simultaneous), at different concentrations and incubation times. The cell viability was evaluated by MTT assay. Results: mangiferin (1-200 µg/mL) was not cytotoxic in both cell lines. Mangiferin (1-200 µg/mL) for 3h plus cisplatin at not citotoxic concentrations (1 µM and 5 µM) for 72 h in sequential combined treatment showed a significant increase of cell death in CT26.WT, without inducing significant increase of cell death in CHO-K1 cells at low concentrations of both compounds. In the case of combined mangiferina and 5-fluorouracil (0,1 µM and 0,5 µM) treatments, cell death rose in a significant way in simultaneous combined treatments for 72 h where as sequential combined therapy with 5-fluorouracil for 72 h plus mangiferin for 24 h in CT26.WT cells, a significant rise was not induced in the cell line death of CHO-K1 hamster Conclusions: mangiferin in combination with low non cytotoxic concentrations of cisplatin and 5-fluorouracil promotes cell death and increases the cytotoxicity of these chemotherapeutic agents in experimental conditions of this study(AU)

Evaluación del efecto del tratamiento combinado de mangiferina con cisplatino y 5-fluorouracilo en células CT26. WT y CHO-K1 / Evaluation of combination treatment effect of mangiferin with cisplatin and 5-fluorouracil in CT26. WT and CKO-K1 cells

INTRODUCCIÓN: la mangiferina posee diferentes propiedades farmacológicas, y otras están por ser investigadas, tal como su actividad antitumoral como agente adyuvante a la quimioterapia antineoplásica convencional en la terapia combinada. OBJETIVO: evaluar el efecto antiproliferativo de la mangiferina sola y combinada con concentraciones bajas de agentes quimioterapéuticos. MÉTODOS: las líneas celulares de carcinoma de colon de ratón CT26.WT y normal de ovario de hámster chino CHO-K1, se trataron con mangiferina en combinación con cisplatino y 5-fluorouracilo bajo diferentes esquemas de tratamiento (secuencial y simultáneo), a diferentes concentraciones y tiempos de incubación. La viabilidad celular se determinó por el ensayo de MTT. RESULTADOS: la mangiferina (1-200 µg/mL) no fue citotóxica para ambas líneas celulares. El cotratamiento secuencial con mangiferina (1-200 µg/mL) por 3 h y cisplatino a concentraciones no citotóxicas (1 µM y 5 µM) durante 72 h, mostró un incremento significativo de la muerte celular en CT26.WT, sin inducir incremento significativo de la muerte en células CHO-K1, a concentraciones bajas de ambos compuestos. En el caso de los cotratamientos con mangiferina y 5-fluorouracilo (0,1 µM y 0,5 µM), se incrementó significativamente la muerte celular en los cotratamientos simultáneo por 72 h y secuencial 5-fluorouracilo 72 h y mangiferina 24 h en células CT26.WT; pero solo en este último, no se incrementó significativamente la muerte celular en CHO-K1. CONCLUSIONES: la mangiferina en combinación con concentraciones bajas no citotóxicas de cisplatino y 5-fluorouracilo, promueve la muerte celular e incrementa la citotoxicidad de estos agentes quimioterapéuticos en las condiciones de experimentación realizadas(AU)

INTRODUCTION: mangiferin has several pharmacological properties, but others remain to be deeply explored, such as antitumor activity since it may serve as adjuvant agent in conventional antitumoral chemotherapy in a combined treatment. OBJECTIVE: to evaluate the antiproliferative effect of the use of mangiferin alone and in combination with low concentrations of chemotherapeutic agents. METHODS: the CT26.WT mouse colon carcinoma and the CHO-K1 hamster ovary normal cell lines were treated with mangiferin in combination with cisplatin and 5-fluorouracil in several treatment schedules (sequential and simultaneous), at different concentrations and incubation times. The cell viability was evaluated by MTT assay. RESULTS: mangiferin (1-200 µg/mL) was not cytotoxic in both cell lines. Mangiferin (1-200 µg/mL) for 3h plus cisplatin at not citotoxic concentrations (1 µM and 5 µM) for 72 h in sequential combined treatment showed a significant increase of cell death in CT26.WT, without inducing significant increase of cell death in CHO-K1 cells at low concentrations of both compounds. In the case of combined mangiferina and 5-fluorouracil (0,1 µM and 0,5 µM) treatments, cell death rose in a significant way in simultaneous combined treatments for 72 h whereas sequential combined therapy with 5-fluorouracil for 72 h plus mangiferin for 24 h in CT26.WT cells, a significant rise was not induced in the cell line death of CHO-K1 hamster CONCLUSIONS: mangiferin in combination with low non cytotoxic concentrations of cisplatin and 5-fluorouracil promotes cell death and increases the cytotoxicity of these chemotherapeutic agents in experimental conditions of this study(AU)

Antioxidant effects of JM-20 on rat brain mitochondria and synaptosomes: mitoprotection against Ca²âº-induced mitochondrial impairment.

Because mitochondrial oxidative stress and impairment are important mediators of neuronal damage in neurodegenerative diseases and in brain ischemia/reperfusion, in the present study, we evaluated the antioxidant and mitoprotective effect of a new promising neuroprotective molecule, JM-20, in mitochondria and synaptosomes isolated from rat brains. JM-20 inhibited succinate-mediated H2O2 generation in both mitochondria and synaptosomes incubated in depolarized (high K(+)) medium at extremely low micromolar concentration and with identical IC50 values of 0.91 µM. JM-20 also repressed glucose-induced H2O2 generation stimulated by rotenone or by antimycin A in synaptosomes incubated in high sodium-polarized medium at extremely low IC50 values of 0.395 µM and 2.452 µM, respectively. JM-20 was unable to react directly with H2O2 or with superoxide anion radicals but displayed a cathodic reduction peak at -0.71V, which is close to that of oxygen (-0.8V), indicating high electron affinity. JM-20 also inhibited uncoupled respiration in mitochondria or synaptosomes and was a more effective inhibitor in the presence of the respiratory substrates glutamate/malate than in the presence of succinate. JM-20 also prevented Ca(2+)-induced mitochondrial permeability transition pore opening, membrane potential dissipation and cytochrome c release, which are key pathogenic events during stroke. This molecule also prevented Ca(2+) influx into synaptosomes and mitochondria; the former effect was a consequence of the latter because JM-20 inhibition followed the patterns of carbonyl cyanide p-trifluoromethoxyphenyl hydrazone (FCCP), which is a classic mitochondrial uncoupler. Because the mitochondrion is considered an important source and target of neuronal cell death signaling after an ischemic insult, the antioxidant and protective effects of JM-20 against the deleterious effects of Ca(2+) observed at the mitochondrial level in this study may endow this molecule with the ability to succeed in mitochondrion-targeted strategies to combat ischemic brain damage.