RESUMEN
Based on the known antioxidant effect of flavonoids, baicalin (baic) found in roots of Scutellaria has been selected. Its coordination complex with the oxidovanadium(IV) cation, Na4[VO(baic)2].6H2O (VIVO(baic)), was synthesized at pH9 in ethanol and characterized by physicochemical methods. Spectrophotometric studies at pH9 showed a ligand: metal stoichiometry of 2:1. By vibrational spectroscopy a coordination mode through the cis 5-OH and 6-OH deprotonated groups is inferred. EPR spectroscopy shows an environment of four aryloxide (ArO-) groups in the equatorial plane of the VO moiety, both in solution and in the solid complex. The antioxidant capacity against superoxide and peroxyl radicals of VIVO(baic) resulted greater than for baicalin and correlated with previous results obtained for other VOflavonoid complexes. The coordination mode produces delocalization of the electron density and the stabilization of the radical formed by interaction with external radicals. The complex and the ligand displayed no toxic (Artemia salina test) and no mutagenic (Ames test) effects. The complex improved the ability of the ligand to reduce cell viability of human lung cancer cell lines (A549) generating reactive oxygen species (ROS) in cells, being this effect reversed by pre-incubation of the cells with antioxidants such as vitamins C and E. The addition of NAC (N-acetyl-l-cysteine, a sequestering agent of free radicals) suppresses the anticancer effect, confirming the oxidative stress mechanism. The complex interacted with bovine serum albumin (BSA) with stronger binding than baicalin and the mechanisms involved H bonding and van der Waals interactions.
Asunto(s)
Antineoplásicos , Antioxidantes , Complejos de Coordinación , Flavonoides , Neoplasias Pulmonares/tratamiento farmacológico , Vanadatos , Células A549 , Antineoplásicos/síntesis química , Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes/síntesis química , Antioxidantes/química , Antioxidantes/farmacología , Complejos de Coordinación/síntesis química , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Flavonoides/química , Flavonoides/farmacología , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Especies Reactivas de Oxígeno/metabolismo , Vanadatos/síntesis química , Vanadatos/química , Vanadatos/farmacologíaRESUMEN
The natural antioxidant flavonoid diosmin, found in citric fruits, showed low antioxidant properties among other flavonoids due to its structural characteristics and low cytotoxicity against lung (A549) and breast (T47D, SKBR3 and MDAMB231) cancer cell lines. The anticancer behavior has been improved by the metal complex generated with the flavonoid and the oxidovanadium(IV) ion. This new complex, [VO(dios)(OH)3]Na5·6H2O (VOdios), has been synthesized and characterized both in solid and solution states. The interaction of the metal ion through the sugar moiety of diosmin precluded the improvement of the antioxidant effects. However, the cell-killing effects tested in human lung A549 and breast T47D, SKBR3 and MDAMB231 cancer cell lines, were enhanced by complexation. The anti-proliferative effects on the human lung cancer cell line were accompanied by cellular ROS generation and an increase in cytoplasm condensation. The breast cancer cell lines did not produce caspase3/7 activation, mitochondrial potential reduction and ROS generation. Therefore, a non-apoptotic form of cell death in a caspase- and oxidative stress-independent manner has been proposed. The protein binding ability has been monitored by the quenching of tryptophan emission in the presence of the compounds using bovine serum albumin (BSA) as a model protein. Both compounds could be distributed and transported in vivo and the complex displayed stronger binding affinity and higher contributions to the hydrogen bond and van der Waals forces.
Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Antioxidantes/química , Antioxidantes/farmacología , Diosmina/análogos & derivados , Diosmina/farmacología , Vanadio/química , Vanadio/farmacología , Animales , Caspasas/metabolismo , Bovinos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Complejos de Coordinación/química , Complejos de Coordinación/farmacología , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Neoplasias/patología , Estrés Oxidativo/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismo , Albúmina Sérica Bovina/metabolismoRESUMEN
To improve the antidepressant action of sertraline a new salt with coumarin-3-carboxylate anion (SerH-CCA) has been synthesized by two different methods and characterized by FTIR spectroscopy and structural determinations by X-ray diffraction methods. The new salt is stabilized by strong intermolecular H-bonds involving the protonated amine group of SerH and the deprotonated carboxylate group of CCA. These findings can be correlated with the interpretation of the infrared spectrum. The salt, sertraline (SerHCl) and the sodium salt of coumarin-3-carboxylate (NaCCA) were orally administered male Wistar rats (10 mg/kg, based on sertraline). Rats were evaluated in separate groups by means of the forced swimming (FST). SerH-CCA produced antidepressant effects in a magnitude that exceeded SerHCl individual effects. None of these treatments affected activity levels by the open field OFT tests. We have also determined that the ion pair also improve the binding to bovine serum albumin (BSA) of the drug but retain its antimicrobial activity. It is reasonable to conclude that the replacement of chloride anion by a large organic anion in sertraline strengthens the pharmacological action of the native drug, binding to BSA with higher activity and retaining the antimicrobial activity of the antidepressant compound.
Asunto(s)
Antidepresivos/química , Antidepresivos/farmacocinética , Cumarinas/química , Sertralina/química , Sertralina/farmacocinética , Animales , Antiinfecciosos/química , Antiinfecciosos/farmacocinética , Antiinfecciosos/farmacología , Antidepresivos/farmacología , Disponibilidad Biológica , Cristalización/métodos , Depresión/tratamiento farmacológico , Masculino , Actividad Motora/efectos de los fármacos , Ratas , Ratas Wistar , Sertralina/farmacología , Natación/fisiología , Difracción de Rayos X/métodosRESUMEN
Chemotherapy using metal coordination compounds for cancer treatment is the work of the ongoing research. Continuing our research on the improvement of the anticancer activity of natural flavonoids by metal complexation, a coordination compound of the natural antioxidant flavone luteolin (lut) and the oxidovanadium(IV) cation has been synthesized and characterized. Using different physicochemical measurements some structural aspects of [VO(lut)(H2O)2]Na·3H2O (VOlut) were determined. The metal coordinated to two cis-deprotonated oxygen atoms (ArO(-)) of the ligand and two H2O molecules. Magnetic measurements in solid state indicated the presence of an effective exchange pathway between adjacent vanadium ions. VOlut improved the antioxidant capacity of luteolin only against hydroxyl radical. The antitumoral effects were evaluated on MDAMB231 breast cancer and A549 lung cancer cell lines. VOlut exhibited higher viability inhibition (IC50=17 µM) than the ligand on MDAMB231 cells but they have the same behavior on A549 cells (ca. IC50=60 µM). At least oxidative stress processes were active during cancer cell-killing. When metals chelated through the carbonyl group and one adjacent OH group of the flavonoid an effective improvement of the biological properties has been observed. In VOlut the different coordination may be the cause of the small improvement of some of the tested properties of the flavonoid. Luteolin and VOlut could be distributed and transported in vivo. Luteolin interacted in the microenvironment of the tryptophan group of the serum binding protein, BSA, by means of electrostatic forces and its complex bind the protein by H bonding and van der Waals interactions.
Asunto(s)
Antineoplásicos/química , Antioxidantes/química , Luteolina/química , Albúmina Sérica Bovina/química , Compuestos de Vanadio/química , Espectroscopía de Resonancia por Spin del Electrón , Unión Proteica , Espectrofotometría UltravioletaRESUMEN
Naringenin, a natural antioxidant present in grapefruit, oranges and the skin of tomatoes showed low antioxidant properties among other flavonoids due to its structural characteristics. Since many flavonoids were shown to have cell-killing and antioxidant activities, naringenin was investigated herein. In parallel with its antioxidant activities the flavonoid showed very low cytotoxicity at concentrations up to 100 µM against lung (A549) and breast (SKBr3 and MDAMB231) cancer cell lines. Furthermore, a newly-synthesized and characterized complex of naringenin and oxidovanadium(IV) ([V(IV)O(nar)2] · 2H2O, VOnar, with weak ferromagnetic coupling) was also studied. As a result, VOnar acted as a better compound on cell-killing and antioxidant activities (in vitro) than naringenin. The anti-proliferative effect of VOnar was accompanied by reactive oxygen species (ROS) generation, cell membrane and DNA damages, cell cycle arrest, caspase 3/7 activation and mitochondrial potential reduction. The higher parameters observed for the MDAMB231 cell line have been related to its low glutathione (GSH) content. The assays of the interaction of bovine serum albumin (BSA) with the complex showed the affinity of protein toward it and that there is only one binding site on the BSA molecule. However, metal complexation decreased the binding affinity to BSA of naringenin probably due to a steric hindrance of the complex.