RESUMO
Asperuloside (ASP) and geniposide (GP) are iridoids that have shown various biological properties, such as reduction of inflammation, oxidative stress, and neuroprotection. The aim of this study was to investigate the mechanism of action of ASP and GP through the experimental model of pilocarpine-induced seizures. Mice were treated daily with saline, valproic acid (VPA), GP (5, 25, or 50 mg/kg), or ASP (20 or 40 mg/kg) for 8 days. Pilocarpine (PILO) treatment was administered after the last day of treatment, and the epileptic behavior was recorded for 1 h and analyzed by an adapted scale. Afterward, the hippocampus and blood samples were collected for western blot analyses, ELISA and comet assay, and bone marrow to the micronucleus test. We evaluated the expression of the inflammatory marker cyclooxygenase-2 (COX-2), GluN2B, a subunit of the NMDA receptor, pGluR1, an AMPA receptor, and the enzyme GAD-1 by western blot and the cytokine TNF-α by ELISA. The treatments with GP and ASP were capable to decrease the latency to the first seizure, although they did not change the latency to status epilepticus (SE). ASP demonstrated a genotoxic potential analyzed by comet assay; however, the micronuclei frequency was not increased in the bone marrow. The GP and ASP treatments were capable to reduce COX-2 and GluN2B receptor expression after PILO exposure. This study suggests that GP and ASP have a protective effect on PILO-induced seizures, decreasing GluN2B receptor and COX-2 expression.
Assuntos
Pilocarpina , Receptores de N-Metil-D-Aspartato , Ratos , Camundongos , Animais , Pilocarpina/toxicidade , Ciclo-Oxigenase 2/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Ratos Wistar , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Convulsões/metabolismo , Iridoides/farmacologia , Iridoides/uso terapêutico , Hipocampo , Modelos Animais de DoençasRESUMO
ETHNOPHARMACOLOGICAL RELEVANCE: Chilean population relies on medicinal plants for treating a wide range of illnesses, especially those of the gastrointestinal system. Junellia spathulata (Gillies & Hook.) Moldenke var. spathulata (Verbenaceae), called as "verbena-azul-de-cordilleira", is a medicinal plant native to Argentina and Chile traditionally used for treating digestive disorders. Although the species of the genus are important as therapeutic resources for the Andean population, the plants are very scarcely studied. AIMS OF THE STUDY: The purpose of the present study was to find out the main constituents and investigate the protective effect of J. spathulata against oxidative stress induced by the potent oxidant 2,2'-azobis (2-amidinopropane) dihydrochloride (AAPH) in human hepatoblastoma cells. MATERIALS AND METHODS: The crude methanol extract of J. spathulata and an iridoid obtained by chromatographic processes were tested to access the hepatoprotective effect and cytotoxicity in HepG2 cell. In addition, the reducing power of the samples and their ability to scavenge free radicals were evaluated using FRAP and ORAC assay systems. RESULTS: The iridoid asperuloside, the main compound of the crude methanol extract of J. spathulata, was isolated and identified by means of NMR analysis. The crude methanol extract of J. spathulata and asperuloside protected HepG2 cells against oxidative damage triggered by AAPH-derived free radicals. This effect can be credited to the ability of the extract and asperuloside to protect the liver cells from chemical-induced injury, which might be correlated to their free radical scavenging potential. CONCLUSIONS: This study experimentally evidenced the ethnopharmacological usefulness of J. spathulata as a treatment of digestive disorders. Our result could stimulate further investigations of hepatoprotective agents in other Chilean Junellia species.
Assuntos
Monoterpenos Ciclopentânicos/farmacologia , Sequestradores de Radicais Livres/farmacologia , Glucosídeos/farmacologia , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/farmacologia , Piranos/farmacologia , Verbenaceae , Sobrevivência Celular/efeitos dos fármacos , Chile , Monoterpenos Ciclopentânicos/isolamento & purificação , Sequestradores de Radicais Livres/isolamento & purificação , Glucosídeos/isolamento & purificação , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Extratos Vegetais/isolamento & purificação , Piranos/isolamento & purificação , Verbenaceae/químicaRESUMO
ABSTRACT The phytochemical study of Galium tunetanum Lam., Rubiaceae, leaves led to the isolation of 13 compounds from the chloroform-methanol and the methanol extracts, including six iridoid glycosides, one non-glycoside iridoid, two p-coumaroyl iridoid glycosides, two phenolic acids, and two flavonoid glycosides. The structural determination of the isolated compounds was performed by mono- and bidimensional NMR spectroscopic data, as well as ESI-MS experiments. All compounds were isolated from this species for the first time. The anti-angiogenic effects of the isolated iridoids were also reported on new blood vessels formation using the chick embryo chorioallantoic membrane as in vivo model. Results showed that among the isolated iridoids tested at the dose of 2 µg/egg, asperuloside (1), geniposidic acid (2), and iridoid V1 (3) reduced microvessel formation of the chorioallantoic membrane on morphological observations using a stereomicroscope. The anti-angiogenic effects of the active compounds, expressed as percentages of inhibition versus control, were 67% (1), 59% (2), and 54% (3), respectively. In addition, the active compounds were able to inhibit angiogenesis in the chorioallantoic membrane assay, in a dose-dependent manner (0.5-2 µg/egg) as compared to the standard retinoic acid.