ABSTRACT
SUMMARY: Magnolia bark extract supplementation has an anti-oxidative role in mammalians. However, its role in physiological aged-associated heart insufficiency is not known yet. Therefore, we investigated the effects of a magnolia bark complex, including magnolol and honokiol components (MAHOC), in elderly rat hearts (24-month-old aged group). One group of aged rats was supplemented with MAHOC (400 mg/kg/d, for 12 weeks) besides the standard rat diet while the second group of elderly rats and adult rats (to 6-month- old adult-group) were only fed with the standard rat diet. The morphological analysis using light microscopy has shown marked myofibrillar losses, densely localized fibroblasts, vacuolizations, infiltrated cell accumulations, and collagen fibers in the myocardium of the elderly rats compared to the adults. We also detected a markedly increased amount of degenerated cardiomyocytes including the euchromatic nucleus. The MAHOC supplementation of the elderly rats provided marked ameliorations in these abnormal morphological changes in the heart tissue. Furthermore, electrophysiological analysis of electrocardiograms (ECGs) in the supplemented group showed significant attenuations in the prolonged durations of P-waves, QRS-complexes, QT-intervals, and low heart rates compared to the unsupplemented elderly group. The biochemical analysis also showed significant attenuations in the activity of arylesterase and total antioxidant status in the myocardium of the supplemented group. We further determined significant attenuations in the activity of a mitochondrial enzyme succinate dehydrogenase, known as a source of reactive oxygen species (ROS), and the decreased level of ATP/ADP in the heart homogenates of the supplemented group. Moreover, under in vitro conditions by using an aging-mimicked cardiac cell line induced by D-galactose, we demonstrated that MAHOC treatment could provide prevention of depolarization in mitochondria membrane potential and high-level ROS production. Overall, our data presented significant myocardial ameliorations in physiological aging-associated morphological alterations parallel to the function and biochemical attenuations with MAHOC supplementation, at most, through recoveries in mitochondria.
La suplementación con extracto de corteza de magnolia tiene un papel antioxidante en los mamíferos, sin embargo, su rol en la insuficiencia cardíaca asociada al envejecimiento fisiológico aún no se conoce. Por lo anterior, investigamos los efectos de un complejo de corteza de magnolia, incluidos los componentes magnolol y honokiol (MAHOC), en corazones de ratas seniles (grupo de edad de 24 meses). La alimentación de grupo de ratas seniles se complementó con MAHOC (400 mg/kg/d, durante 12 semanas) además de la dieta estándar, mientras que el segundo grupo de ratas seniles y ratas adultas (hasta el grupo de adultos de 6 meses) solo recibió la dieta estándar para ratas. El análisis morfológico mediante microscopía óptica ha mostrado marcadas pérdidas miofibrilares, fibroblastos densamente localizados, vacuolizaciones, acumulaciones de células infiltradas y fibras de colágeno en el miocardio de las ratas seniles en comparación con las adultas. También detectamos una cantidad notablemente mayor de cardiomiocitos degradados, incluido el núcleo eucromático. La suplementación con MAHOC de las ratas seniles proporcionó mejoras marcadas en estos cambios morfológicos anormales en el tejido cardiaco. Por otra parte, el análisis de los electrocardiogramas (ECG) en el grupo suplementado mostró atenuaciones significativas en las duraciones prolongadas de las ondas P, los complejos QRS, los intervalos QT y las frecuencias cardíacas bajas, en comparación con el grupo de ratas seniles sin suplementación alimenticia. El análisis bioquímico también mostró atenuaciones significativas en la actividad de la arilesterasa y el estado antioxidante total en el miocardio del grupo suplementado. Determinamos además atenuaciones significativas en la actividad de la enzima mitocondrial succinato deshidrogenasa, conocida como fuente de especies reactivas de oxígeno (ROS), y la disminución del nivel de ATP/ADP en los homogeneizados de corazón del grupo suplementado. Además, en condiciones in vitro mediante el uso de una línea de células cardíacas, imitando el envejecimiento inducido por D- galactosa, demostramos que el tratamiento con MAHOC podría prevenir la despolarización en el potencial de membrana de las mitocondrias y la producción de ROS de alto nivel. En general, nuestros datos presentaron mejoras miocárdicas significativas en alteraciones morfológicas asociadas con el envejecimiento fisiológico paralelas a la función y atenuaciones bioquímicas con la suplementación con MAHOC, como máximo, a través de recuperaciones en las mitocondrias.
Subject(s)
Animals , Male , Rats , Biphenyl Compounds/administration & dosage , Aging , Magnolia , Heart/drug effects , Antioxidants/administration & dosage , Plant Extracts , Reactive Oxygen Species , Rats, Wistar , Lignans/administration & dosage , Heart/physiologyABSTRACT
Background This study investigated the effect of Punica granatum L. (pomegranate) juice on the rabbit basilar artery in an experimental subarachnoid hemorrhage (SAH) model. Methods Eighteen adult male New Zealand white rabbits were randomly divided into three groups: a control group (n = 6), SAH group (n = 6), and SAH + treatment group (n = 6). Basilar artery diameter was measured with magnetic resonance angiography (MRA) in all groups at the beginning of the study. Experimental SAH was created by injecting autologous arterial blood into the cisterna magna. In the treatment group, the subjects were administered a daily dose of 30 ml/kg pomegranate juice via gastric gavage for 4 days after the SAH. The SAH group and SAH + treatment group underwent cerebral MRA after 72 hours. After a neurologic score assessment, all the animals were killed. The wall thickness and lumen area of the basilar artery were measured histometrically in all groups, and the apoptotic cell percentage in the artery was identified. The mean diameter of the basilar artery during MRA was measured. Results Pomegranate improved neurologic functions compared with the SAH group (p < 0.01). The mean basilar artery diameter on MRA in the SAH + treatment group was larger than in the SAH group and smaller than in the control group (p < 0.01 and p < 0.05, respectively). The mean vessel wall thickness value in the SAH + treatment group was lower than in the SAH group (p < 0.01), whereas there was no difference between the control and the SAH + treatment group (p > 0.05). The apoptotic cell rate in the SAH + treatment group was significantly lower than in the SAH group (p < 0.001). Evaluation of the basilar artery luminal area showed no difference between the three groups (p > 0.05). Discussion Pomegranate was shown to have a vasospasm- attenuating effect on the basilar artery in the rabbit SAH model for the first time in our study.