Morphological and Functional Analysis of Cardiac Ameliorations in Elderly Rats Supplemented with a Magnolol Extract Complex / Análisis Morfológico y Funcional de las Mejoras Cardíacas en Ratas Ancianas Suplementadas con un Complejo de Extracto de Magnolol

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.

In vitro anti-metastatic activity of enterolactone, a mammalian lignan derived from flax lignan, and down-regulation of matrix metalloproteinases in MCF-7 and MDA MB 231 cell lines.

Background: Actin cytoskeleton is involved in actin-based cell adhesion, cell motility, and matrix metalloproteinases(MMPs) MMP2, MMP9, MMP11 and MMP14 are responsible for cell invasion in breast cancer metastasis. The dietary intake of lignan from flax seed gets converted to enterolactone (EL) and enterodiol in the human system. Here we show that the enterolactone has a very significant anti-metastatic activity as demonstrated by its ability to inhibit adhesion and invasion and migration in MCF-7 and MDA MB231 cell lines. Materials and Methods: Migration inhibition assay, actin-based cell motility assay along with reverse transcriptase polymerase chain reaction (RT-PCR) for MMP2, MMP9, MMP11 and MMP14 genes were performed in MCF-7 and MDA MB 231 cell lines. Results: Enterolactone seems to inhibit actin-based cell motility as evidenced by confocal imaging and photo documentation of cell migration assay. The results are supported by the observation that the enterolactone in vitro significantly down-regulates the metastasis-related metalloproteinases MMP2, MMP9 and MMP14 gene expressions. No significant alteration in the MMP11 gene expression was found. Conclusions: Therefore we suggest that the anti-metastatic activity of EL is attributed to its ability to inhibit cell adhesion, cell invasion and cell motility. EL affects normal filopodia and lamellipodia structures, polymerization of actin filaments at their leading edges and thereby inhibits actin-based cell adhesion and cell motility. The process involves multiple force-generating mechanisms of actin filaments i.e. protrusion, traction, deadhesion and tail-retraction. By down-regulating the metastasis-related MMP2, MMP9 and MMP14 gene expressions, EL may be responsible for cell invasion step of metastasis.

Liposomal honokiol, a potent anti-angiogenesis agent, in combination with radiotherapy produces a synergistic antitumor efficacy without increasing toxicity

Honokiol is an active compound purified from magnolia that has been shown to induce cell differentiation, apoptosis, and anti-angiogenesis effects, as well as an enhancement in tumor growth delay in combination with chemotherapeutic agents in several mouse xenograft models. Our goal was to investigate the radiosensitization effect of honokiol on lung carcinoma. The radiosensitization effect of liposomal honokiol in Lewis lung carcinoma cells (LL/2) was analyzed using an in vitro clonogenic survival assay. For an in vivo study, Lewis lung carcinoma-bearing C57BL/6 mice were treated with either liposomal honokiol at 25 mg/kg or 5 Gy of single tumor radiation, or a combination of both over 12 days of treatment. The tumor growth delay and the survival time were evaluated. In addition, histological analysis of tumor sections was performed to examine changes by detecting the microvessel density and apoptosis in tumor tissues. In the clonogenic survival assay, LL/2 cells treated with IC50 Lipo-HNK for 24 h showed a radiation enhancement ratio of 1.9. After 12 days of combination treatment, the tumor volume decreased 78% and produced an anti-tumor activity 1.3-fold greater than a predicted additive effect of honokiol and radiation alone. This combination treatment also caused an 8.7 day delay in tumor growth. The cell cycle distribution and histological analysis demonstrated that liposomal honokiol has an anti-tumor effect via inducing apoptosis and inhibiting angiogenesis. Liposomal honokiol can enhance tumor cell radiosensitivity in vitro and in vivo, indicating that radiotherapy combined with liposomal honokiol can lead to greater anti-tumor efficacy.