Cardiovascular protection of magnolol: cell-type specificity and dose-related effects

The Use of Triphenyl Phosphonium Cation Enhances the Mitochondrial Antiplatelet Effect of the Compound Magnolol

Although platelets are anucleated cells, they have fully functional mitochondria, and currently, it is known that several processes that occur in the platelet require the action of mitochondria. There are plenty of mitochondrial-targeted compounds described in the literature related to cancer, however, only a small number of studies have approached their interaction with platelet mitochondria and/or their effects on platelet activity. Recent studies have shown that magnolia extract and mitochondria-targeted magnolol can inhibit mitochondrial respiration and cell proliferation in melanoma and oral cancer cells, respectively, and they can also induce ROS and mitophagy. In this study, the effect of triphenylphosphonium cation, linked by alkyl chains of different lengths, to the organic compound magnolol on human-washed platelets was evaluated. We demonstrated that the addition of triphenylphosphonium by a four-carbon linker to magnolol (MGN4) considerably enhanced the Magnolol antiplatelet effect by a 3-fold decrease in the IC50. Additionally, platelets exposed to MGN4 5 µM showed several differences from the control including increased basal respiration, collagen-induced respiration, ATP-independent respiration, and reduced ATP-dependent respiration and non-mitochondrial respiration.

Plants and their Bioactive Compounds as a Possible Treatment for Traumatic Brain Injury-Induced Multi-Organ Dysfunction Syndrome

BACKGROUND & OBJECTIVE

Traumatic brain injury is an outcome of the physical or mechanical impact of external forces on the brain. Thus, the silent epidemic has complex pathophysiology affecting the brain along with extracranial or systemic complications in more than one organ system, including the heart, lungs, liver, kidney, gastrointestinal and endocrine system. which is referred to as Multi-Organ Dysfunction Syndrome. It is driven by three interconnected mechanisms such as systemic hyperinflammation, paroxysmal sympathetic hyperactivity, and immunosuppression-induced sepsis. These multifaceted pathologies accelerate the risk of mortality in clinical settings by interfering with the functions of distant organs through hypertension, cardiac arrhythmias, acute lung injury, neurogenic pulmonary edema, reduced gastrointestinal motility, Cushing ulcers, acute liver failure, acute kidney injury, coagulopathy, endocrine dysfunction, and many other impairments. The pharmaceutical treatment approach for this is highly specific in its mode of action and linked to a variety of side effects, including hallucinations, seizures, anaphylaxis, teeth, bone staining, etc. Therefore, alternative natural medicine treatments are widely accepted due to their broad complementary or synergistic effects on the physiological system with minor side effects.

CONCLUSION

This review is a compilation of the possible mechanisms behind the occurrence of multiorgan dysfunction and reported medicinal plants with organoprotective activity that have not been yet explored against traumatic brain injury and thereby, highlighting the marked possibilities of their effectiveness in the management of multiorgan dysfunction. As a result, we attempted to respond to the hypothesis against the usage of medicinal plants to treat neurodegenerative diseases.

Magnolol reduces myocardial injury induced by renal ischemia and reperfusion

BACKGROUND

Magnolol is a component of the bark of Magnolia officinalis, which is a traditional herbal remedy used in China. In this study, we investigated whether magnolol can reduce myocardial injury induced by renal ischemia and reperfusion (I/R).

METHODS

Renal I/R was elicited by a 60-minute occlusion of the bilateral renal arteries and a 24-hour reperfusion in Sprague-Dawley rats. Magnolol was administered intravenously 10 minutes before renal I/R to evaluate its effects on myocardial injury induced by renal I/R.

RESULTS

Renal I/R significantly increased the serum levels of creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and cardiac troponin I and caused myocardial damage. The terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive nuclei and caspase-3 activation was significantly increased in the myocardium, indicating increase of apoptosis. Echocardiography revealed left ventricular dysfunction, as evidenced by reduction of left ventricular ejection fraction and left ventricular fractional shortening. Furthermore, serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, and IL-6 were significantly elevated, while the IL-10 level was suppressed. However, intravenously, pretreatment with magnolol at doses of 0.003 and 0.006 mg/kg 10 minutes before renal I/R significantly prevented the increases of CPK, LDH, and cardiac troponin I levels, as well as the histological damage and the apoptosis in the myocardium. Echocardiography showed significant improvement of left ventricular function. Furthermore, the increases in TNF-α, IL-1β, and IL-6 and the decrease in IL-10 were significantly limited, while Bcl-2 was increased and Bax was decreased in the myocardium. Phosphorylation of Akt and extracellular signal-regulated kinases 1 and 2 was increased, while phosphorylation of p38 and c-Jun N-terminal kinase was reduced.

CONCLUSION

Magnolol reduces myocardial injury induced by renal I/R. The underlying mechanisms for this effect might be related to modulation of the production of pro- and anti-inflammatory cytokines and the limiting of apoptosis.

Study on the Active Constituents and Molecular Mechanism of Zhishi Xiebai Guizhi Decoction in the Treatment of CHD Based on UPLC-UESI-Q Exactive Focus, Gene Expression Profiling, Network Pharmacology, and Experimental Validation

As one of the most common clinical cardiovascular diseases (CVDs), coronary heart disease (CHD) is the most common cause of death in the world. It has been confirmed that Zhishi Xiebai Guizhi decoction (ZXGD), a classical prescription of the traditional Chinese medicine (TCM), has achieved certain effects in the treatment of CHD; however, the mechanism still remains controversial. In this paper, an integrated approach, including UPLC-UESI-Q Exactive Focus, gene expression profiling, network pharmacology, and experimental validation, was introduced to systematically investigate the mechanism of ZXGD in the treatment of CHD. First, UPLC-UESI-Q Exactive Focus was applied to identify the chemical compounds of ZXGD. Then, the targets of the components for ZXGD were predicted by MedChem Studio software embed in the integrative pharmacology-based research platform of TCM, and the differentially expressed genes (DEGs) of CHD were obtained by gene expression profiling in gene expression omnibus database. The common genes of the above two genes were obtained by Venn analysis as the targets of GXGD in treatment with CHD. Third, the core targets were screened out by protein-protein interaction network analysis, and the kyoto encyclopedia of genes and genomes pathway enrichment analysis was performed by the database for annotation, visualization, and integrated discovery bioinformatics resources. After that, the formula-herb-compound-target-pathway network was constructed to explore the mechanism of ZXGD in the treatment of CHD. Finally, molecular docking and the vitro experiment were carried out to validate some key targets. As a result, a total of 39 compounds, 12 core targets, and 4 pathways contributed to ZXGD for the treatment of CHD. This study preliminarily provided a foundation for the study on the mechanism against CHD for ZXGD and may be a reference for the compatibility mechanism and the extended application of TCM compound prescription.

Inhibition of the HIF-1 Survival Pathway as a Strategy to Augment Photodynamic Therapy Efficacy

Photodynamic therapy (PDT) is a non-to-minimally invasive treatment modality that utilizes photoactivatable drugs called photosensitizers to disrupt tumors with locally photoproduced reactive oxygen species (ROS). Photosensitizer activation by light results in hyperoxidative stress and subsequent tumor cell death, vascular shutdown and hypoxia, and an antitumor immune response. However, sublethally afflicted tumor cells initiate several survival mechanisms that account for decreased PDT efficacy. The hypoxia inducible factor 1 (HIF-1) pathway is one of the most effective cell survival pathways that contributes to cell recovery from PDT-induced damage. Several hundred target genes of the HIF-1 heterodimeric complex collectively mediate processes that are involved in tumor cell survival directly and indirectly (e.g., vascularization, glucose metabolism, proliferation, and metastasis). The broad spectrum of biological ramifications culminating from the activation of HIF-1 target genes reflects the importance of HIF-1 in the context of therapeutic recalcitrance. This chapter elaborates on the involvement of HIF-1 in cancer biology, the hypoxic response mechanisms, and the role of HIF-1 in PDT. An overview of inhibitors that either directly or indirectly impede HIF-1-mediated survival signaling is provided. The inhibitors may be used as pharmacological adjuvants in combination with PDT to augment therapeutic efficacy.

The rich pharmacological activities of Magnolia officinalis and secondary effects based on significant intestinal contributions

ETHNOPHARMACOLOGICAL RELEVANCE

Magnolia officinalis Cortex (M. officinalis) is a traditional herbal drug widely used in Asian countries. Depending on its multiple biological activities, M. officinalis is used to regulate gastrointestinal (GI) motility, relieve cough and asthma, prevent cardiovascular and cerebrovascular diseases, and treat depression and anxiety.

AIM OF THE REVIEW

We aimed to review the abundant form of pharmacodynamics activity and potential mechanisms of action of M. officinalis and the characteristics of the internal processes of the main components. The potential mechanisms of local and distance actions of M. officinalis based on GI tract was provided, and it was used to reveal the interconnections between traditional use, phytochemistry, and pharmacology.

MATERIALS AND METHODS

Published literatures about M. officinalis and its main components were collected from several scientific databases, including PubMed, Elsevier, ScienceDirect, Google Scholar and Web of Science etc. RESULTS: M. officinalis was shown multiple effects including effects on digestive system, respiratory system, central system, which is consistent with traditional applications, as well as some other activities such as cardiovascular system, anticancer, anti-inflammatory and antioxidant effects and so on. The mechanisms of these activities are abundant. Its chief ingredients such as magnolol and honokiol can be metabolized into active metabolites in vivo, which can increase water solubility and bioavailability and exert pharmacological activity in the whole body. In the GI tract, M. officinalis and its main ingredient can regulate GI hormones and substance metabolism, protect the intestinal barrier and affect the gut microbiota (GM). These actions are effective to improve local discomfort and some distal symptoms such as depression, asthma, or metabolic disorders.

CONCLUSIONS

Although M. officinalis has rich pharmacological effects, the GI tract makes great contributions to it. The GI tract is not only an important place for absorption and metabolism but also a key site to help M. officinalis exert local and distal efficacy. Pharmacodynamical studies on the efficacies of distal tissues based on the contributions of the GI tract hold great potential for understanding the benefits of M. officinalis and providing new ideas for the treatment of important diseases.

Synergistic effects of autophagy/mitophagy inhibitors and magnolol promote apoptosis and antitumor efficacy

Mitochondria as a signaling platform play crucial roles in deciding cell fate. Many classic anticancer agents are known to trigger cell death through induction of mitochondrial damage. Mitophagy, one selective autophagy, is the key mitochondrial quality control that effectively removes damaged mitochondria. However, the precise roles of mitophagy in tumorigenesis and anticancer agent treatment remain largely unclear. Here, we examined the functional implication of mitophagy in the anticancer properties of magnolol, a natural product isolated from herbal Magnolia officinalis. First, we found that magnolol induces mitochondrial depolarization, causes excessive mitochondrial fragmentation, and increases mitochondrial reactive oxygen species (mtROS). Second, magnolol induces PTEN-induced putative kinase protein 1 (PINK1)‒Parkin-mediated mitophagy through regulating two positive feedforward amplification loops. Third, magnolol triggers cancer cell death and inhibits neuroblastoma tumor growth via the intrinsic apoptosis pathway. Moreover, magnolol prolongs the survival time of tumor-bearing mice. Finally, inhibition of mitophagy by PINK1/Parkin knockdown or using inhibitors targeting different autophagy/mitophagy stages significantly promotes magnolol-induced cell death and enhances magnolol's anticancer efficacy, both in vitro and in vivo. Altogether, our study demonstrates that magnolol can induce autophagy/mitophagy and apoptosis, whereas blockage of autophagy/mitophagy remarkably enhances the anticancer efficacy of magnolol, suggesting that targeting mitophagy may be a promising strategy to overcome chemoresistance and improve anticancer therapy.

Magnolol Triggers Caspase-Mediated Apoptotic Cell Death in Human Oral Cancer Cells through JNK1/2 and p38 Pathways

Magnolol is a natural compound extracted from Chinese herbal medicine and can induce apoptosis in numerous types of cancer cells. However, the molecular mechanisms of magnolol in oral cancer are still unclear. In this study, we investigated the anti-cancer effects and underlying mechanisms of magnolol in human oral cancer cell lines. Our results exhibited that magnolol inhibited the cell proliferation via inducing the sub-G1 phase and cell apoptosis of HSC-3 and SCC-9 cells. The human apoptosis array and Western blot assay showed that magnolol increased the expression of cleaved caspase-3 proteins and heme oxygenase-1 (HO-1). Moreover, we proved that magnolol induces apoptosis in oral cancer cell lines via the c-Jun N-terminal kinase (JNK)1/2 and p38 pathways. Overall, the current study supports the role for magnolol as a therapeutic approach for oral cancer through JNK1/2- and p38-mediated caspase activation.

Tournefortia sarmentosa Inhibits the Hydrogen Peroxide-Induced Death of H9c2 Cardiomyocytes

Tournefortia sarmentosa is a traditional Chinese medicine used to reduce tissue swelling, to exert the antioxidant effect, and to detoxify tissue. T. sarmentosa is also used to promote development in children and treat heart dysfunction. However, many of the mechanisms underlying the effects of T. sarmentosa in the treatment of disease remain unexplored. In this study, we investigated the antioxidant effect of T. sarmentosa on rat H9c2 cardiomyocytes treated with hydrogen peroxide (H₂O₂). T. sarmentosa reduced the cell death induced by H₂O₂. T. sarmentosa inhibited H₂O₂-induced changes in cell morphology, activation of cell death-related caspases, and production of reactive oxygen species. In addition, we further analyzed the potential active components of T. sarmentosa and found that the compounds present in the T. sarmentosa extract, including caffeic acid, rosmarinic acid, salvianolic acid A, and salvianolic acid B, exert effects similar to those of the T. sarmentosa extract in inhibiting H₂O₂-induced H9c2 cell death. Therefore, according to the results of this study, the ability of the T. sarmentosa extract to treat heart disease may be related to its antioxidant activity and its ability to reduce the cellular damage caused by free radicals.

Alzheimer's disease treatment: The share of herbal medicines

One of the most frequent forms of dementia in neurological disorders is Alzheimer's disease (AD). It is a chronic neurodegenerative disease characterized by impaired learning and memory. Pathological symptoms as extracellular amyloid-beta (Aβ) plaques and intracellular accumulation of neurofibrillary tangles occur in AD. Due to the aging of the population and increased prevalence of AD, discovery of new therapeutic agents with the highest effectiveness and fewer side effect seems to be necessary. Numerous synthetic medicines such as tacrine, donepezil, galantamine, rivastigmine, memantine, glutathione, ascorbic acid, ubiquinone, ibuprofen, and ladostigil are routinely used for reduction of the symptoms and prevention of disease progression. Nowadays, herbal medicines have attracted popular attention for numerous beneficial effects with little side effects. Lavandula angustifolia, Ginkgo biloba, Melissa officinalis, Crocus sativus, Ginseng, Salvia miltiorrhiza, and Magnolia officinalis have been widely used for relief of symptoms of some neurological disorders. This paper reviews the therapeutic effects of phytomedicines with prominent effects against various factors implicated in the emergence and progression of AD.

Novel oligomeric neolignans with PTP1B inhibitory activity from the bark of Magnolia officinalis var. biloba

The barks of Magnolia officinalis var. biloba, Magnoliae cortex, have been used as traditional Chinese medicines for several centuries. In this study, phytochemical investigation of M. officinalis var. biloba bark extract afforded five pairs of novel enantiomeric oligomeric neolignans, (±)-mooligomers A-E (1-5). (±)-1 and (±)-2 were two diastereomeric pairs of enantiomers with six C6-C3 subunits, and (±)-4 was a pair of previously unreported tetrameric neolignans bearing eight C6-C3 subunits. (±)-5 is the first example of a naturally occurring trilignan featuring an eight-membered ring with a magnolol moiety. The absolute configurations of (±)-1-(±)-5 were elucidated on the basis of HRESIMS, 1D and 2D NMR spectroscopy and electronic circular dichroism (ECD) calculations. Among the compounds tested for their PTP1B inhibitory activities, (±)-2, (±)-4 and (±)-5 displayed significant PTP1B inhibitory activities with IC₅₀ values of 0.14-2.10 μM. Furthermore, a Molecular docking simulation of PTP1B and active compounds [(±)-2, (±)-4 and (±)-5] exhibited that these active compounds possess low binding affinities ranging from - 5.9 to - 7.7 kcal/mol.

Magnolol alleviates Alzheimer's disease-like pathology in transgenic C. elegans by promoting microglia phagocytosis and the degradation of beta-amyloid through activation of PPAR-γ

This study aims to investigate whether magnolol (MG), a natural neolignane compound, can prevent AD induced by beta-amyloid (Aβ) and the possible mechanisms involved. MG dose-dependently reduces Aβ deposition, toxicity and memory impairment caused by Aβ in transgenic C. elegans. More importantly, these effects are reversed by GW9662, a selective peroxisome proliferator-activated receptor-γ (PPAR-γ) antagonist. MG is more effective in enhancing PPAR-γ luciferase levels than honokiol (HK). Meanwhile, MG has the potential to bind with the ligand binding domain of PPAR-γ (PPAR-γ-LBD). As expected, MG inhibited the luciferase activity of NF-κB and its target genes of inflammatory cytokines, and this effect was blocked by GW9662. The luciferase activity of Nrf2-ARE expression can be activated by MG and decreased Aβ-induced reactive oxygen species (ROS). The target gene LXR of PPAR-γ is activated by MG, which upregulates ApoE and promotes microglia phagocytosis and the degradation of Aβ, and these effects were also reversed by GW9662. In summary, MG can attenuate Aβ-induced AD and the underlying mechanism is the reduction of inflammation and promotion of phagocytosis and degradation of Aβ, which is dependent on PPAR-γ.

Hydromorphine postconditioning protects isolated rat heart against ischemia-reperfusion injury via activating P13K/Akt/eNOS signaling

INTRODUCTION

Myocardial ischemia/reperfusion injury (myocardial I/R injury) has a high disability rate and mortality. Novel treatments for myocardial I/R injury are necessary.

AIM

In order to explore the protective effect of hydromorphine on myocardial I/R injury, we illuminate the underlying mechanism of the protective effect.

RESULTS

Hydromorphine significantly reduced myocardial infarct size (IFN/AAR), CKMB (Creatine Kinase MB) and TN-T (Troponin T) release, and improved cardiac function compared with I/R group. However, these advantageous effects were partly suppressed in the presence of hydromorphine. Myocardial I/R injury significantly decreased the phosphorylation of Akt and eNOS, and down-regulated total nitric oxide and nitrotyrosine content, while these inhibitory effects were partly abolished by hydromorphine. Conversely, the activated effects of hydromorphine on the phosphorylation of Akt and eNOS, and NO release were totally reversed by LY294002, which, used individually, show the same influence on reperfusion injury.

CONCLUSIONS

These findings suggest that hydromorphine postconditioning may protect isolated rat heart against reperfusion injury via activating P13K/Akt/eNOS signaling.

Magnolol Alleviates Inflammatory Responses and Lipid Accumulation by AMP-Activated Protein Kinase-Dependent Peroxisome Proliferator-Activated Receptor α Activation

Magnolol (MG) is a kind of lignin isolated from Magnolia officinalis, which serves several different biological functions, such as antifungal, anticancer, antioxidant, and hepatoprotective functions. This study aimed to evaluate the protective effect of MG against oleic acid (OA)-induced hepatic steatosis and inflammatory damage in HepG2 cells and in a tyloxapol (Ty)-induced hyperlipidemia mouse model. Our findings indicated that MG can effectively inhibit OA-stimulated tumor necrosis factor α (TNF-α) secretion, reactive oxygen species generation, and triglyceride (TG) accumulation. Further study manifested that MG significantly suppressed OA-activated mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways and that these inflammatory responses can be negated by pretreatment with inhibitors of extracellular regulated protein kinase and c-Jun N-terminal kinase (U0126 and SP600125, respectively). In addition, MG dramatically upregulated peroxisome proliferator-activated receptor α (PPARα) translocation and reduced sterol regulatory element-binding protein 1c (SREBP-1c) protein synthesis and excretion, both of which are dependent upon the phosphorylation of adenosine monophosphate (AMP)-activated protein kinase (AMPK), acetyl-CoA carboxylase, and AKT kinase (AKT). However, MG suspended the activation of PPARα expression and was thus blocked by pretreatment with LY294002 and compound c (specific inhibitors of AKT and AMPK). Furthermore, MG clearly alleviated serum TG and total cholesterol release; upregulated AKT, AMPK, and PPARα expression; suppressed SREBP-1c generation; and alleviated hepatic steatosis and dyslipidemia in Ty-induced hyperlipidemia mice. Taken together, these results suggest that MG exerts protective effects against steatosis, hyperlipidemia, and the underlying mechanism, which may be closely associated with AKT/AMPK/PPARα activation and MAPK/NF-κB/SREBP-1c inhibition.

Magnolol inhibits venous remodeling in mice

Due to gravity the venous vasculature in the lower extremities is exposed to elevated pressure levels which may be amplified by obesity or pregnancy. As a consequence, venules dilate and may be slowly transformed into varicose or spider veins. In fact, chronically elevated venous pressure was sufficient to cause the corkscrew-like enlargement of superficial veins in mice. We hypothesized that biomechanical activation of endothelial cells contributes to this process and investigated the inhibitory capacity of Magnolol in this context - a natural compound that features multiple properties counteracting cellular stress. While Magnolol did not influence endothelial capillary sprout formation, it interfered with proliferation, ERK1/2 activity, gelatinase activity as well as baseline production of reactive oxygen species in these cells or murine veins. The anti-oxidative and anti-proliferative capacity of Magnolol was mediated through stimulation of heme oxygenase-1 expression. Finally, local transdermal application of Magnolol attenuated pressure-mediated development of varicose/spider veins in mice and was accompanied by the absence of proliferating and MMP-2 positive endothelial cells. Collectively, our data identified Magnolol as a potent inhibitor of biomechanically evoked endothelial cell activity during pressure-mediated venous remodeling processes which contribute to the development of varicose and spider veins.

Biological activity and toxicity of the Chinese herb Magnolia officinalis Rehder & E. Wilson (Houpo) and its constituents

Traditional Chinese herbal drugs have been used for thousands of years in Chinese pharmacopoeia. The bark of Magnolia officinalis Rehder & E. Wilson, known under the pinyin name "Houpo", has been traditionally used in Chinese and Japanese medicines for the treatment of anxiety, asthma, depression, gastrointestinal disorders, headache, and more. Moreover, Magnolia bark extract is a major constituent of currently marketed dietary supplements and cosmetic products. Much pharmacological activity has been reported for this herb and its major compounds, notably antioxidant, anti-inflammatory, antibiotic and antispasmodic effects. However, the mechanisms underlying this have not been elucidated and only a very few clinical trials have been published. In vitro and in vivo toxicity studies have also been published and indicate some intriguing features. The present review aims to summarize the literature on M. officinalis bark composition, utilisation, pharmacology, and safety.

Magnolol Reduces Renal Ischemia and Reperfusion Injury via Inhibition of Apoptosis

Magnolol, a constituent of the bark of Magnolia officinalis, has been reported to decrease myocardial stunning and infarct size. In this study, we investigated whether magnolol can reduce renal ischemia and reperfusion (I/R) injury. Renal I/R, induced by a 60-min occlusion of bilateral renal arteries and a 24-h reperfusion, significantly increased blood urea nitrogen (BUN) and creatinine levels, and caused histological damage to the kidneys of rats. Apoptosis, as evaluated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining and caspase-3 activation, was significantly increased in the kidneys. Furthermore, serum levels of tumor necrosis factor-[Formula: see text] (TNF-[Formula: see text]), interleukin-1β (IL-1β), and interleukin-6 (IL-6) were significantly elevated, while the interleukin-10 (IL-10) level was suppressed. However, intravenous pretreatment with magnolol at doses of 0.003[Formula: see text]mg/kg and 0.006[Formula: see text]mg/kg 10[Formula: see text]min before renal I/R significantly limited the increases of BUN, creatinine, the histological damage, and apoptosis in the kidneys. The increases in TNF-[Formula: see text], IL-1β, and IL-6, and the decrease in IL-10 were also significantly inhibited. Additionally, magnolol increased Bcl-2 and decreased Bax in the kidneys. Phosphorylation of the prosurvival kinases, including Akt and extracellular signal-regulated kinases 1 and 2 (ERK1/2), was elevated, while phosphorylation of the pro-apoptotic mitogen-activated protein kinases, including p38 and c-Jun N-terminal kinase (JNK), was suppressed. In conclusion, magnolol reduces renal I/R injury. The underlying mechanisms for this effect might be related to the prevention of apoptosis, possibly via the inhibition of both extrinsic and intrinsic apoptotic pathways, including the reduction of TNF-[Formula: see text] production and the modulation of pro- and anti-apoptotic signaling elements.

Nine phenylethanoid glycosides from Magnolia officinalis var. biloba fruits and their protective effects against free radical-induced oxidative damage

To systematically study the chemical constituents in Magnolia officinalis var. biloba fruits, nine phenylethanoid glycosides were isolated by solvent extraction, silica gel, and preparative high-performance liquid chromatography (HPLC). Their structures were elucidated by 1D and 2D NMR analyses, including COSY, HMQC and HMBC correlations, and HPLC analysis of sugar residue. Nine phenylethanoid glycosides, namely, magnoloside I_a (1), magnoloside I_c (2), crassifolioside (3), magnoloside I_b (4), magnoloside III_a (5), magnoloside IV_a (6), magnoloside II_a (7), magnoloside II_b (8) and magnoloside V_a (9), were first isolated from the n-butanol fraction of Magnolia officinalis var. biloba fruits alcohol extract. Free radical scavenging activities of the nine phenylethanoid glycosides were assessed using the DPPH, ABTS, and superoxide anion radical scavenging assays. Simultaneously, protective effects of all compounds against free radical-induced oxidative damage were evaluated by two different kinds of mitochondrial damage model. The protective effects were assessed by mitochondrial swelling, the formations of malondialdehyde (MDA) and lipid hydroperoxide (LOOH), the activities of catalase (CAT), glutathione reductase (GR) and superoxide dismutase (SOD). All phenylethanoid glycosides showed significant protective effects.

Chemical composition, antioxidant activity and cytotoxicity on tumour cells of the essential oil from flowers of Magnolia grandiflora cultivated in Iran

Magnolia grandiflora (Magnoliaceae) is an evergreen tree with fragrant and showy flowers native to southeastern USA but widely cultivated all over the world and used in cosmetics industry in treatment of skin diseases. Here, we report on the chemical analysis of the essential oil obtained from flowers of plants cultivated in Iran, together with the evaluation of its antioxidant and cytotoxic activities. The essential oil composition was dominated by bioactive sesquiterpenes, namely β-elemene, bicyclogermacrene, germacrene D and (E)-caryophyllene. The oil exhibited moderate radical scavenging activity towards the [Formula: see text] radical, and mild non-selective inhibitory effects against A375, MDA-MB 231 and T98 G tumour cell lines. The latter were influenced by the presence of the anticancer β-elemene. These results provided new insights for potential application of M. grandiflora volatile oil in the pharmaceutical and cosmetics industry where only the non-volatile magnolol and honokiol have hitherto been fully exploited.

Magnolol reduces bleomycin-induced rodent lung fibrosis

Magnolol, a compound extracted from the Chinese medicinal herb Magnolia officinalis, has been proved to exert multiple pharmacological effects, including anti-oxidant and anti-inflammation activities. In this study, how it influenced bleomycin-induced lung fibrosis of rats was investigated. A single intratracheal instillation of bleomycin (5 mg/Kg, sacrificed 7 and 28 days post bleomycin instillation) caused body weight decrease and lung indices increase. Hodroxyproline content, myeloperoxidase (MPO) activity, tumor necrosis factor-α (TNF-α) and transforming growth factor-β (TGF-β) levels increased in the rat lung tissues after bleomycin administration, while superoxide dismutase (SOD) activity decreased in the rat lung tissues. Collagen were excessively deposited in rat lung tissues after bleomycin treatment. However, oral administration of magnolol (10 mg/Kg, 20 mg/Kg, 30 mg/Kg) apparently and significantly inhibited the fibrotic process. It partly reversed the bleomycin-induced increase of hydroxyproline content, MPO activity, TNF-α and TGF-β levels in the lung tissues, significantly inhibited the bleomycin-induced decrease of SOD activity, Excessive collagen deposition was also inhibited by magnolol administration. In summary, our results suggested that magnolol might be a potent anti-inflammatory and anti-fibrotic agent against bleomycin-induced lung fibrosis.

Magnolol causes alterations in the cell cycle in androgen insensitive human prostate cancer cells in vitro by affecting expression of key cell cycle regulatory proteins

Prostate cancer, one of the most common cancers in the Western world, affects many men worldwide. This study investigated the effects of magnolol, a compound found in the roots and bark of the magnolia tree Magnolia officinalis, on the behavior of 2 androgen insensitive human prostate cancer cell lines, DU145 and PC3, in vitro. Magnolol, in a 24-h exposure at 40 and 80 μM, was found to be cytotoxic to cells. Magnolol also affected cell cycle progression of DU145 and PC3 cells, resulting in alterations to the cell cycle and subsequently decreasing the proportion of cells entering the G2/M-phase of the cell cycle. Magnolol inhibited the expression of cell cycle regulatory proteins including cyclins A, B1, D1, and E, as well as CDK2 and CDK4. Protein expression levels of pRBp107 decreased and pRBp130 protein expression levels increased in response to magnolol exposure, whereas p16(INK4a), p21, and p27 protein expression levels were apparently unchanged post 24-h exposure. Magnolol exposure at 6 h did increase p27 protein expression levels. This study has demonstrated that magnolol can alter the behavior of androgen insensitive human prostate cancer cells in vitro and suggests that magnolol may have potential as a novel anti-prostate cancer agent.

Honokiol, a constituent of Magnolia species, inhibits adrenergic contraction of human prostate strips and induces stromal cell death

Purpose

Smooth muscle contraction and prostate growth are important targets for medical therapy of lower urinary tract symptoms (LUTS) in patients with benign prostatic hyperplasia. Honokiol and Magnolol are lignan constituents of Magnolia species, which are used in traditional Asian medicine. Here, we examined effects of honokiol and magnolol on contraction of human prostate tissue and on growth of stromal cells.

Methods

Prostate tissues were obtained from radical prostatectomy. Contraction of prostate strips was examined in organ bath studies. Effects in stromal cells were assessed in cultured immortalized human prostate stromal cells (WPMY-1). Ki-67 mRNA was assessed by reverse transcription-polymerase chain reaction, and proliferation by a fluorescence 5-ethynyl-2′-deoxyuridine assay.

Results

Honokiol (100μM) reduced noradrenaline-induced contractions, which was significant at 10 to 100μM noradrenaline. Honokiol reduced phenylephrine-induced contractions, which was significant at 3 to 100μM phenylephrine. Honokiol reduced electric field stimulation-induced contractions very slightly. In WPMY-1 cells, honokiol (24 hours) induced cell death. Magnolol (100μM) was without effects on contraction, and cellular viability.

Conclusions

Honokiol inhibits smooth muscle contraction in the human prostate, and induces cell death in cultured stromal cells. Because prostate smooth muscle tone and prostate growth may cause LUTS, it appears possible that honokiol improves voiding symptoms.

The magnolia bioactive constituent 4-O-methylhonokiol protects against high-fat diet-induced obesity and systemic insulin resistance in mice

Obesity is caused by a combination of both genetic and environmental risks. Disruption in energy balance is one of these risk factors. In the present study, the preventive effect on high-fat diet- (HFD-) induced obesity and insulin resistance in mice by Magnolia bioactive constituent 4-O-methylhonokiol (MH) was compared with Magnolia officinalis extract BL153. C57BL/6J mice were fed by normal diet or by HFD with gavage-administered vehicle, BL153, low-dose MH, and high-dose MH simultaneously for 24 weeks, respectively. Either MH or BL153 slightly inhibited body-weight gain of mice by HFD feeding although the food intake had no obvious difference. Body fat mass and the epididymal white adipose tissue weight were also mildly decreased by MH or BL153. Moreover, MH significantly lowered HFD-induced plasma triglyceride, cholesterol levels and activity of alanine transaminase (ALT), liver weight and hepatic triglyceride level, and ameliorated hepatic steatosis. BL153 only significantly reduced ALT and liver triglyceride level. Concurrently, low-dose MH improved HFD-induced hyperinsulinemia and insulin resistance. Furthermore, the infiltration of mast cells in adipose tissue was decreased in MH or in BL153 treatment. These results suggested that Magnolia bioactive constituent MH might exhibit potential benefits for HFD-induced obesity by improvement of lipid metabolism and insulin resistance.

BL153 partially prevents high-fat diet induced liver damage probably via inhibition of lipid accumulation, inflammation, and oxidative stress

The present study was to investigate whether a magnolia extract, named BL153, can prevent obesity-induced liver damage and identify the possible protective mechanism. To this end, obese mice were induced by feeding with high fat diet (HFD, 60% kcal as fat) and the age-matched control mice were fed with control diet (10% kcal as fat) for 6 months. Simultaneously these mice were treated with or without BL153 daily at 3 dose levels (2.5, 5, and 10 mg/kg) by gavage. HFD feeding significantly increased the body weight and the liver weight. Administration of BL153 significantly reduced the liver weight but without effects on body weight. As a critical step of the development of NAFLD, hepatic fibrosis was induced in the mice fed with HFD, shown by upregulating the expression of connective tissue growth factor and transforming growth factor beta 1, which were significantly attenuated by BL153 in a dose-dependent manner. Mechanism study revealed that BL153 significantly suppressed HFD induced hepatic lipid accumulation and oxidative stress and slightly prevented liver inflammation. These results suggest that HFD induced fibrosis in the liver can be prevented partially by BL153, probably due to reduction of hepatic lipid accumulation, inflammation and oxidative stress.

Magnolol attenuates neointima formation by inducing cell cycle arrest via inhibition of ERK1/2 and NF-kappaB activation in vascular smooth muscle cells

BACKGROUND

Endovascular injury induces switching of contractile phenotype of vascular smooth muscle cells (VSMCs) to synthetic phenotype, thereby causing proliferation of VSMCs leading to intimal thickening. The purpose of this study was to assess the effect of magnolol on the proliferation of VSMCs in vitro and neointima formation in vivo, as well as the related cell signaling mechanisms.

METHODS

Tumor necrosis factor alpha (TNF-alpha) induced proliferation ofVSMCs was assessed using colorimetric assay. Cell cycle progression and mRNA expression of cell cycle associated molecules were determined by flow cytometry and reverse transcription polymerase chain reaction (RT-PCR) respectively. The signaling molecules such as ERK1/2,JNK, P38 and NF-kappaB were determined by Western blot analysis. In addition, rat carotid artery balloon injury model was performed to assess the effect of magnolol on neointima formation in vivo.

RESULTS

Oral administration of magnolol significantly inhibited intimal area and intimal/medial ratio (I/M). Our in vitro assays revealed magnolol dose dependently induced cell cycle arrest at G0/G1. Also, magnolol inhibited mRNA and protein expression of cyclin D1, cyclin E, CDK4 and CDK2 in vitro and in vivo. The cell cycle arrest was associated with inhibition of ERK1/2 phosphorylation and NF-kappaB translocation.

CONCLUSION

Magnolol suppressed proliferation of VSMCs in vitro and attenuated neointima formation in vivo by inducing cell cycle arrest at G0/G1 through modulation of cyclin D1, cyclin E, CDK4 and CDK2 expression.

GENERAL SIGNIFICANCE

Thus, the results suggest that magnolol could be a potential therapeutic candidate for the prevention of restenosis and atherosclerosis.

Enhancing the bioavailability of magnolol in rabbits using melting solid dispersion with polyvinylpyrrolidone

OBJECTIVE

Preparation of magnolol-loaded amorphous solid dispersion was investigated for improving the bioavailability.

MATERIALS AND METHODS

A solid dispersion of magnolol was prepared with polyvinylpyrrolidone K-30 (PVP) by melting method, and the physical properties were characterized by using differential scanning calorimetry, powder X-ray diffractometry, Fourier transformation-infrared spectroscopy and scanning electron microscope. In addition, dissolution test was also performed. Subsequently, the bioavailability of magnolol pure compound, its physical mixture and solid dispersion were compared in rabbits. The blood samples withdrawn via marginal ear vein at specific time points were assayed by HPLC method.

RESULTS

Oral administration of the solid dispersion of magnolol with PVP significantly increased the systemic exposures of magnolol and magnolol sulfates/glucuronides by 80.1% and 142.8%, respectively, compared to those given with magnolol pure compound.

CONCLUSION

Magnolol-loaded amorphous solid dispersion with PVP has demonstrated enhanced bioavailability of magnolol in rabbits.