Profiles of Essential Oils and Correlations with Phenolic Acids and Primary Metabolites in Flower Buds of Magnolia heptapeta and Magnolia denudata var. purpurascens.

Magnolia flower buds are a source of herbal medicines with various active compounds. In this study, differences in the distribution and abundance of major essential oils, phenolic acids, and primary metabolites between white flower buds of Magnolia heptapeta and violet flower buds of Magnolia denudata var. purpurascens were characterised. A multivariate analysis revealed clear separation between the white and violet flower buds with respect to primary and secondary metabolites closely related to metabolic systems. White flower buds contained large amounts of monoterpene hydrocarbons (MH), phenolic acids, aromatic amino acids, and monosaccharides, related to the production of isoprenes, as MH precursors, and the activity of MH synthase. However, concentrations of ß-myrcene, a major MH compound, were higher in violet flower buds than in white flower buds, possibly due to higher threonine levels and low acidic conditions induced by comparatively low levels of some organic acids. Moreover, levels of stress-related metabolites, such as oxygenated monoterpenes, proline, and glutamic acid, were higher in violet flower buds than in white flower buds. Our results support the feasibility of metabolic profiling for the identification of phytochemical differences and improve our understanding of the correlated biological pathways for primary and secondary metabolites.

Diversity of Essential Oil-Secretory Cells and Oil Composition in Flowers and Buds of Magnolia sirindhorniae and Its Biological Activities.

Magnolia sirindhorniae Noot. & Chalermglin produces fragrant flowers. The volatile oil secretary cells, quantity and quality as well as antioxidant and antimicrobial activities of the oils extracted from buds and flowers, have been investigated. The distribution of essential oil secretory cell in bud and flower revealed that the density and size of the oil cells were significantly higher in flowers compared to buds. In different floral parts, carpel has a higher oil cell density followed by gynophore and tepal. The histochemical analysis revealed the essential oil is synthesized in oil secretory cells. The volatile oil yield was 0.25 % in the buds and 0.50 % in flowers. GC/FID and GC/MS analysis identified 33 compounds contributing 83.2-83.5 % of the total essential oil composition. Linalool is the main constituent contributing 58.9 % and 51.0 % in the buds and flowers oils, respectively. The essential oil extracted from the flowers showed higher antimicrobial efficacy against Klebsiella pneumoniae and Staphylococcus aureus. Similarly, the essential oil isolated from the flowers depicts higher free radical scavenging, and antioxidant activity compared to buds' oil.

Thin-layer chromatographic quantification of magnolol and honokiol in dietary supplements and selected biological properties of these preparations.

Two isomeric biphenyl neolignans, magnolol and honokiol, are considered as constituents responsible for the healing effect of magnolia bark, a traditional Oriental medicine. To survey the increasing number of dietary supplements that contain magnolia bark or its extract, an affordable quantitative thin-layer chromatography (TLC) - densitometry method was developed. The methanol extracts were analyzed on the silica gel plates after manual sample application using n-hexane - ethyl acetate - ethanol (16:3:1, v/v/v) as a mobile phase. For quantitation, the chromatograms were scanned in the absorbance mode at the wavelength λ = 290 nm. The limits of detection and quantitation were 90 and 280 ng/zone for magnolol and 70 and 200 ng/zone for honokiol, respectively. None of the two targeted neolignans were detected in two of the six analyzed supplements. In the other four samples, the measured amounts were between 0.95-114.69 mg g-1 for magnolol and 4.88-84.86 mg g-1 for honokiol. Moreover, separations of these two neolignans on the TLC and high-performance TLC (HPTLC) layers were compared and HPTLC was combined with antioxidant (DPPH) and antibacterial (Bacillus subtilis and Aliivibrio fischeri) assays and mass spectrometry (MS), using the elution-based interface. Both magnolol and honokiol exhibited effects in all bioactivity assays. The HPTLC-MS tests confirmed purity of neolignan zones in the extracts of dietary supplements and supported tentative identification of the alkaloid piperine and the isoflavone daidzein as additional bioactive components of the investigated dietary supplements. Using the same mobile phase in the orthogonal directions 2D-HPTLC-MS experiments proved degradation, i.e., instability of magnolol and honokiol on the silica gel adsorbent.

Structures and Inhibitory Activities for Interleukin-2 Production of Seasonally Variable Constituents in Flower Parts of Magnolia kobus at Different Growth Stages.

Magnolia Flower is a crude drug used for the treatment of headaches, toothaches, and nasal congestion. Here, we focused on Magnolia kobus, one of the botanical origins of Magnolia Flower, and collected the flower parts at different growth stages to compare chemical compositions and investigate potential inhibitory activities against interleukin-2 (IL-2) production in murine splenic T cells. After determining the structures, we examined the inhibitory effects of the constituents of the bud, the medicinal part of the crude drug, against IL-2 production. We first extracted the flower parts of M. kobus from the bud to fallen bloom stages and analysed the chemical compositions to identify the constituents characteristic to the buds. We found that the inhibitory activity of the buds against IL-2 production was more potent than that of the blooms. We isolated two known compounds, tiliroside (1) and syringin (2), characteristic to the buds from the methanol (MeOH) extract of Magnolia Flower. Moreover, we examined the inhibitory activities of both compounds against IL-2 production and found that tiliroside (1) but not syringin (2), showed strong inhibitory activity against IL-2 production and inhibited its mRNA expression. Thus, our strategy to examine the relationship between chemical compositions and biological activities during plant maturation could not only contribute to the scientific evaluation of medicinal parts of crude drugs but also assist in identifying biologically active constituents that have not yet been reported.

An Oviposition Stimulant for a Magnoliaceae-Feeding Swallowtail Butterfly, Graphium doson, from its Primary Host Plant, Michelia compressa.

Chemical examination of plant constituents responsible for oviposition by a Magnoliaceae-feeding butterfly, Graphium doson, was conducted using its major host plant, Michelia compressa. A methanol extract prepared from young leaves of the plant elicited a strong oviposition response from females. The methanolic extract was then separated by solvent partition into three fractions: CHCl3, i-BuOH, and aqueous fractions. Active substance(s) resided in both i-BuOH- and water-soluble fractions. Bioassay-guided further fractionation of the water-soluble substances by means of various chromatographic techniques led to the isolation of an oviposition stimulant. The stimulant was identified as D-(+)-pinitol on the basis of 13C NMR spectra and physicochemical properties. D-(+)-Pinitol singly exhibited a moderate oviposition-stimulatory activity at a dose of 150 µg/cm2. This compound was present also in another host plant, Magnolia grandiflora, in a sufficient amount to induce oviposition behavior of G. doson females. Certain cyclitols including D-(+)-pinitol have been reported to be involved in stimulation of oviposition by some Aristolochiaceae- and Rutaceae-feeding papilionid butterflies. A possible pathway of phytochemical-mediated host shifts in the Papilionidae, in which certain cyclitols could enact important mediators, is discussed in relation to the evolution of cyclitol biosynthesis in plants.

Magnolia officinalis reduces the long-term effects of the status epilepticus induced by kainic acid in immature rats.

During critical periods of neurodevelopment, the immature brain is susceptible to neuronal hyperexcitability, alterations such as hyperthermia, hypoxia, brain trauma or a preexisting neuroinflammatory condition can trigger, promote and prolong epileptiform activity and facilitate the development of epilepsy. The goal of the present study was to evaluate the long-term neuroprotective effects Magnolia officinalis extract, on a model of recurrent status epilepticus (SE) in immature rats. Sprague-Dawley rats were treated with kainic acid (KA) (3 mg/kg, dissolved in saline solution) beginning at day 10 P N every 24 h for five days (10 P N-14PN). Two experimental groups (KA) received two treatments for 10 days (14-24 P N): one group was treated with 300 mg/kg Magnolia Officinalis (MO) (KA-MO), and another was treated with 20 mg/kg of celecoxib (Clbx) (KA-Clbx) as a control drug. A SHAM control group at day 90 P N was established. Seizure susceptibility was analyzed through an after-discharge threshold (ADT) evaluation, and electroencephalographic activity was recorded. The results obtained from the ADT evaluation and the analysis of the electroencephalographic activity under basal conditions showed that the MO and Clbx treatments protected against epileptiform activity, and decreases long-term excitability. All rats in the KA-MO and KA-Clbx groups presented a phase I seizure on the Racine scale, corresponding to the shaking of a wet dog. In contrast, the KA group showed phase V convulsive activity on the Racine scale. Similarly, MO and Clbx exerted neuroprotective effects on hippocampal neurons and reduced gliosis in the same areas. Based on these results, early intervention with MO and Clbx treatments to prevent the inflammatory activity derived from SE in early phases of neurodevelopment exerts neuroprotective effects on epileptogenesis in adult stages.

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 Ia (1), magnoloside Ic (2), crassifolioside (3), magnoloside Ib (4), magnoloside IIIa (5), magnoloside IVa (6), magnoloside IIa (7), magnoloside IIb (8) and magnoloside Va (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.

Extracts of Magnolia Species-Induced Prevention of Diabetic Complications: A Brief Review.

Diabetic complications are the major cause of mortality for the patients with diabetes. Oxidative stress and inflammation have been recognized as important contributors for the development of many diabetic complications, such as diabetic nephropathy, hepatopathy, cardiomyopathy, and other cardiovascular diseases. Several studies have established the anti-inflammatory and oxidative roles of bioactive constituents in Magnolia bark, which has been widely used in the traditional herbal medicines in Chinese society. These findings have attracted various scientists to investigate the effect of bioactive constituents in Magnolia bark on diabetic complications. The aim of this review is to present a systematic overview of bioactive constituents in Magnolia bark that induce the prevention of obesity, hyperglycemia, hyperlipidemia, and diabetic complications, including cardiovascular, liver, and kidney.

[Screening target genes for bimolecular marking methods of Magnolia quality].

The study used use bimolecular marking methods to evaluate the lignans of Magnolia officinalis and M. officinalis var. biloba. First, we compare the chemical constituents between M. officinalis and M. officinalis var.biloba. There were significant differences in concentration of magnolignan I between leaves of these two varieties. Then we further select the p-hydroxyphenyl lignin to mining the key enzyme genes of biosynthesis from Magnolia transcriptome, and screened an encoding cinnamyl alcohol dehydrogease gene as the candidate marker of bimolecular marking methods of Magnolia quality by comparing of the expression level and structure variation in homologous gene between M. officinalis and M. officinalis var.biloba. The established method provides the technical support for bimolecular marking methods of Magnolia quality evaluation.

[Identification and bioinformatics analysis of genes associated with MVA pathway in Magnolia officinalis].

Methyl valerate (MVA) pathway is one of the important ways for synthesis of terpenoids. This study was based on data of the transcriptome sequencing of Magnolia officinalis, the associated genes MoACOT, MoHMGS, MoHMGR, MoMK in methyl valerate (MVA) pathway, were completed in detail by using bioinformatics methods. The results of analysis showed that MoACOT and MoMK were stable hydrophobic proteins, MoHMGS and MoHMGR were unstable hydrophobic protein. The secondary structures of all proteins were hybrid architecture,and alpha helical were the major motifs. There were no clear transmembrane domains in MoACOT, MoHMGS and MoMK, but two transmembrane domains were founded in MoHMGR which were from 39-61 aa and 82-104 aa resepectively. The results of evolutionary relationship analysis showed that MoACOT, MoHMGS, MoHMGR and MoMK had relative close relationship to angiosperm or dicotyledonous plants, and accorded with genetic evolution rule. From transcriptome data, transcripted level of MoACOT, MoHMGS, MoHMGR, MoMK in M. officinalis and M. officinalis var. biloba was not significantly different. The result provided theoretical reference for study on Methyl valerate (MVA) pathway of terpenoid of M. officinalis.

Inhibitory effects of magnolol and honokiol on human calcitonin aggregation.

Amyloid formation is associated with multiple amyloidosis diseases. Human calcitonin (hCT) is a typical amyloidogenic peptide, its aggregation is associated with medullary carcinoma of the thyroid (MTC), and also limits its clinical application. Magnolia officinalis is a traditional Chinese herbal medicine; its two major polyphenol components, magnolol (Mag) and honokiol (Hon), have displayed multiple functions. Polyphenols like flavonoids and their derivatives have been extensively studied as amyloid inhibitors. However, the anti-amyloidogenic property of a biphenyl backbone containing polyphenols such as Mag and Hon has not been reported. In this study, these two compounds were tested for their effects on hCT aggregation. We found that Mag and Hon both inhibited the amyloid formation of hCT, whereas Mag showed a stronger inhibitory effect; moreover, they both dose-dependently disassembled preformed hCT aggregates. Further immuno-dot blot and dynamic light scattering studies suggested Mag and Hon suppressed the aggregation of hCT both at the oligomerization and the fibrillation stages, while MTT-based and dye-leakage assays demonstrated that Mag and Hon effectively reduced cytotoxicity caused by hCT aggregates. Furthermore, isothermal titration calorimetry indicated Mag and Hon both interact with hCT. Together, our study suggested a potential anti-amyloidogenic property of these two compounds and their structure related derivatives.

Honokiol abrogates leptin-induced tumor progression by inhibiting Wnt1-MTA1-ß-catenin signaling axis in a microRNA-34a dependent manner.

Obesity greatly influences risk, progression and prognosis of breast cancer. As molecular effects of obesity are largely mediated by adipocytokine leptin, finding effective novel strategies to antagonize neoplastic effects of leptin is desirable to disrupt obesity-cancer axis. Present study is designed to test the efficacy of honokiol (HNK), a bioactive polyphenol from Magnolia grandiflora, against oncogenic actions of leptin and systematically elucidate the underlying mechanisms. Our results show that HNK significantly inhibits leptin-induced breast-cancer cell-growth, invasion, migration and leptin-induced breast-tumor-xenograft growth. Using a phospho-kinase screening array, we discover that HNK inhibits phosphorylation and activation of key molecules of leptin-signaling-network. Specifically, HNK inhibits leptin-induced Wnt1-MTA1-ß-catenin signaling in vitro and in vivo. Finally, an integral role of miR-34a in HNK-mediated inhibition of Wnt1-MTA1-ß-catenin axis was discovered. HNK inhibits Stat3 phosphorylation, abrogates its recruitment to miR-34a promoter and this release of repressor-Stat3 results in miR-34a activation leading to Wnt1-MTA1-ß-catenin inhibition. Accordingly, HNK treatment inhibited breast tumor growth in diet-induced-obese mouse model (exhibiting high leptin levels) in a manner associated with activation of miR-34a and inhibition of MTA1-ß-catenin. These data provide first in vitro and in vivo evidence for the leptin-antagonist potential of HNK revealing a crosstalk between HNK and miR34a and Wnt1-MTA1-ß-catenin axis.

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 protects osteoblastic MC3T3-E1 cells against antimycin A-induced cytotoxicity through activation of mitochondrial function.

Antimycin A treatment of cells blocks the mitochondrial electron transport chain and leads to elevated ROS generation. In the present study, we investigated the protective effects of magnolol, a hydroxylated biphenyl compound isolated from Magnolia officinalis, on antimycin A-induced toxicity in osteoblastic MC3T3-E1 cells. Osteoblastic MC3T3-E1 cells were pre-incubated with magnolol before treatment with antimycin A. Cell viability and mineralization of osteoblasts were assessed by MTT assay and Alizarin Red staining, respectively. Mitochondrial dysfunction in cells was measured by mitochondrial membrane potential (MMP), complex IV activity, and ATP level. The cellular antioxidant effect of magnolol in osteoblastic MC3T3-E1 cells was assessed by measuring cardiolipin oxidation, mitochondrial superoxide levels, and nitrotyrosine content. Phosphorylated cAMP-response element-binding protein (CREB ) was evaluated using ELISA assay. Pretreatment with magnolol prior to antimycin A exposure significantly reduced antimycin A-induced osteoblast dysfunction by preventing MMP dissipation, ATP loss, and CREB inactivation. Magnolol also reduced cardiolipin peroxidation, mitochondrial superoxide, and nitrotyrosine production induced by antimycin A. These results suggest that magnolol has a protective effect against antimycin A-induced cell damage by its antioxidant effects and the attenuation of mitochondrial dysfunction. All these data indicate that magnolol may reduce or prevent osteoblast degeneration in osteoporosis or other degenerative disorders.

Honokiol protects osteoblastic MC3T3-E1 cells against antimycin A-induced cytotoxicity.

OBJECTIVE: Honokiol is a phenolic compound isolated from the bark of Magnolia officinalis, a plant widely used in traditional medicine. Antimycin A, which inhibits complex III of the electron transport system, has been used as a reactive oxygen species generator in biological systems. In the present study, we investigated the protective effects of honokiol on antimycin A-induced dysfunction in osteoblastic MC3T3-E1 cells. MATERIALS AND METHODS: Osteoblastic MC3T3-E1 cells were pre-incubated with honokiol before treatment with antimycin A, and markers of mitochondrial function and oxidative damage were examined. In addition, the effects of honokiol on the activation of PI3K (phosphoinositide 3-kinase) and CREB (cAMP-responsive element-binding protein) were examined in MC3T3-E1 cells. RESULTS: Honokiol significantly (P < 0.05) increased cell viability and calcium deposition and decreased the production of ROS in the presence of antimycin A. Moreover, pretreatment with honokiol prior to antimycin A exposure significantly reduced antimycin A-induced mitochondrial membrane potential (MMP) dissipation, complex IV inactivation, nitrotyrosine formation, and thioredoxin reductase inactivation. Honokiol also induced the activation of PI3K and CREB inhibited by antimycin A, which demonstrates that honokiol utilizes the PI3K and CREB pathway to augment metabolic activity inhibited by antimycin A. CONCLUSION: Honokiol may reduce or prevent osteoblast degeneration in osteoporosis or other degenerative disorders.

Antiplatelet activity of obovatol, a biphenolic component of Magnolia Obovata, in rat arterial thrombosis and rabbit platelet aggregation.

AIM: Thrombosis occurs in the coronary arteries via the activation of platelets, and leads to acute myocardial infarction and sudden death. Obovatol, a major biphenolic component of Magnolia Obovata leaves, displays anti-inflammatory and acyl Co-A cholesterol acyltrasferase inhibitory effects. The purpose of this study was to determine the effects of obovatol on thrombus formation in vivo and platelet activation in vitro and ex vivo. METHODS: We investigated the antiplatelet and antithrombotic activities of obovatol in rat carotid arterial thrombosis in vivo along with platelet aggregation in vitro and ex vivo. Its possible cellular mechanism of antiplatelet activity was investigated by testing PLC-γ2 activation, arachidonic acid cascade, calcium mobilization and granule secretion. RESULTS: Oral administration of obovatol prevented carotid thrombosis, but also significantly inhibited collagen-induced platelet aggregation. Obovatol did not change coagulation times, such as activated partial thromboplastin time and prothrombin time, indicating that the antithrombotic effect of obovatol might be due to antiplatelet activity rather than anticoagulation activity. Obovatol inhibited in vitro collagen- and arachidonic acid-induced rabbit platelet aggregation in a concentration-dependent manner (1-10 µM), with IC(50) values of 2.4 ± 0.8 and 4.8 ± 0.9 µM, respectively. Obovatol blocked collagen-mediated phospholipase C-γ2 phosphorylation, cytoplasmic calcium mobilization, arachidonic acid liberation and serotonin secretion. CONCLUSION: Obovatol has a potent antithrombotic effect, which may be due to antiplatelet activity. The antiplatelet activity of obovatol is mediated by inhibition of PLC-γ2 phosphorylation. Thus, obovatol may be a potential candidate to treat cardiovascular disease.

Honokiol and magnolol production by in vitro micropropagated plants of Magnolia dealbata, an endangered endemic Mexican species.

An efficient protocol for the in vitro propagation of Magnolia dealbata Zucc., an important medicinal plant that is the source of the anxiolytic and anticancer compounds honokiol and magnolol, was established. This plant is wild-crafted, and conservationists have expressed concerns with regard to the sustainability of production. In the present work, two factors were found to be of importance for the regeneration of M. dealbata and the production of honokiol and magnolol. These factors were the type of explants and the combination and concentration of plant-growth regulators. Green, compact, nodular organogenic callus was obtained from leaf explants in a medium fortified with Murashige and Skoog salts and supplemented with 1.5 mg/L 2,4-dicholorophenoxyacetic acid and 1.5 mg/L kinetin. Shoots multiplication from callus cultures was achieved in the Murashige and Skoog (MS) medium with 1.5 mg/L thidiazuron (TDZ). Phenol secretion was controlled by the addition of 250 mg/L of activated charcoal. For rooting, shoots were transferred to MS medium supplemented with several auxins. After root induction, the plants were hardened in earthen pots containing sand, soil, and vermiculite. The contents of honokiol (HK) and magnolol (MG) were determined in different plant materials by high-performance liquid chromatography-diode-array detection techniques. This analysis revealed that the honokiol and magnolol content in aerial and underground parts of micropropagated M. dealbata were higher than that observed in wild plants (both 6 months old). Our results suggest that conservation of M. dealbata is possible by means of in vitro multiplication of leaf-derived callus. The usefulness of M. dealbata regeneration and production of HK and MG may be attributed to the proper selection of explant sourcing and identification of the correct growth medium to support adequate growth. This careful selection of explants and growth medium leads to a very useful source of plant material for pharmacological and phytomedicinal screening applications and, above all, would safeguard this plant species from the threat of extinction.

Obovatol from Magnolia obovata inhibits vascular smooth muscle cell proliferation and intimal hyperplasia by inducing p21Cip1.

AIMS: Obovatol is isolated from Magnolia obovata leaves and this active component has various pharmacological properties such as anti-oxidant, anti-platelet, anti-fungal and anti-inflammatory activities. In the present study, we investigated the inhibitory effects of obovatol on in vitro vascular smooth muscle cell (VSMC) proliferation and in vivo neointimal formation in a rat carotid artery injury model. METHODS AND RESULTS: Obovatol (1-5 microM) exerted concentration-dependent inhibition on platelet-derived growth factor (PDGF)-BB-induced rat VSMC proliferation, without exhibiting any cellular toxicity or apoptosis, as determined by cell count, [3H]thymidine incorporation and Annexin-V-binding analyses. Treatment with obovatol blocked the cell cycle in G1 phase by down-regulating the expression of cyclins and CDKs, and selectively up-regulating the expression of p21Cip1, a well-known CDK inhibitor. Effects of perivascular delivery of obovatol were assessed 14 days after injury. The angiographic mean luminal diameters of the obovatol-treated groups (100 microg and 1 mg: 0.78+/-0.06 and 0.77+/-0.07AU, respectively) were significantly larger than that of the control group (0.58+/-0.07AU). The obovatol-treated groups (100 microg and 1mg: 0.14+/-0.04 and 0.09+/-0.03 mm2, respectively) showed significant reduction in neointimal formation versus the control group (0.17+/-0.02 mm2). Immunohistochemical staining demonstrated strong expression of p21Cip1 in the neointima of the obovatol-treated groups. CONCLUSIONS: These data suggest that obovatol inhibits VSMC proliferation by perturbing cell cycle progression, possibly due to activation of p21Cip1 pathway. These results also show that obovatol may have potential as an anti-proliferative agent for the treatment of restenosis and atherosclerosis.

Interaction of lipid bodies with other cell organelles in the maturing pollen of Magnolia x soulangeana (Magnoliaceae).

The pollen grain maturation in Magnolia x soulangeana was studied ultrastructurally and cytochemically using both the light and transmission electron microscope. Emphasis was given on the storage lipid bodies of the vegetative cell (VC) and their interaction with other cell organelles. Stereological analysis of electron micrographs was performed to evaluate the variation in volume density (V(V)), surface density, and surface-to-volume ratio (S/V) of various cell organelles during pollen maturation. The size and numerical density of the lipid bodies, and their frequency of association with other cell organelles, were also determined. It was noted that during pollen ontogeny and maturation, the lipid bodies changed their pattern of distribution in the VC cytoplasm, which may be a good marker for the succeeding stages of pollen development. Also, the size, osmiophily, and V(V) of the lipid bodies were progressively reduced during pollen maturation whereas the S/V was significantly increased. This seems to indicate that the lipid bodies are mobilized in part during this period of pollen maturation. In particular, the intermediate and mature pollen showed a high percentage of lipid bodies establishing a physical contact with either glyoxysomes, either protein storage vacuoles, or small vesicles presumably originated from dictyosomes. This physical contact was found in both the chemically fixed and rapid freeze-fixed pollen indicating that it is neither artifactual nor casual. On the basis of this intimate association with other cell organelles and the morphometric analysis performed, we suggest that the mobilization of lipid bodies is likely mediated not only by glyoxysomes but also by other catabolic pathways involving the interaction of lipid bodies with either protein storage vacuoles or small Golgi vesicles.

In vitro anti-inflammatory activity of lignans isolated from Magnolia fargesii.

The overproduction of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) causes neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Four lignans, (+)-eudesmin (1), (+)-magnolin (2), (+)-yangambin (3) and a new structure named as epimagnolin B (4) were isolated from Magnolia fargesii (Magnoliaceae) as the inhibitors of NO production in LPS-activated microglia. The most potent compound 4 inhibited the production of NO and PGE(2) and the expression of respective enzyme iNOS and COX-2 through the suppression of I-kappaB-alpha degradation and nuclear translocation of p65 subunit of NF-kappaB.