lignans and hinokiresinol

Growing evidence suggests that therapeutic strategies to modulate the post-ischemic inflammatory responses are promising approaches to improve stroke outcome. Although the endocannabinoid system has been emerged as an endogenous therapeutic target to regulate inflammation after stroke insult, the downstream mechanisms and their potentials for therapeutic intervention remain controversial. Here we identified trans- and cis-hinokiresinols as novel non-selective antagonists for two G-protein-coupled cannabinoid receptors, cannabinoid receptor type 1 and type 2. The Electric Cell-substrate Impedance Sensing and Boyden chamber migration assays using primary microglial cultures revealed that both hinokiresinols significantly inhibited an endocannabinoid, 2-arachidonoylglycerol-induced migration. Hinokiresinols modulated 2-arachidonoylglycerol-induced mitochondrial bioenergetics in microglia as evidenced by inhibition of ATP turnover and reduction in respiratory capacity, thereby resulting in impaired migration activity. In rats subjected to transient middle cerebral artery occlusion (1.5-h) followed by 24-h reperfusion, post-ischemic treatment with hinokiresinols (2 and 7-h after the onset of ischemia, 10 mg/kg) significantly reduced cerebral infarct and infiltration of ED1-positive microglial/macrophage cells into cerebral ischemic lesions in vivo. Co-administration of exogenous 2-AG (1 mg/kg, i.v., single dose at 2 h after starting MCAO) abolished the protective effect of trans-hinokiresionol. These results suggest that hinokiresinols may serve as stroke treatment by targeting the endocannabinoid system. Alteration of mitochondrial bioenergetics and consequent inhibition of inflammatory cells migration may be a novel mechanism underlying anti-ischemic effects conferred by cannabinoid receptor antagonists.

Topics: Animals; Arachidonic Acids; Brain Ischemia; Cannabinoid Receptor Agonists; Cannabinoid Receptor Antagonists; Cell Movement; Cell Respiration; Cells, Cultured; Disease Models, Animal; Endocannabinoids; Glycerides; Lignans; Macrophages; Male; Microglia; Mitochondria; Phenols; Rats

During cerebral ischemia, neurons are injured by various mechanisms including excitotoxicity, oxidative stress, and inflammatory responses. Thus, pharmacological manipulation of multiple cytotoxic pathways has been pursued for the treatment of ischemic injury. Cis-hinokiresinol, a naturally occurring phenylpropanoid, was previously reported to possess anti-oxidant, anti-inflammatory and estrogen-like activities. In the present study, we investigated anti-ischemic effects of trans- and cis-hinokiresinols using in vitro as well as in vivo experimental models. The ORAC and DPPH assays showed that two isomers had similar free radical scavenging activities. However, only trans-hinokiresinol significantly decreased neuronal injury in cultured cortical neurons exposed to oxygen-glucose deprivation (75 min) followed by re-oxygenation (9 h). The differential neuroprotective effect could be due to the stereo-specific augmentation of Cu/Zn-SOD activity by trans-hinokiresinol, when compared with cis-hinokiresinol. Similarly, in rats subjected to transient middle cerebral artery occlusion (1.5 h) followed by 24-h reperfusion, pre-ischemic treatment with trans-hinokiresinol, but not with cis-isomer, reduced cerebral infarct volume. Interestingly, however, post-ischemic treatment with both hinokiresinols (2 and 7 h after onset of ischemia) significantly reduced cerebral infarct. When administered after onset of ischemia, trans-hinokiresinol, but not its cis-isomer reduced nitrotyrosine immunoreactivity in ischemic regions. In contrast, both hinokiresinols suppressed neutrophil infiltration and IL-1β release to a similar extent. The observed differential anti-oxidant, but comparable anti-inflammatory, activities may explain the stereo-specific anti-ischemic activities and different therapeutic time windows of the hinokiresinols examined. More detailed delineation of the anti-ischemic mechanism(s) of hinokiresinols may provide a better strategy for development of efficacious regimens for cerebral ischemic stroke.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Antioxidants; Brain Ischemia; Cells, Cultured; Lignans; Male; Phenols; Rats; Rats, Sprague-Dawley; Stereoisomerism; Time Factors; Treatment Outcome

Asparagus officinalis hinokiresinol synthase (HRS) is composed of two subunits, HRSalpha and HRSbeta. Individually, each subunit forms (E)-hinokiresinol (EHR) from 4-coumaryl 4-coumarate, whereas a mixture of both subunits forms (Z)-hinokiresinol (ZHR) from the same substrate. In this study, we analyzed the enantiomeric compositions of ZHR and EHR formed after incubation of 4-coumaryl 4-coumarate with recombinant subunit proteins, recHRSalpha and/or recHRSbeta, and with naturally occurring A. officinalis ZHR. The enantiomeric composition of ZHR formed by the mixture of recHRSalpha and recHRSbeta was (+)-100% enantiomer excess (e.e.), identical to that of A. officinalis ZHR. In contrast, the enantiomeric compositions of EHR formed by recHRSalpha and recHRSbeta, individually, were (-)-20.6 and (-)-9.0% e.e., respectively. These results clearly demonstrate that the subunit composition of A. officinalis HRS controls not only cis/trans isomerism but also enantioselectivity in hinokiresinol formation.

Topics: Asparagus Plant; Isomerism; Ligases; Lignans; Phenols; Protein Subunits

A three-step synthesis of the norneolignan skeleton involving the Carroll rearrangement as the key step has been developed and used for synthesis of the norneolignan skeleton, 1,3-diphenylpenta-1,4-diene and hinokiresinol.

Topics: Lignans; Magnetic Resonance Spectroscopy; Phenols

cis-Hinokiresinol, also known as (+)-nyasol, was isolated for the first time from an aquatic herbaceous plant, Trapa pseudoincisa NAKAI, via silica gel and octadecyl silica gel column chromatographies. The chemical structure was determined via analyses of the spectroscopic data, including NMR, MS and IR. cis-Hinokiresinol was also found to exhibit antioxidant and antiatherogenic activities. The ICso values for the scavenging activities of cis-hinokiresinol on ABTS cation and superoxide anion radicals were 45.6 and 40.5 microM, respectively. The IC50 values for the inhibitory effects on Lp-PLA2, hACAT1, hACAT2 and LDL-oxidation were 284.7, 280.6, 398.9 and 5.6 microM, respectively.

Topics: Antioxidants; Atherosclerosis; Humans; Lignans; Lipoproteins, LDL; Lythraceae; Phenols; Phospholipase A2 Inhibitors

The selective formation of E- or Z-isomers is an important process in natural product metabolism. We show that the subunit composition of an enzyme can alter the geometrical composition of the enzymatic products. Hinokiresinol synthase, purified from Asparagus officinalis cell cultures, is responsible for the conversion of (7E,7'E)-4-coumaryl 4-coumarate to (Z)-hinokiresinol, the first step in norlignan formation. The protein is most likely a heterodimer composed of two distinct subunits, which share identity with members of the phloem protein 2 gene superfamily. Interestingly, each recombinant subunit of hinokiresinol synthase expressed in Escherichia coli solely converted (7E,7'E)-4-coumaryl 4-coumarate to the unnatural (E)-hinokiresinol, the E-isomer of (Z)-hinokiresinol. By contrast, a mixture of recombinant subunits catalyzed the formation of (Z)-hinokiresinol from the same substrate.

Topics: Acyl Coenzyme A; Asparagus Plant; Cells, Cultured; Cloning, Molecular; Dimerization; DNA, Complementary; Escherichia coli; Gas Chromatography-Mass Spectrometry; Lignans; Mass Spectrometry; Models, Chemical; Molecular Sequence Data; Phenols; Phylogeny; Plant Lectins

The biosynthetic relationship between the two norlignans agatharesinol and trans-hinokiresinol was investigated. Fresh sapwood sticks of Cryptomeria japonica were fed with stable isotope-labeled compounds, namely p-coumaryl alcohol-[9,9-(2)H], p-coumaryl alcohol-[9-(18)O] and trans-hinokiresinol-[1-(2)H], and then incubated under high-humidity for approximately 20 days, during which the two norlignans were produced simultaneously. While trans-hinokiresinol was strongly deuterium-labeled after feeding with p-coumaryl alcohol-[9,9-(2)H], agatharesinol was only lightly labeled after feeding with either p-coumaryl alcohol-[9,9-(2)H] or -[9-(18)O]. These results suggest that p-coumaryl alcohol, which is a precursor of hinokiresinol, is not involved in the biosynthesis of agatharesinol. Therefore, the norlignan carbon skeleton of agatharesinol must be framed from different types of phenylpropanoid monomers compared to those utilized by the trans-hinokiresinol pathway. The biosynthesis of these two norlignans seems to branch at an early stage, i.e., before the framing of the norlignan carbon skeleton. Furthermore, agatharesinol was not labeled with deuterium after feeding with (2)H-labeled trans-hinokiresinol, which has the simplest norlignan structure. This result strongly supports the suggestion that the conversion of trans-hinokiresinol to agatharesinol is not part of the biosynthesis of norlignans and that early branching occurs instead.

Topics: Coumaric Acids; Cryptomeria; Deuterium; Humidity; Lignans; Oxygen Isotopes; Phenols; Plant Stems; Propionates

The antiallergic effect of hinokiresinol isolated from the whole plant of TRAPA Pseudoincisa S. at. Z. was measured in vitro and in vivo. Hinokiresinol not only potently inhibited beta-hexosaminidase release from RBL-2H3 cells induced by IgE, with an IC50 value of 98 microM, but also inhibited the proinflammatory cytokines IL-6, IL-4 and TNF-alpha in RBL-2H3 cells stimulated by IgE. Orally and intraperitoneally administered hinokiresinol potently inhibited the passive anaphylaxis reaction in mice induced by IgE.

Topics: Administration, Oral; Animals; Anti-Allergic Agents; Dose-Response Relationship, Drug; Immunoglobulin E; Inhibitory Concentration 50; Injections, Intraperitoneal; Leukotriene B4; Lignans; Magnoliopsida; Male; Mice; Mice, Inbred ICR; Passive Cutaneous Anaphylaxis; Phenols; Phytotherapy

The absolute configuration of the norlignan (+)-nyasol was determined to be S by comparison of the experimental vibrational circular dichroism data with first-principle calculations taking into account the eight lowest energy conformations. The established absolute configuration of (+)-nyasol enables establishment of the absolute configuration of (-)-hinokiresinol, which is concluded to be S. A total synthesis and resolution of hinokiresinol has been performed to resolve the conflicting reports of the coupling constant of the vinylic protons of the disubstituted double bond in this molecule. Racemic hinokiresinol was resolved. Both enantiomers possess the same antiplasmodial activity.

Topics: Animals; Antimalarials; Circular Dichroism; Lignans; Molecular Structure; Phenols; Plasmodium falciparum; Stereoisomerism

Total extract of resin from Araucaria angustifolia was analyzed by gas chromatography/mass spectrometry and 32 lignans were identified. Lignan acetates are present in the resin and consist of four secoisolariciresinol acetates, six lariciresinol acetates, two 7'-hydroxylariciresinol acetates and an isolariciresinol acetate, which have hitherto not been reported in the plant kingdom. Shonanin and 7'-hydroxylariciresinol type lignans are also present in A. angustifolia resin. Lignans containing syringyl moieties, characteristic for angiosperms, occur in the resin and consist of 5-methoxylariciresinol-9-acetate, 5'-methoxylariciresinol-9-acetate, 5-methoxypinoresinol dimethyl ether and 5-methoxypinoresinol. This is noteworthy because syringyl moieties have only been reported for Thuja species (Cupressaceae) among the gymnosperms. The mass spectra of the various lignan trimethylsilyl derivatives are discussed with the interpretations of the fragmentation patterns.

Topics: Butylene Glycols; Furans; Gas Chromatography-Mass Spectrometry; Lignans; Lignin; Naphthols; Phenols; Pinus; Resins, Plant; Trimethylsilyl Compounds

An enzyme preparation from the cultured cells of Cryptomeria japonica catalyses the formation of a heartwood norlignan, (E)-hinokiresinol, from two distinct phenylpropanoid monomers: 4-coumaroyl CoA and 4-coumaryl alcohol, and from a dimer: 4-coumaryl 4-coumarate.

Topics: Cells, Cultured; Coumaric Acids; Cryptomeria; Lignans; Mass Spectrometry; Molecular Structure; Phenols

cis-Hinokiresinol (CHR) is a norlignan constituent from Anemarrhena asphodeloides BUNGE (Liliaceae), which shows hyaluronidase inhibitory activity. In the present studies, we have demonstrated that CHR selectively inhibited endothelial cell proliferation compared with cancer cells, and especially basic fibroblast growth factor (bFGF) or vascular endothelial growth factor (VEGF)-induced endothelial cell proliferation. Furthermore, endothelial cell migration and tube formation, two important steps in the angiogenic process, were also inhibited by CHR. Moreover, CHR reduced the vessel growth induced by VEGF in the mouse corneal neovascularization model. These results suggest that CHR may prove useful for the development of a novel angiogenesis inhibitor.

Topics: Anemarrhena; Angiogenesis Inhibitors; Animals; Cell Division; Cell Line; Cell Movement; Cornea; Dose-Response Relationship, Drug; Endothelial Cells; Endothelium, Vascular; Fibroblast Growth Factor 2; Hyaluronoglucosaminidase; Lignans; Mice; Mice, Inbred BALB C; Neovascularization, Pathologic; Pharmacognosy; Phenols; Rhizome; Stereoisomerism; Tumor Cells, Cultured; Umbilical Veins

Naturally occurring phenylpropanoids, hinokiresinol (trans-hinokiresinol) and nyasol (cis-hinokiresinol) were found to possess appreciable estrogen receptor binding activity. Strong differences in activity were observed between the geometrical isomers and enantiomers. Among these, (3S)-cis-hinokiresinol displayed the highest activity, one order of magnitude greater than the activity of genistein. Furthermore, cis- and trans-hinokiresinol stimulated the proliferation of estrogen-dependent T47D breast cancer cells, and their stimulatory effects were blocked by an estrogen antagonist, indicating that the compounds are estrogen agonists. In addition, the absolute configuration of C-3 in (+)-cis-hinokiresinol has been assigned as S by comparison with the circular dichroism spectra of the hydrogenated products prepared from cis and trans ((3S)-trans-hinokiresinol: previously assigned) isomers. These results incidentally provide us with an unambiguous answer to contradictory reports regarding the assignment of the full stereochemisry of cis- and trans-hinokiresinol that have existed in the literature for more than two decades.

Topics: Animals; Cattle; Cell Division; Estradiol; Estrogen Antagonists; Estrogens, Non-Steroidal; Female; Humans; In Vitro Techniques; Isoflavones; Lignans; Magnetic Resonance Spectroscopy; Phenols; Phytoestrogens; Plant Preparations; Plants, Medicinal; Polyunsaturated Alkamides; Stereoisomerism; Tumor Cells, Cultured; Uterus

Topics: Humans; Leukotriene B4; Lignans; Liliaceae; Molecular Structure; Neutrophils; Phenols; Spectrum Analysis