Anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan from Myristica fragrans

Myristica fragrans Extract Inhibits Platelet Desialylation and Activation to Ameliorate Sepsis-Associated Thrombocytopenia in a Murine CLP-Induced Sepsis Model

Sepsis, characterized by an uncontrolled host inflammatory response to infections, remains a leading cause of death in critically ill patients worldwide. Sepsis-associated thrombocytopenia (SAT), a common disease in patients with sepsis, is an indicator of disease severity. Therefore, alleviating SAT is an important aspect of sepsis treatment; however, platelet transfusion is the only available treatment strategy for SAT. The pathogenesis of SAT involves increased platelet desialylation and activation. In this study, we investigated the effects of Myristica fragrans ethanol extract (MF) on sepsis and SAT. Desialylation and activation of platelets treated with sialidase and adenosine diphosphate (platelet agonist) were assessed using flow cytometry. The extract inhibited platelet desialylation and activation via inhibiting bacterial sialidase activity in washed platelets. Moreover, MF improved survival and reduced organ damage and inflammation in a mouse model of cecal ligation and puncture (CLP)-induced sepsis. It also prevented platelet desialylation and activation via inhibiting circulating sialidase activity, while maintaining platelet count. Inhibition of platelet desialylation reduces hepatic Ashwell-Morell receptor-mediated platelet clearance, thereby reducing hepatic JAK2/STAT3 phosphorylation and thrombopoietin mRNA expression. This study lays a foundation for the development of plant-derived therapeutics for sepsis and SAT and provides insights into sialidase-inhibition-based sepsis treatment strategies.

Acylphenols and Dimeric Acylphenols from the Genus Myristica: A Review of Their Phytochemistry and Pharmacology

The genus Myristica is a medicinally important genus belonging to the Myristicaceae. Traditional medicinal systems in Asia have employed plants from the genus Myristica to treat a variety of ailments. Acylphenols and dimeric acylphenols are a rare group of secondary metabolites, which, to date, have only been identified in the Myristicaceae, in particular, in the genus Myristica. The aim of the review would be to provide scientific evidence that the medicinal properties of the genus Myristica could be attributed to the acylphenols and dimeric acylphenols present in the various parts of its plants and highlight the potential in the development of the acylphenols and dimeric acylphenols as pharmaceutical products. SciFinder-n, Web of Science, Scopus, ScienceDirect, and PubMed were used to conduct the literature search between 2013-2022 on the phytochemistry and the pharmacology of acylphenols and dimeric acylphenols from the genus Myristica. The review discusses the distribution of the 25 acylphenols and dimeric acylphenols within the genus Myristica, their extraction, isolation, and characterization from the respective Myristica species, the structural similarities and differences within each group and between the different groups of the acylphenols and dimeric acylphenols, and their in vitro pharmacological activities.

New Monoterpene-Conjugated Phenolic Constituents from Nutmeg and Their Autophagy Modulating Activities

The seed of Myristica fragrans Houtt (nutmeg) is one of the important spices that have been extensively used in the culinary, food, beverage, and also in medicinal products industry. Previous phytochemical studies on nutmeg were mainly focused on lignans and neolignans. However, the other constituents have been poorly studied. In this study, 11 new monoterpene-conjugated phenolic derivatives, named myrifratins A-K (1-11), and five known compounds were isolated from nutmeg. The novel neolignan-diarylnonanoid-monoterpene conjugates (1 and 2) were first isolated in nature. Compounds 3-7 were rarely monoterpene-diarylnonanoid-conjugated derivatives, and 8-11 were the first examples of monoterpene-neolignan conjugates. Compounds 4-6, 12, and 13 showed potent autophagy inhibitory activities in a concentration-dependent manner. Our findings showed an uncommon class of monoterpene-conjugated phenolic derivatives in nature and reported their autophagy inhibition activities for the first time, which may give a new insight into the benefits or safety of nutmeg in foods.

Alpinetin: A Review of Its Pharmacology and Pharmacokinetics

Flavonoids isolated from medicinal herbs have been utilized as valuable health-care agents due to their virous biological applications. Alpinetin is a natural flavonoid that emerges in many widely used medicinal plants, and has been frequently applied in Chinese patent drugs. Accumulated evidence has demonstrated that alpinetin possesses a broad range of pharmacological activities such as antitumor, antiinflammation, hepatoprotective, cardiovascular protective, lung protective, antibacterial, antiviral, neuroprotective, and other properties through regulating multiple signaling pathways with low systemic toxicity. However, pharmacokinetic studies have documented that alpinetin may have poor oral bioavailability correlated to its extensive glucuronidation. Currently, the reported pharmacological properties and pharmacokinetics profiles of alpinetin are rare to be scientifically reviewed. In this article, we aimed to highlight the mechanisms of action of alpinetin in various diseases to strongly support its curative potentials for prospective clinical applications. We also summarized the pharmacokinetics properties and proposed some viable strategies to convey an appreciable reference for future advances of alpinetin in drug development.

Procoagulant Substance and Mechanism of Myristica fragrans

The effect and mechanisms of Myristica fragrans on blood clotting were evaluated by evaluating blood coagulation time and the fibrinolytic system. The compounds 2 and 5 were isolated from the herbal extract and their activities were assessed for the first time. None of the tested compounds had fibrinolytic activity, but could inhibit the fibrinolytic activity of urokinase. Compound 2 showed the highest inhibitory activity (IC₅₀ = 1.747 mg·mL^-1) followed by compounds 4 (IC₅₀ = 1.818 mg·mL^-1) and 1 (IC₅₀ = 2.407 mg·mL^-1), which were higher than that of the compound in Danshen drug tablets (IC₅₀ = 6.577 mg·mL^-1) used in China. Moreover, compounds 1 and 2 showed strong α-glucosidase inhibitory activity in a dose-dependent manner with IC₅₀ values 21.76 ± 0.59 and 21.31 ± 0.00 μg·mL^-1, respectively. These results demonstrated that the compounds are promising candidates as procoagulant and antidiabetic agents.

Chemical diversity and pharmacological significance of the secondary metabolites of nutmeg (Myristica fragrans Houtt.)

Nutmeg is a valued kitchen spice that has been used for centuries all over the world. In addition to its use in flavoring foods and beverages, nutmeg has been used in traditional remedies for stomach and kidney disorders. The antioxidant, antimicrobial and central nervous system effects of nutmeg have also been reported in literature. Nutmeg is a rich source of fixed and essential oil, triterpenes, and various types of phenolic compounds. Many of the secondary metabolites of nutmeg exhibit biological activities that may support its use in traditional medicine. This article provides an overview of the chemistry of secondary metabolites isolated from nutmeg kernel and mace including common methods for analysis of extracts and pure compounds as well as recent approaches towards total synthesis of some of the major constituents. A summary of the most significant pharmacological investigations of potential drug leads isolated from nutmeg and reported in the last decade is also included.

Kainic acid-induced albumin leak across the blood-brain barrier facilitates epileptiform hyperexcitability in limbic regions

OBJECTIVE

Systemic administration of kainic acid (KA) is a widely used procedure utilized to develop a model of temporal lobe epilepsy (TLE). Despite its ability to induce status epilepticus (SE) in vivo, KA applied to in vitro preparations induces only interictal-like activity and/or isolated ictal discharges. The possibility that extravasation of the serum protein albumin from the vascular compartment enhances KA-induced brain excitability is investigated here.

METHODS

Epileptiform activity was induced by arterial perfusion of 6 μm KA in the in vitro isolated guinea pig brain preparation. Simultaneous field potential recordings were carried out bilaterally from limbic (CA1, dentate gyrus [DG], and entorhinal cortex) and extralimbic regions (piriform cortex and neocortex). Blood-brain barrier (BBB) breakdown associated with KA-induced epileptiform activity was assessed by parenchymal leakage of intravascular fluorescein-isothiocyanate albumin. Seizure-induced brain inflammation was evaluated by western blot analysis of interleukin (IL)-1β expression in brain tissue.

RESULTS

KA infusion caused synchronized activity at 15-30 Hz in limbic (but not extralimbic) cortical areas, associated with a brief, single seizure-like event. A second bolus of KA, 60 min after the induction of the first ictal event, did not further enhance excitability. Perfusion of serum albumin between the two administrations of KA enhanced epileptiform discharges and allowed a recurrent ictal event during the second KA infusion.

SIGNIFICANCE

Our data show that arterial KA administration selectively alters the synchronization of limbic networks. However, KA is not sufficient to generate recurrent seizures unless serum albumin is co-perfused during KA administration. These findings suggest a role of serum albumin in facilitating acute seizure generation.

A Comparative Pharmacokinetic Study of Myrislignan by UHPLC-MS After Oral Administration of a Monomer and Myristica fragrans Extract to Rats

An ultra-high performance liquid chromatography coupled with mass spectrometry (UHPLC-MS) method was developed and validated to quantify myrislignan in rat plasma using podophyllotoxin as an internal standard (IS). The chromatographic separation of myrislignan and IS was performed on a 3.0 µm Hypersil C18 column (50 mm × 4.6 mm) with methanol and water containing 0.1% acetic acid (80:20, v/v) as the mobile phase at a flow rate of 0.3 mL/min. An electrospray ionization was used in the positive selective-ion monitoring mode for the target ions at m/z 397 and m/z 437 for the quantification of myrislignan and IS. The total run time was 3.6 min for each run. The calibration curve was linear over the range of 0.75-300 ng/mL (r> 0.995) with the lower limit of quantitation at 0.75 ng/mL. Intra- and interday precision was below 11.49%, and the mean accuracy ranged from -9.75 to 7.45%. The proposed method was successfully applied to evaluate the pharmacokinetic properties of myrislignan after oral administration of the myrislignan monomer and Myristica fragrans extract in rats. Statistical analyses indicate that the pharmacokinetic properties of myrislignan in rats have significant differences between two groups.

New neolignans from the seeds of Myristica fragrans that inhibit nitric oxide production

Five new 8-O-4' type neolignans, named myrifralignan A-E (1-5), together with five known analogues (6-10), were isolated from the seeds of Myristica fragrans Houtt. Their chemical structures were determined using several spectroscopic methods. Compounds 3-10 exhibited potent inhibitory activity against the production of nitric oxide (NO) in the RAW264.7 cell line stimulated by lipopolysaccaride. Myrislignan (7) and machilin D (10) were the most potent inhibitors of NO production amongst these compounds. The IC50 values of myrislignan and machilin D were 21.2 and 18.5 μM. And, their inhibitory activity was more than L-N(6)-(1-iminoethyl)-lysine, a selective inhibitor of inducible nitric oxide synthase (IC50=27.1 μM). Furthermore, real-time PCR analysis revealed that these neolignans could significantly suppress the expression of inducible nitric oxide synthase mRNA. These results demonstrated that the 8-O-4' type neolignans are promising candidates as anti-inflammatory agents.