Antiepileptic and Neuroprotective Effects of Rheum tanguticum Root Extract on Trimethyltin-Induced Epilepsy and Neurodegeneration: In Vivo and in Silico Analyses.

BACKGROUND: Rheum tanguticum root, cataloged as "Daehwang" in the Korean Pharmacopeia, is rich in various anthraquinones known for their anti-inflammatory and antioxidant properties. Formulations containing Daehwang are traditionally employed for treating neurological conditions. This study aimed to substantiate the antiepileptic and neuroprotective efficacy of R. tanguticum root extract (RTE) against trimethyltin (TMT)-induced epileptic seizures and hippocampal neurodegeneration. METHODS: The constituents of RTE were identified by ultra-performance liquid chromatography (UPLC). Experimental animals were grouped into the following five categories: control, TMT, and three TMT+RTE groups with dosages of 10, 30, and 100 mg/kg. Seizure severity was assessed daily for comparison between the groups. Brain tissue samples were examined to determine the extent of neurodegeneration and neuroinflammation using histological and molecular biology techniques. Network pharmacology analysis involved extracting herbal targets for Daehwang and disease targets for epilepsy from multiple databases. A protein-protein interaction network was built using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, and pivotal targets were determined by topological analysis. Enrichment analysis was performed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool to elucidate the underlying mechanisms. RESULTS: The RTE formulation was found to contain sennoside A, sennoside B, chrysophanol, emodin, physcion, (+)-catechin, and quercetin-3-O-glucuronoid. RTE effectively inhibited TMT-induced seizures at 10, 30, and 100 mg/kg dosages and attenuated hippocampal neuronal decay and neuroinflammation at 30 and 100 mg/kg dosages. Furthermore, RTE significantly reduced mRNA levels of tumor necrosis factor (TNF-α), glial fibrillary acidic protein (GFAP), and c-fos in hippocampal tissues. Network analysis revealed TNF, Interleukin-1 beta (IL-1ß), Interleukin-6 (IL-6), Protein c-fos (FOS), RAC-alpha serine/threonine-protein kinase (AKT1), and Mammalian target of rapamycin (mTOR) as the core targets. Enrichment analysis demonstrated significant involvement of R. tanguticum components in neurodegeneration (p = 4.35 × 10-5) and TNF signaling pathway (p = 9.94 × 10-5). CONCLUSIONS: The in vivo and in silico analyses performed in this study suggests that RTE can potentially modulate TMT-induced epileptic seizures and neurodegeneration. Therefore, R. tanguticum root is a promising herbal treatment option for antiepileptic and neuroprotective applications.

Anti-inflammatory spiroditerpenoids from Penicillium bialowiezense.

Inflammation is a vital process that maintains tissue homeostasis. However, it is widely known that uncontrolled inflammation can contribute to the development of various diseases. This study aimed to discover anti-inflammatory metabolites from Penicillium bialowiezense. Seven spiroditerpenoids, including two new compounds, breviones P and Q (1 and 2), were isolated and characterized by various spectroscopic and spectrometric methods. All isolated compounds were initially tested for their inhibitory effects against lipopolysaccharide-induced nitric oxide (NO) production in RAW 264.7 macrophages. Of these, brevione A (3) exhibited this activity with a half-maximal inhibitory concentration value of 9.5 µM. Further mechanistic studies demonstrated that 3 could suppress the expression of pro-inflammatory cytokines and mediators, such as NO, prostaglandin E2, interleukin (IL)-1ß, tumor necrosis factor-α, IL-6, and IL-12 by inhibiting the activation of nuclear factor-kappa B and c-Jun N-terminal kinase.

Phenolic constituents isolated from Senna tora sprouts and their neuroprotective effects against glutamate-induced oxidative stress in HT22 and R28 cells.

The consumption of sprouts has been steadily increasing due to their being an excellent source of nutrition. It is known that the bioactive constituents of legumes can be increased after germination. In this study, the extract from Senna tora sprouts is shown to exhibit improved radical scavenging activities and better neuroprotective effects in HT22 hippocampal neuronal (HT22) and R28 retina precursor (R28) cells than those from seeds due to an increased content of phenolic constituents, especially compounds 1 and 3-6. A phytochemical investigation of S. tora sprouts resulted in the isolation of two new naphthopyrone glycosides (1-2) with 27 previously reported compounds. Their structures were determined via interpreting spectroscopic data. Compounds 1 and 3-6 were found to possess radical scavenging activities and neuroprotective effects against oxidative stress in both neuronal cells. Hence, Senna tora sprouts and their constituents may be developed as natural neuroprotective agents via antioxidative effects.

Chemical constituents from basidiomycete Basidioradulum radula culture medium and their cytotoxic effect on human prostate cancer DU-145 cells.

Eight new naphtho[1,2-c]furan derivatives (1-8) along with six known analogues (9-14) were isolated from culture medium of the basidiomycete Basidioradulum radula. The structures of these compounds were identified using spectroscopic analysis, and their absolute configurations were resolved using X-ray diffraction, ECD, and VCD. Compounds 7 and 14 inhibited the cell viability of human prostate cancer DU-145 cells with IC50 values of 7.54 ± 0.03 µM and 5.04 ± 0.03 µM, respectively. At 8 µM, compounds 7 and 14 increased the percentage of apoptotic cells and upregulated the protein expression related to the apoptosis caspase pathways in DU-145 cells. Furthermore, the hallmarks of cells undergoing apoptosis, such as chromatin condensation, were also observed at this concentration. However, compound 7 and 14 showed no effect on the proliferation of splenocytes isolated from cyclophosphamide-induce immunosuppressed mice.

Anti-inflammatory Metabolites from Chaetomium nigricolor.

Twelve metabolites were obtained from the culture media of Chaetomium nigricolor, including a new furan derivative, methyl succinyl Sumiki's acid (1), and two new atropisomers of the previously reported bis-naphtho-γ-pyrones, (aS)-asperpyrone A and (aS)-fonsecinone A (2 and 3). The structures were elucidated by spectroscopic, chemical, and chiroptical techniques. Compounds 2 and 3 inhibited nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Compound 2 was found to inhibit nuclear factor-kappa B and c-Jun N-terminal kinase activation, in turn suppressing pro-inflammatory mediators and cytokines including nitric oxide, prostaglandin E2, interleukin (IL)-1ß, tumor necrosis factor-α, IL-6, and IL-12.

Chemical Constituents from the Aerial Parts of Elsholtzia ciliata and Their Protective Activities on Glutamate-Induced HT22 Cell Death.

A new phenolic glucoside, (7E,9E)-3-hydroxyavenalumic acid-3-O-[6'-O-(E)-caffeoyl]-ß-d-glucopyranoside (1), and three new acetylated flavone glycosides, acacetin-7-O-[ß-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-ß-d-glucopyranoside (3), acacetin-7-O-[6″″-O-acetyl-ß-d-glucopyranosyl(1″″→2″)-3‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-ß-d-glucopyranoside (5), and acacetin-7-O-[3″″,6″″-di-O-acetyl-ß-d-glucopyranosyl(1″″→2″)-4‴-O-acetyl-α-l-rhamnopyranosyl(1‴→6″)]-ß-d-glucopyranoside (7), as well as 34 known compounds (2, 4, 6, and 8-38) were isolated from the aerial parts of Elsholtzia ciliata. The chemical structures of the new compounds were determined by spectroscopic/spectrometric data interpretation using NMR and HRESIMS. The neuroprotective effect of the isolated compounds was evaluated by a cell viability assay on HT22 murine hippocampal neuronal cells. Among them, 23 compounds, including new substances 1 and 3, exhibited neuroprotective effects against glutamate-induced HT22 cell death. In particular, compounds 2, 16, 17, 20, 22, 28, 29, and 31 presented potent neuroprotective effects with EC50 values of 1.5-8.3 µM.

Furanocoumarins from the Roots of Angelica dahurica with Inhibitory Activity against Intracellular Reactive Oxygen Species Accumulation.

Five new furanocoumarins, dahuribirin H (1), dahuribirin I (2), (2'S)-(+)-5-(2'-hydroxy-3'-methylbut-3'-enyloxy)-8-(3''-methylbut-2″-enyloxy)psoralen (3), (2'R)-(+)-5-(2',3'-epoxy-3'-methylbutoxy)-8-(3″-methylbut-2″-enyloxy)psoralen (4), and 5-methoxy-8-((Z)-4'-(3″-methylbutanoate)-3'-methylbut-2'-enyloxy)psoralen (5), along with 15 known compounds (6-20), were isolated from the roots of Angelica dahurica. The structures of the new compounds were elucidated by spectroscopic analysis, along with electronic circular dichroism calculations and Mosher ester analysis. Compounds 3, 4, 11, 13, and 16 reduced H2O2-induced cell death in HepG2 cells and attenuated reactive oxygen species (ROS) formation without showing cytotoxicity, suggesting that these compounds might have cytoprotective effects against H2O2-induced oxidative damage via ROS scavenging activities.

Xylodon flaviporus-Derived Drimane Sesquiterpenoids That Inhibit Osteoclast Differentiation.

The presence of excessive osteoclasts is a major factor in skeletal diseases. The present study aimed to discover osteoclast differentiation inhibitors from the basidiomycete Xylodon flaviporus. Seven new drimane sesquiterpenoids (1-7) and 7-ketoisodrimenin-5-ene (8) were obtained and characterized by various spectroscopic methods. The isolated compounds were evaluated for their inhibitory effects against receptor activator of nuclear factor-kappa-B ligand-induced osteoclastogenesis in mouse bone marrow macrophages. Compounds 1, 3, and 6 showed potent activities with IC50 values of 1.6, 0.9, and 2.1 µM, respectively, while 4, 5, and 7 exhibited relatively weak activities with IC50 values of 10.7, 10.1, and 8.5 µM, respectively.

Gentisyl Alcohol Inhibits Proliferation and Induces Apoptosis via Mitochondrial Dysfunction and Regulation of MAPK and PI3K/AKT Pathways in Epithelial Ovarian Cancer Cells.

Ovarian cancer is one of the prevalent gynecological cancers occurring in women. In particular, the efficiency of standard therapeutic methods decreases when recurrence and chemoresistance ensue. To assist standard anti-cancer agents in the cure of ovarian cancer, development and application of new compounds such as small molecules or natural products are required. Gentisyl alcohol is one of the secondary metabolites that can be obtained by purification from bacteria or fungi and is known to have antibacterial, antifungal, antiviral, and anti-cancer effects. In the present study, we verified the effect of gentisyl alcohol derived from marine Arthrinium sp. on suppressing proliferation and inducing apoptosis via DNA fragmentation in human ovarian cancers cells (ES2 and OV90 cells). We also confirmed that there was an accumulation of sub-G1 cells and a loss of mitochondrial membrane potential with calcium dysregulation in gentisyl alcohol-treated ovarian cancer cells. Moreover, gentisyl alcohol up-regulated signal transduction of MAPK and PI3K/AKT pathways. Collectively, our results demonstrated the possibility of gentisyl alcohol as a novel therapeutic agent for human ovarian cancer.

Identification of Two New Phenanthrenes from Dendrobii Herba and Their Cytotoxicity towards Human Hypopharynx Squamous Carcinoma Cell (FaDu).

Two new phenanthrenes, (1R,2R)-1,7-hydroxy-2,8-methoxy-2,3-dihydrophenanthrene-4(1H)-one (1) and 2,7-dihydroxy-phenanthrene-1,4-dione (2), were isolated from the ethyl acetate-soluble fraction of Dendrobii Herba, together with seven known phenanthrenes (3-9), two bibenzyls (10-12), and a lignan (13). Structures of 1 and 2 were elucidated by analyzing one-dimensional (1D) and two-dimensional (2D)-NMR and High-resolution electrospray ionization mass spectra (HR-ESI-MS) data. The absolute configuration of compound 1 was confirmed by the circular dichroism (CD) spectroscopic method. In cytotoxicity assay using FaDu human hypopharynx squamous carcinoma cell line, compounds 3-6, 8, 10, and 12 showed activities, with IC50 values that ranged from 2.55 to 17.70 µM.

Chemical Constituents of Apios americana Tubers and Their Inhibitory Activities on Nitric Oxide Production in Lipopolysaccharide-Stimulated RAW 264.7 Macrophages.

Apios americana is an important food crop producing edible tubers with high nutritional and medicinal values and is widely cultivated in many countries. Despite its usefulness, research on its secondary metabolites and biological activities has been limited. In the present study, a new coumaronochromone, (2 R,3 S)-3,7,4'-trihydroxy-5-methoxycoumaronochromone (1), and two new isoflavone glucosides, 7,2',4'-trihydroxy-5-methoxyisoflavone-4'- O-ß-d-glucopyranoside (3) and 5,7,4'-trihydroxyisoflavone-7- O-ß-d-gentiotrioside (5), were isolated from the tubers of A. americana via chromatographic separation. Seventeen known compounds (2, 4, and 6-20) were also obtained from this plant part. The chemical structures of 1, 3, and 5 were determined by the interpretation of spectroscopic data. The absolute structure of the new compound 1 was established from experimental and calculated electronic circular dichroism spectra. This is the first study to determine the absolute configuration of a 3-hydroxycoumaronochromone derivative. The potential anti-inflammatory activity of the 20 isolates obtained was evaluated by measuring their inhibitory effects on nitric oxide production in lipopolysaccharide-stimulated RAW 264.7 macrophages. Among the isolates, seven compounds (1, 3, 6-8, 15, and 20) showed substantial inhibition of nitric oxide production in RAW 264.7 cells, with the most active being compound 1 (IC50 value of 0.38 ± 0.04 µM).

Iridoids from the Roots of Patrinia scabra and Their Inhibitory Potential on LPS-Induced Nitric Oxide Production.

An activity-guided fractionation procedure of the 70% aqueous EtOH extract from the roots of Patrinia scabra led to the isolation and characterization of five new iridoids, patriscabrins A-E (1-5), along with 13 known compounds. The structures of 1-5 were determined by interpretation of spectroscopic data, particularly by 1D and 2D NMR, ECD, and VCD studies. Thereafter, isolates were evaluated for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells. Of these, the new iridoids 2 and 5 and the known lignan patrineolignan B (6) exhibited IC50 values of 14.7 to 17.8 µM.

Diversity and Ecology of Marine Algicolous Arthrinium Species as a Source of Bioactive Natural Products.

In our previous study, all Arthrinium isolates from Sargassum sp. showed high bioactivities, but studies on marine Arthrinium spp. are insufficient. In this study, a phylogenetic analysis of 28 Arthrinium isolates from seaweeds and egg masses of Arctoscopus japonicus was conducted using internal transcribed spacers, nuclear large subunit rDNA, ß-tubulin, and translation elongation factor region sequences, and their bioactivities were investigated. They were analyzed as 15 species, and 11 of them were found to be new species. Most of the extracts exhibited radical-scavenging activity, and some showed antifungal activities, tyrosinase inhibition, and quorum sensing inhibition. It was implied that marine algicolous Arthrinium spp. support the regulation of reactive oxygen species in symbiotic algae and protect against pathogens and bacterial biofilm formation. The antioxidant from Arthrinium sp. 10 KUC21332 was separated by bioassay-guided isolation and identified to be gentisyl alcohol, and the antioxidant of Arthrinium saccharicola KUC21221 was identical. These results demonstrate that many unexploited Arthrinium species still exist in marine environments and that they are a great source of bioactive compounds.

Mass spectrometry-guided isolation of thiodiketopiperazines from an EtOAc-extract of Setosphaeria rostrata culture medium and their anti-skin aging effects on TNF-α-induced human dermal fibroblasts.

Using mass spectrometry (MS)-guided isolation methods, a new thiodiketopiperazine derivative (1) and exserohilone (2) were isolated from an EtOAc-extract of Setosphaeria rostrata culture medium. The chemical structure of the new compound was elucidated by MS and NMR spectroscopy, and the absolute configurations were established by the quantum mechanical calculations of electronic circular dichroism. All isolated compounds were examined for their effects on reactive oxygen species (ROS) production, matrix metalloproteinase 1 (MMP-1) secretion, and procollagen type I α1 secretion in tumor necrosis factor (TNF)-α-induced human dermal fibroblasts. Compound 1 and exserohilone (2) exhibited the inhibition of TNF-α-induced ROS generation and MMP-1 secretion. Additionally, compound 1 and exserohilone (2) increased the procollagen type I α1 secretion. Compound 1 docked computationally into the active site of MMP-1 (-6.0 kcal/mol).

Chemical Constituents from the Roots of Angelica reflexa That Improve Glucose-Stimulated Insulin Secretion by Regulating Pancreatic ß-Cell Metabolism.

The aim of this study was to discover bioactive constituents of Angelica reflexa that improve glucose-stimulated insulin secretion (GSIS) in pancreatic ß-cells. Herein, three new compounds, namely, koseonolin A (1), koseonolin B (2), and isohydroxylomatin (3), along with 28 compounds (4-31) were isolated from the roots of A. reflexa by chromatographic methods. The chemical structures of new compounds (1-3) were elucidated through spectroscopic/spectrometric methods such as NMR and HRESIMS. In particular, the absolute configuration of the new compounds (1 and 3) was performed by electronic circular dichroism (ECD) studies. The effects of the root extract of A. reflexa (KH2E) and isolated compounds (1-31) on GSIS were detected by GSIS assay, ADP/ATP ratio assay, and Western blot assay. We observed that KH2E enhanced GSIS. Among the compounds 1-31, isohydroxylomatin (3), (-)-marmesin (17), and marmesinin (19) increased GSIS. In particular, marmesinin (19) was the most effective; this effect was superior to treatment with gliclazide. GSI values were: 13.21 ± 0.12 and 7.02 ± 0.32 for marmesinin (19) and gliclazide at a same concentration of 10 µM, respectively. Gliclazide is often performed in patients with type 2 diabetes (T2D). KH2E and marmesinin (19) enhanced the protein expressions associated with pancreatic ß-cell metabolism such as peroxisome proliferator-activated receptor γ, pancreatic and duodenal homeobox 1, and insulin receptor substrate-2. The effect of marmesinin (19) on GSIS was improved by an L-type Ca2+ channel agonist and K+ channel blocker and was inhibited by an L-type Ca2+ channel blocker and K+ channel activator. Marmesinin (19) may improve hyperglycemia by enhancing GSIS in pancreatic ß-cells. Thus, marmesinin (19) may have potential use in developing novel anti-T2D therapy. These findings promote the potential application of marmesinin (19) toward the management of hyperglycemia in T2D.

New Sesquiterpene Glycosides from the Flowers of Aster koraiensis and Their Inhibition Activities on EGF- and TPA-Induced Cell Transformation.

In total, four new eudesmane-type sesquiterpene glycosides, askoseosides A-D (1-4), and 18 known compounds (5-22) were isolated from the flowers of Aster koraiensis via chromatographic techniques. Chemical structures of the isolated compounds were identified by spectroscopic/spectrometric methods, including NMR and HRESIMS, and the absolute configuration of the new compounds (1 and 2) was performed by electronic circular dichroism (ECD) studies. Further, the anticancer activities of the isolated compounds (1-22) were evaluated using the epidermal growth factor (EGF)-induced as well as the 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced cell transformation assay. Among the 22 compounds, compounds 4, 9, 11, 13-15, 17, 18, and 22 significantly inhibited both EGF- and TPA-induced colony growth. In particular, askoseoside D (4, EGF: 57.8%; TPA: 67.1%), apigenin (9, EGF: 88.6%; TPA: 80.2%), apigenin-7-O-ß-d-glucuronopyranoside (14, EGF: 79.2%; TPA: 70.7%), and 1-(3',4'-dihydroxycinnamoyl) cyclopentane-2,3-diol (22, EGF: 60.0%; TPA: 72.1%) showed higher potent activities.

Neuroprotective effect of Geijigadaehwang-tang against trimethyltin-induced hippocampal neurodegeneration: An in vitro and in vivo study.

ETHNOPHARMACOLOGICAL RELEVANCE: Patients with dementia are diagnosed with deficiency patterns and interior patterns in traditional Chinese medicine due to decreased physical strength, mental atrophy including cognitive function, and decreased motor function in the gastrointestinal tract. Since "greater yin symptom" in Shanghanlun has been interpreted as interior, deficiency, and cold pattern in traditional Chinese medicine, it is necessary to determine whether Geijigadaehwang-tang (GDT) has therapeutic effects on neurodegenerative diseases and the underlying mechanism if it has such effects. AIMS OF THE STUDY: Trimethyltin (TMT), a neurotoxic organotin compound, has been used to induce several neurodegenerative diseases, including epilepsy and Alzheimer's disease. This study aimed to evaluate the therapeutic efficacy of GDT for TMT-induced hippocampal neurodegeneration and seizures and to determine the mechanisms involved at the molecular level. MATERIALS AND METHODS: The main components of GDT were analyzed using ultra-performance liquid chromatography. TMT was used to induce neurotoxicity in microglial BV-2 cells and C57BL6 mice. GDT was administered at various doses to determine its neuroprotective and seizure inhibition effects. The inhibitory effects of GDT on TMT-induced apoptosis, inflammatory pathways, and oxidative stress pathways were determined in the mouse hippocampal tissues. RESULTS: GDT contained emodin, chrysophanol, albiflorin, paeoniflorin, 6-gingerol, and liquiritin apioside. In microglial BV-2 cells treated with TMT, GDT showed dose-dependent neuroprotective effects. Oral administration of GDT five times for 2.5 days before and after TMT injection inhibited seizures at doses of 180 and 540 mg/kg and inhibited neuronal death in the hippocampus. In hippocampal tissues extracted from mice, GDT inhibited the protein expression of ionized calcium binding adaptor molecule 1, glial fibrillary acidic protein, nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein 3, and phosphorylated nuclear factor (NF)-κB/total-NFκB ratio. Additionally, GDT inhibited the messenger RNA levels of tumor necrosis factor-α, inducible nitric oxide synthase, apoptosis-associated speck-like protein containing a caspase recruitment domain, caspase-1, interleukin-1ß, nuclear factor erythroid-2-related factor 2, and heme oxygenase-1. CONCLUSION: This study's results imply that GDT might have neuroprotective potential in neurodegenerative diseases through neuronal death inhibition and anti-inflammatory and antioxidant mechanisms.

Gekko gecko extract attenuates airway inflammation and mucus hypersecretion in a murine model of ovalbumin-induced asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Gekko gecko is used as a traditional medicine for various diseases including respiratory disorders in northeast Asian countries, mainly Korea, Japan, and China. AIM OF THE STUDY: Allergic asthma is a chronic respiratory disease caused by an inappropriate immune response. Due to the recent spread of coronavirus disease 2019, interest in the treatment of pulmonary disorders has rapidly increased. In this study, we investigated the anti-asthmatic effects of G. gecko extract (GGE) using an established mouse model of ovalbumin-induced asthma. MATERIALS AND METHODS: To evaluate the anti-asthmatic effects of GGE, we evaluated histological changes and the responses of inflammatory mediators related to allergic airway inflammation. Furthermore, we investigated the regulatory effects of GGE on type 2 helper T (Th2) cell activation. RESULTS: Administration of GGE attenuated asthmatic phenotypes, including inflammatory cell infiltration, mucus production, and expression of Th2 cytokines. Furthermore, GGE treatment reduced Th2 cell activation and differentiation. CONCLUSIONS: These results indicate that GGE alleviates allergic airway inflammation by regulating Th2 cell activation and differentiation.

Cicadidae Periostracum Attenuates Atopic Dermatitis Symptoms and Pathology via the Regulation of NLRP3 Inflammasome Activation.

Atopic dermatitis (AD) is a multifactorial inflammatory skin disease of complex etiology. Despite its increasing prevalence, treatment for AD is still limited. Crude drugs, including herbal extracts or natural resources, are being used to treat AD symptoms, with minimum side effects. Cicadidae Periostracum (CP), derived from the slough of insects belonging to the family Cicadidae, is a commonly used crude drug in traditional Asian medicine to treat/control epilepsy, shock, and edema. However, the effect of CP on AD-like skin lesions is unknown. In this study, we examined the effect of a CP water extract on AD disease development in vivo, using a house dust mite-induced AD mouse model, and in vitro, using HaCaT keratinocytes and a 3D human skin equivalent system. Importantly, CP administration alleviated house dust mite-induced AD-like symptoms, suggested by the quantified dermatitis scores, animal scratching behaviors, skin moisture retention capacity, and skin lesion and ear thickness. Furthermore, histopathological analysis demonstrated that CP decreased intralesional mast cell infiltration. In addition, CP treatments decreased the systemic levels of immunoglobulin E, histamine, and thymic stromal lymphopoietin (TSLP) and the local mRNA expression of TSLP and several Th1/Th2 cytokines. Our data suggest that these effects were mediated by the inhibition of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) inflammasome activation. In vivo and in vitro CP treatments resulted in the downregulation of inflammasome components, such as ASC and cleaved caspase-1, as well as related mediators such as IL-1ß and reactive oxygen species. Collectively, our results suggest that CP is a potential therapeutic agent for AD, controlling inflammatory responses through the suppression of NLRP3 inflammasome activation.

Clerodane Diterpenoids Identified from Polyalthia longifolia Showing Antifungal Activity against Plant Pathogens.

In the search for new natural resources showing plant disease control effects, we found that the methanol extract of Polyalthia longifolia suppressed fungal disease development in plants. To identify the bioactive substances, the methanol extract of P. longifolia was extracted by organic solvents, and consequently, four new 2-oxo-clerodane diterpenes (1-4), a new 4(3 → 2)-abeo-clerodane diterpene (5), together with ten known compounds (6-16) were isolated and identified from the extracts. Of the new compounds, compound 2 showed a broad spectrum of antifungal activity with moderated minimum inhibitory concentration (MIC) values in a range of 50-100 µg/mL against tested fungal pathogens. Considering with the known compounds, compound 6 showed the most potent antifungal activity with an MIC value in the range of 6.3-12.5 µg/mL. When compound 6 was evaluated for an in vivo antifungal activity against rice blast, tomato late blight, and pepper anthracnose, compound 6 reduced the plant disease by at least 60% compared to the untreated control at concentrations of 250 and 500 µg/mL. Together, our results suggested that the methanol extract of twigs and leaves of P. longifolia and its major compound 6 could be used as a source for the development of eco-friendly plant protection agents.