The Inhibition Activity of Natural Methoxyflavonoid from Inula britannica on Soluble Epoxide Hydrolase and NO Production in RAW264.7 Cells.

Soluble epoxide hydrolase (sEH) is an enzyme targeted for the treatment of inflammation and cardiovascular diseases. Activated inflammatory cells produce nitric oxide (NO), which induces oxidative stress and exacerbates inflammation. We identify an inhibitor able to suppress sEH and thus NO production. Five flavonoids 1-5 isolated from Inula britannica flowers were evaluated for their abilities to inhibit sEH with IC50 values of 12.1 ± 0.1 to 62.8 ± 1.8 µM and for their effects on enzyme kinetics. A simulation study using computational chemistry was conducted as well. Furthermore, five inhibitors (1-5) were confirmed to suppress NO levels at 10 µM. The results showed that flavonoids 1-5 exhibited inhibitory activity in all tests, with compound 3 exhibiting the most significant efficacy. Thus, in the development of anti-inflammatory inhibitors, compound 3 is a promising natural candidate.

Influence of Feeding Time on a Non-steroidal Anti-inflammatory Drug-induced Small Intestinal Injury Mouse Model.

BACKGROUND/AIM: Non-steroidal anti-inflammatory drugs (NSAIDs), the most widely used pharmaceuticals, induce various adverse effects, including gastrointestinal injuries, such as ulcers and bleeding. Animal models of NSAID-induced small intestinal injury (NSI) have been extensively employed for the development of preventive and therapeutic agents. However, some experimental variations related to feeding times have been observed following NSI induction. This study aimed to investigate the impact of feeding time on an NSI mouse model. MATERIALS AND METHODS: The mice were divided into eight groups: normal, sham, and model groups (with feeding times of 2 h, 6 h, 10 h, 14 h, 18 h, and 22 h; n=10 in each group). The mice were fasted for 18 h before the injection of indomethacin (15 mg/kg, subcutaneously), except for the normal group. Food supply was halted at specific time points (2 h, 6 h, 10 h, 14 h, 18 h, and 22 h); however, the normal and sham groups were continuously fed throughout the experiment. The length of the small intestine was measured, and histological analysis was performed 24 h after induction. RESULTS: Up to 14 h after induction, NSI, indicated by small intestine shortening, remained consistent, with a reduction in length of approximately 10-20%. However, feeding for more than 14 h significantly exacerbated NSI, both anatomically and histologically. CONCLUSION: The ulcerative changes observed in the small intestine 14 h after indomethacin injection may be closely associated with the influence of food on NSI.

Kushenol C from Sophora flavescens protects against UVB-induced skin damage in mice through suppression of inflammation and oxidative stress.

Sophora flavescens has been used in traditional medicine for the treatment of various diseases such as viral hepatitis, fever, cancer, and pain. It is known to contain many bioactive compounds including prenylated flavonoids such as kurarinone, sophoraflavanone G, kuraridine and isoxanthohumol. These flavonoids have been confirmed to have anti-inflammatory, α-glucosidase inhibitory and antioxidant performances. However, the protective activities against UV-induced skin damage of kushenol C from S. flavescens have not yet been elucidated. In this study, we explored the protective effect of kushenol C against the skin damage induced by UVB in mice. Our results showed that kushenol C treatment significantly recovered UVB-induced skin damage, the degradation of collagen, mast cell infiltration, together with epidermal hyperplasia in mice. Furthermore, the treatment of kushenol C remarkably suppressed the generation of pro-inflammatory mediators in the mice irradiated by UVB. More so, treatment with kushenol C suppressed the oxidative stress in mice irradiated by UVB. In conclusion, these results showed that kushenol C from S. flavescens has potentialities to treat skin injury via suppressing skin damage induced by UVB and oxidative stress.

Anti-inflammatory of disenecionyl cis-khellactone in LPS-stimulated RAW264.7 cells and the its inhibitory activity on soluble epoxide hydrolase.

The objective of the present study was to investigate anti-inflammatory effects of disenecionyl cis-khellactone (DK) isolated from Peucedanum japonicum Thunberg, a traditional edible plant, in RAW264.7 cells stimulated with lipopolysaccharide (LPS). Anti-inflammatory effects of DK were analyzed using various techniques, including NO assay, Western blot analysis, enzyme-linked immunosorbent assay (ELISA), real-time PCR, and immunofluorescence staining. It was revealed that DK reduced the production of pro-inflammatory cytokines including Monocyte chemoattractant protein-1 (MCP-1), Tumor necrosis factor-α (TNF-α), Interleukin 1ß (IL-1ß), and Interleukin 6 (IL-6) in RAW264.7 cells stimulated with LPS. It was revealed that DK effectively downregulated expression levels of iNOS and COX-2 due to inhibition of NF-κB activation and suppressing the phosphorylation of p38 and jun N-terminal kinase (JNK) mitogen-activated protein kinase (MAPK) phosphorylation. Also, soluble epoxide hydrolase activity and expression were decreased by the proinflammatory inhibitor, DK. Finally, findings of this study suggest that DK isolated from P. japonicum might have potential as a therapeutic candidate for inflammatory diseases.

Inhibitory activity of lignanamides isolated from hemp seed hulls(Cannabis sativa L.) against soluble epoxide hydrolase.

Soluble epoxide hydrolase (sEH) is a therapeutic target for inflammation. In the present study, we isolated one new (1) and four known (2-5) compounds from the ethyl acetate fraction of hemp seed hulls. Their structures were elucidated as lignanamides via nuclear magnetic resonance and mass spectral analyses. All five compounds inhibited sEH activity, with half-maximal inhibitory concentrations of 2.7 ± 0.3 to 18.3 ± 1.0 µM. These lignanamides showed a competitive mechanism of inhibition via binding to sEH, with ki values below 10 µmol. Molecular simulations revealed that compounds 1-5 fit stably into the active site of sEH, and the key amino acid residues participating in their bonds were identified. It was confirmed that the potential inhibitors 4 and 5 continuously maintained a distance of 3.5 Å from one (Tyr383) and four amino (Asp335, Tyr383, Asn472, tyr516) residues, respectively. These findings provide a framework for the development of naturally derived sEH inhibitors.

Inhibitory Activity of Natural cis-Khellactone on Soluble Epoxide Hydrolase and Proinflammatory Cytokine Production in Lipopolysaccharides-Stimulated RAW264.7 Cells.

The pursuit of anti-inflammatory agents has led to intensive research on the inhibition of soluble epoxide hydrolase (sEH) and cytokine production using medicinal plants. In this study, we evaluated the efficacy of cis-khellactone, a compound isolated for the first time from the roots of Peucedanum japonicum. The compound was found to be a competitive inhibitor of sEH, exhibiting an IC50 value of 3.1 ± 2.5 µM and ki value of 3.5 µM. Molecular docking and dynamics simulations illustrated the binding pose of (-)cis-khellactone within the active site of sEH. The results suggest that binding of the inhibitor to the enzyme is largely dependent on the Trp336-Gln384 loop within the active site. Further, cis-khellactone was found to inhibit pro-inflammatory cytokines, including NO, iNOS, IL-1ß, and IL-4. These findings affirm that cis-khellactone could serve as a natural therapeutic candidate for the treatment of inflammation.

Isocucurbic Acid Derivatives and Soluble Epoxide Hydroxylase Inhibitors from the Flowers of Chrysanthemum indicum L.

Soluble epoxide hydrolase (sEH) inhibitory activity guided fractionation and isolation of two new isocucurbic acid derivatives (1 and 2) and nine known compounds (3-11) from the flowers of Chrysanthemum indicum L. Their structures were elucidated on the basis of spectroscopic data interpretation and comparison with those reported in previous studies. Luteolin (3), acacetin-7-O-ß-D-glucopyranoside (6), and methyl 3,4-di-O-caffeoylquinate (10) displayed sEH inhibitory activities with IC50 values ranging from 13.7±3.6 to 20.8±0.4 µM. Enzyme kinetic analysis revealed that 3, 6, and 10 were non-competitive inhibitors with Ki values of 14.8±0.5, 31.2±0.8, and 3.9±0.2 µM, respectively. Additionally, molecular docking studies indicated compound 10 had the ability to form six hydrogen bonds at sEH active site, resulting binding energy as low as -9.58 Kcal/mol.

Inhibition by components of Glycyrrhiza uralensis of 3CLpro and HCoV-OC43 proliferation.

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). 3CLpro is a key enzyme in coronavirus proliferation and a treatment target for COVID-19. In vitro and in silico, compounds 1-3 from Glycyrrhiza uralensis had inhibitory activity and binding affinity for 3CLpro. These compounds decreased HCoV-OC43 cytotoxicity in RD cells. Moreover, they inhibited viral growth by reducing the amounts of the necessary proteins (M, N, and RDRP). Therefore, compounds 1-3 are inhibitors of 3CLpro and HCoV-OC43 proliferation.

Eupatin, a Flavonoid, Inhibits Coronavirus 3CL Protease and Replication.

The coronavirus disease 2019 (COVID-19) pandemic has caused more than six million deaths worldwide since 2019. Although vaccines are available, novel variants of coronavirus are expected to appear continuously, and there is a need for a more effective remedy for coronavirus disease. In this report, we isolated eupatin from Inula japonica flowers and showed that it inhibits the coronavirus 3 chymotrypsin-like (3CL) protease as well as viral replication. We showed that eupatin treatment inhibits SARS-CoV-2 3CL-protease, and computational modeling demonstrated that it interacts with key residues of 3CL-protease. Further, the treatment decreased the number of plaques formed by human coronavirus OC43 (HCoV-OC43) infection and decreased viral protein and RNA levels in the media. These results indicate that eupatin inhibits coronavirus replication.

Inhibition of Soluble Epoxide Hydrolase Activity by Components of Glycyrrhiza uralensis.

Soluble epoxide hydrolase (sEH) is a target enzyme for the treatment of inflammation and cardiovascular disease. A Glycyrrhiza uralensis extract exhibited ~50% inhibition of sEH at 100 µg/mL, and column chromatography yielded compounds 1-11. Inhibitors 1, 4-6, 9, and 11 were non-competitive; inhibitors 3, 7, 8, and 10 were competitive. The IC50 value of inhibitor 10 was below 2 µM. Molecular simulation was used to identify the sEH binding site. Glycycoumarin (10) requires further evaluation in cells and animals.

Anti-inflammatory effects of Peucedanum japonicum Thunberg leaves extract in Lipopolysaccharide-stimulated RAW264.7 cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Peucedanum japonicum Thunberg are perennial herbaceous plants known to be cultivated for food and traditional medicinal purposes. P. japonicum has been used in traditional medicine to soothe coughs and colds, and to treat many other inflammatory diseases. However, there are no studies on the anti-inflammatory effects of the leaves. AIM OF THE STUDY: Inflammation plays an important role in our body as a defense response of biological tissues to certain stimuli. However, the excessive inflammatory response can lead to various diseases. This study aimed to investigate the anti-inflammatory effects of P. japonicum leaves extract (PJLE) in LPS-stimulated RAW 264.7 cells. MATERIAL AND METHODS: Nitric Oxide (NO) production assay measured by NO assay. Inducible NO synthase (iNOS), COX-2, MAPKs, AKT, NF-κB, HO-1, Nrf-2 were examined by western blotting. PGE2, TNF-α, and IL-6 were analyzed by ELSIA. Nuclear translocation of NF-κB was detected by immunofluorescence staining. RESULTS: PJLE suppressed inducible nitric oxygen synthase (iNOS) and prostaglandin-endoperoxide synthase 2 (cyclooxygenase-2, COX-2) expression, increased heme oxygenase 1 (HO-1) expression, and decreased nitric oxide production. And PJLE inhibited the phosphorylation of AKT, MAPK, and NF-κB. Taken together, PJLE down-regulated inflammatory factors such as iNOS and COX-2 by inhibiting the phosphorylation of AKT, MAPK, and NF-κB. CONCLUSIONS: These results suggest that PJLE can be used as a therapeutic material to modulate inflammatory diseases.

The inhibitory activity of methoxyl flavonoids derived from Inula britannica flowers on SARS-CoV-2 3CLpro.

In our ongoing efforts to identify effective natural antiviral agents, four methoxy flavonoids (1-4) were isolated from the Inula britannica flower extract. Their structures were elucidated using nuclear magnetic resonance. Flavonoids 1-4 exhibited inhibitory activity against SARS- CoV-2 3CLpro with IC50 values of 41.6 ± 2.5, 35.9 ± 0.9, 32.8 ± 1.2, and 96.6 ± 3.4 µM, respectively. Flavonoids 1-3 inhibited 3CLpro in a competitive manner. Based on molecular simulations, key amino acids that form hydrogen bond with inhibitor 3 were identified. Finally, we found that inhibitors (1-3) suppressed HCoV-OC43 coronavirus proliferation at micromole concentrations.

The Luteolinidin and Petunidin 3-O-Glucoside: A Competitive Inhibitor of Tyrosinase.

The enzyme tyrosinase plays a key role in the early stages of melanin biosynthesis. This study evaluated the inhibitory activity of anthocyanidin (1) and anthocyanins (2-6) on the catalytic reaction. Of the six derivatives examined, 1-3 showed inhibitory activity with IC50 values of 3.7 ± 0.1, 10.3 ± 1.0, and 41.3 ± 3.2 µM, respectively. Based on enzyme kinetics, 1-3 were confirmed to be competitive inhibitors with Ki values of 2.8, 9.0, and 51.9 µM, respectively. Molecular docking analysis revealed the formation of a binary encounter complex between 1-3 and the tyrosinase catalytic site. Luteolinidin (1) and petunidin 3-O-glucoside (2) may serve as tyrosinase inhibitors to block melanin production.

Inhibitory Activity of Quaternary Isoquinoline Alkaloids on Soluble Epoxide Hydrolase.

The quaternary isoquinoline alkaloids of palmatine (1), berberine (2), and jatrorrhizine (3) were evaluated in terms of their ability to inhibit soluble epoxide hydrolase (sEH). They had similar inhibitory activities, with IC50 values of 29.6 ± 0.5, 33.4 ± 0.8, and 27.3 ± 0.4 µM, respectively. Their respective Ki values of 26.9, 46.8, and 44.5 µM-determined by enzyme kinetics-indicated that they inhibited the catalytic reaction by binding noncompetitively with sEH. The application of computational chemistry to the in vitro results revealed the site of the receptor to which the ligand would likely bind. Accordingly, three alkaloids were identified as having a suitable basic skeleton for lead compound development of sEH inhibitors.

Antimelanogenic activity of patuletin from Inula japonica flowers in B16F10 melanoma cells and zebrafish embryos.

During the search for natural melanogenesis inhibitors, patuletin, a flavonoid, was isolated from Inula japonica flowers. We investigated the antimelanogenic effects of patuletin on B16F10 melanoma cells and zebrafish embryos. Patuletin dose-dependently reduced melanocyte-stimulating hormone-induced melanogenesis and L-DOPA oxidation in B16F10 cells. Western blot analysis showed that patuletin reduced cellular tyrosinase expression in a dose-dependent manner. Patuletin treatment significantly decreased melanin pigmentation in the embryo compared to the untreated controls.

Inhibitory Activity of 4-O-Benzoyl-3'-O-(OMethylsinapoyl) Sucrose from Polygala tenuifolia on Escherichia coliß-Glucuronidase.

Bacterial ß-glucuronidase in the intestine is involved in the conversion of 7-ethyl-10- hydroxycamptochecin glucuronide (derived from irinotecan) to 7-ethyl-10-hydroxycamptothecin, which causes intestinal bleeding and diarrhea (side effects of anti-cancer drugs). Twelve compounds (1-12) from Polygala tenuifolia were evaluated in terms of ß-glucuronidase inhibition in vitro. 4-O-Benzoyl-3'-O-(O-methylsinapoyl) sucrose (C3) was highly inhibitory at low concentrations. C3 (an uncompetitive inhibitor) exhibited a ki value of 13.4 µM; inhibitory activity increased as the substrate concentration rose. Molecular simulation revealed that C3 bound principally to the Gln158-Tyr160 enzyme loop. Thus, C3 will serve as a lead compound for development of new ß- glucuronidase inhibitors.

Inhibitory Effects of Cucurbitane-Type Triterpenoids from Momordica charantia Fruit on Lipopolysaccharide-Stimulated Pro-Inflammatory Cytokine Production in Bone Marrow-Derived Dendritic Cells.

The bitter melon, Momordica charantia L., was once an important food and medicinal herb. Various studies have focused on the potential treatment of stomach disease with M. charantia and on its anti-diabetic properties. However, very little is known about the specific compounds responsible for its anti-inflammatory activities. In addition, the in vitro inhibitory effect of M. charantia on pro-inflammatory cytokine production by lipopolysaccharide (LPS)-stimulated bone marrow-derived dendritic cells (BMDCs) has not been reported. Phytochemical investigation of M. charantia fruit led to the isolation of 15 compounds (1-15). Their chemical structures were elucidated spectroscopically (one- and two-dimensional nuclear magnetic resonance) and with electrospray ionization mass spectrometry. The anti-inflammatory effects of the isolated compounds were evaluated by measuring the production of the pro-inflammatory cytokines interleukin IL-6, IL-12 p40, and tumor necrosis factor α (TNF-α) in LPS-stimulated BMDCs. The cucurbitanes were potent inhibitors of the cytokines TNF-α, IL-6, and IL-12 p40, indicating promising anti-inflammatory effects. Based on these studies and in silico simulations, we determined that the ligand likely docked in the receptors. These results suggest that cucurbitanes from M. charantia are potential candidates for treating inflammatory diseases.

Efficacy of Acupuncture for Insomnia: A Systematic Review and Meta-Analysis.

Patients with insomnia frequently use acupuncture as an alternative treatment to pharmacotherapy globally. The aim of this paper is to assess the effect of acupuncture on insomnia. Seven medical databases, including MEDLINE, EMBASE, CENTRAL, CNKI, RISS, NDSL, and OASIS, were used to identify studies published through July 09, 2020. Twenty-four randomized controlled trials (RCTs) were included in this qualitative review comparing acupuncture to either pharmacotherapy or sham-acupuncture therapy. Methodological quality was assessed, using the Cochrane risk of bias (ROB). In the subsequent quantitative meta-analysis of studies comparing acupuncture versus pharmacotherapy, fifteen RCTs demonstrated that acupuncture had a significant effect on patients with insomnia as assessed by the Pittsburgh sleep quality index (PSQI) (RR: -0.74; 95% CI: -1.07 to -0.40; [Formula: see text] ¡0.0001; [Formula: see text] = 89%; [Formula: see text] = 1475). A subgroup analysis showed that there was no significant effect after weeks 1 and 2, but six studies found that acupuncture had a significant effect insomnia at week 3 (RR: -0.97; 95% CI: -1.65 to -0.28; [Formula: see text] = 0.006; [Formula: see text] = 91%; [Formula: see text] = 463) and nine studies demonstrated a significant effect at week 4 (RR: -0.70; 95% CI: -1.15 to -0.25; [Formula: see text] = 0.002; [Formula: see text] = 85%; [Formula: see text] = 594). These results suggest that insomnia patients may experience significant improvement in symptoms after more than three weeks of acupuncture treatment compared to pharmacological treatments.

Association between longitudinal blood pressure and prognosis after treatment of cerebral aneurysm: A nationwide population-based cohort study.

BACKGROUND: High blood pressure is a major risk factor for the development and rupture of cerebral aneurysm. Endovascular coil embolization and surgical clipping are established procedures to treat cerebral aneurysm. However, longitudinal data of blood pressure after the treatment of cerebral aneurysm and its impact on long-term prognosis are not well known. METHODS: This retrospective cohort study included 1275 patients who underwent endovascular coil embolization (n = 558) or surgical clipping (n = 717) of cerebral aneurysm in 2002-2015 using the nationwide health screening database of Korea. Systolic and diastolic blood pressure of patients were repeatedly obtained from the nationwide health screening program. We performed a multivariate time-dependent Cox regression analysis of the primary composite outcome of stroke, myocardial infarction, and all-cause death. RESULTS: During the mean follow-up period of 6.13 ± 3.41 years, 89 patients suffered the primary outcome. Among the total 3546 times of blood pressure measurement, uncontrolled high blood pressure (systolic ≥140 mmHg or diastolic ≥90 mmHg) was 22.9%. There was a significantly increased risk of primary outcome with high systolic (adjusted HR [95% CI] per 10 mmHg, 1.16 [1.01-1.35]) and diastolic (adjusted HR [95% CI] per 10 mmHg, 1.32 [1.06-1.64]) blood pressure. CONCLUSIONS: High blood pressure is prevalent even in patients who received treatment for cerebral aneurysm, which is significantly associated with poor outcome. Strict control of high blood pressure may further improve the prognosis of patients with cerebral aneurysm.

Inhibition of soluble epoxide hydrolase by phytochemical constituents of the root bark of Ulmus davidiana var. japonica.

A novel compound 1 and nine known compounds (2-10) were isolated by open column chromatography analysis of the root bark of Ulmus davidiana. Pure compounds (1-10) were tested in vitro to determine the inhibitory activity of the catalytic reaction of soluble epoxide hydrolase (sEH). Compounds 1, 2, 4, 6-8, and 10 had IC50 values ranging from 11.4 ± 2.3 to 36.9 ± 2.6 µM. We used molecular docking to simulate inhibitor binding of each compound and estimated the binding pose of the catalytic site of sEH. From this analysis, the compound 2 was revealed to be a potential inhibitor of sEH in vitro and in silico. Additionally, molecular dynamics (MD) study was performed to find detailed interaction signals of inhibitor 2 with enzyme. Finally, compound 2 is promising candidates for the development of a new sEH inhibitor from natural plants.