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.

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.

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.

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 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.

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.

Kushenol C Prevents Tert-Butyl Hydroperoxide and Acetaminophen-Induced Liver Injury.

Sophora flavescens, also known as Kushen, has traditionally been used as a herbal medicine. In the present study we evaluated the ameliorative effects of kushenol C (KC) from S. flavescens against tBHP (tert-Butyl hydroperoxide)-induced oxidative stress in hepatocellular carcinoma (HEPG2) cells and acetaminophen (APAP)-induced hepatotoxicity in mice. KC pretreatment protected the HEPG2 cells against oxidative stress by reducing cell death, apoptosis and reactive oxygen species (ROS) generation. KC pretreatment also upregulated pro-caspase 3 and GSH (glutathione) as well as expression of 8-Oxoguanine DNA Glycosylase (OGG1) in the HEPG2 cells. The mechanism of action was partly related by KC's activation of Akt (Protein kinase B (PKB)) and Nrf2 (Nuclear factor (erythroid-derived 2)-like 2) in the HepG2 cells. In in vivo investigations, coadministration of mice with KC and APAP significantly attenuated APAP-induced hepatotoxicity and liver damage, as the serum enzymatic activity of aspartate aminotransferase and alanine aminotransferase, as well as liver lipid peroxidation and cleaved caspase 3 expression, were reduced in APAP-treated mice. Coadministration with KC also up-regulated antioxidant enzyme expression and prevented the production of proinflammatory mediators in APAP-treated mice. Taken together, these results showed that KC treatment has potential as a therapeutic agent against liver injury through the suppression of oxidative stress.

In vitro Anti-Inflammatory and Anti-Oxidative Stress Activities of Kushenol C Isolated from the Roots of Sophora flavescens.

Kushenol C (KC) is a prenylated flavonoid isolated from the roots of Sophora flavescens aiton. Little is known about its anti-inflammatory and anti-oxidative stress activities. Here, we investigated the anti-inflammatory and anti-oxidative stress effects of KC in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages, and tert-butyl hydroperoxide (tBHP)-induced oxidative stress in HaCaT cells. The results demonstrated that KC dose-dependently suppressed the production of inflammatory mediators, including NO, PGE2, IL-6, IL1ß, MCP-1, and IFN-ß in LPS-stimulated RAW264.7 macrophages. The study demonstrated that the inhibition of STAT1, STAT6, and NF-κB activations by KC might have been responsible for the inhibition of NO, PGE2, IL-6, IL1ß, MCP-1, and IFN-ß in the LPS-stimulated RAW264.7 macrophages. KC also upregulated the expression of HO-1 and its activities in the LPS-stimulated RAW264.7 macrophages. The upregulation of Nrf2 transcription activities by KC in the LPS-stimulated RAW264.7 macrophages was demonstrated to be responsible for the upregulation of HO-1 expression and its activity in LPS-stimulated RAW264.7 macrophages. In HaCaT cells, KC prevented DNA damage and cell death by upregulating the endogenous antioxidant defense system involving glutathione, superoxide dismutase, and catalase, which prevented reactive oxygen species production from tert-butyl hydroperoxide (tBHP)-induced oxidative stress in HaCaT cells. The upregulated activation of Nrf2 and Akt in the PI3K-Akt signaling pathway by KC was demonstrated to be responsible for the anti-oxidative stress activity of KC in HaCaT cells. Collectively, the study suggests that KC can be further investigated as a potential anti-inflammatory candidate for the treatment of inflammatory diseases.

Inhibitory Activity of Flavonoids, Chrysoeriol and Luteolin-7-O-Glucopyranoside, on Soluble Epoxide Hydrolase from Capsicum chinense.

: Three flavonoids derived from the leaves of Capsicum chinense Jacq. were identified as chrysoeriol (1), luteolin-7-O-glucopyranoside (2), and isorhamnetin-7-O-glucopyranoside (3). They had IC50 values of 11.6±2.9, 14.4±1.5, and 42.7±3.5 µg/mL against soluble epoxide hydrolase (sEH), respectively. The three inhibitors (1-3) were found to non-competitively bind into the allosteric site of the enzyme with Ki values of 10.5±3.2, 11.9 ±2.8 and 38.0±4.1 µg/mL, respectively. The potential inhibitors 1 and 2 were located at the left edge ofa U-tube shape that contained the enzyme active site. Additionally, we observed changes in several factors involved in the binding of these complexes under 300 K and 1 bar. Finally, it was confirmed that each inhibitor, 1 and 2, could be complexed with sEH by the "induced fit" and "lock-and-key" models.

Isolation of soluble epoxide hydrolase inhibitor of capsaicin analogs from Capsicum chinense Jacq. cv. Habanero.

Capsaicin (1) and dihydrocapsaicin (2) were isolated from the aerial parts of Capsicum chinense Jacq. cv. Habanero. In in vitro studies, the exhibited potent inhibitory activity against soluble epoxide hydrolase (sEH), with IC50 values of 5.6 ±â€¯1.2 and 7.3 ±â€¯0.7 µM. Enzyme kinetics suggested that the two compounds (1 and 2) were competitive inhibitors with Ki values of 2.5 ±â€¯1.0 and 4.7 ±â€¯2.3 µM, respectively. Molecular docking and molecular dynamic studies showed that capsaicin analogs (1 and 2) bound strongly with Asp335, Tyr383, and Tyr466 residues in the active site. These results suggest that the two inhibitors (1 and 2) represent potentially therapeutic inhibitors of sEH.

Pharmacokinetic study comparing pure desoxo-narchinol A and nardosinonediol with extracts from Nardostachys jatamansi.

Nardostachyos Radix et Rhizoma (NR) is a valuable medicinal herb widely used in Korea, India, and China for the treatment of many diseases. Desoxo-narchinol A (DA) and nardosinonediol (ND) are the two main bioactive compounds belonging to the sesquiterpene group. Desoxo-narchinol A possesses anti-inflammatory activity while ND exhibits anti-depressant and cardioprotective activities. A pharmacokinetic study is important to decide whether the isolated compounds or the NR extract have better pharmacological activity. Hence, we developed an analytical method for studying the pharmacokinetics of DA and ND after oral administration of the pure compounds and herbal extract. An optimized liquid chromatography-mass spectrometry method (LC-MS/MS) with solid-phase extraction (SPE) for sample preparation was developed. A ZORBAX Extend C18 column (2.1 × 50 mm, 3.5 µm) was used under gradient elution with acetonitrile and 0.1% formic acid in water as the mobile phase. Validation experiments assessing accuracy, precision, and stability were satisfactory; the lower limit of quantification was 5 ng/mL. For the pharmacokinetic study, three groups of rats were administrated pure DA, pure ND, or NR extract orally. Concentrations of DA and ND in their plasma were determined by the developed method. Pharmacokinetic parameters, including the time to achieve maximum plasma concentration (Tmax) and the area under the plasma concentration curve from time zero to infinity (AUC0-∞), were compared for the herbal extract and pure compounds. The Tmax of the pure compound and the NR extract for DA was 7.50 and 8.33 min, respectively, compared to 5.00 and 5.83 min for the pure compound and the NR extract for ND, respectively. The AUC0-∞ of the pure compound and the NR extract for DA was 156.34 and 133.90 µg min/mL, respectively, and that for the NR extract for ND was 6.42 and 4.15 µg min/mL, respectively. LC-MS/MS was used to determine DA and ND in rat plasma. The pharmacokinetic profile of each pure compound and those in the extract were characterized and compared.

Cholinesterases inhibition studies of biological active compounds from the rhizomes of Alpinia officinarum Hance and in silico molecular dynamics.

Six diarylheptanoids (1-6) and two flavonoids (7 and 8) derived from Alpinia officinarum were evaluated for their ability to inhibit acetylcholinesterase. Compound 1 showed the highest degree of inhibition, with an IC50 of approximately 2 µM, followed by moderate degrees of inhibition by 2, 4 and 7, with IC50 values ranging from 20 to 40 µM. The remaining isolated compounds 3, 5, 6 and 8 had IC50 values greater than 50 µM. Enzyme kinetic studies showed that the compounds with high or moderate activity were competitive inhibitors, anchored to the active site of acetylcholinesterase. In particular, compounds 1 and 2 were docked at slightly different positions from those occupied by 4 and 7. Furthermore, molecular dynamics studies showed that compound 1 maintained its interactions with residues Thr74 and Phe295 throughout the simulation trajectory. Our findings suggest that compound 1 is a potential therapeutically relevant inhibitor of acetylcholinesterase.

Kushenol A and 8-prenylkaempferol, tyrosinase inhibitors, derived from Sophora flavescens.

Tyrosinase is known for an enzyme that plays a key role in producing the initial precursor of melanin biosynthesis. Inhibition of the catalytic reaction of this enzyme led to some advantage such as skin-whitening and anti-insect agents. To find a natural compound with inhibitory activity towards tyrosinase, the five flavonoids of kushenol A (1), 8-prenylkaempferol (2), kushenol C (3), formononetin (4) and 8-prenylnaringenin (5) were isolated by column chromatography from a 95% methanol extract of Sophora flavescens. The ability of these flavonoids to block the conversion of L-tyrosine to L-DOPA by tyrosinase was tested in vitro. Compounds 1 and 2 exhibited potent inhibitory activity, with IC50 values less than 10 µM. Furthermore, enzyme kinetics and molecular docking analysis revealed the formation of a binary encounter complex between compounds 1-4 and the enzyme. Also, all of the isolated compounds (1-5) were confirmed to possess antioxidant activity.

Tyrosinase inhibitory components from the seeds of Cassia tora.

Ten compounds (1-10) isolated from the seeds of Cassia tora were evaluated for tyrosinase inhibition. Compounds 3, 4, and 7 inhibited tyrosinase enzymatic activity in a dose-dependent manner, with IC50 values of 3.0 ± 0.8, 7.0 ± 0.4, and 9.2 ± 3.4 µM, respectively. Kinetic analyses revealed a mechanism consistent with competitive inhibition. In silico molecular docking showed that compounds 3 and 4 docked in the active site of tyrosinase, whereas 7 interacted with Ala246 and Val248 at outside of the active site, and His244 and Glu256 at inside. Additionally, compounds 3, 4, and 7 suppressed melanogenesis in α-MSH-treated B16F10 melanoma cells at a concentration of 10 µM.

Chemical Constituents from Apios americana and Their Inhibitory Activity on Tyrosinase.

The goal of this study was to identify phytochemicals with inhibitory activity against tyrosinase. Nine compounds 1-9 were isolated from the tubers of Apios americana. This is the first report of aromadendrin 5-methyl ether (1) being isolated from the Apios species. Among them, compounds 2 and 8 showed inhibitory activity toward tyrosinase. Based on a Dixon plot, the potential Ki values of competitive inhibitors 2 and 8 were calculated as 10.3 ± 0.8 µM and 44.2 ± 1.7 µM, respectively. An IC50 value of 13.2 ± 1.0 µM was calculated for the slow-binding inhibitor 2 after preincubation with tyrosinase. Additionally, the predicted binding sites between the receptor and ligand, as well as secondary structure changes, in the presence of 2 were examined by molecular simulation.

Quinoxaline-, dopamine-, and amino acid-derived metabolites from the edible insect Protaetia brevitarsis seulensis.

Edible insects have been reported to produce metabolites showing various pharmacological activities, recently emerging as rich sources of health functional food. In particular, the larvae of Protaetia brevitarsis seulensis (Kolbe) have been used as traditional Korean medicines for treating diverse diseases, such as breast cancer, inflammatory disease, hepatic cancer, liver cirrhosis, and hepatitis. However, only few chemical investigations were reported on the insect larvae. Therefore, the aim of this study was to discover and identify biologically active chemical components of the larvae of P. brevitarsis seulensis. As a result, a quinoxaline-derived alkaloid (1) was isolated, which was not reported previously from natural sources. In addition, other related compounds (2, 4-10, 15, 16) were also encountered for the first time from the larvae. The structures of all the isolated compounds were established mainly by analysis of HRESIMS, NMR, and electronic circular dichroism data. Compound 5 exhibited inhibition of tyrosinase with IC50 value of 44.8 µM.

α-Glucosidase inhibition by prenylated and lavandulyl compounds from Sophora flavescens roots and in silico analysis.

The enzyme α-glucosidase is a good drug target for the treatment of diabetes mellitus. Four minor flavonoids (1-4) from roots of Sophora flavescens showed the inhibitory activity, with IC50 values ranging from 11.0±0.3 to 50.6±1.3µM, toward α-glucosidase. An enzyme kinetics analysis of them revealed that the compounds 1 and 4 were non-competitive, and compounds 2 and 3 were un-competitive inhibitors. For molecular docking, 3-dimensional structure of α-glucosidase was built by homology modeling. As the result, four compounds 1-4 were confirmed to interact into common binding site of α-glucosidase. In addition, all of the four prenylated and lavandulyl compounds (1-4) were abundant in an ethyl acetate fraction separated from a methanol extract, and the potential inhibitor (3) was extracted best using tetrahydrofuran.

Tyrosinase inhibitory components from Aloe vera and their antiviral activity.

A new compound, 9-dihydroxyl-2'-O-(Z)-cinnamoyl-7-methoxy-aloesin (1), and eight known compounds (2-9) were isolated from Aloe vera. Their structures were elucidated using 1D/2D nuclear magnetic resonance and mass spectra. Compound 9 exhibited reversible competitive inhibitory activity against the enzyme tyrosinase, with an IC50 value of 9.8 ± 0.9 µM. A molecular simulation revealed that compound 9 interacts via hydrogen bonding with residues His244, Thr261, and Val283 of tyrosinase. Additionally, compounds 3 and 7 were shown by half-leaf assays to exhibit inhibitory activity towards Pepper mild mottle virus.

Inhibitory Components from Glycosmis stenocarpa on Pepper Mild Mottle Virus.

The goal of this study was to identify a source of natural plant compounds with inhibitory activity against pepper mild mottle virus (PMMoV). We showed, using a half-leaf assay, that murrayafoline-A (1) and isomahanine (2) isolated from the aerial parts of Glycosmis stenocarpa have inhibitory activity against PMMoV through curative, inactivation, and protection effects. Using a leaf-disk assay, we confirmed that 2 inhibited virus replication in Nicotiana benthamiana. Using electron microscopy, we found that a mixture of the virus with 2 resulted in damage to the rod-shaped virus.