Inhibitory effects of eutigosides isolated fromEurya emarginata on the inflammatory mediators in RAW264.7 cells

Effects of Eurya japonica extracts on human corneal epithelial cells and experimental dry eye

Eurya japonica (EJ) leaves have been indicated to exert anti-oxidative and anti-inflammatory effects. Dry eye disease (DED) is a chronic inflammatory disease and oxidative stress is closely associated with DED. The aim of the present study was to analyze the therapeutic efficacy of EJ in DED using human corneal epithelial (HCE) cells and a mouse model of experimental dry eye (EDE). EJ extracts (0.001, 0.01 and 0.1%) were used to treat HCE cells. Cell viability and mitochondrial function were detected using a EZ-Cytox cell viability assay kit and mitochondrial membrane potential assays. Dichlorofluorescein diacetate (DCF-DA) assay was used to measure cellular reactive oxygen species (ROS) levels. Subsequently, eye drops consisting of BSS or 0.001%, 0.01 and 0.1% EJ extracts were applied for treatment of EDE. At 7 days, conjunctival ROS production was measured using a DCF-DA assay. Tumor necrosis factor (TNF)-α, interleukin (IL)-1β, 10 kDa interferon gamma-induced protein 10 (IP-10) and monokine induced by interferon-γ (MIG) levels in the conjunctiva were analyzed using a multiplex immunobead assay. Tear film and ocular surface parameters were measured. Treatment with EJ extracts in HCE cells effectively improved cell viability, ROS levels and mitochondrial function. Mice treated with 0.01 and 0.1% EJ extracts indicated a significant decrease in ROS, TNF-α, IL-1β, IP-10 and MIG levels compared with the EDE or BSS groups. Furthermore, a significant improvement in all clinical parameters was observed in the 0.01 and 0.1% EJ extract groups. EJ extracts could decrease cytotoxicity and ROS production in HCE cells. Additionally, topical EJ extracts reduced oxidative damage and inflammation and improved clinical signs of EDE, suggesting that EJ extracts may be used as an adjunctive therapy for DED.

Advances in the Tyrosinase Inhibitors from Plant Source

Tyrosinase is a multifunctional copper-containing oxidase which catalyses the oxidation of tyrosine to produce melanin. The alteration in melanin biosynthesis occurs in many diseases. The pigment has a protecting role against skin photo-carcinogenesis, but anomalous melanin pigmentation is an aesthetic problem in human beings. Moreover, the formation of neuromelanin in human brain could contribute to the neurodegeneration associated with Parkinson's disease. Finally, tyrosinase is also responsible for undesired browning in fruits and vegetables. These topics encouraged the search for new inhibitors of this enzyme for pharmaceutical, cosmetic and foods industries. This review is to report recent trends in the discovery of tyrosinase inhibitors from plant sources, to provide a rationale for the continued study of natural tyrosinase inhibitors, and to recognise the potential therapeutic rewards associated with the identification of these agents.

Two new ent-kaurane diterpenes from the stems of Eurya chinensis

Two new ent-kaurane diterpenes (1-2), together with five known analogs, were isolated from the stems of Eurya chinensis. The structures of new compounds were established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 3 exhibited noticeable anti-inflammatory activity as denoted by inhibiting LPS-induced nitric oxide (NO) production in RAW264.7 cells with an IC₅₀ value of 7.82 μM. Compound 4 showed potent cytotoxic activity against human cancer cell lines NCI-H46, HepG2 and SW480 with IC₅₀ values ranging from 7.45 to 8.54 μM.

A new ent-kaurane diterpene derivative from the stems of Eurya chinensis R.Br

One new ent-kaurane diterpene derivative (1), along with four known diterpenes, was isolated from the stems of Eurya chinensis R.Br. The structure of the new compound was established by extensive analysis of mass spectrometric and 1D and 2D NMR spectroscopic data. Compound 1 showed moderate anti-inflammatory activities with IC₅₀ value of 8.12 μM. This is the first example of diterpenoids with 4-hydroxy-4-(2-hydroxyethyl)-1-hydroxyl-cyclohexanoyl substituent.

Anti-inflammatory and antimicrobial coumarins from the stems of Eurya chinensis

Two new coumarins, named (±)-euryacoumarin A (1) and 6-demethylobtusinin (2), and one new natural coumarin, named euryacoumarin B (3), along with two known compounds, scopoletin (4) and obtusinol (5), were isolated from the stems of Eurya chinensis. Their structures were elucidated by means of extensive spectroscopic methods and comparison with data reported in the literatures. Compound 1 exhibited significant inhibition of LPS-induced nitric oxide (NO) production in RAW264.7 cells with IC₅₀ value of 35.64 ± 1.73 μM, and showed marginal antibacterial activities against Bacillus subtilis and B. cereus with MIC values of 50.59 ± 2.12 and 35.42 ± 0.96 μM, respectively.

Euryachins A and B, a new type of diterpenoids from Eurya chinensis with potent NO production inhibitory activity

Euryachins A (1) and B (2), new typediterpenoid euryamanes, were isolated from the branches of Eurya chinensis. The absolute configuration of 1 was determined by single-crystal X-ray diffraction. Both 1 and 2 exhibited significant NO production inhibitory activity.

Analysis of the inhibitory activity of Abeliophyllum distichum leaf constituents against aldose reductase by using high-speed counter current chromatography

We isolated five phenolic glycosides (acteoside, eutigoside B, isoacteoside, rutin and cornoside) from Abeliophyllum distichum leaves by high-speed counter current chromatography (HSCCC) using a solvent system of ethyl acetate:n-butanol:water (8:0.7:5). We determined the purity of the 5 compounds by high-performance liquid chromatography, and confirmed their chemical structures by using nuclear magnetic resonance data. We examined the inhibitory effect of these compounds on rat lens aldose reductase. Among these compounds, acteoside (1) showed the most potent inhibitory effect, with an IC₅₀ value of 1.39 μM. The inhibitory effect of 1 was 5.0 times greater than that of quercetin (7.05 μM), which was used as a positive control. These results suggest that acteoside may be a promising agent for the prevention or treatment of diabetic complications. Moreover, HSCCC is a promising method for the isolation and purification of biologically active compounds from natural products.

The synergistic anti-inflammatory effect of the combination of sodium ferulate and oxymatrine and its modulation on inflammation-associated mediators in RAW 264.7 cells

ETHNOPHARMACOLOGICAL RELEVANCE

The combination of Radix Angelicae sinensis (Oliv.) Diels and Radix Sophora flavescens Ait. was extensively used in traditional Chinese medicine to treat inflammatory diseases, such as acne, heart disease, and hepatitis. Sodium ferulate (SF) and oxymatrine (OMT) were effective component of Radix Angelicae sinensis (Oliv.) Diels and Radix Sophora flavescens Ait., respectively.

AIM OF THE STUDY

In this study, we investigated the synergistic anti-inflammatory effect of the combination of SF and OMT, and its modulation on inflammation-associated mediators in RAW 264.7 cells.

MATERIALS AND METHODS

In vivo, the anti-inflammatory effects of the combination of SF and OMT were evaluated with the xylene-induced mouse ear edema model and the carrageenan-induced rat paw edema model. In vitro, chemokines and cytokines mRNA expressions in lipopolysaccharide (LPS)-activated RAW 264.7 cells were determined by real-time PCR (RT-PCR) microarray analysis. The levels of interleukin-11 (IL-11), C-reactive protein (CRP) and interferon-γ (INF-γ) in the supernatant of LPS-stimulated RAW 264.7 cells were measured by enzyme-linked immune-sorbent assay (ELISA).

RESULTS

The combination of SF and OMT could significantly inhibit the edema in the xylene-induced mouse ear edema and carrageenan-induced rat paw edema, but no effect was found when each drug was used alone according to above doses. The combination exhibited a better effect in down-regulating mRNA expressions of inflammation-associated mediators in LPS-stimulated RAW 264.7 cells than SF or OMT alone. The ELISA results showed that the combination synergistically inhibited LPS-induced IL-11, CRP and INF-γ production in a dose-dependent manner.

CONCLUSION

The combination of SF and OMT showed synergistic anti-inflammatory effect, and the activity was probably related to its modulation on inflammation-associated mediators, especially IL-11, CRP and INF-γ.

Eutigoside C inhibits the production of inflammatory mediators (NO, PGE2, IL-6) by down-regulating NF-κB and MAP kinase activity in LPS-stimulated RAW 264.7 cells

Eutigoside C, a compound isolated from the leaves of Eurya emarginata, is thought to be an active anti-inflammatory compound which operates through an unknown mechanism. In the present study we investigated the molecular mechanisms of eutigoside C activity in lipopolysacchardide (LPS)-stimulated murine macrophage RAW 264.7 cells. Treatment with eutigoside C inhibited LPS-stimulated production of nitric oxide (NO), prostaglandin E2 (PGE2) and interleukin-6 (IL-6). To further elucidate the mechanism of this inhibitory effect of eutigoside C, we studied LPS-induced nuclear factor (NF)-κB activation and mitogen-activated protein (MAP) kinase phosphorylation. Eutigoside C suppressed NF-κB DNA binding activity, interfering with nuclear translocation of NF-κB. Eutigoside C suppressed the phosphorylation of three MAP kinases (ERK1/2, JNK and p38). These results suggest that eutigoside C inhibits the production of inflammatory mediators (NO, PGE2 and interleukin-6) by suppressing the activation and translocation of NF-κB and the phosphorylation of MAP kinases (ERK1/2, JNK and p38) in LPS-stimulated murine macrophage RAW 264.7 cells.

NMR and UPLC-qTOF-MS/MS characterisation of novel phenylethanol derivatives of phenylpropanoid glucosides from the leaves of strawberry (Fragaria x ananassa cv. Jonsok)

INTRODUCTION

Strawberry (Fragaria x ananassa) is rich in polyphenols, particularly anthocyanins, flavonols, condensed tannins and ellagic tannins. In addition to the fruits, the leaves of strawberry also contain a wide range of phenolic compound classes, but have not been investigated to the same extent as the fruit.

OBJECTIVE

To characterise a metabolite group present in the leaves of strawberry, that was not amenable for identification based on earlier information available in the literature.

METHODOLOGY

Methanolic extracts of strawberry leaves were analysed by UPLC-qTOF-MS/MS and iterative quantum mechanical NMR spectral analysis.

RESULTS

The structures of phenylethanol derivatives of phenylpropanoid glucosides Eutigoside A ( F4) and its two isomeric forms 2-(4-hydroxyphenyl)ethyl-[6-O-(Z)-coumaroyl]-beta-D-glucopyranoside (F6) and 4-(2-hydroxyethyl)phenyl-[6-O-(E)-coumaroyl]-beta-D-glucopyranoside (F1) were resolved by NMR and UPLC-qTOF-MS/MS. In addition, two other derivatives of phenylpropanoid glucosides similar to Eutigoside A but possessing different phenolic acid moieties, namely Grayanoside A ( F5) and 2-(4-hydroxyphenyl)ethyl-[6-O-(E)-caffeoyl]-beta-D-glucopyranoside (F14), were similarly identified. Also, accurate characteristic coupling constants for the subunits are reported and their usefulness in structural analysis is highlighted.

CONCLUSION

Chemical analysis of the leaves of strawberry (Fragaria x ananassa cv. Jonsok) resulted in the identification of a compound class, phenylethanol derivatives of phenylpropanoid glycosides, not previously found in strawberry.