Agnieszka Filipek

Oenothera paradoxa defatted seeds extract and its bioactive component penta-O-galloyl-β-D-glucose decreased production of reactive oxygen species and inhibited release of leukotriene B4, interleukin-8, elastase, and myeloperoxidase in human neutrophils.

In this study, we analyzed ex vivo the effect of an aqueous extract of Oenothera paradoxa defatted seeds on the formation of neutrophil-derived oxidants. For defining active compounds, we also tested lypophilic extract constituents such as gallic acid, (+)-catechin, ellagic acid, and penta-O-galloyl-β-D-glucose and a hydrophilic fraction containing polymeric procyanidins. The anti-inflammatory potential of the extract and compounds was tested by determining the release from activated neutrophils of elastase, myeloperoxidase, interleukin-8 (IL-8), and leukotriene B4 (LTB4), which are considered relevant for the pathogenesis of cardiovascular diseases. The extract of O. paradoxa defatted seeds displays potent antioxidant effects against both 4β-phorbol-12β-myristate-α13-acetate- and formyl-met-leu-phenylalanine-induced reactive oxygen species production in neutrophils with IC50 values around 0.2 μg/mL. All types of polyphenolics present in the extract contributed to the extract antioxidant activity. According to their IC50 values, penta-O-galloyl-β-D-glucose was the more potent constituent of the extract. In cell-free assays, we demonstrated that this effect is partially due to the scavenging of O2- and H2O2 oxygen species. The extract and especially penta-O-galloyl-β-D-glucose significantly inhibit elastase, myeloperoxidase IL-8, and LTB4 release with an IC50 for penta-O-galloyl-β-D-glucose of 17±1, 15±1, 6.5±2.5, and around 20 μM, respectively. The inhibition of penta-O-galloyl-β-D-glucose on reactive oxygen species and especially on O2- production, myeloperoxidase, and chemoattractant release may reduce the interaction of polymorphonuclear leukocyte with the vascular endothelium and by that potentially diminish the risk of progression of atherosclerosis development.

In vitro antioxidant and anti-inflammatory activities of extracts from Potentilla recta and its main ellagitannin, agrimoniin.

ETHNOPHARMACOLOGICAL RELEVANCE Potentilla recta is one of the numerous cinquefoil species growing in Poland. It is used in traditional medicine e.g. in the treatment of skin inflammation. AIM OF THE STUDY The purpose of the present study is to evaluate antioxidant and anti-inflammatory activities of extracts and subfractions of the P. recta herb (obtained by using solvents of different polarity) in in vitro systems as well as to examine their chemical composition. MATERIALS AND METHODS Antioxidant activities of the extracts, subfractions and agrimoniin were evaluated using DPPH and three other radicals (O2(-), H2O2, and HClO) generated in cell-free systems. Anti-hyaluronidase activity was measured by using the turbidimetric method. Inhibition of lipoxidase activity was measured spectrophotometrically, using linoleic acid as a substrate. The composition of the most active subfraction was determined using the HPLC-DAD-MS(n) method. RESULTS All tested samples showed scavenging activity against all the examined reactive species in a concentration-dependent manner. The highest scavenging activity against DPPH, H2O2 and HClO was observed in the ethyl acetate subfraction (PRE3) (SC50 ± SEM [μg/mL]: 25.39 ± 2.49, 1.79 ± 0.25 and 8.52 ± 1.16 respectively). It was only in the xanthine/xanthine oxidase system that the antioxidation potential of the diethyl ether subfraction (PRE2) (SC50 ± SEM [μg/mL]: 6.59 ± 1.33) was higher than that of the subfraction PRE3 (SC50 ± SEM [μg/mL]: 8.57 ± 1.37). Also, in the studies of lipoxidase and hyaluronidase inhibition activity the strongest effect was observed for PRE3, with IC50 [μg/mL] = 86.31 ± 5.46, and 12.99 ± 1.31, respectively. The chromatographic method (HPTLC-DPPH) revealed that the principal substance responsible for the activity, is a tannin like compound. Isolated agrimoniin showed significant reactive oxygen species scavenging activity and significant enzyme inhibition activity (including xanthine oxidase inhibition activity). Agrimoniin exerted the strongest scavenging activity against H2O2 (SC50 ± SEM [μM]: 0.20 ± 0.01). This compound also significantly inhibited the enzymatic activity of lipoxidase (IC50 [μM] = 36.47 ± 1.29), and, particularly, of hyaluronidase (IC50 [μM] = 2.65 ± 0.40). CONCLUSIONS The strong scavenging activity against H2O2, and the inhibition of the enzymatic activity of lipoxidase, and particularly, hyaluronidase observed for the tested subfractions and agrimoniin, partly explain the beneficial effects of P. recta in treatment of skin inflammation.

Effects of Penta‐O‐galloyl‐β‐D‐glucose on Human Neutrophil Function: significant Down‐Regulation of L‐selectin Expression

Penta‐O‐galloyl‐β‐D‐glucose (PGG) occurrs in high concentrations in medicinal herbs such as Rhus chinensis, Paeonia suffruticosa, Acer truncatum and Terminalia chebula, which demonstrate anti‐inflammatory activity. We investigated the effect of PGG on stimulated and non‐stimulated neutrophils in processes which included reactive oxygen species generation (ROS), metalloproteinase‐9 and interleukin‐8 secretion (IL‐8), β2 integrin (CD11b) and L‐selectin (CD62L) expression and apoptosis. In concentrations of 5 μM–20 μM, PGG demonstrated statistically significant inhibition of ROS generation, IL‐8 secretion and β2 integrin expression in stimulated neutrophils. The inhibition of L‐selectin expression by PGG resulted in prevention in neutrophils’ endothelial attachment. The result obtained may explain the anti‐inflammatory activity of this compound and underline the contribution of PGG in the activity of PGG rich plant extracts. Copyright

Oleacein enhances anti-inflammatory activity of human macrophages by increasing CD163 receptor expression.

BACKGROUND Oleacein (dialdehydic form of decarboxymethyl elenolic acid linked to hydroxytyrosol; 3,4-DHPEA-EDA) have been proven to possess antioxidant and anti-inflammatory activity. PURPOSE In this study, we examined whether oleacein could increase CD163 and IL-10 receptor expression as well as HO-1 intracellular secretion in human macrophages. METHODS Effect of oleacein (10 and 20 μmol/l) or oleacein together with complexes of haemoglobin (Hb) and haptoglobin 1-1 (Hp11) or haptoglobin 2-2 (Hp22) on expression of IL-10 and CD163 receptor was determined by Flow Cytometry. Expression of CD163mRNA was measured by real-time quantitative RT-PCR. Heme oxygenase 1 (HO-1) intracellular secretion in macrophages was investigated by enzyme-linked immunosorbent assay (ELISA). RESULTS Oleacein (OC) together with complexes HbHp11 or HbHp22 stimulated the expression of CD163 (30-100-fold), IL-10 (170-300-fold) and HO-1 secretion (60-130-fold) after 5 days of coincubation. The 2-fold (24 h), 4-fold (48 h) increase of CD163 mRNA level and its final (72 h) decrease was also observed. CONCLUSION Our results suggested that oleacein enhances anti-inflammatory activity of complexes haemoglobin with haptoglobin 1-1 and 2-2 and could play a potential role in the prevention of inflammatory disease related to atherosclerosis.

Hydroxycinnamoyl derivatives and secoiridoid glycoside derivatives from Syringa vulgaris flowers and their effects on the pro-inflammatory responses of human neutrophils

Thirteen new compounds including caffeoyl-glucaric and p-coumaroyl-altraric acid derivatives, one monoterpenoid glucoside, four secoiridoid glycosides, and three hydroxycinnamoyl phenylpropanoid glycosides esterified with an oleoside 11-methyl ester along with fifteen known compounds were isolated from flowers of Syringa vulgaris L. (Oleaceae). Their structures were elucidated by high-resolution spectroscopic methods. The tested compounds were able to decrease the production of reactive oxygen species. Moreover, oleoechinacoside (13), demethylhydroxyoleonuezhenide (14), demethyloleonuezhenide (15), syringaoleoacteoside (25) and oleoacteoside (26) at the concentration of 50μM, moderately suppressed the LPS-stimulated release of pro-inflammatory chemokine IL-8 and TNF-α from human neutrophils. Moreover, oleonuezhenide (12), oleoside 11-methyl ester (16) and oleoacteoside (26) at the concentration of 50μM were able to induce the surface expression of interleukin 10 receptor, which is suppressed by the incubation of monocyte/macrophage cells with LPS.

Lignans From Forsythia x Intermedia Leaves and Flowers Attenuate the Pro-inflammatory Function of Leukocytes and Their Interaction With Endothelial Cells

Aim of the study: Taking into account that overactivated leukocytes are an important factor in the development of many chronic diseases, we investigated the activity of phytochemically characterized (HPLC-DAD-MSn) extracts from forsythia leaves and flowers on the pro- and anti-inflammatory functions of leukocytes (effects on IL-1β, IL-8, TNF-α, and TGFβ release) and their adherence to endothelial cells. Using bio-guided fractionation, we isolated the active compounds and determined their biological activity, and we included the positive control quercetin. Methods: The effect on IL-1β, TNF-α, IL-8, and TGF-α production by leukocytes was measured by enzyme-linked immunosorbent assay (ELISA). The surface expression of adhesion molecules was analyzed with flow cytometry, and the neutrophil attachment to the endothelial cells was assessed fluorimetrically. The effects on p38MAPK, ERK1/2 and JNK phosphorylation were determined using western blots. Results: Leaf extracts had the effect of decreasing TNF-α production in neutrophils and monocyte/macrophage cells. The bio-guided fractionation led to the isolation of the following lignan aglycones: (+)-pinoresinol, (+)-epipinoresinol, (−)-matairesinol, (+)-phillygenin, and (−)-arctigenin. Only phillygenin was able to stimulate the anti-inflammatory function of macrophages by inducing TGF-β release and IL-10 receptor surface expression. Arctigenin, phillygenin, and a metabolite produced by the gut microbiota, enterolactone, decreased TNF-α and IL-1β production and neutrophil adhesion to endothelial cells, probably by attenuating the p38 and ERK kinase pathways. Conclusion: Forsythia x intermedia is a valuable source of active lignans, which may be potential candidates for treating inflammatory diseases that are associated with the excessive production of cytokines such as TNF-α and IL-1β.

Oleacein may inhibit destabilization of carotid plaques from hypertensive patients. Impact on high mobility group protein-1

BACKGROUND In patients with hypertension the haemorrhage into carotid atherosclerotic plaque increases risk of plaque destabilization and rupture. Our previous study showed that oleacein, a secoiridoid present in extra virgin olive oil, enhanced uptake of haemoglobin-haptoglobin complex and change macrophage phenotype from pro-inflammatory M1 to anti-inflammatory M2. PURPOSE The aim this study was to investigate a potential role of oleacein in attenuation of carotid plaque destabilisation ex vivo. METHODS Samples of atherosclerotic plaque were harvested from 20 patients with hypertension /11 women and 9 men/, who underwent carotid endarterectomy after transient ischemic attacks. Matching pieces of each plaque were incubated with increased concentration of pure oleacein /range 0-20 µM/ for 24 h. HMGB1, MMP-9, MMP-9/NGAL, TF and IL-10, as well as HO-1 secretion from plaque was measured by enzyme-linked immunosorbent assay /ELISA/. Statistical significance was set at P < 0.05 and P < 0.001. RESULTS Oleacein at the concentrations of 10 and 20 µM significantly (P < 0.001) decreased secretion of HMGB1 (up 90%), MMP-9 (up to 80%), MMP-9/NGAL complex (up to 80%) and TF (more than 90%) from the treated plaque, as compared to control. At the same time IL-10 and HO-1 release increased by more than 80% (P < 0.001). CONCLUSION Our results indicate that oleacein possess ability to attenuate the destabilization of carotid plaque and could be potentially useful in the reduction of ischemic stroke risk.