Ellagitannins from Rubus berries for the control of gastric inflammation: in vitro and in vivo studies.

Ellagitannins have shown anti-inflammatory and anti-Helicobacter pylori properties; however, their anti-inflammatory activity at gastric level was not previously investigated. The aim of this research was to evaluate the effects of ellagitannins from Rubus berries on gastric inflammation. Ellagitannin enriched extracts (ETs) were prepared from Rubus fruticosus L. (blackberry) and Rubus idaeus L. (raspberry). The anti-inflammatory activity was tested on gastric cell line AGS stimulated by TNF-α and IL-1ß for evaluating the effect on NF-kB driven transcription, nuclear translocation and IL-8 secretion. In vivo the protective effect of ellagitannins was evaluated in a rat model of ethanol-induced gastric lesions. Rats were treated orally for ten days with 20 mg/kg/day of ETs, and ethanol was given one hour before the sacrifice. Gastric mucosa was isolated and used for the determination of IL-8 release, NF-kB nuclear translocation, Trolox equivalents, superoxide dismutase and catalase activities. In vitro, ETs inhibited TNF-α induced NF-kB driven transcription (IC50: 0.67-1.73 µg/mL) and reduced TNF-α-induced NF-kB nuclear translocation (57%-67% at 2 µg/mL). ETs inhibited IL-8 secretion induced by TNF-α and IL-1ß at low concentrations (IC50 range of 0.7-4 µg/mL). Sanguiin H-6 and lambertianin C, the major ETs present in the extracts, were found to be responsible, at least in part, for the effect of the mixtures. ETs of blackberry and raspberry decreased Ulcer Index by 88% and 75% respectively and protected from the ethanol induced oxidative stress in rats. CINC-1 (the rat homologue of IL-8) secretion in the gastric mucosa was reduced in the animals receiving blackberry and raspberry ETs. The effect of ETs on CINC-1 was associated to a decrease of NF-κB nuclear translocation in ETs treated animals. The results of the present study report for the first time the preventing effect of ETs in gastric inflammation and support for their use in dietary regimens against peptic ulcer.

An amino acids mixture improves the hepatotoxicity induced by acetaminophen in mice.

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, but at high dose it leads to undesirable side effects, such as hepatotoxicity and nephrotoxicity. The aim of this study was to evaluate the protective role of DDM-GSH, a mixture of L-cysteine, L-methionine, and L-serine in a weight ratio of 2 : 1 : 1, in comparison to N-acetylcysteine (NAC), against acetaminophen- (APAP-) induced hepatotoxicity in mice. Toxicity was induced in mice by the intraperitoneal (ip) administration of low dose (2 mmol/kg) or high dose (8 mmol/kg) of APAP. DDM-GSH (0.4 to 1.6 mmol/kg) was given ip to mice 1 h before the APAP administration. The same was done with NAC (0.9 to 3.6 mmol/kg), the standard antidote of APAP toxicity. Mice were sacrificed 8 h after the APAP injection to determine liver weight, serum alanine aminotransferase (ALT), and total glutathione (GSH) depletion and malondialdehyde (MDA) accumulation in liver tissues. DDM-GSH improved mouse survival rates better than NAC against a high dose of APAP. Moreover, DDM-GSH significantly reduced in a dose-dependent manner not only APAP-induced increases of ALT but also APAP-induced hepatic GSH depletion and MDA accumulation. Our results suggest that DDM-GSH may be more potent than NAC in protecting the liver from APAP-induced liver injury.

Interaction between ticlopidine or warfarin or cardioaspirin with a highly standardized deterpened Ginkgo biloba extract (VR456) in rat and human.

Ginkgo biloba is available in Europe as an over-the-counter drug and it is reported to cause hemorrhage when co-administered with other anti-platelet agents. We set out to study the interactions of ticlopidine with Ginkgo biloba extract or VR456, a new highly standardized deterpened extract from Ginkgo biloba leaves. Male Wistar rats were used to study the effects of ticlopidine (50-100 mg/kg/day), given alone and in combination for 5 days with Ginkgo biloba extract (50 mg/kg/day) or VR456 (50 mg/kg/day), on bleeding time and ex vivo ADP-induced platelet aggregation measurements. In addition, human studies were performed with the compounds under investigation. Combined treatment of ticlopidine and undeterpened Ginkgo biloba extract increased anti-platelet effect and prolonged the bleeding time in the rat. On the contrary, the combination treatment of ticlopidine and VR456 increased anti-platelet effect but did not prolong bleeding time. Moreover, daily administration of 360 mg of VR456 for 14 days to ticlopidine-treated humans did not highlight any unwanted effect and did not alter PT/INR and PTT parameters. Same results have been also obtained in warfarin or in cardioaspirin-treated patients. These data point out the clear role played by the terpenoid, PAF-antagonist fraction of Ginkgo biloba extract in affecting bleeding risk in anticoagulant-treated subjects and suggest VR456 as a possible option treatment in geriatric people subjected to anticoagulant treatment where the use of standard Ginkgo biloba extracts are discouraged.

Anti-ischemic activity and endothelium-dependent vasorelaxant effect of hydrolysable tannins from the leaves of Rhus coriaria (Sumac) in isolated rabbit heart and thoracic aorta.

The aim of this work was to investigate the cardioprotective activity of hydrolysable gallotannins from Rhus coriaria L. leaves extract (RCLE) in isolated rabbit heart preparations, submitted to low-flow ischemia/reperfusion damage. RCLE induces a dose-dependent normalization of coronary perfusion pressure (CPP), reducing left ventricular contracture during ischemia, and improving left ventricular developed pressure and the maximum rate of rise and fall of left ventricular pressure at reperfusion. Creatinine kinase (CK) and lactate dehydrogenase (LDH) outflow were significantly reduced during reperfusion. In parallel there was a rise in the release of the cytoprotective 6-ketoprostaglandin F (1alpha) (6-keto-PGF (1alpha)) and a decrease of tumor necrosis factor-alpha (TNF-alpha), both significant only at the highest RCLE concentrations (150-500 microg/mL). The vasorelaxant activity of RCLE was studied in isolated rabbit aorta rings precontracted with norepinephrine (NE) with and without endothelium. The vasorelaxation induced by RCLE was predominantly endothelium-dependent as demonstrated by the loss of RCLE vasorelaxant ability in i) de-endothelized rings and ii) in intact aortic rings after pretreatment with NG-monomethyl- L-arginine (L-NMMA) and 1 H-[1.2.4]oxadiazolo[4.3- A]quinoxalin-1-one (ODQ). The inhibition of vasorelaxation in intact rings by indomethacin (INDO) demonstrates the ability of RCLE to modulate the coronary endothelium cyclooxygenase (COX) pathway. The K-ATP channel antagonist glibenclamide (GLIB) was ineffective. The antioxidant activity of RCLE, investigated in the 1,1-diphenyl-2-picrylhydrazyl (DPPH) model and in living cell systems (rat erythrocytes), was stronger than that of gallic acid, ascorbic acid and trolox. The structure of its main bioactive constituents, profiled by HPLC-ESI-HR-S, comprised a mixture of polygalloylated D-glucopyranose with different degrees of galloylation and 3- O-methylgallic acid. The cardiovascular protective effect of RCLE seems to be due to an interplay of different factors: COX pathway activation, TNF-alpha inhibition, endothelial nitric oxide synthase (eNOS) activation, and free radical and ROS scavenging.

Anti-inflammatory and gastrointestinal effects of a novel diclofenac derivative.

S-diclofenac (2-[(2,6-dichlorophenyl)amino]benzeneacetic acid 4-(3H-1,2,dithiol-3-thione-5-yl)phenyl ester; ACS 15) is a novel molecule comprising a hydrogen sulfide (H2S)-releasing dithiol-thione moiety attached by an ester linkage to diclofenac. S-diclofenac administration inhibited lipopolysaccharide-induced inflammation (as evidenced by reduced lung and liver myeloperoxidase activity) and caused significantly less gastric toxicity than diclofenac. S-diclofenac did not affect blood pressure or heart rate of the anesthetized rat. S-diclofenac administration downregulated expression of genes encoding enzymes which synthesize nitric oxide, prostanoids, and H2S; reduced plasma IL-1beta/TNF-alpha; and elevated plasma IL-10. Reduced liver NF-kappaB p65 and AP-1/c-fos DNA-binding activity was also observed. These effects were mimicked in large part by a combination of diclofenac plus an H2S-releasing moiety (ADT-OH). Incubation of S-diclofenac (100 microM) with rat plasma or liver homogenate caused a time-dependent release of H2S, which was inhibited by sodium fluoride (10 mM). Administration of S-diclofenac (47.2 micromol/kg, i.p.) to conscious rats significantly increased plasma H2S concentration (at 45 min and 6 h). We propose that H2S release from S-diclofenac in vivo contributes to the observed effects.

LC-MS characterization of terpene lactones in plasma of experimental animals treated with Ginkgo biloba extracts Correlation with pharmacological activity.

Liquid chromatography/atmospheric pressure chemical ionization ion trap mass spectrometry (LC/APCI-ITMS) was applied to determine the concentration of terpene lactone in plasma of guinea pigs after chronic administration of Ginkgo biloba extract enriched in ginkgoterpenes in free form (IDN 5380) or complexed with soy phosphlipids (IDN 5381). Oral treatment of the animals with ginkgoterpenes resulted to inhibit the bronchoconstriction (ITP) and the concomitant increase of the levels of thromboxane B2 (TXB2) in the circulation caused by histamine (HIST) and platelet activating factor (PAF) in normal guinea pigs or by ovalbumin (OA) in actively sensitized guinea pigs. To compare the protective activities of G. biloba forms (IDN 5380 and IDN 5381), ED50 and dose ratio (DR) values for both parameters (ITP and TXB2) were evaluated. The phytosomic form (IDN 5381) significantly reduced (two- to four-fold as compared to free form, P < 0.001) the HIST, PAF or OA-induced airway changes and TXB2 release. In addition it has been observed that the absence of ginkgolide C (GC) in plasma samples (in human and animals) was due to its rapid methylation.

Wild artichoke prevents the age-associated loss of vasomotor function.

Endothelial dysfunction, which is more often observed in conduit arteries such as the aorta, carotid, femoral, and brachial arteries, is largely due to alterations in cellular signal transduction initiated by an escalating cycle of damage triggered by oxidative stress. This phenomenon is exacerbated in the elderly, where a progressive loss of vascular endothelial function and concurrent loss of vasomotor control is frequent. In a previous study, we demonstrated that the wild artichoke (Cynara cardunculus) is able to increase the production of the vasorelaxant factor nitric oxide by cultured aortic endothelial cells. We now extended that study to verify (1) the vasorelaxant potential of C. cardunculus on isolated rat aortic rings and (2) whether the vasomodulating properties of C. cardunculus are maintained in vivo, after administration to aged rats. The results demonstrate that the wild artichoke and its main components, namely, luteolin and apigenin, improve aortic relaxation when added to the incubation bath. Moreover, the feeding of wild artichoke [10 mg (kg of polyphenols)(-1) day(-1)] to aged rats significantly restores proper vasomotion, to a degree similar to that observed in young animals. This study provides further justification to the advice to consume wild greens as part of a balanced diet and suggests that close attention should be paid to the diet of the elderly, because it can effectively modulate important parameters of cardiovascular risk.

Liquid chromatography/atmospheric pressure chemical ionization ion trap mass spectrometry of terpene lactones in plasma of animals.

Liquid chromatography/atmospheric pressure chemical ionization ion trap mass spectrometry (LC/APCI-ITMS) was applied to evaluate the bioavailibility of two different forms (free and complexed with soy phospholipids) of pure bilobalide and ginkgolide B in rats after acute administration. The same technique was used to measure the levels of ginkgolide A, B and bilobalide in plasma of guinea pigs fed Ginkgo biloba extract enriched in terpene lactones after chronic administration. The ratio R(P)/R(A) increased two to four times after the administration in the phytosomic form, where R(P) and R(A) represent the percentage ratio between the concentration of each terpene lactone in plasma and in the administrated form, respectively.

The water-soluble vitamin E analogue Trolox protects against ischaemia/reperfusion damage in vitro and ex vivo. A comparison with vitamin E.

We investigated the activities, both in vitro and ex vivo, of the water-soluble vitamin analogue Trolox in a model of isolated heart ischaemia-reperfusion and we compared them with those of alpha -tocopherol. Isolated rat hearts were perfused with Krebs-Henseleit solution. For in vitro experiments, the hearts were perfused with Trolox (20 micromol l (-1)) and were subsequently subjected to 20 min of global ischaemia and 40 min of post-ischaemic reperfusion. For ex vivo experiments, either Trolox or alpha -tocopherol (10 mg kg(-1) ) were administered by gastric gavage 60 min before excision of the heart. Various parameters of cardiac function were evaluated and oxidative damage was assessed by TBARS production. Trolox significantly enhanced cardiac recovery after ischaemia/reperfusion, both when it was perfused in vitro and after its oral administration. Vitamin E also favourably affected cardiac recovery but did so less effectively than Trolox. Further, the production of TBARS was significantly inhibited by Trolox, suggesting that its beneficial effects are due to its antioxidant activities. In conclusion, perfusion of isolated rat hearts with low concentrations of the water-soluble vitamin E analogue Trolox effectively enhances cardiac recovery after a 20 min ischaemic period and decreases reperfusion-induced oxidative damage. Interestingly, Trolox retains its activities after oral administration. Vitamin E, when administered per os, also increases functional recovery but does so less potently than Trolox. These differential effects are likely due to the scavenging, by Trolox, of reactive oxygen species generated in the water phase.