Inflammatory Effects of the Plant Protection Product Stifenia (FEN560) on Vertebrates.

Plant defense stimulators (PDSs) rely on the activation of plant innate immunity in order to protect crops against various pests. These molecules are thought to be a safer alternative to classical plant protection products. Given that innate immune systems share common features in plants and vertebrates, PDS can potentially cross-react with innate immunity of non-target organisms. To test this hypothesis, we studied effects of the commercial PDS Stifenia (FEN560), which is composed of crushed fenugreek seeds. We tested various concentrations of Stifenia (0.03-1 mg mL-1) on human peripheral blood mononuclear cells and checked, 20 h later, cell metabolic activity (MA) using XTT assay, cell death by flow cytometry analysis, and IL-1ß inflammatory cytokine released in the culture medium using ELISA. Stifenia induced a general decrease of the cell MA, which was concomitant with a dose-dependent release of IL-1ß. Our results highlight the activation of human immune cells. The inflammatory effect of Stifenia was partially inhibited by pan-caspase inhibitor. Accordingly, Stifenia induced the release of p20 caspase-1 fragment into the culture medium suggesting the involvement of the NLRP3 inflammasome. Furthermore, we observed that Stifenia can induce cell death. We also tested the effect of Stifenia on Zebrafish larvae. After 24 h of exposure, Stifenia induced a dose-dependent IL-1ß and TNFα gene expression. The human-cell-based approach developed in this work revealed a high sensitivity concerning inflammatory properties of a plant protection product. These tests could be routinely used to screen the potential adverse effects of this type of compounds. Finally, our results suggest a potential danger of using extensively certain PDS for crop protection.

Triterpenoid saponins from the roots of Spergularia marginata.

Phytochemical investigations of the roots of Spergularia marginata had led to the isolation of four previously undescribed triterpenoid saponins, a known one and one spinasterol glycoside. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-ß-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 â†’ 2)-α-L-rhamnopyranosyl-(1 â†’ 3)-ß-D-xylopyranosyl-(1 â†’ 4)-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L- arabinopyranosyl ester, 3-O-ß-D-glucopyranosyl-(1 â†’ 3)-ß-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 â†’ 2)-α-L-rhamnopyranosyl-(1 â†’ 3)-ß-D-xylopyranosyl-(1 â†’ 4)-α-L-rhamnopyranosyl-(1 â†’ 2)- α-L-arabinopyranosyl ester, 3-O-ß-D-glucopyranosyl-(1 â†’ 4)-3-O-sulfate-ß-D-glucuronopyranosyl echinocystic acid 28-O-α-L-arabinopyranosyl-(1 â†’ 2)-α-L-rhamnopyranosyl-(1 â†’ 3)-ß-D-xylopyranosyl-(1 â†’ 4)-α-L-rhamnopyranosyl-(1 â†’ 2)-α-L-arabinopyranosyl ester, and 3-O-ß-D-glucopyranosyl-(1 â†’ 4)-ß-D-glucuronopyranosyl 21-O-acetyl acacic acid. Their cytotoxicity was evaluated against two human cancer cell lines SW480 and MCF-7. The most active compound showed a cytotoxicity with IC50 14.2 ± 0.8 µM (SW480), and 18.7 ± 0.8 µM (MCF-7), respectively.

New pregnane and phenolic glycosides from Solenostemma argel.

From the aerial parts, pericarps and roots of Solenostemma argel, three new pregnane glycosides (1-3) with two known ones and a new phenolic glycoside (4) have been isolated. Their structures were established by extensive 1D - and 2D NMR and mass spectroscopic analysis. The cytotoxicity of all compounds was evaluated against two human tumor cell lines (SW 480, MCF-7), but none of them was active in the concentration range 0.9-59.0µM. Compounds 2 and the known argeloside F at non toxic concentrations for the PBMCs (27.3µM and 27.6µM, respectively) significantly decreased the Il-1ß production by LPS-stimulated PBMCs. All isolated compounds showed a significant antioxidant potential with ORAC values in the concentration range 3481-9617µmoleq. Trolox/100g.

Microwave-assisted synthesis, anti-inflammatory and anti-proliferative activities of new maslinic acid derivatives bearing 1,5- and 1,4-disubstituted triazoles.

In this work, 40 analogs with a natural maslinic acid core (from Olea europaea L.) and various aromatic azides were synthesized. A regiospecific, facile and practical synthesis of 1,5-triazolyl derivatives by Ru(II)-catalyzed azide-alkyne cycloaddition (RuAAC), and mono-, bis- and tri-1,4-triazolyl derivatives by Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) was described. All the reactions were assisted by microwave irradiation avoiding toxic reagents and solvents. The new products were obtained from the reaction mixture by simple purification in almost quantitative yields and the reaction times were in general shorter than those reported in the literature. Their chemical structures were elucidated on the basis of extensive spectroscopic methods including ESI-HRMS, 1D and 2D-NMR. Most of the compounds were evaluated for their anti-inflammatory activity using LPS-stimulated human peripheral blood mononuclear cells (PBMCs) and antiproliferative effects towards cultured murine EMT-6 (Breast) and human SW480 (colon) cancer cell lines.

Steroidal saponins from Chlorophytum deistelianum.

Phytochemical investigation of the aerial parts of Chlorophytum deistelianum led to the isolation of four previously undescribed steroidal saponins called chlorodeistelianosides A-D with five known ones. Their structures were established mainly by extensive 1D and 2D NMR spectroscopic techniques and mass spectrometry as (25R)-3ß-[(ß-D-glucopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→4)]-ß-D-xylopyranosyl-(1→3)-[ß-D-glucopyranosyl-(1→2)]-ß-D-glucopyranosyl-(1→4)-ß-D-galactopyranosyl)oxy]-5α-spirostan-12-one, (24S,25S)-24-[(ß-D-glucopyranosyl)oxy]-3ß-[(ß-d-glucopyranosyl-(1→2)-[ß-D-xylopyranosyl-(1→3)]-ß-D-glucopyranosyl-(1→4)-ß-D-galactopyranosyl)oxy]-5α-spirostan-12-one, (25R)-26-[(ß-D-glucopyranosyl)oxy]-2α-hydroxy-22α-methoxy-5α-furostan-3ß-yl ß-D-glucopyranosyl-(1→2)-[ß-D-xylopyranosyl-(1→3)]-ß-D-glucopyranosyl-(1→4)-ß-D-galactopyranoside, and (25R)-26-[(ß-D-glucopyranosyl)oxy]-3ß-[(ß-D-glucopyranosyl-(1→2)-[ß-D-xylopyranosyl-(1→3)]-ß-D-glucopyranosyl-(1→4)-ß-D-galactopyranosyl)oxy]-5α-furost-20(22)-en-12-one. Cytotoxicity of most compounds was evaluated against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2). Among them, three known spirostane-type glycosides exhibited cytotoxicity on both cell lines with IC50 ranging from 8 to 10 µM.

Oleanolic acid and hederagenin glycosides from Weigela stelzneri.

Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-xylopyranosyloleanolic acid, 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-glucopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-xylopyranosyloleanolic acid, 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid 28-O-ß-D-glucopyranosyl-(1 → 6)-ß-D-glucopyranosyl ester, and 3-O-ß-D-glucopyranosyl-(1 → 2)-α-L-arabinopyranosylhederagenin 28-O-ß-D-xylopyranosyl-(1 → 6)-[α-L-rhamnopyranosyl-(1 → 2)]-ß-D-glucopyranosyl ester. The majority of the isolated compounds were evaluated for their cytotoxicity against two tumor cell lines (SW480 and EMT-6), and for their anti-inflammatory activity. The compounds 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid and 3-O-ß-D-glucopyranosyl-(1 → 2)-[ß-D-xylopyranosyl-(1 → 4)]-ß-D-xylopyranosyl-(1 → 4)-ß-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-ß-D-xylopyranosyloleanolic acid exhibited the strongest cytotoxicity on both cancer cell lines. They revealed a 50% significant inhibitory effect of the IL-1ß production by PBMCs stimulated with LPS at a concentration inducing a very low toxicity of 23% and 28%, respectively.

A New Aromatic Compound from the Stem Bark of Terminalia catappa.

A new aromatic compound 3,4,5-trimethoxyphenyl-1-O-(4-sulfo)-ß-D-glucopyranoside (1), in addition to two triterpenoid saponins (chebuloside II, arjunoglucoside II), two triterpenes (arjunolic acid and 3-betulinic acid) and sitosterol-3-O-ß-D-glucopyranoside have been isolated from the barks of Terminalia catappa. Their structures have been established on the basis of spectroscopic techniques (1D/2D NMR) and MS. Their cytotoxicity and antiinflammatory activity, together with the antioxidant capacity of compound 1 were also evaluated.

Triterpenoid saponins from the roots of two Gypsophila species.

Two triterpenoid saponins with two known ones have been isolated from the roots of Gypsophila arrostii var. nebulosa, and two new ones from the roots of Gypsophila bicolor. Their structures were established by extensive NMR and mass spectroscopic techniques as 3-O-ß-d-galactopyranosyl-(1→2)-[ß-d-xylopyranosyl-(1→3)]-ß-d-glucuronopyranosylquillaic acid 28-O-ß-d-xylopyranosyl-(1→4)-[ß-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[ß-d-glucopyranosyl-(1→4)]-ß-d-fucopyranosyl ester (1), 3-O-ß-d-galactopyranosyl-(1→2)-[ß-d-xylopyranosyl-(1→3)]-ß-d-glucuronopyranosylgypsogenin 28-O-ß-d-xylopyranosyl-(1→4)-[ß-d-glucopyranosyl-(1→3)]-α-l-rhamnopyranosyl-(1→2)-[ß-d-glucopyranosyl-(1→4)]-ß-d-fucopyranosyl ester (2), 3-O-ß-d-galactopyranosyl-(1→2)-[ß-d-xylopyranosyl-(1→3)]-ß-d-glucuronopyranosylgypsogenin 28-O-ß-d-xylopyranosyl-(1→3)-ß-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-[(4-O-acetyl)-ß-d-quinovopyranosyl-(1→4)]-ß-d-fucopyranosyl ester (3), gypsogenic acid 28-O-ß-d-glucopyranosyl-(1→3)-{6-O-[3-hydroxy-3-methylglutaryl]-ß-d-glucopyranosyl-(1→6)}-ß-d-galactopyranosyl ester (4). Three compounds were evaluated against one human colon cancer cell line SW480 and one rat cardiomyoblast cell line H9c2.

In vitro inflammatory/anti-inflammatory effects of nitrate esters of purines.

Six purine analogues bearing a nitrate ester group (potential NO donor) were tested on human THP-1 macrophages to investigate their effects on the inflammatory response. Only three analogues increased the basal level of IL-1ß. Two analogues exacerbated the inflammatory response induced by ATP but not that induced by H2O2. Only 6-[4-(6-nitroxyacetyl)piperazin-1-yl]-9H-purine (compound MK128) abolished ATP or H2O2-induced IL-1ß production in the culture medium. Similar results were reproduced on macrophages differentiated from buffy coats and stimulated with LPS. MK128 was the only analogue to release NO and leading to nitrite formation in the culture medium. The EC50 for inhibition of induced IL-1ß production by the cells was estimated to be 10-12µg/ml (about 36µM) and corresponded to the production of around 30µM nitrites in the culture medium. This anti-inflammatory effect of MK128 was mimicked by trinitrin used in 10 fold higher concentrations. Preincubation of cells with NO trapper cPTIO partially abolished the beneficial effect of MK128 while MK137, a ONO2 deprived analogue of MK128, was not able to inhibit induced IL-1ß production and proved to be inflammatory. Moreover, purinergic channel inhibitors (oATP and U73122) inhibited the MK137 inflammatory effect. Finally, MK128 reduced the quantity of p20 caspase-1 produced in the culture medium. We suggest that MK128 inhibits IL-1ß production via NO production and subsequent inflammasome component nitrosylation. On the opposite MK137, deprived from ONO2 group, could act as agonist of purinergic receptors and could thus activate inflammasome.

Triterpenoid saponins from Polycarpaea corymbosa Lamk. var. eriantha Hochst.

Four triterpenoid saponins (1-4) were isolated from Polycarpaea corymbosa Lamk. var. eriantha Hochst along with the known apoanagallosaponin IV (5). Their structures were elucidated by spectroscopic data analysis. Among the compounds 1, 3-5 which were evaluated for their cytotoxicity against three tumor cell lines (SW480, DU145 and EMT6), compound 1 exhibited cytotoxicity with IC50 values ranging from 4.61 to 22.61 µM, which was greater than that of etoposide. Compound 2 was tested only against SW480 and a cardiomyoblast cell line (H9c2), and was inactive.

Cytotoxic steroidal glycosides from Allium flavum.

Three new spirostane-type glycosides (1-3) were isolated from the whole plant of Allium flavum. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-galactopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (1), (20S,25R)-2α-hydroxyspirost-5-en-3ß-yl O-ß-D-xylopyranosyl-(1→3)-[ß-D-glucopyranosyl-(1→2)]-ß-D-galactopyranosyl-(1→4)-ß-D-galactopyranoside (2), and (20S,25R)-spirost-5-en-3ß-yl O-α-L-rhamnopyranosyl-(1→4)-[ß-D-glucopyranosyl-(1→2)]-ß-D-glucopyranoside (3). The three saponins were evaluated for cytotoxicity against a human cancer cell line (colorectal SW480).

Acylated oleanane-type saponins from Ganophyllum giganteum.

Five oleanane-type saponins, 3-O-ß-D-glucuronopyranosylzanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (1), 3-O-ß-D-glucopyranosylzanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (2), zanhic acid 28-O-ß-D-xylopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-(4-O-acetyl)-ß-D-fucopyranosyl ester (3), zanhic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-ß-D-fucopyranosyl ester (4), medicagenic acid 28-O-α-L-rhamnopyranosyl-(1→2)-4-O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy]-ß-D-fucopyranosyl ester (5), were isolated from the root barks of Ganophyllum giganteum. Compounds 4 and 5 possessed an unusual substitution of the C-4 position of the ß-D-fucopyranosyl moiety by a C10 ester group formed by two symmetrical C5 nilic acid. From a chemotaxonomic point of view, their structures are in accordance with the previous saponins isolated from the Doratoxyleae tribe of the Sapindaceae family. Their cytotoxicity and anti-inflammatory activity were also evaluated.

New triterpenoid estersaponins from the root barks of Pittosporum verticillatum subsp. verticillatum and evaluation of cytotoxicities.

The phytochemical investigation of the root barks of Pittosporum verticillatum Bojer subsp. verticillatum led to the isolation of three new triterpene saponins, 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-R1-barrigenol (1), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-(2-acetoxy-2-methylbutanoyl)-28-O-acetyl-R1-barrigenol (2), 3-O-[ß-D-glucopyranosyl-(1→2)]-[α-L-arabinopyranosyl-(1→3)]-[α-L-arabinofuranosyl-(1→4)]-ß-D-glucuronopyranosyl-21-O-ß,ß-dimethylacryloyl-22-O-angeloyl-R1-barrigenol (3), and one known saponin senaciapittoside B (4). Their structures were elucidated mainly by 1D- and 2D-NMR spectroscopy and HRESIMS. Compounds 1-4 were evaluated for their cytotoxicity against one human cancer cell line (SW480) and one rat cardiomyoblast cell line (H9c2).

Steroidal saponins from Dracaena marginata.

Three new steroidal saponins and ten known ones were isolated from the bark of Dracaena marginata, along with two known steroidal saponins from the roots. Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments and mass spectrometry as (25R)-26-(beta-D-glucopyranosyloxy)3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (1), (25R)-26-(beta-D-glucopyranosyloxy)-3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (2), and (25S)-3beta-hydroxyspirost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (3).

Solanum incanum and S. heteracanthum as sources of biologically active steroid glycosides: confirmation of their synonymy.

A new spirostanol saponin (1), along with four known saponins, dioscin (2), protodioscin (3), methyl-protodioscin (4), and indioside D (5), and one known steroid glycoalkaloid solamargine (6) were isolated from the two synonymous species, Solanum incanum and S. heteracanthum. The structure of the new saponin was established as (23S,25R)-spirost-5-en-3ß,23-diol 3-O-{ß-D-xylopyranosyl-(1→2)-O-α-L-rhamnopyranosyl-(1→4)-[O-α-L-rhamnopyranosyl-(1→2)]-ß-D-glucopyranoside}, by using a combination of 1D and 2D NMR techniques including (1)H, (13)C, COSY, TOCSY, NOESY, HSQC and HMBC experiments and by mass spectrometry. The compounds 1, 3, 4 and 5 were evaluated for cytotoxicity against five cancer cell lines and for antioxidant and cytoprotective activity.

Postnatal overfeeding in rats leads to moderate overweight and to cardiometabolic and oxidative alterations in adulthood.

In contrast to the masses of data on obesity, few data are available concerning the cardiometabolic and oxidative consequences of moderate overweight. The model of postnatal overfeeding (OF) induces an increase in body weight at weaning that remains during adult life. Litters of Wistar rats were either maintained at 12 pups (normal-fed group, NF), or reduced to 3 pups at birth in order to induce OF. At 6 months of age, metabolic parameters, circulating oxidative stress and aortic and coronary vasoreactivity were assessed. Cardiac susceptibility to ischemia-reperfusion injury was also evaluated ex vivo as were markers of cardiac remodeling. OF led to an increase in body weight at weaning (+50%); the increase in body weight persisted throughout adult life, but was less marked (+10%). Significant increases in plasma levels of fasting glucose, insulin and leptin were found in OF rats. An increase in both plasma hydroperoxides and cardiac superoxide dismutase activity and a decrease in plasma ascorbate were found in OF rats. Vasoreactivity was not modified, but ex vivo, after 30 min of ischemia, isolated hearts from OF rats showed lower recovery of coronary flow along with a greater release of LDH. Studies on heart tissues showed an increase in collagen content and increased expression and activity of MMP-2. Our findings show that moderate overweight in adult rats, induced by postnatal overfeeding, leads to both metabolic and oxidative disturbances as well as a higher susceptibility to cardiac injury after ischemia ex vivo, which may be explained, at least in part, by ventricular remodeling.

General oxidative stress during doxorubicin-induced cardiotoxicity in rats: absence of cardioprotection and low antioxidant efficiency of alpha-lipoic acid.

To evaluate the effects of alpha-lipoic acid (AL) in a model of doxorubicin (DOX)-induced cardiotoxicity, male Wistar rats were treated with DOX (1 mg/kg/d; 10 d) in combination or not with AL (50 mg/kg/d; 15 d). Plasma oxidative stress was determined by hydroperoxides (ROOH) and the ascorbyl radical/ascorbate ratio. One and two months later, the functional parameters of the hearts were determined in vivo by catheterization and cardiac oxidative stress was assessed by malonedialdehyde (MDA) and O2*⁻ (dihydroethidium fluorescence) content in tissue. After two months, body weight was higher in the DOX-AL group than in DOX (+16%), but this was due to ascites. Histological liver alterations were observed in both the DOX and DOX-AL groups. Plasma ROOH concentrations decreased after 10 days of AL treatment, but were greater in both the DOX and DOX-AL groups. After two months, a decrease in the cardiac contractility index (-27% and -29%, respectively) and cardiac hypertrophy were observed in DOX and DOX-AL. These dysfunctions were associated with 1) a reduction in plasma ascorbate levels and an increase in the ascorbyl/ascorbate ratio and 2) an increase MDA and O2*⁻ content in cardiac tissue. In conclusion, a cumulative dose of 10 mg/kg doxorubicin induced functional alterations in the heart associated with plasma and cardiac oxidative stress. The co-administration of the antioxidant compound AL had no beneficial effects in this situation.

Effect of a chronic cholesterol-rich diet on vascular structure and oxidative stress in LDLR-/- mice.

AIMS: There is conflicting evidence regarding the relationship between hypercholesterolemia and oxidative stress in vessels. To test the potential relationship, a mouse model of hypercholesterolemia was used. METHODS: Low density lipoprotein receptor-deficient (LDLR(-/-)) and control (C57Bl/6) mice were fed a normal or (1.25%) high-cholesterol (HC) diet for 8 weeks, and the incidence of this chronic diet was evaluated on the degree of vascular oxidative stress and vascular structure (collagen content and lipid infiltration expressed in arbitrary units: AU=%/mm(2)). RESULTS: Animals treated with the HC diet presented an increase in lipid infiltration (0.35±0.13 vs. 1.7±0.18 control and 1.04±0.16 vs. 1.84±0.23 LDLR(-/-), AU p<0.05) associated with higher collagen content (control: 2.13±0.40 vs. 3.46±0.36 and LDLR(-/-): 2.37±0.36 vs. 3.79±0.60; AU p<0.05 red Sirius staining). Interestingly, ROS production in the aorta was only increased in the LDLR(-/-) +cholesterol group (0.17±0.04 and 0.16±0.05 in the control groups, 0.14±0.02 vs. 0.34±0.06 in the LDLR(-/-) groups, p<0.05). C57Bl/6 and LDLR(-/-) mice presented altered vascular structure associated with the rich cholesterol diet, which was not necessarily associated with increased oxidative stress. CONCLUSION: These findings highlight the complex interrelation between oxidative stress and lipid metabolism in the circulatory tract.

A cholesterol-rich diet improves resistance to ischemic insult in mouse hearts but suppresses the beneficial effect of post-conditioning.

BACKGROUND: Conflicting evidence is reported about the beneficial effects of post-conditioning (Post-C) in pathologic conditions. A pathologic mouse model of hypercholesterolemia was used. The study examined the effect of Post-Con cardiac recovery after the ischemia-reperfusion sequence and the effect of Post-Con on low-density lipoprotein receptor-deficient (LDLR(-/-)) mice and control animals. METHODS: LDLR(-/-) and C57bl/6 mice were fed for 8 weeks with a high-cholesterol (1.25%) or normal diet. The hearts were isolated and perfused on a working heart apparatus. The hearts underwent 20 minutes of global total ischemia, followed by 36 minutes of reperfusion. Post-Con was applied at the onset of reperfusion with three 10-second cycles of ischemia-reperfusion. Tissue injury was evaluated (triphenyl-tetrazolium chloride staining), and superoxide anion production was assessed (dihydroethidium). RESULTS: Post-ischemia recovery was very low in the control and LDLR(-/-) groups, and Post-C induced an increase in functional recovery (p < 0.05). The high-cholesterol groups showed better cardiac recovery, but Post-C did not accentuate this improvement. Post-C was associated with a significant reduction in tissue injury and superoxide production in LDLR(-/-) and C57bl/6 (p < 0.05), but these effects were not observed in animals fed the high-cholesterol diet. CONCLUSIONS: Our results demonstrated that control and LDLR(-/-) mice may be protected by Post-C, and an 8-week high-cholesterol diet led to improved recovery of the myocardium after the ischemia-reperfusion sequence in both series. However, the endogenous protective mechanism of Post-C appears to be lost in the presence of hypercholesterolemia.

Rapeseed protein in a high-fat mixed meal alleviates postprandial systemic and vascular oxidative stress and prevents vascular endothelial dysfunction in healthy rats.

High-saturated fat and high-sucrose meals induce vascular endothelial dysfunction, the early hallmark of atherogenesis. The impact of dietary protein on vascular homeostasis remains misunderstood. In this study, we investigated whether rapeseed protein, an emergent arginine- and cysteine-rich protein, can acutely modulate the onset of adverse effects induced by a high-saturated fat meal (HFM). In a series of crossover experiments, healthy rats received 3 HFM (saturated fat: 60%; sucrose: 20%; protein: 20% energy) with the protein source being either total milk protein (MP; control), rapeseed protein (RP), or MP supplemented with cysteine and arginine to the same level as in RP (MP+AA). Endothelium-related vascular reactivity, measured as an acetylcholine-induced transient decrease in blood pressure, and plasma triglycerides, hydroperoxides, cyclic GMP (cGMP), and free 3-nitrotyrosine were measured before and 2, 4, and 6 h after meals. Superoxide anion production, expressed as ethidine fluorescence, was measured in the aorta 6 h after meals. Whereas plasma triglycerides rose similarly in all meals, the decrease in vascular reactivity after MP was attenuated after MP+AA and entirely prevented after RP. The type of meal had no consistent effect on plasma cGMP and free 3-nitrotyrosine over the postprandial period. The postprandial increase in plasma hydroperoxides differed according to the meal, and concentrations were 43% lower 6 h after MP+AA and RP than after MP. Aortic superoxide anion production was 36% lower 6 h after RP than MP. These results show that substituting rapeseed protein for milk protein markedly reduces vascular and oxidative disturbances induced by an HFM and this may be mediated in part by cysteine and arginine.