epsilon-Viniferin

Biomed Res Int. 2014;2014:461756.

Bacteriostatic antimicrobial combination: antagonistic interaction between epsilon-viniferin and vancomycin against methicillin-resistant Staphylococcus aureus.[Pubmed: 24783205]

METHODS AND RESULTS:
The combined effect of epsilon-Viniferin and johorenol A with the standard antibiotics, vancomycin and linezolid, was assessed against MRSA ATCC 33591 and HUKM clinical isolate. The MIC value of epsilon-Viniferin against ATCC 33591 and johorenol A against both strains was 0.05 mg/mL whereas HUKM strain was susceptible to 0.1 mg/mL of epsilon-Viniferin. MDC study showed that only combination between epsilon-Viniferin and vancomycin was synergistic against ATCC 33591 (FICI 0.25) and HUKM (FICI 0.19). All the other combinations (epsilon-Viniferin-linezolid, johorenol A-vancomycin, and johorenol A-linezolid) were either indifferent or additive against both strains. However, despite the FICI value showing synergistic effect for epsilon-Viniferin-vancomycin, TKA analysis displayed antagonistic interaction with bacteriostatic action against both strains. As conclusion, epsilon-Viniferin can be considered as a bacteriostatic stilbenoid as it antagonized the bactericidal activity of vancomycin.
CONCLUSIONS:
These findings therefore disputed previous report that epsilon-Viniferin acted in synergism with vancomycin but revealed that it targets similar site in close proximity to vancomycin's action, possibly at the bacterial membrane protein.

J Agric Food Chem. 2013 Jul 24;61(29):7120-6.

Inhibition of Pseudomonas aeruginosa and Escherichia coli O157:H7 biofilm formation by plant metabolite ε-viniferin.[Pubmed: 23819562]

Pathogenic biofilms are associated with persistent infection due to their high resistances to diverse antibiotics. Pseudomonas aeruginosa infects plants, animals, and humans and is a major cause of nosocomial diseases in patients with cystic fibrosis.
METHODS AND RESULTS:
In the present study, the antibiofilm abilities of 522 plant extracts against P. aeruginosa PA14 were examined. Three Carex plant extracts at a concentration of 200 μg/mL inhibited P. aeruginosa biofilm formation by >80% without affecting planktonic cell growth. In the most active extract of Carex pumila , resveratrol dimer ε-viniferin was one of the main antibiofilm compounds against P. aeruginosa. Interestingly, ε-viniferin at 10 μg/mL inhibited biofilm formation of enterohemorrhagic Escherichia coli O157:H7 by 98%.
CONCLUSIONS:
Although Carex extracts and trans-resveratrol are known to possess antimicrobial activity, this study is the first to report that C. pumila extract and ε-viniferin have antibiofilm activity against P. aeruginosa and E. coli O157:H7.

J Agric Food Chem. 2002 Feb 27;50(5):1213-7.

Antioxidant properties of trans-epsilon-viniferin as compared to stilbene derivatives in aqueous and nonaqueous media.[Pubmed: 11853506]

trans-epsilon-Viniferin, the dimer of resveratrol, extracted from Vitis vinifera, has been evaluated for its antioxidant capacity.
METHODS AND RESULTS:
Its properties have been compared to those of resveratrol and synthetic stilbenic derivatives (4-hydroxystilbene, 4,4'-dihydroxystilbene, 3,5-dihydroxystilbene, and trimethylresveratrol), in regard to their liposolubility using two media with different polarity. The bleaching of beta-carotene by lipoperoxyl (LOO.) radicals in an oil/water (O/W) emulsion and the scavenging of superoxide anions (O(-)(2) in dimethyl sulfoxide (DMSO) using 5,5-dimethyl-1-pyrroline-N-oxide as a spin trap were followed using UV-visible and electron paramagnetic resonance, respectively. epsilon-Viniferin exhibits the best antioxidant capacity in the DMSO/O(-)(2) polar system (IC(50) = 0.14 mM) while 4,4'-dihydroxystilbene presents the highest antioxidant capacity in the O/W/LOO. system (inhibition of beta-carotene bleaching, 82%). Partition coefficients and kinetics of partition between 1-octanol and water were measured to discuss the antioxidant efficiency of the compounds in relation with their chemical structure.

Biosci Biotechnol Biochem. 2012;76(5):954-60.

ε-Viniferin is more effective than its monomer resveratrol in improving the functions of vascular endothelial cells and the heart.[Pubmed: 22738966]

The present study compared the effects of resveratrol and its dimer epsilon-Viniferin on vascular endothelial cells (VECs) functions, and on the blood pressure and cardiac mass of spontaneously hypertensive rats (SHRs).
METHODS AND RESULTS:
epsilon-Viniferin was more potent than resveratrol in most of these effects. epsilon-Viniferin, but not resveratrol inhibited angiotensin-converting enzyme activity in vitro. Three weeks of epsilon-Viniferin treatment (5 mg/kg) reduced the systolic blood pressure and improved the whole cardiac mass and left ventricle mass indexes in SHRs. In contrast, resveratrol administration (2.5 mg/kg) failed to lower the blood pressure and significantly improve these mass indexes.
CONCLUSIONS:
These data suggest that epsilon-Viniferin as well as resveratrol may be involved in protecting the functions of VECs and the heart.

Eur J Pharmacol. 2006 Aug 7;542(1-3):54-60.

(-)-Trans-epsilon-viniferin, a polyphenol present in wines, is an inhibitor of noradrenaline and 5-hydroxytryptamine uptake and of monoamine oxidase activity.[Pubmed: 16828740 ]

METHODS AND RESULTS:
(-)-Trans-epsilon-Viniferin (epsilon-Viniferin, 5-200 microM), a dimer of resveratrol, concentration-dependently inhibited the uptake of [3H]noradrenaline and [3H]5-HT by synaptosomes from rat brain (being slightly but significantly more selective against [3H]noradrenaline) and the uptake of [3H]5-HT by human platelets. On the other hand, epsilon-Viniferin (5-200 microM) concentration-dependently inhibited the enzymatic activity of commercial (human recombinant) monoamine oxidase (MAO) isoform (MAO-A and MAO-B) activity, being slightly but significantly more selective against MAO-B than against MAO-A.
CONCLUSIONS:
Taking into account that the principal groups of drugs used to treat major depression are noradrenaline/5-HT uptake or MAO inhibitors, under the assumption that epsilon-Viniferin exhibits a similar behaviour in humans in vivo, our results suggest that this natural polyphenol may be of value as a structural template for the design and development of new antidepressant drugs with two important biochemical activities combined in the same chemical structure: noradrenaline/5-HT uptake and MAO inhibitory activity.