SDS-PAGE analysis revealed that what was considered the major protein of beer is actually formed by two polypeptides with the same molecular mass (-40 kDa), but different hydrodynamic volumes in their incompletely unfolded conformation. The two polypeptides share common properties, although the one with the more open conformation is associated with sugars, whereas the other is not. Immunoblotting experiments with polyclonal antibodies raised against the two electrophoretically purified polypeptides indicated that they are immunologically related and allowed the identification of their precursors in barley grain. These latter are two heat-resistant albumins whose electrophoretic behavior corresponded to that of beer proteins. These two albumins coincide with protein Z, the first member of the serpin superfamily described in plants.

The aim of the present study was to examine the effects of verbascoside (VB) in rats subjected to experimental colitis. Colitis was induced in rats by intracolonic instillation of 2,4 dinitrobenzene sulfonic acid (DNBS; 25 mg/rat). VB was administered daily per os (0.2 and 2 mg/kg) 4 days after DNBS administration in the colon. Treatment with VB significantly (P < 0.01) reduced macroscopic damage score, loss of body weight, myeloperoxidase activity and thiobarbituric acid-reactant substances. Moreover, the intensity of the positive staining for tumor necrosis factor-alpha, interleukin-1beta, intercellular adhesion molecule-1, P-selectin, inducible nitric oxide synthase, and poly(ADP ribose) was also significantly (P < 0.01) reduced by VB treatment. Therefore, VB treatment significantly (P < 0.01) reduced the degree of NF-kappaB p65 and activation of the pro-active form metalloproteinase (MMP)-2 and pro-MMP-9 activity. The results of this study suggested that VB functions as an intracellular radical scavenger and so reduces the microscopic and macroscopic signs of colitis in the rat. Therefore, administration of VB may be beneficial for the treatment of inflammatory bowel disease.

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The glycosylated phenylpropanoid verbascoside (VB), isolated from cultured cells of the medicinal plant Syringa vulgaris (Oleaceae), has previously been characterized as an effective scavenger of biologically active free radicals and an inhibitor of lipid peroxidation. The aim of the present study was to evaluate in a rat glioma cell line (C6) the effect of VB biotechnologically produced by S. vulgaris plant cell cultures in the regulation of the inflammatory response. We used a model of central nervous system inflammation induced by bacterial endotoxin/cytokine (lipopolysaccharide (LPS)/interferon (IFN)-gamma, 1 microg/ml and 100 U/ml, respectively). Our results show that the treatment with LPS/IFN-gamma for 24 h elicited the induction of inducible nitric oxide synthase (iNOS) activity as determined by NO(x) accumulation in the culture medium. Preincubation with VB (10-100 microg/ml) abrogated the mixed cytokine-mediated induction of iNOS. The effect was concentration-dependent. Our studies also showed an inhibitory effect of VB on neuronal nitric oxide synthase expression. Moreover, Western blot analysis showed that this glycoside prevents specifically the activation of the proinflammatory enzyme cyclooxygenase (COX)-2 in glioma cells without simultaneous inhibition of COX-1 enzyme. Moreover, we found that VB reduced the expression of proinflammatory enzymes in LPS/IFN-gamma through the inhibition of the activation of nuclear factor kappa B and mitogen-activated protein kinase signaling pathway. The mechanisms underlying in vitro the neuroprotective properties of VB involve modulation of transcription factors and consequent altered gene expression, resulting in downregulation of inflammation. These findings provide support that VB may provide a promising approach for the treatment of oxidative-stress-related neurodegenerative diseases.

The glycosylated phenylpropanoid verbascoside isolated from cultured cells of the medicinal plant Syringa vulgaris (Oleaceae) has previously been characterized as an effective scavenger of biologically active free radicals such as hydroxyl, superoxide, and nitric oxide, as a chelator of redox active transition metal ions (Fe (2+), Fe (3+), Cu (2+), and Ni (2+)), and an inhibitor of lipid peroxidation. In the present work, we have compared the cytoprotective effects of the biotechnologically produced verbascoside with two commercially available polyphenols (the glycosylated flavonoid rutin and its aglycone quercetin) against free radical-mediated UVC-induced cellular death in cultures of human keratinocytes (HaCaT) and breast cancer cells (MCF 7). We have shown that all the polyphenols studied afforded effective protection against UVC-induced necrosis and did not prevent UVC-induced apoptosis in both normal and tumor cell lines. The cytoprotection did not correlate either with UVC absorbance by polyphenols or with their superoxide radical scavenging properties. However, UVC protection strongly depended on the lipid peroxidation inhibiting and Fe (2+) chelating properties of polyphenols. We suggest that these plant polyphenols could be feasible for a photoprotection of human skin.