Anti-Helicobacter pylori and urease inhibitory activities of resveratrol and red wine Luísa Paulo a , Mónica Oleastro b , Eugenia Gallardo a , João António Queiroz a , Fernanda Domingues a, ⁎ a CICS-UBI, Centro de Investigação em Ciências da Saúde, Universidade da Beira Interior, Av. Infante D. Henrique, 6201-556 Covilhã, Portugal b Unidade Helicobacter/Campylobacter, Laboratório Nacional de Referência de Infecções Gastrentestinais, Departamento de Doenças Infecciosas, Instituto Nacional Saúde Dr Ricardo Jorge, I. P., Lisboa, Portugal abstract article info Article history: Received 8 November 2010 Accepted 12 February 2011 Keywords: Resveratrol Helicobacter pylori Urease Wine There is considerable interest in alternative approaches for the eradication of Helicobacter pylori using biologically active compounds including antioxidants from a wide range of natural sources. In this work we have investigated the antibacterial properties of resveratrol towards different H. pylori strains. In addition we studied the inhibition of H. pylori urease by resveratrol and red wine. In those assays, resveratrol inhibited the growth of all the 17 H. pylori strains tested, with inhibition diameters ranging from 16 to 28 mm and minimum inhibitory concentration values varying from 25 to 100 μg/mL, confirming its antimicrobial properties. Moreover, resveratrol and red wines showed an inhibitory effect on H. pylori urease activity, which is considered a virulence factor of this organism and essential for colonization and establishment of the infection. Further kinetic analysis revealed that inhibition occurred in a non-competitive and concentration-dependent manner. Overall, the results suggest that resveratrol and red wine may have potential for new therapy schemes that include natural products as an alternative therapeutic approach. © 2011 Elsevier Ltd. All rights reserved. 1. Introduction Helicobacter pylori is a Gram-negative spiral-shaped, fastidious, microaerophilic bacillus which rapidly hydrolyses urea as part of its adapted survival methods (Montecucco & Rappuoli, 2001; Vale & Vitor, 2010). It has been implicated as the etiologic agent of chronic gastritis, peptic ulcer, gastric adenocarcinoma and related gastrodu- odenal disorders (Graham, 1994). Several potential virulence factors may be responsible for the pathogenicity of H. pylori, such as cagA, vacA and urease (Montecucco & Rappuoli, 2001). The cagA and vacA genes are the two major H. pylori virulence markers. The cagA gene is a strain-specific gene, belonging to the cag pathogenicity island, which has been associated with severe gastric disease (Blaser et al., 1995; Censini et al., 1996). The vacA gene encodes for a vacuolating toxin and is characterized by a mosaic structure for which different alleles have been identified in the signal (s), middle and intermediate regions of the gene (Atherton et al., 1995; Rhead et al., 2007). Only the vacA s1 type has been associated with in vitro cytotoxin activity (McClain et al., 2001). The bacterium produces high levels of the enzyme urease which converts urea into ammonia, producing a local alkaline environment that enables the organism to survive on the acidic environment of the stomach as well as aids its initial colonization of the gastric mucosa (Mobley, Cortesia, Rosenthal, & Jones, 1988; Nagata, Satoh, Iwahi, Shimoyama, & Tamura, 1993). Successful treatment of chronic H. pylori infections leads to the resolution of gastritis and a decrease of ulcer recurrence. Unfortu- nately, eradication of H. pylori has proved to be difficult, and an optimal regimen has not yet been defined (O'Connor, Gisbert, & O'Morain, 2009). Triple therapy using at least two antibiotics and either bismuth or a proton pump inhibitor results in eradication rates of 90% (Marshall, 1993). However, these regimens are complicated, have significant side effects and compliance problems, often leading to relapse. Since complete cure is not always achieved with triple therapy, alternative therapeutic agents are sought. It is why the search for new antimicrobial agents to eradicate H. pylori and yield better therapeutic results is of critical importance, especially in developing countries where the rates of H. pylori infections are high. Thus, in recent years a growing interest in biologically active compounds, including antioxidants from plants and other natural sources, has been observed, as some epidemiological studies have shown a correlation between seropositivity to H. pylori and environmental factors, including diet (Brenner, Berg et al., 1999; Ruggiero et al., 2007). Indeed, a low incidence of infection has been associated with the consumption of vegetables, wine and green tea. The phytoalexin resveratrol (3,4′,5-trihydroxistilbene) has been attributed to numerous beneficial biological effects (Anastasiadi, Pratsinis, Kletsas, Skaltsounis, & Haroutounian, 2010; Bertelli & Das, 2009; Jang et al., 1997), including potent antimicrobial activity (Chan, 2002; Daroch et al., 2001; Dochertyl, McEwen, Sweet, Bailey, & Booth, 2007; Mahady & Pendland, 2000; Mahady, Pendland, & Chadwick, 2003; Paulo, Ferreira, Gallardo, Queiroz, & Domingues, 2010; Shan, Cai, Brooks, & Corke, 2008; Wang et al., 2006). In addition, some studies also suggest that wine possesses antimicrobial activity against various pathogens (Boban et al., 2010; Food Research International 44 (2011) 964–969 ⁎ Corresponding author. Tel.: +351 275 329 002; fax: +351 275 329 099. E-mail address: fdomingues@ubi.pt (F. Domingues). 0963-9969/$ – see front matter © 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.foodres.2011.02.017 Contents lists available at ScienceDirect Food Research International journal homepage: www.elsevier.com/locate/foodres