**Concepción Medrano-Padial 1, María Puerto 1, F. Javier Moreno 2, Tristan Richard 3, Emma Cantos-Villar <sup>4</sup> and Silvia Pichardo 1,\***


Received: 19 September 2019; Accepted: 7 October 2019; Published: 9 October 2019

**Abstract:** The reduction of sulfur dioxide in wine is a consumer's demand, considering the allergic effects that may occur in people who are sensitive to it. Stilbenes are candidates of great interest for this purpose because of their antioxidant/antimicrobial activities and health properties, and also because they are naturally found in the grapevine. In the present study, the in vitro toxicity of an extract from grapevine shoots (with a stilbene richness of 45.4%) was assessed in two human cell lines. Significant damage was observed from 30 μg/mL after 24 h, and 40 μg/mL after 48 h of exposure. Similarly, the ultrastructural study revealed a significant impairment of cell growing. The extract was able to protect cells against an induced oxidative stress at all concentrations studied. In view of the promising results, a more exhaustive toxicological assessment of the extract is needed to confirm the safety of its further use as additive in wine.

**Keywords:** cytotoxicity; stilbene; wine; antioxidant; Caco-2; Hep-G2
