Verification of the Utility of the Standardized <i>Melissa officinalis</i> Extract to Control Gut Contractility in Sheep—Ex Vivo Study

Background: Modern societies and policymakers increasingly emphasize the advancement of organic farming practices and the preservation of rural culture. Sheep farming faces several challenges, including environmental impacts, antibiotic usage, and public concerns regarding animal welfare. The purpose of this study was to investigate the effects of <i>Melissa officinalis</i> extract and its principal phenolic acids on the motility of the sheep jejunum and colon, with the goal of assessing their potential as health-promoting feed additives, particularly in animals with dysmotilities. Methods: The trials were performed on isolated jejunum and colon preparations collected from sheep undergoing routine slaughter. The effect of extracts from <i>Melissa Officinalis</i> and three major phenolic acids (rosmarinic, chlorogenic, and lithospermic) was evaluated to identify their ability to modify the spontaneous and pharmacologically-induced contractility of circular and longitudinal smooth muscle. Results: Regarding spontaneous contractions: <i>Melissa officinalis</i> extract, rosmarinic acid, and lithospermic acid caused a significant decrease in spontaneous contractility in the jejunum and colon, while chlorogenic acid exhibited myocontractile effects except for colon circular preparations where the effect was myorelaxant as in the other acids. In the case of ACh-induced contractions, all acids and the <i>Melissa officinalis</i> extract caused mostly a significant decrease in the magnitude of acetylcholine-induced contractions in both longitudinal and circular smooth muscle strips of the colon and jejunum. Conclusions: The findings suggest a predominantly myorelaxant effect of the <i>Melissa officinalis</i> extract and its major phenolic acids on the smooth muscle of the sheep jejunum and colon. These results underscore the potential application of the <i>Melissa officinalis</i> extract as a feed additive to modulate intestinal motility and address challenges in livestock production.