A Comprehensive Review on Essential Oil Composition and Gastric Effect of <i>Minthostachys mollis</i>: An Ethnomedicinal Resource from Andes

<i>Minthostachys mollis</i> (muña) is one of the most widely used phytotherapeutic resources in Andean countries for the treatment of gastrointestinal system disorders. There are wild and cultivated types with different essential oil (EO) compositions, which are related to the gastrointestinal activities of the plant. One of the two main EO types is rich in pulegone and menthone (PMEO), and the other one is rich in carvacrol and/or its congeners. Geographical and/or climatic factors are probably contributors to these differences in <i>M. mollis</i> chemical profile, so that the PMEO type is highly predominant in Peruvian collection sites. Moreover, the variation of methods of extraction also importantly influences the quantitative and qualitative profile within each EO type. Analgesic, anti-inflammatory, antibacterial, and antiulcer activities of muña extract and infusion were shown, explaining the gastroprotective action of the plant. Combined infusion with some other species, such as <i>Plantago major</i>, <i>Malva sylvestris</i>, <i>Solanum tuberosum</i> and <i>Uncaria tomentosa</i>, shows better results than the extracts, likely due to the synergistic action. Furthermore, in addition to the EO compounds, the major phenolics and flavonoids exhibit pronounced anti-inflammatory and gastroprotective activities, such as rosmarinic acid, isosakuretin, and naringenin, whereas pulegone, menthone, carvacrol, and thymol are the EO constituents related to the analgesic, anti-inflammatory, and antimicrobial activities.