Local/traditional uses, secondary metabolites and biological activities of Mashua (Tropaeolum tuberosum Ruíz & Pavón).

ETHNOPHARMACOLOGICAL RELEVANCE: Tropaeolum tuberosum Ruíz & Pavón (Tropaeolaceae). Sim (commonly called Mashua) is an indigenous plant that has medicinal values for various ethnic groups of the regions of the Andes mountain range of South America, which use it for the treatment of diseases venereal, lung and skin; for the healing of internal and external wounds; and as an analgesic for kidney and bladder pain. AIM OF THE REVIEW: We critically summarised the current evidence on the botanic characterisation and distribution, ethnopharmacology, secondary metabolites, pharmacological activities, qualitative and quantitative analysis, and toxicology of T. tuberosum.
MATERIALS AND METHODS: The relevant information on T. tuberosum was gathered from worldwide accepted scientific databases via electronic search (Google scholar, Elsevier, SciFinder, ScienceDirect, PubMed, SpringerLink, Web of Science, Scopus, Wiley Online, Mendeley, Scielo and Dialnet electronic databases). Information was also obtained from the literature and books as well as PhD and MSc dissertations. Plant names were validated by 'The Plant List' (www.theplantlist.org).
RESULTS: T. tuberosum has diverse uses in local and popular medicine, specifically for relieving pain and infections in humans. Regarding its biological activities, polar extracts (aqueous, hydroalcoholic) and isolated compounds from the tubers have exhibited a wide range of in vitro and in vivo pharmacological effects, including antibacterial, antioxidant, anti-inflammatory activities. Quantitative analysis (e.g., NMR, HPLC, GC-MS) indicated the presence of a set of secondary metabolites, including hydroxybenzoic acids, tannins, flavanols, anthocyanins, glucosinolates, isothiocyanates, phytosterols, fatty acids and alkamides in the tubers of T. tuberosum. Likewise, glucosinolates have been identified in the seeds and isothiocyanates have been detected in leaves, flowers and seeds.
CONCLUSIONS: T. tuberosum has been tested for various biological activities and the extracts (tubers in particular) demonstrated a promising potential as an antibacterial, antioxidant, anti-inflammatory and inhibitors of benign prostatic hyperplasia. A lack of alignment between the ethno-medicinal uses and existing biological screenings was observed, indicating the need to explore its potential for the treatment against respiratory affections, urinary affections and blood diseases. Likewise, it is necessary to analyse deeply the relationship that exists between the different tuber colours of T. tuberosum and its use for the treatment of certain diseases. Validation of clinical studies of the antibacterial, antioxidant/anti-inflammatory, anti-spermatogenic activities and as inhibitors of benign prostatic hyperplasia is required. Moreover, studies on the toxicity, bioavailability, and pharmacokinetics, in addition to clinical trials, are indispensable for assessing the safety and efficacy of the active metabolites or extracts obtained from T. tuberosum. Other areas that need investigation are the development of future applications based on their active metabolites, such as neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, Huntington's disease). Finally, the work purposes to motivate other research groups to carry out a series of scientific studies that can fill the gaps that exist with respect to Mashua properties, and thus be able to change the focus of T. tuberosum (Mashua) that currently has in the consumer society.