Traditional production systems, phytochemical composition of fruit, seeds and flowers, and nutritional-nutraceutical potential of four Mexican cucurbits

Mexico is the center of origin, domestication, and diversification of four cultivated species of cucurbits: Cucurbita pepo L., C. ficifolia Bouché, C. moschata (Duch. ex Lam.) Duch. Ex Poir. and C. argyrosperma Huber. These cucurbits exhibit high intraspecific diversity and are part of the food culture of more than 60 indigenous groups settled in Mexico. All of these indigenous groups recognize these cultivated cucurbits using specific names in local languages; for example, in the Mixteco language, shikiniñu, chompa, shikin-ñaami and shikin-tinduyu refer to the species C. pepo, C. argyrosperma, C. moschata and C. ficifolia, respectively. Commonly, cucurbits are sown in association with maize and beans into the traditional 'milpa' system, backyards or orchards for easy access to edible fruits, flowers and tender shoots; moreover, the seeds of the mature fruits are part of indigenous-cultural gastronomy. Every crop cycle, farmers of the same and neighboring communities select and exchange cucurbit seeds for cultivation, thus preserving the highest on-farm phenotypic and genetic diversity of cultivated cucurbits in the Mesoamerican region, which features high species diversity. In addition to food use, the leaves, stems, fruits or seeds of cucurbits are used in traditional medicine to treat skin damage and liver, kidney or urinary problems, and they exhibit hypoglycemic and antidiabetic properties. Additionally, water-ground seeds are used as a vermifuge. The composition of the fruits (pulp), flowers and seeds contain essential nutritional and nutraceutical properties for human health. Experimentally, through biological models with mice or in in vitro cell culture, extracts or foods derived from the stems, leaves or fruits of cucurbits have shown hypoglycemic, anti-obesity, antiadipogenic, antilipogenic, anti-inflammatory, and anticancer effects, as well as beneficial effects for the treatment of urinary tract disorders. To date, the chemical composition of wild species related to the cultivated forms of these fruits has not been determined in detail.