Nutraceutical Potential of Seven “Quelites” Harvested in the Northern Highlands of Puebla-México

The northern highlands of Puebla harbor several plant foods consumed since pre-Columbian times. Most of the native vegetables from this geographical region are still uncharacterized at the nutraceutical level. This investigation was focused on the elucidation of chemical and biochemical properties of the edible organs from Rhamnus pompana, Solanum nigrescens, Sechium edule, Yucca aloifolia, Piper auritum, Amaranthus hybridus and Rumex obtusifolius, which are used as traditional foods in this region. The content of basic nutrients (including vitamins of the B complex), nutraceuticals (carotenoids, flavonoids, and fatty acids), phenolics (including antioxidant capacity), and inhibitory properties of these plants on specific enzymes linked to carbohydrate and lipid metabolism were determined. In addition, extracts of these plants were evaluated against pathogenic microorganisms of the gastrointestinal tract. Our results demonstrated statistically significant divergences (p < 0.05) in the content protein (12.5 g/100 g), fiber (9.8 g/100 g), fat (81.2 mg/100 g), beta-carotene (2.48 mg/100 g), beta-cryptoxanthin (1.24 mg/100 g), thiamine (159.6 µg/100 g), riboflavin (106.4 µg/100 g), and vitamin B6 between Y. aloifolia and other plants studied. All plants showed low amounts of reducing sugars (<150 mg/100 g) and sodium (<70 mg/100 g), but the berries of R. pompana exhibited substantial differences (p < 0.05) in the levels of vitamin C (14.6 mg/100 mg). The edible leaves of R. obtusifolius were particularly rich in quercetin (4.38 mg/100 g), kaempferol (2.38 mg/100 g) and lutein (2.52 mg/100 g), whereas the aerial parts of S. edule contained high concentrations of folate (50.6 µg/100 g). All plants showed variable phenolic content and antioxidant capacity; however, Y. aloifolia had the highest values (23 GAE/mg/g and 440 TEAC/µM/g). The ethanolic extracts from Y. aloifolia efficiently inhibited pancreatic lipase (IC50, 43.76 µg/mL) and alpha-glucosidase (IC50, 60.04 µg/mL), whereas those from S. edule inhibited alpha-glucosidase (IC50, 47.4 µg/mL) and HMG-CoA reductase (IC50, 33.6 µg/mL). Only the ethanolic extracts of R. pompana (IC50, 35.36 µg/mL) and Y. aloifolia (IC50, 53.28 µg/mL) inhibited ornithine decarboxylase. All plant extracts exerted moderated antimicrobial activity in at least one species associated with the gastrointestinal tract.