Steroidal Saponin and Flavonol Content and Antioxidant Activity during Sporophyte Development of Maguey (Agave salmiana).

Agave salmiana Otto ex Salm-Dyck has traditionally been used for the production of fermented beverage known as "pulque" that has recently gained acceptance as a functional food. However, the plant requires up to 10 years to be used as raw material. The objective of this work was to evaluate the antioxidant and bioactive principles of Agave salmiana during different stages of development. Wild grown plants from Coahuila, Mexico, were identified based on leaf and spine traits to obtain a representative sample from six different stages of development (I-VI) from 1 to 7 years old. Total phenolic content (TPC), antioxidant activity (AOX), as well as composition and content of flavonols and saponins by HPLC-MS-TOF and HPLC-ELSD-PDA were evaluated. Concentrations of TPC were found to be between 5 to 13 mg gallic acid equivalents/g, reaching a maximum at stage II. The AOX presented a negative tendency from stage I to stage VI (from 148 to 50 µmol Trolox equivalents/g respectively). Kaempferol, quercetin and five saponins were identified. Similar to AOX, flavonols presented a negative concentration tendency with a reduction of 65% between the stage I and VI. Plants of stage III and IV presented the highest content of saponins, particularly chlorogenin glycoside, containing 3.19 and 2.90 mg protodioscin equivalents/g, respectively. These data suggest that plants from stages I to IV may be used as a source of antioxidant and bioactive principles, and that the content of these metabolites could be used as a marker to determine the developmental stage of the plant.

Effect of prebiotics of Agave salmiana fed to healthy Wistar rats.

BACKGROUND: Inulin and other fructans are synthesized and stored in mezcal agave (Agave salmiana). Fructans provide several health benefits and have excellent technological properties, but only few data report their physiological effect when added in the diet. RESULTS: Here, we studied the physiological effects of fructans obtained from A. salmiana when added in the diet of Wistar rats. Results showed favorable changes on Wistar rats when the fructans was added to their diet, including the decrease of the pH in the feces and the increase of the number of lactic acid bacteria (CFU g-1 ) (Lactobacillus spp. and Bifidobacterium spp.), even these changes were enhanced with the synbiotic diet (fructans plus B. animalis subsp. lactis). Synbiotic diet, developed changes in the reduction of cholesterol and triglycerides concentrations in serum, with statistical differences (P < 0.05). Histological analysis of colon sections showed that synbiotic diet promoted colon cells growth suggesting that fructans from A. salmiana confer beneficial health effects through gut microbiota modulation. CONCLUSION: Our data underline the advantage of targeting the gut microbiota by colonic nutrients like specific structure of fructans from A. salmiana, with their beneficial effects. More studies are necessary to define the role of fructans to develop more solid therapeutic solutions in humans. © 2016 Society of Chemical Industry.

Effect of Agave americana and Agave salmiana Ripeness on Saponin Content from Aguamiel (Agave Sap).

Steroidal saponins have shown beneficial health effects. Agave spp. leaves and rhizomes are sources of these compounds, but their presence has not been reported in the aguamiel. Aguamiel is the sweet edible sap from mature agave, and its quality is influenced by the plant ripening stage. The purpose of this research was to identify and quantitate saponins in aguamiel from Agave americana and Agave salmiana at two ripening stages. Saponins and sapogenins were identified with HPLC/ESI-MS/TOF and quantitated with HPLC/ELSD. Results proved the presence of saponins derived from kammogenin, manogenin, gentrogenin, and hecogenin. The saponin content in aguamiel from immature A. salmiana was 2-fold higher (478.3 protodioscin equivalents (PE) µg/g aguamiel (DM)) compared with A. americana (179.0 PE µg/g aguamiel (DM)). In both species, saponin content decreased when plants reached sexual maturity. This should be considered before evaluating the effects of Agave spp. as a source of bioactive saponins.