Obtención de Fructooligosacáridos de Agave y su Potencial Biológico: Un Artículo de Revisión

The Agave genus is considered native to Mexico, of the 310 reported species, 272 are found in Mexican territory and 135 species are endemic to our country. From the commercial and ecological point of view, the Agave genus has been used for a long time to obtain numerous benefits. However, its use stands out for the elaboration of alcoholic beverages such as tequila and mezcal. Given the economic relevance of the production of these beverages, a great amount of agro-industrial waste is generated. This adverse effect can be mitigated since the agave plant is an important source of fructans, which, when hydrolyzed, result in the so-called fructooligosaccharides. These fructooligosaccharides can be obtained by: the use of presses, leaching, filtration, thermal and acid hydrolysis. Additionally, enzymatic hydrolysis is a viable option that allows to obtain fructooligosaccharides, without the need to use high temperatures or acids that generate even more contaminants. Finally, these agave fructooligosaccharides have beneficial properties for the health of consumers such as: prebiotic activity, aid in the absorption of minerals in the intestine, aid in weight loss and decrease blood glucose concentration. This manuscript summarizes the different methodologies used to extract fructans from agave, as well as the effects of their consumption on health.El género Agave es considerado originario de México, de las 310 especies reportadas, 272 se encuentran en territorio mexicano y 135 especies son endémicas de nuestro país. Desde el punto de vista comercial y ecológico, el género Agave ha sido aprovechado por el hombre durante mucho tiempo para la obtención de numerosos beneficios. No obstante, destaca su uso para la elaboración de bebidas alcohólicas como el tequila y el mezcal. Dada la relevancia económica de estas bebidas, se generan una gran cantidad de residuos agroindustriales. Este efecto adverso puede ser mitigado ya que la planta de agave es una fuente importante de fructanos, que al ser hidrolizados dan como resultados los llamados fructooligosacáridos. Estos carbohidratos se pueden obtener mediante: uso de prensas, lixiviación, filtración, hidrólisis térmica y ácida. Adicionalmente, la hidrólisis enzimática es una opción viable que permite obtener fructooligosacáridos sin la necesidad de emplear altas temperaturas o ácidos que generen aún más contaminantes. Finalmente, estos fructooligosacáridos de agave presentan propiedades benéficas en la salud de los consumidores tales como: actividad prebiótica, ayudar en la absorción de minerales en el intestino, ayudar en la disminución de peso y disminuyen la concentración de glucosa en sangre. Este manuscrito resume las diferentes técnicas empleadas para la extracción de fructanos de agave, así como los efectos de su consumo en la salud

An In Silico Approach to Enzymatic Synthesis of Fucooligosaccharides Using α-L-Fucosidase from Thermotoga maritima

Abstract: Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzy- matic methods show great promise, and α-L-fucosidase from Thermotoga maritima has emerged as a powerful catalyst for their production. Nonetheless, the enzyme’s limited substrate scope has de- layed its wider application. The present work aims to compare the relative reactivity of fucose, pNP-fucose, and ethyl-fucose, while also exploring the molecular interactions of these fucosyl-donors with the enzyme through a combination DFT and docking analysis. The HOMO-LUMO band gaps range from −7.14571 to −4.24429 eV, with α/β-pNP-fucose and α-fucose being the three most reactive compounds. Moderate association energies between −6.4 to −5.5 kcal·mol−1 were found in the dock- ing analysis, with α-pNP-fucose and both anomers of ethyl-fucose demonstrating the poorest affinity. In the case of α/β-lactose affinity to the β-fucose/enzyme complex, no significant differ- ences were shown. We conclude that the best fucosyl-donors for transfucosylation are those that maintain an enzyme affinity and reactivity similar to pNP-fucose

A Proof-Of-Principle Study of Epigenetic Therapy Added to Neoadjuvant Doxorubicin Cyclophosphamide for Locally Advanced Breast Cancer

BACKGROUND: Aberrant DNA methylation and histone deacetylation participate in cancer development and progression; hence, their reversal by inhibitors of DNA methylation and histone deacetylases (HDACs) is at present undergoing clinical testing in cancer therapy. As epigenetic alterations are common to breast cancer, in this proof-of-concept study demethylating hydralazine, plus the HDAC inhibitor magnesium valproate, were added to neoadjuvant doxorubicin and cyclophosphamide in locally advanced breast cancer to assess their safety and biological efficacy. METHODOLOGY: This was a single-arm interventional trial on breast cancer patients (ClinicalTrials.gov Identifier: NCT00395655). After signing informed consent, patients were typed for acetylator phenotype and then treated with hydralazine at 182 mg for rapid-, or 83 mg for slow-acetylators, and magnesium valproate at 30 mg/kg, starting from day –7 until chemotherapy ended, the latter consisting of four cycles of doxorubicin 60 mg/m(2) and cyclophosphamide 600 mg/m(2) every 21 days. Core-needle biopsies were taken from primary breast tumors at diagnosis and at day 8 of treatment with hydralazine and valproate. MAIN FINDINGS: 16 patients were included and received treatment as planned. All were evaluated for clinical response and toxicity and 15 for pathological response. Treatment was well-tolerated. The most common toxicity was drowsiness grades 1–2. Five (31%) patients had clinical CR and eight (50%) PR for an ORR of 81%. No patient progressed. One of 15 operated patients (6.6%) had pathological CR and 70% had residual disease <3 cm. There was a statistically significant decrease in global 5(m)C content and HDAC activity. Hydralazine and magnesium valproate up- and down-regulated at least 3-fold, 1,091 and 89 genes, respectively. CONCLUSIONS: Hydralazine and magnesium valproate produce DNA demethylation, HDAC inhibition, and gene reactivation in primary tumors. Doxorubicin and cyclophosphamide treatment is safe, well-tolerated, and appears to increase the efficacy of chemotherapy. A randomized phase III study is ongoing to support the efficacy of so-called epigenetic or transcriptional cancer therapy

Survival and proteolytic capacity of probiotics in a fermented milk enriched with agave juice and stored in refrigeration

Abstract In this study, the survival and proteolysis of lactic acid bacteria Lactobacillus casei Shirota and Lactobacillus rhamnosus GG were measured in fermented milks enriched with agave juice and inulin. Fermentations were terminated at pH 4.5 and stored for 21 days at 4 °C. Survival was determined by viable count in MRS-agar. The production of free amino groups was performed by the TNBS method and peptide separation was performed by SDS-PAGE. During fermentation, pH decreased faster in milk with agave juice than with inulin. There was no significant difference in the concentration of free amino groups (0.632 ± 0.007 and 0.627 ± 0.007 mg/L) between the two fermentation systems for any microorganism. The concentration of lactic acid bacteria in the presence of agave juice was higher than the recommended concentration for probiotic foods (7.59 log CFU/mL for L. rhamnosus GG and 8.26 log CFU/mL for L. casei Shirota). The production of free amino groups and peptides of low molecular weight continued in refrigeration and was higher in systems with agave juice. This could represent a proteolytic activation in the presence of this carbon source. The results showed that agave juice might be a functional ingredient with prebiotic character in symbiotic systems

ACE-Inhibitory Activity of Whey Proteins Fractions Derived of Fermentation by <i>Lacticaseibacillus rhamnosus</i> GG and <i>Streptococcus thermophilus</i> SY-102

Many studies have reported the benefits of probiotic microorganisms and the production of angiotensin-converting enzyme (ACE) inhibitors. Determining the proteolytic and ACE inhibition capacities during whey fermentation was the goal of the study. Lacticaseibacillus rhamnosus GG, Streptococcus thermophilus SY-102, and both bacteria together were initially inoculated into whey, reaching an initial concentration of 108 CFU per milliliter in each fermentation system. Through the use of TNBS, SDS-PAGE, and SEC-HPLC methods, the proteolytic profile was examined. An in vitro investigation was performed to test the ACE inhibition capacity. With S. thermophilus, the logarithmic phase of microbial development was shorter than with L. rhamnosus (6 and 12 h, respectively). The logarithmic phase in the co-culture fermentation, however, was extended to 24 h. There were no significant differences in pH between the fermentations. However, the co-culture had a greater concentration of protein hydrolysis (453 ± 0.06 μg/mL), as indicated by the amount of free amino groups. Similarly, this fermentation produced more low molecular weight peptides. The higher inhibition activity, which increased at the conclusion of the fermentation with the co-culture and reached 53.42%, was influenced by the higher peptide synthesis. These findings highlighted the significance of creating useful co-culture products

Differences in the Proteolytic System of Lactic Acid Bacteria Affect the Release of DPP-IV Inhibitory Peptides from Whey Proteins

This work analyzed the antidiabetic activity of peptides from whey proteins after hydrolysis by Lactobacillus rhamnosus GG and Streptococcus thermophilus SY-102, emphasizing the differences between the proteolytic systems of both bacteria. Peptide fractions from whey proteins may have biological functions, such as antidiabetic functions, which inhibit the DPP-IV enzyme, and lactic acid bacteria could release them. A whey solution of 10% was fermented with selected lactic acid bacteria in monoculture and coculture, analyzing kinetic parameters and the proteolytic profile, using the 2,4,6-trinitrobenzene sulfonic acid technique for free amino groups’ determination and Tris-tricine polyacrylamide gel electrophoresis. An in vitro inhibition assay of the DPP-IV enzyme was used. The kinetic parameters showed a faster duplication rate in the monoculture with L. rhamnosus GG than in the co-culture, which was related to lactic acid production. Co-culture does not have the highest production of free amino groups and peptides. Still, peptide fractions with lower molecular weight (L. rhamnosus GG increased from 0 to 63.3%. This demonstrates that the proteolytic capacity and the proteolytic system of each lactic acid bacteria determine the structure of the released peptides

An In Silico Approach to Enzymatic Synthesis of Fucooligosaccharides Using α-l-Fucosidase from Thermotoga maritima

Fucooligosaccharides comprise the primary group of human milk oligosaccharides. Due to their beneficial properties, a series of synthetic methods have been proposed to obtain them. Enzymatic methods show great promise, and α-l-fucosidase from Thermotoga maritima has emerged as a powerful catalyst for their production. Nonetheless, the enzyme’s limited substrate scope has delayed its wider application. The present work aims to compare the relative reactivity of fucose, pNP-fucose, and ethyl-fucose, while also exploring the molecular interactions of these fucosyl-donors with the enzyme through a combination DFT and docking analysis. The HOMO-LUMO band gaps range from −7.14571 to −4.24429 eV, with α/β-pNP-fucose and α-fucose being the three most reactive compounds. Moderate association energies between −6.4 to −5.5 kcal·mol−1 were found in the docking analysis, with α-pNP-fucose and both anomers of ethyl-fucose demonstrating the poorest affinity. In the case of α/β-lactose affinity to the β-fucose/enzyme complex, no significant differences were shown. We conclude that the best fucosyl-donors for transfucosylation are those that maintain an enzyme affinity and reactivity similar to pNP-fucose

A novel scoring system to measure radiographic abnormalities and related spirometric values in cured pulmonary tuberculosis.

BACKGROUND: Despite chemotherapy, patients with cured pulmonary tuberculosis may result in lung functional impairment. OBJECTIVE: To evaluate a novel scoring system based on the degree of radiographic abnormalities and related spirometric values in patients with cured pulmonary tuberculosis. METHODS: One hundred and twenty seven patients with cured pulmonary tuberculosis were prospectively enrolled in a referral hospital specializing in respiratory diseases. Spirometry was performed and the extent of radiographic abnormalities was evaluated twice by each of two readers to generate a novel quantitative score. Scoring reproducibility was analyzed by the intra-class correlation coefficient (ICC) and the Bland-Altman method. Multiple linear regression models were performed to assess the association of the extent of radiographic abnormalities with spirometric values. RESULTS: The intra-observer agreement for scoring of radiographic abnormalities (SRA) showed an ICC of 0.81 (CI:95%, 0.67-0.95) and 0.78 (CI:95%, 0.65-0.92), for reader 1 and 2, respectively. Inter-observer reproducibility for the first measurement was 0.83 (CI:95%, 0.71-0.95), and for the second measurement was 0.74 (CI:95%, 0.58-0.90). The Bland-Altman analysis of the intra-observer agreement showed a mean bias of 0.87% and -0.55% and an inter-observer agreement of -0.35% and -1.78%, indicating a minor average systematic variability. After adjustment for age, gender, height, smoking status, pack-years of smoking, and degree of dyspnea, the scoring degree of radiographic abnormalities was significantly and negatively associated with absolute and percent predicted values of FVC: -0.07 (CI:95%, -0.01 to -0.04); -2.48 (CI:95%, -3.45 to -1.50); and FEV1 -0.07 (CI:95%, -0.10 to -0.05); -2.92 (CI:95%, -3.87 to -1.97) respectively, in the patients studied. CONCLUSION: The extent of radiographic abnormalities, as evaluated through our novel scoring system, was inversely associated with spirometric values, and exhibited good reliability and reproducibility. As intra-observer and inter-observer agreement of the SRA varied from good to excellent, the use of SRA in this setting appears acceptable