Dataset Information

In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts.

ABSTRACT:

Scope

Known pharmacological activities of guava (Psidium guajava) include modulation of blood glucose levels. However, mechanistic details remain unclear in many cases.

Methods and results

This study investigated the effects of different guava leaf and fruit extracts on intestinal glucose transport in vitro and on postprandial glucose levels in vivo. Substantial dose- and time-dependent glucose transport inhibition (up to 80%) was observed for both guava fruit and leaf extracts, at conceivable physiological concentrations in Caco-2 cells. Using sodium-containing (both glucose transporters, sodium-dependent glucose transporter 1 [SGLT1] and glucose transporter 2 [GLUT2], are active) and sodium-free (only GLUT2 is active) conditions, we show that inhibition of GLUT2 was greater than that of SGLT1. Inhibitory properties of guava extracts also remained stable after digestive juice treatment, indicating a good chemical stability of the active substances. Furthermore, we could unequivocally show that guava extracts significantly reduced blood glucose levels (?fourfold reduction) in a time-dependent manner in vivo (C57BL/6N mice). Extracts were characterized with respect to their main putative bioactive compounds (polyphenols) using HPLC and LC-MS.

Conclusion

The data demonstrated that guava leaf and fruit extracts can potentially contribute to the regulation of blood glucose levels.

SUBMITTER: Muller U

PROVIDER: S-EPMC6001447 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts.

Müller Ulrike U Stübl Flora F Schwarzinger Bettina B Sandner Georg G Iken Marcus M Himmelsbach Markus M Schwarzinger Clemens C Ollinger Nicole N Stadlbauer Verena V Höglinger Otmar O Kühne Tobias T Lanzerstorfer Peter P Weghuber Julian J

Molecular nutrition & food research 20180517 11

<h4>Scope</h4>Known pharmacological activities of guava (Psidium guajava) include modulation of blood glucose levels. However, mechanistic details remain unclear in many cases.<h4>Methods and results</h4>This study investigated the effects of different guava leaf and fruit extracts on intestinal glucose transport in vitro and on postprandial glucose levels in vivo. Substantial dose- and time-dependent glucose transport inhibition (up to 80%) was observed for both guava fruit and leaf extracts, a ...[more]

PMID: 29688623

Similar Datasets

Project description:The Brazilian guava processing industry generates 5.5 M Mg guava waste year(-1) that could be recycled sustainably in guava agro-ecosystems as slow-release fertilizer. Our objectives were to elaborate nutrient budgets and to diagnose soil, foliar, and fruit nutrient balances in guava orchards fertilized with guava waste. We hypothesized that (1) guava waste are balanced fertilizer sources that can sustain crop yield and soil nutrient stocks, and (2) guava agroecosystems remain productive within narrow ranges of nutrient balances. A 6-year experiment was conducted in 8-year old guava orchard applying 0-9-18-27-36 Mg ha(-1) guava waste (dry mass basis) and the locally recommended mineral fertilization. Nutrient budgets were compiled as balance sheets. Foliar and fruit nutrient balances were computed as isometric log ratios to avoid data redundancy or resonance due to nutrient interactions and the closure to measurement unit. The N, P, and several other nutrients were applied in excess of crop removal while K was in deficit whatever the guava waste treatment. The foliar diagnostic accuracy reached 93% using isometric log ratios and knn classification, generating reliable foliar nutrient and concentration ranges at high yield level. The plant mined the soil K reserves without any significant effect on fruit yield and foliar nutrient balances involving K. High guava productivity can be reached at lower soil test K and P values than thought before. Parsimonious dosage of fresh guava waste should be supplemented with mineral K fertilizers to recycle guava waste sustainably in guava agroecosystems. Brazilian growers can benefit from this research by lowering soil test P and K threshold values to avoid over-fertilization and using fresh guava waste supplemented with mineral fertilizers, especially K. Because yield was negatively correlated with fruit acidity and Brix index, balanced plant nutrition and fertilization diagnosis will have to consider not only fruit yield targets but also fruit quality to meet requirements for guava processing.

Project description:Inhibition of intestinal glucose resorption can serve as an effective strategy for the prevention of an increase in blood glucose levels. We have recently shown that various extracts prepared from guava (Psidium guajava) inhibit sodium-dependent glucose cotransporter 1 (SGLT1)- and glucose transporter 2 (GLUT2)-mediated glucose transport in vitro (Caco-2 cells) and in vivo (C57BL/6N mice). However, the efficacy in humans remains to be confirmed. For this purpose, we conducted a parallelized, randomized clinical study with young healthy adults. Thirty-one volunteers performed an oral glucose tolerance test (OGTT) in which the control group received a glucose solution and the intervention group received a glucose solution containing a guava fruit extract prepared by supercritical CO2 extraction. The exact same extract was used for our previous in vitro and in vivo experiments. Blood samples were collected prior to and up to two hours after glucose consumption to quantitate blood glucose and insulin levels. Our results show that, in comparison to the control group, consumption of guava fruit extract resulted in a significantly reduced increase in postprandial glucose response over the basal fasting plasma glucose levels after 30 min (Δ control 2.60 ± 1.09 mmol/L versus Δ intervention 1.96 ± 0.96 mmol/L; p = 0.039) and 90 min (Δ control 0.44 ± 0.74 mmol/L versus Δ intervention -0.18 ± 0.88 mmol/L; p = 0.023). In addition, we observed a slightly reduced, but non-significant insulin secretion (Δ control 353.82 ± 183.31 pmol/L versus Δ intervention 288.43 ± 126.19 pmol/L, p = 0.302). Interestingly, storage time and repeated freeze-thawing operations appeared to negatively influence the efficacy of the applied extract. Several analytical methods (HPLC-MS, GC-MS, and NMR) were applied to identify putative bioactive compounds in the CO2 extract used. We could assign several substances at relevant concentrations including kojic acid (0.33 mg/mL) and 5-hydroxymethylfurfural (2.76 mg/mL). Taken together, this clinical trial and previous in vitro and in vivo experiments confirm the efficacy of our guava fruit extract in inhibiting intestinal glucose resorption, possibly in combination with reduced insulin secretion. Based on these findings, the development of food supplements or functional foods containing this extract appears promising for patients with diabetes and for the prevention of insulin resistance. Trial registration: 415-E/2319/15-2018 (Ethics Commissions of Salzburg).

Dataset Information

In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts.

Scope

Methods and results

Conclusion

Publications

In Vitro and In Vivo Inhibition of Intestinal Glucose Transport by Guava (Psidium Guajava) Extracts.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets