Hypoglycemic and Vasorelaxant Effect of Passiflora edulis Fruit Peel By-Product.

Passiflora edulis fo. flavicarpa (Passifloraceae) is popularly known as yellow passion fruit and its fruit peels are considered a rich by-product in bioactive compounds which has greatly beneficial health properties. The objective of this study was to evaluate the effects of P. edulis fruit peel extracts in a type 1 diabetes model and the potential vasorelaxant effect. The aqueous and hydroethanolic extracts were obtained from P. edulis fruit peels and orientin and isorientin flavonoids were identified in both extracts through ultra-high performance liquid chromatography. Pectin was only identified in the aqueous extract by high-performance steric exclusion chromatography and nuclear magnetic resonance. Regarding the vascular system, the hydroethanolic extract showed better vasorelaxant effects in the mesenteric artery rings when compared to the aqueous extract. These effects mainly occur by opening the potassium channels. In the type 1 diabetes model, extracts at doses of 400 and 600 mg/kg were able to restore the effect of insulin in diabetic rats which were not responding to its action. The antidiabetic effect was more significant for the aqueous extract. Thus, the results suggest that the hydroethanolic and aqueous extracts have greater potential to be used to treat cardiovascular diseases such as hypertension and as a hypoglycemic agent, respectively. Taken together, P. edulis fruit peel extracts proved to be a source of valuable bioactive raw material to produce nutraceuticals or pharmaceutical products.

High methoxyl pectin from the soluble dietary fiber of passion fruit peel forms weak gel without the requirement of sugar addition.

Passion fruit peel (PFP) is a by-product from the fruit processing industry, accounting for approximately 50 % of the fruit weight. It is well known for its health properties, although few studies evaluated its rheological properties. PFP polysaccharides (PFPP) contain a high methoxyl pectin (HMP), specifically a 70 % methyl-esterified homogalacturonan. Flow behaviour analysis of PFPP (with or without sucrose) revealed a shear-thinning non-Newtonian behaviour. Dynamic oscillatory tests showed a weak gel-like behaviour, even without sucrose addition. Moreover, under simulated pasteurization process PFPP maintained its gel structure. Taken together we demonstrated that PFPP has divergent behaviour from commercial HMP, since it does not require sucrose or low pH to form gel. The present work reinforces the use of PFP as a source of soluble dietary fibres and pectins, providing its alternative application as a rheological modifier in a wide range of products, including those with low sugar.

Oral Glutamine Supplementation Reduces Obesity, Pro-Inflammatory Markers, and Improves Insulin Sensitivity in DIO Wistar Rats and Reduces Waist Circumference in Overweight and Obese Humans.

In the present study, we aimed to investigate whether chronic oral glutamine (Gln) supplementation may alter metabolic parameters and the inflammatory profile in overweight and obese humans as well as whether Gln may modulate molecular pathways in key tissues linked to the insulin action in rats. Thirty-nine overweight/obese volunteers received 30 g of Gln or alanine (Ala-control) for 14 days. Body weight (BW), waist circumference (WC), hormones, and pro-inflammatory markers were evaluated. To investigate molecular mechanisms, Gln or Ala was given to Wistar rats on a high-fat diet (HFD), and metabolic parameters, euglycemic hyperinsulinemic clamp with tracers, and Western blot were done. Gln reduced WC and serum lipopolysaccharide (LPS) in overweight volunteers. In the obese group, Gln diminished WC and serum insulin. There was a positive correlation between the reduction on WC and LPS. In rats on HFD, Gln reduced adiposity, improved insulin action and signaling, and reversed both defects in glucose metabolism in the liver and muscle. Gln supplementation increased muscle glucose uptake and reversed the increased hepatic glucose production, in parallel with a reduced glucose uptake in adipose tissue. This insulin resistance in AT was accompanied by enhanced IRS1 O-linked-glycosamine association in this tissue, but not in the liver and muscle. These data suggest that Gln supplementation leads to insulin resistance specifically in adipose tissue via the hexosamine pathway and reduces adipose mass, which is associated with improvement in the systemic insulin action. Thus, further investigation with Gln supplementation should be performed for longer periods in humans before prescribing as a beneficial therapeutic approach for individuals who are overweight and obese.

Oral supplementation with L-glutamine alters gut microbiota of obese and overweight adults: A pilot study.

OBJECTIVE: The aim of this study was to determine whether oral supplementation with L-glutamine (GLN) modifies the gut microbiota composition in overweight and obese adults. METHODS: Thirty-three overweight and obese adults, ages between 23 and 59 y and body mass index between 25.03 and 47.12 kg/m(2), were randomly assigned to receive either oral supplementation with 30 g of L-alanine (ALA group control) or 30 g of GLN (GLN group) daily for 14 d. We analyzed the gut microbiota composition with new-generation sequencing techniques and bioinformatics analysis. RESULTS: After 14 d of supplementation, adults in the GLN group exhibited statistically significant differences in the Firmicutes and Actinobacteria phyla compared with those in the ALA group. The ratio of Firmicutes to Bacteroidetes, a good biomarker for obesity, decreased in the GLN group from 0.85 to 0.57, whereas it increased from 0.91 to 1.12 in the ALA group. At the genus level, Dialister, Dorea, Pseudobutyrivibrio, and Veillonella, belonging to the Firmicutes phylum, had statistically significant reduction. CONCLUSION: Oral supplementation with GLN, for a short time, altered the composition of the gut microbiota in overweight and obese humans reducing the Firmicutes to Bacteroidetes ratio, which resembled weight loss programs already seen in the literature.