Exploring the α-amylase-inhibitory properties of tannin-rich extracts of Cytinus hypocistis on starch digestion.

Cytinus hypocistis(L.) L. is an edible parasitic plant that grows within the roots of its host. In addition to its use as famine food in the past, it is also tradidionally used for treating several illnesses such as intestinal problems, inflammations, tumors, and bleeding. This species is rich in hydrolysable tannins, compounds often associated with inhibiting starch digestion. Therefore, the present work investigated how effectively C. hypocistis tannin-rich extracts inhibited enzymes involved in starch digestion and if such effect also occurs in vivo. The latter premise was approached using the starch tolerance test in mice. Two optimized hydroethanolic extracts were used, a heat-assisted and an ultrasound-assisted extract, with known hydrolysable tannin content. Both extracts demonstrated potent inhibition of α-amylase. Inhibitions were of the mixed type with inhibitor constants in the 15 µg/mL range. The inhibition of the intestinal α-glucosidase was at least ten times less effective. The inhibition of the α-amylase was negatively affected by in vitro gastrointestinal digestion and bovine serum albumin. In vivo, both extracts inhibited starch digestion at doses between 100 and 400 mg/mL in healthy mice. The highest doses of the ultrasound and heat extracts diminished the peak glucose levels in the starch tolerance test by 46 and 59.3%, respectively. In streptozotocin diabetic mice, this inhibition occurred only at the dose of 400 mg/mL. Under this condition, diminution of the peak glucose concentration in the starch tolerance test was equal to 36.7% and 48.8% for the ultrasound and heat extracts, respectively. Maltose digestion was not inhibited by the C. hypocistis extracts. Qualitatively and quantitatively, thus, the actions of both extracts were similar. The results allow adding a new biological property to C. hypocistis, namely, the ability to decrease the hyper-glycemic excursion after a starch-rich meal, propitiating at the same time a diminished caloric intake.

Pigments and vitamins from plants as functional ingredients: Current trends and perspectives.

The food manufacturing industry has increasingly focused in the development of wholesome and safer products, including certified labeled "super foods," "healthy foods" and "functional foods," which are currently under great demand worldwide. Plant pigments and vitamins are amidst the most common additives incorporated to foodstuff, not only for improving their nutritional status but also for coloration, preservation, and even therapeutic purposes. The recovery of pigments from agro industrial wastes using green emerging approaches is a current trend and clearly the best alternative to ensure their sustainable obtainment and make these ingredients more popular, although still full of challenging aspects. Stability and bioavailability limitations of these active molecules in food matrices have been increasingly studied, and a number of methods have been proposed to minimize these issues, among which the incorporation of a co-pigment, exclusion of O2 during processing and storage, and above all, microencapsulation and nanoencapsulation techniques. The most recent advances and challenges in the application of natural pigments and vitamins in functional foods, considering only reports of the last 5 years, were the focus of this chapter.

Yerba mate aqueous extract improves the oxidative and inflammatory states of rats with adjuvant-induced arthritis.

Healthy and adjuvant-induced arthritic rats were treated for 23 days with daily doses of 400 and 800 mg kg-1Ilex paraguariensis extract. This treatment (a) diminished the ROS levels in the liver and brain, (b) decreased oxidative protein and lipid damage in liver and brain, (c) increased the plasma antioxidant capacity, (d) increased the GSH levels and the GSH/GSSH ratio in both the liver and the brain, (e) almost restored the enzymatic activities linked to the metabolism of GSH-GSSG, and (f) reversed the modified activities of xanthine oxidase, superoxide dismutase and catalase. The anti-inflammatory actions (firstly) and the antioxidant actions (in the second place) of the yerba mate constituents (e.g., chlorogenic acid derivatives) are the causes of these beneficial effects. Daily ingestion of traditional yerba mate beverages may be effective in attenuating the symptoms of inflammatory diseases, especially in older adults.

Analysis of a whole diet in terms of phenolic content and antioxidant capacity: effects of a simulated gastrointestinal digestion.

This work compares the phenolic contents and the total antioxidant capacity of the 36 most popular Brazilian foods submitted to aqueous extraction or in vitro digestion. The purpose was to evaluate the extent by which digestion differs from the simple aqueous extraction procedures of several food matrices. After in vitro digestion, cereals, legumes, vegetables, tuberous vegetables, chocolates and fruits showed higher phenolic contents and higher antioxidant activities than those obtained by aqueous extraction. Contrarily, the digestion caused a reduction in the phenolic contents and antioxidant activities of beverages (red wine, coffee and yerba mate). Our results suggest that the phenolics of food groups with solid and complex matrix are protected against enzymatic action and alteration in pH during the digestion, what does not occur in liquid food matrices such as the beverages. This fact would overestimate the antioxidant activities of beverages submitted solely to aqueous extraction.