Human urine metabolomic signature after ingestion of polyphenol-rich juice of purple grumixama (Eugenia brasiliensis Lam.)

Emerging berries from the Brazilian Amazon and Atlantic Forest biomes: new sources of bioactive compounds with potential health benefits

Brazil has a broad geographic biodiversity spread across its six different biomes. However, it has been suffering from the abusive exploitation of its resources, which poses a threat to the local fauna and flora. The Amazon and Atlantic Forest, for example, are birthplaces to rare and edible native species, such as bacaba (Oenocarpus bacaba, Arecaceae) and camu-camu (Myrciaria dubia, Myrtaceae), and cereja-do-Rio Grande (Eugenia involucrata, Myrtaceae) and grumixama (Eugenia brasiliensis, Myrtaceae), respectively. These plants produce fruits which are sources of macro and micronutrients, including sugars, dietary fibers, vitamins, minerals, and/or lipids. Nutritionally, their consumption have the ability to reach partially or totally the daily recommendations for adults of some nutrients. More recently, these fruits have also been exposed as interesting sources of minor bioactive compounds, such as carotenoids, terpenes, and/or polyphenols, the latter which include anthocyanins, phenolic acids, and tannins. Particularly, bacaba stands out for being a rich source of polyunsaturated fatty acids (around 22%, dry weight) and dietary fibers (6.5-21%, dry weight); camu-camu has very high contents of vitamin C (up to 5000 mg per 100 g of pulp, dry basis); and cereja-do-Rio-Grande and grumixama are abundant sources of anthocyanins. Although they are still underexplored, several in vitro and in vivo studies with different parts of the fruits, including the peel, seed, and pulp, indicate their health potential through anti-oxidative, anti-obesity, antihyperglycemic, antidyslipidemic, antimicrobial, and/or anticancer effects. All things considered, the focus of this research was to highlight the bioactive potential and health impact of native fruits from the Amazon and Atlantic Forest biomes.

Brazilian berry waste as a source of bioactive compounds: grumixama (Eugenia brasiliensis Lam.) as a case study

Grumixama, Eugenia brasiliensis Lam., is a Brazilian berry little explored commercially and scientifically. However, local small producers market this fruit in the form of frozen pulp, which generates bioresidues, composed of seeds and peels. With the view to propose strategies for valuing grumixama, this study aimed to determine the chemical composition and assess the bioactivities of the hydroethanolic extracts of the whole residue (GR), seed (GS) and peel (GP) fractions of E. brasiliensis. From the results, GP had the highest concentration of organic acids (oxalic, malic, ascorbic and citric acids), total tocopherols, condensed tannins, anthocyanins, and other flavonoids. On the other hand, GS showed the highest content of monounsaturated fatty acids and hydrolysable tannins, whereas GR displayed a mixture of compounds detected in each of its parts. Regarding the bioactivities, low extract concentrations were required in two in vitro antioxidant assays, namely TBARS (EC₅₀ = 0.90-1.34 μg mL^-1) and OxHLIA (IC₅₀ = 21-65 μg mL^-1). Furthermore, GP had the highest inhibition activity of cellular oxidation in the CAA assay (80 ± 0.6%), while GS showed the highest anti-inflammatory activity via nitric oxide production inhibition (EC₅₀ = 98.0 ± 0.5 μg mL^-1). All samples induced cell growth inhibition of the tested tumor cells (GI₅₀ = 14.7-186 μg mL^-1) besides antibacterial and antifungal effects at low concentrations, but all samples were harmful to normal cells at moderate concentrations (GI₅₀ = 145-268 μg mL^-1). Therefore, E. brasiliensis residue could be a good source of bioactive compounds to be used in several areas. However, additional studies are needed to confirm its safety as well as to unravel the mechanisms behind its biological activities.

Bioactive compounds, antioxidant capacity and anti-inflammatory activity of native fruits from Brazil

The purpose of this study was to extract, identify, and quantify the phenolic compounds in grumixama (Eugenia brasilienses Lam.) and guabiju (Myrcianthes pungens), native fruits from southern region of Brazil, and to explore their antioxidant and anti-inflammatory properties. The phenolic compounds were extracted with acidified water and acidified methanol and evaluated for their bioactive constituents, antioxidant capacity, and anti-inflammatory properties. Spectrophotometric quantification shows tannins to be the most prevalent at 2.3 to 5.8 g/100g fresh fruit with acidified methanol containing higher concentrations of different phenolics than acidified water. HPLC analysis indicates that gallic acid, catechin, vanillic acid, and ellagic acid are the most prevalent phenolics in the two fruits extracts. Scavenging of DPPH and NO radicals showed inhibition by as much as 95% and 80%, respectively, at 2.5 gallic acid equivalent (GAE)/mL of the extract. At 50 μg GAE/mL, the release of pro-inflammatory molecules NO and IL-6 was significantly reduced with acidified methanol extract having higher inhibitory activity. Our results revealed that these native fruits, grown in the south of Brazil, are rich sources of phenolic compounds and have great antioxidant and anti-inflammatory activity.

Purple grumixama anthocyanins (Eugenia brasiliensis Lam.) attenuate obesity and insulin resistance in high-fat diet mice

Some polyphenols have been reported to modulate the expression of several genes related to lipid metabolism and insulin signaling, ameliorating metabolic disorders. We investigated the potential for the polyphenols of two varieties of grumixama, the purple fruit rich in anthocyanins and the yellow fruit, both also rich in ellagitannins, to attenuate obesity-associated metabolic disorders. Mice were fed a high fat and high sucrose diet, supplemented daily with yellow and purple extracts (200 mg per kg of body weight) for eight weeks. Purple grumixama supplementation was found to decrease body weight gain, improve insulin sensitivity and glucose-induced hyperinsulinemia, and reduce hepatic triglyceride accumulation. A decrease in intrahepatic lipids in mice treated with the purple grumixama extract was associated with lipid metabolism modulation by the PPAR signaling pathway. LPL, ApoE, and LDLr were found to be down-regulated, while Acox1 and ApoB were found to be upregulated. Some of these genes were also modulated by the yellow extract. In addition, both extracts decreased oGTT and plasma LPS. The results were associated with the presence of phenolic acids and urolithins. In conclusion, most likely the anthocyanins from the purple grumixama phenolic extract is responsible for reducing obesity and insulin resistance.

Identification of Milk and Cheese Intake Biomarkers in Healthy Adults Reveals High Interindividual Variability of Lewis System-Related Oligosaccharides

BACKGROUND

The use of biomarkers of food intake (BFIs) in blood and urine has shown great promise for assessing dietary intake and complementing traditional dietary assessment tools whose use is prone to misreporting.

OBJECTIVE

Untargeted LC-MS metabolomics was applied to identify candidate BFIs for assessing the intake of milk and cheese and to explore the metabolic response to the ingestion of these foods.

METHODS

A randomized controlled crossover study was conducted in healthy adults [5 women, 6 men; age: 23.6 ± 5.0 y; BMI (kg/m2): 22.1 ± 1.7].  After a single isocaloric intake of milk (600 mL), cheese (100 g), or soy-based drink (600 mL), serum and urine samples were collected postprandially up to 6 h and after fasting after 24 h. Untargeted metabolomics was conducted using LC-MS. Discriminant metabolites were selected in serum by multivariate statistical analysis, and their mass distribution and postprandial kinetics were compared.

RESULTS

Serum metabolites discriminant for cheese intake had a significantly lower mass distribution than metabolites characterizing milk intake (P = 4.1 × 10-4). Candidate BFIs for milk or cheese included saccharides, a hydroxy acid, amino acids, amino acid derivatives, and dipeptides. Two serum oligosaccharides, blood group H disaccharide (BGH) and Lewis A trisaccharide (LeA), specifically reflected milk intake but with high interindividual variability. The 2 oligosaccharides showed related but opposing trends: subjects showing an increase in either oligosaccharide did not show any increase in the other oligosaccharide. This result was confirmed in urine.

CONCLUSIONS

New candidate BFIs for milk or cheese could be identified in healthy adults, most of which were related to protein metabolism. The increase in serum of LeA and BGH after cow-milk intake in adults calls for further investigations considering the beneficial health effects on newborns of such oligosaccharides in maternal milk. The trial is registered at clinicaltrials.gov as NCT02705560.