Bilberry (Vaccinium myrtillus L.) Extracts Comparative Analysis Regarding Their Phytonutrient Profiles, Antioxidant Capacity along with the In Vivo Rescue Effects Tested on a Drosophila melanogaster High-Sugar Diet Model

Bilberries (Vaccinium myrtillus L.) have been reported to hold a plentitude of health-promoting properties beyond basic nutrition, mainly attributed to their anthocyanin content and antioxidant activity. In this article, we built the phytochemical profile of three wild bilberry fruit extract formulations (aqueous, methanolic, and hydro-methanolic) using UHPLC-ESI-MS/MS putative analysis, identifying 88 individual phytochemicals, mainly flavonoids (total content 8.41 ± 0.11 mg QE/g dw), free amino acids, polyphenols (total content 21.68 ± 0.19 mg GAE/g dw), carboxylic acids, and vitamins. Furthermore, the antioxidant activity of the extract was assessed, reaching 78.03 ± 0.16% DPPH free radical scavenging activity, comparable to literature values determined for bilberry extracts of other origin. Due to the increased prevalence of metabolic syndrome and based on the reviewed benefits of bilberries, we tested the most potent formulation of our bilberry extracts in this biological context. The in vivo rescue effect of a bilberry extract supplemented diet on Drosophila melanogaster was assessed by monitoring biochemical and genomic markers. Hemolymph trehalose levels were halved upon addition of 3% hydro-methanolic bilberry extract to a high-sugar (1.5 M sucrose) diet, as compared to the non-supplemented high-sugar diet. Noteworthy, the rescue seen for flies kept on the bilberry extract supplemented high-sugar diet appeared to parallel the trehalose levels observed in the case of the control diet (50 mM sucrose) flies. Moreover, next to the trehalose-lowering type of in vivo effects, other gene expression related rescues were also detected for genes such as InR, Akh, AstA, AstC, Irk, Npc2g, and CCHa2 upon supplementation of the high-sugar diet with our hydro-methanolic bilberry fruit extract. Our findings suggest that such a bilberry fruit extract could generate physiological and genomic type of compensatory mechanisms so that further translational approaches would advance the understanding of some human specific pathological conditions.

Characterization of Andean Blueberry in Bioactive Compounds, Evaluation of Biological Properties, and In Vitro Bioaccessibility

The aim of this study was to evaluate Andean blueberries (Vaccinium floribundum Kunth) from Ecuador as a potential functional ingredient for the food and pharmaceutical industries. The analysis of bioactive compounds by HPLC–DAD–MSⁿ determined a high content of (poly)phenols, mainly anthocyanins, and the presence of the carotenoid lutein. Regarding its biological properties, Andean blueberry did not show toxicity by the zebrafish embryogenesis test, showing also a lack of the antinutrients lectins. Moreover, the results of in vitro and in vivo antioxidant capacity evaluation suggested its possibility to be used as natural antioxidant. This fruit also exhibited antimicrobial activity toward Staphylococcus aureus and Escherichia coli in low doses. Finally, in vitro gastrointestinal (GI) digestion showed a partial bioaccessibility of (poly) phenols (~50% at the final step), showing high antioxidant capacity in the different GI phases. These results revealed Andean blueberry as an interesting candidate for being used as a functional ingredient and the development of further in vivo and clinical assays.

Vaccinium Extracts as Modulators in Experimental Type 1 Diabetes

Antihyperglycemic effects of four extracts obtained from leaves and fruits of Vaccinium myrtillus and Vaccinium corymbosum were assessed in diabetic rats. In addition, the effects of extracts on diabetic-related complications such as the development of diabetic cataract and oxidative stress were evaluated. Type 1 diabetes was induced with a single dose of streptozotocin in Wistar rats. The rats were randomly divided into seven equal groups: NC-normal control, DC-diabetic control, PC-positive control treated with metformin, VML-received V. myrtillus leaf extract, VMLF-received VML and fruit extract, VCL-received V. corymbosum leaf extract, and VCLF-received VCL and fruit extract. Body weight and glucose levels were monitored every second week. After 8 weeks of treatment, serum glucose, insulin, and malondialdehyde were measured. Lenses were removed after sacrifice and eight lenses from each group were randomly selected for evaluation of cataract development. A decrease in body weight was observed in all diabetic groups in the first weeks. In the VML group, no significant decrease was observed. Glucose levels during the experiment were high in DC, PC, and VCL groups, with no improvement during the 8 weeks. In VML, VMLF, and VCLF groups, a decrease in blood glucose levels was observed. Similar results regarding serum insulin and glucose levels at the end of the experiment were observed within groups. V. myrtillus extracts prevented the development of cataract compared with the DC group (P < .05).