Nanoencapsulation of Vaccinium ashei Leaf Extract in Eudragit® RS100-Based Nanoparticles Increases Its In Vitro Antioxidant and In Vivo Antidepressant-like Actions.

Depression is a major psychiatric disorder in Brazil and worldwide. Vaccinium ashei (V. ashei) leaves are cultivation by-products with high bioactive compound levels. Here, a hydroalcoholic extract of V. ashei leaves (HEV) was associated with Eudragit® RS100-based nanoparticles (NPHEV) to evaluate the in vitro antioxidant and in vivo antidepressant-like effects. Interfacial deposition of the preformed polymer method was used for NPHEV production. The formulations were evaluated regarding physicochemical characteristics, antioxidant activity (DPPH radical scavenging and oxygen radical absorbance capacity), and antidepressant-like action (1-25 mg/kg, single intragastric administration) assessed in forced swimming and tail suspension tests in male Balb-C mice. The NPHEV presented sizes in the nanometric range (144-206 nm), positive zeta potential values (8-15 mV), polydispersity index below 0.2, and pH in the acid range. The phenolic compound content was near the theoretical values, although the rutin presented higher encapsulation efficiency (~95%) than the chlorogenic acid (~60%). The nanoencapsulation improved the HEV antioxidant effect and antidepressant-like action by reducing the immobility time in both behavioral tests. Hence, Eudragit® RS100 nanoparticles containing HEV were successfully obtained and are a promising alternative to manage depression.

Hydroalcoholic leaves extract of Vaccinium ashei Reade promotes cell cycle arrest and apoptosis on T-cell acute lymphoblastic leukemia.

Vaccinium ashei Reade, popularly known as Rabbiteye blueberry, has several therapeutic properties attributed to the phenolic compounds present in its leaves and fruits. Here, we sought to evaluate the effects of the hydroalcoholic extract from V. ashei leaves (Bluegem cultivar, VAB) in T-cell Acute lymphoblastic leukemia (T-ALL). The VAB extract was toxic to T-ALL cells at the ∼60 µg/ml concentration. T-ALL cell death occurred through apoptosis. VAB extract was found to induce micronuclei formation, p53 pathway activation, and cell cycle arrest. Those mutagenic effects were evidenced through microscopy analysis and molecular p53 pathway activation. A series of phenolic compounds were identified in VAB extract by mass spectrometry, such as vanillic acid, catechin, caffeic acid, chlorogenic acid, rutin, coumaric acid, taxifolin, quercetin and naringenin, some of which are presumed to induce DNA damage. In conclusion, the V. ashei leaves extract may have important secondary metabolites with antileukemic properties.

Influence of Harvest Season and Cultivar on the Variation of Phenolic Compounds Composition and Antioxidant Properties in Vaccinium ashei Leaves.

The effect of variation of harvest season and cultivar on the total phenolic content (TPC), total flavonoid content (TFC), HPLC-UV/DAD profile and antioxidant properties in Vaccinium ashei (Rabbiteye blueberry) leaves grown in Brazil was evaluated. The cultivars collected in December and March were Aliceblue, Powderblue, Climax, Bluegem and FloridaM. It was observed that leaves from March had the highest TPC values (222 ± 1 mg gallic acid equivalents/g to Aliceblue cultivar) and highest TFC values (49.8 ± 0.8 and 48.7 ± 0.7 µg rutin/g to Clímax and Powderblue cultivars, respectively). The chromatographic profile was quantitatively similar, however, the proportions of each compound were influenced by cultivar and harvest season. Chlorogenic acid and rutin were the main identified phenolic compounds, but chlorogenic acid was the most abundant in both harvest seasons. Antioxidant capacities values ranged from 5.80 ± 0.04 to 105 ± 2 µg/mL (DPPH) and 178 ± 5 to 431 ± 8 mmol Trolox/100 g (ORAC). The cultivar Bluegem by March had the highest values in both assays. The results indicate that the blueberry leaves from different cultivars and harvest seasons have different phenolic compounds content and different antioxidant capacities. In addition, the antioxidant properties demonstrated a high correlation with rutin content.