Disclosing the Antioxidant and Neuroprotective Activity of an Anthocyanin-Rich Extract from Sweet Cherry (Prunus avium L.) Using In Vitro and In Vivo Models

In this study, an autochthonous variety of sweet cherry (Prunus avium L.), namely “Moretta di Vignola”, was processed to prepare extracts rich in polyphenols, which were characterized by high-performance liquid chromatography (HPLC) separation coupled to UV/DAD and ESI-MSn analysis. Then, a sweet cherry anthocyanin-rich extract (ACE) was prepared, fully characterized and tested for its activity against Parkinson’s disease (PD) in cellular (BV2 microglia and SH-SY5Y neuroblastoma) and in Drosophila melanogaster rotenone (ROT)-induced model. The extract was also evaluated for its antioxidant activity on Caenorhabditis elegans by assessing nematode resistance to thermal stress. In both cell lines, ACE reduced ROT-induced cell death and it decreased, alone, cellular reactive oxygen species (ROS) content while reinstating control-like ROS values after ROT-induced ROS rise, albeit at different concentrations of both compounds. Moreover, ACE mitigated SH-SY5Y cell cytotoxicity in a non-contact co-culture assay with cell-free supernatants from ROT-treated BV-2 cells. ACE, at 50 µg/mL, ameliorated ROT (250 µM)-provoked spontaneous (24 h duration) and induced (after 3 and 7 days) locomotor activity impairment in D. melanogaster and it also increased survival and counteracted the decrease in fly lifespan registered after exposure to the ROT. Moreover, heads from flies treated with ACE showed a non-significant decrease in ROS levels, while those exposed to ROT markedly increased ROS levels if compared to controls. ACE + ROT significantly placed the ROS content to intermediate values between those of controls and ROT alone. Finally, ACE at 25 µg/mL produced a significant increase in the survival rate of nematodes submitted to thermal stress (35 °C, 6–8 h), at the 2nd and 9th day of adulthood. All in all, ACE from Moretta cherries can be an attractive candidate to formulate a nutraceutical product to be used for the prevention of oxidative stress-induced disorders and related neurodegenerative diseases

Influence of altitude on the physicochemical composition and antioxidant capacity of strawberry: a preliminary systematic review and meta-analysis

Several climatic trends are generally associated with altitude, that may influence the nutritional and phytochemical composition of plants. Strawberry is considered a functional food due to biological activities and health benefits. This systematic review and meta-analysis intend to expose possible variations on physicochemical composition and antioxidant capacity of strawberries in regard to altitude. Thirty eligible studies were included for the final meta-analysis. Two altitude ranges were established: 0 - 1000 and 1000-2000 m above sea level. A random-effects model was used to obtain the results. It was discovered that total soluble solids significantly decreased with altitude. Total titratable acidity increased with altitude. Vitamin C and total anthocyanins showed a significant difference between the groups before we discarded some studies. The analysis of altitude for phenolics and antioxidant capacity evaluated for the DPPH radical scavenging method did not identify any significant differences between the studies. The findings suggest that altitude does not affect the physicochemical composition and antioxidant capacity of strawberries; nonetheless, a more exhaustive study is recommended.[GRAPHICS]

Assessment of the in vivo antioxidant activity of an anthocyanin-rich bilberry extract using the Caenorhabditis elegans model

Anthocyanins have been associated with several health benefits, although the responsible mechanisms are not well established yet. In the present study, an anthocyanin-rich extract from bilberry (Vaccinium myrtillus L.) was tested in order to evaluate its capacity to modulate reactive oxygen species (ROS) production and resistance to thermally induced oxidative stress, using the nematode Caenorhabditis elegans as an in vivo model. The assays were carried out with the wild-type N2 strain and the mutant strains daf-16(mu86) I and hsf-1(sy441), which were grown in the presence of two anthocyanin extract concentrations (5 and 10 µg/mL in the culture medium) and further subjected to thermal stress. The treatment with the anthocyanin extract at 5 µg/mL showed protective effects on the accumulation of ROS and increased thermal resistance in C. elegans, both in stressed and non-stressed young and aged worms. However, detrimental effects were observed in nematodes treated with 10 µg/mL, leading to a higher worm mortality rate compared to controls, which was interpreted as a hormetic response. These findings suggested that the effects of the bilberry extract on C. elegans might not rely on its direct antioxidant capacity, but other mechanisms could also be involved. Additional assays were performed in two mutant strains with loss-of-function for DAF-16 (abnormal DAuer Formation factor 16) and HSF-1 (Heat Shock Factor 1) transcription factors, which act downstream of the insulin/insulin like growth factor-1 (IGF-1) signaling pathway. The results indicated that the modulation of these factors could be behind the improvement in the resistance against thermal stress produced by bilberry anthocyanins in young individuals, whereas they do not totally explain the effects produced in worms in the post-reproductive development stage. Further experiments are needed to continue uncovering the mechanisms behind the biological effects of anthocyanins in living organisms, as well as to establish whether they fall within the hormesis concept

Novel approaches in anthocyanin research - Plant fortification and bioavailability issues

Background: Anthocyanins are a major class of plant phenolic pigments, responsible for the red, purple or blue color of leaves, flowers, tubers, fruits and certain vegetables. They are considered the largest and most important group of water-soluble pigments in nature and have been described to have multiple health-promoting properties. However, the bioavailability of anthocyanins is reportedly extremely low, affected by factors inherent to the molecule's characteristics, as well as by the effect of food processing, transformations during the digestive process and their levels in fruits. Scope and approach: This review aims to discuss current knowledge regarding the effects of technological processes used in the food industry on the stability, bioavailability and biological effect of anthocyanins. In addition, a review of new trends in the improvement of anthocyanin production in plants is presented, which outlines what has been reported about genes involved in the regulation and its expression. Key findings and conclusions: The alterations that anthocyanins suffer, which can affect their bioavailability and biological effects, do not take place solely during the digestion process, caused mainly by pH and intrinsic and bacterial enzymes, but also during the different processing methods that food-containing anthocyanins can undergo. Factors such as thermal and non-thermal processing, storage, oxidative degradation and encapsulation systems have been shown to closely influence anthocyanins' stability and biological effects. In recent times, genetic manipulation aiming at upregulating the gene expression of metabolic pathways has been used to improve fruit quality and anthocyanin content in plant foods, and may also contribute towards counteracting some of the indicated limitations

Protective effect of the medicinal herb infusion “horchata” against oxidative damage in cigarette smokers: An ex vivo study

Cigarette smoking has been associated with an increase in oxidative stress (OS) and is considered a predisposing factor to chronic noncommunicable diseases, whilst dietary antioxidants has been proposed as an alternative to cope with this oxidative stress. In this study, 20 smokers and 20 non-smokers were studied with the aim of determining their antioxidant status, as well as the ability of an infusion of 23 medicinal plants, to counteract the damage caused by OS. The plasma, red blood cells (RBCs) and polymorphonuclear cells (PBMCs) of both groups were incubated or not with the horchata infusion extract and then the OS markers, genotoxicity, nanostructure of RBCs membrane and genes related to oxidative responses and cellular functionality were evaluated. Up to 33 different compounds, mainly quercetin glycosides, were identified in the extract. A significant deterioration in the antioxidant status in smokers compared to non-smokers was found. The horchata infusion extract improved the nanostructure of RBCs and DNA damage, as well as the activity of the endogenous antioxidant enzymes and markers of oxidative damage to lipid, and proteins in plasma, RBCs and PBMCs in both groups, whilst no significant changes were found in the expression of different genes related to OS response

Roots and rhizomes of wild Asparagus: Nutritional composition, bioactivity and nanoencapsulation of the most potent extract

The nutritional composition and bioactive properties of roots and rhizomes of Asparagus stipularis were evaluated. Antioxidant activity of extracts obtained by infusion was evaluated using free radicals scavenging and reducing power methods. Porcine liver primary cell was used to check the hepatotoxicity of infusions. Results revealed that Asparagus samples are likely a source of nutrients, such as dietary fibre and essential fatty acids. HPLC-DAD-ESI/MS characterization of infusions allowed the identification and quantitation of 7 phenolic compounds, all hydroxycinnamoyl derivatives, with caffeic acid as the most abundant. Roots infusion contained the highest amounts of these compounds. It also exhibited the highest antioxidant activity in all assays, with EC50 values of 0.44 ± 0.01, 0.98 ± 0.03 and 0.64 ± 0.01 mg/mL for DPPH, ABTS and FRAP assays, respectively, with no toxicity towards PLP2 primary cell cultures (GI50 > 400 μg/mL). PLGA nanoparticles loaded with root extract were prepared using solvent-evaporation double emulsion method. Nanoparticles size was about 260 nm and a polydispersity index around 0.1, with a zeta potential of about -36 mV, as well as a good encapsulation efficiency of approximately 83%. Their morphology was analysed by SEM and spherical polymeric nanoparticles with a smooth surface were observed. FTIR and DSC were also performed, which allowed corroborating the efficacy of the encapsulation and to confirm the production of a stable and robust system to load Asparagus extracts. The developed nanoparticles are expected to be used as delivery systems for bioactive compounds of A. stipularis and they could be used as an innovative dietary supplement