Evaluation of Polyphenol Anthocyanin-Enriched Extracts of Blackberry, Black Raspberry, Blueberry, Cranberry, Red Raspberry, and Strawberry for Free Radical Scavenging, Reactive Carbonyl Species Trapping, Anti-Glycation, Anti-β-Amyloid Aggregation, and Microglial Neuroprotective Effects

Abstract

Glycation is associated with several neurodegenerative disorders, including Alzheimer’s disease (AD), where it potentiates the aggregation and toxicity of proteins such as β-amyloid (Aβ). Published studies support the anti-glycation and neuroprotective effects of several polyphenol-rich fruits, including berries, which are rich in anthocyanins. Herein, blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts were evaluated for: (1) total phenolic and anthocyanins contents, (2) free radical (DPPH) scavenging and reactive carbonyl species (methylglyoxal; MGO) trapping, (3) anti-glycation (using BSA-fructose and BSA-MGO models), (4) anti-Aβ aggregation (using thermal- and MGO-induced fibrillation models), and, (5) murine microglia (BV-2) neuroprotective properties. Berry crude extracts (CE) were fractionated to yield anthocyanins-free (ACF) and anthocyanins-enriched (ACE) extracts. The berry ACEs (at 100 μg/mL) showed superior free radical scavenging, reactive carbonyl species trapping, and anti-glycation effects compared to their respective ACFs. The berry ACEs (at 100 μg/mL) inhibited both thermal- and MGO-induced Aβ fibrillation. In addition, the berry ACEs (at 20 μg/mL) reduced H2O2-induced reactive oxygen species production, and lipopolysaccharide-induced nitric oxide species in BV-2 microglia as well as decreased H2O2-induced cytotoxicity and caspase-3/7 activity in BV-2 microglia. The free radical scavenging, reactive carbonyl trapping, anti-glycation, anti-Aβ fibrillation, and microglial neuroprotective effects of these berry extracts warrant further in vivo studies to evaluate their potential neuroprotective effects against AD.

A New Italian Purple Corn Variety (Moradyn) Byproduct Extract: Antiglycative and Hypoglycemic In Vitro Activities and Preliminary Bioaccessibility Studies

“…Our antiglycative results are in agreement with the ones previously reported in the literature for berry extracts rich in polyphenols and especially in anthocyanins, which exhibited a strong AGEs inhibitory activity [48]. Moreover, several works also suggested that food byproducts rich in polyphenols are positively correlated with hypoglycemic [51] and antiglycative activities [10,51,52].…”

“…Several authors previously reported the antiglycative activity of different plant extracts mainly containing polyphenols [13,43,46]; in particular, anthocyanins showed a high effectiveness against protein glycation induced by monosaccharides and methylglyoxal (MGO) [47][48][49].…”

Arbuscular Mycorrhizal Fungi Modulate the Crop Performance and Metabolic Profile of Saffron in Soilless Cultivation

“…Saffron root colonisation by AMF could be affected by the cultivation conditions related to the substrate composition, root temperature or the presence of antagonistic fungi naturally occurring in the soil [31,40,41,76]. In our recent studies, AM fungal colonisation was noted in C. sativus roots inoculated with Ri and Ri+Fm, both in soilless (Figures 1 and 2) and in open field conditions [12].…”

“…fruits, that showed also higher content of gallic acid, ellagic acid, catechin, and epicatechin was generally lower in saffron (on average circa −75%, −70%, −92%, and −95%, respectively) [73,75]. Lastly, the content of anthocyanins, that are suggested to have neuroprotective properties [76], was up to 11654.5 mg C3G 100g −1 DW, i.e., a value very high in comparison to fresh fruit extracts from Morus nigra, Rubus idaeus L., and Fragaria ananassa D. (80.0, 33.7, and 35.2 mg C3G 100g −1 , respectively) [75].…”

Extraction of bioactive compounds from purple corn using emerging technologies: A review

“…According to the studies carried out, the purple corn extract contains more phenolic compounds than ethanolic grape skin extracts (0.462 mg gallic acid/g sample), raw blackberry extracts (0.07 mg gallic acid/g sample), and raw blueberry extracts (0.1 mg gallic acid/g sample) (Caldas et al., 2018; Ma et al., 2018).…”