Cell-Line Specific Protection by Berry Polyphenols Against Hydrogen Peroxide Challenge and Lack of Effect on Metabolism of Amyloid Precursor Protein

Polyphenols and neuroprotection: Therapeutic implications for cognitive decline

Dietary polyphenols have been the focus of major interest for their potential benefits on human health. Several preclinical studies have been conducted to provide a rationale for their potential use as therapeutic agents in preventing or ameliorating cognitive decline. However, results from human studies are scarce and poorly documented. The aim of this review was to discuss the potential mechanisms involved in age-related cognitive decline or early stage cognitive impairment and current evidence from clinical human studies conducted on polyphenols and the aforementioned outcomes. The evidence published so far is encouraging but contrasting findings are to be taken into account. Most studies on anthocyanins showed a consistent positive effect on various cognitive aspects related to aging or early stages of cognitive impairment. Studies on cocoa flavanols, resveratrol, and isoflavones provided substantial contrasting results and further research is needed to clarify the therapeutic potential of these compounds. Results from other studies on quercetin, green tea flavanols, hydroxycinnamic acids (such as chlorogenic acid), curcumin, and olive oil tyrosol and derivatives are rather promising but still too few to provide any real conclusions. Future translational studies are needed to address issues related to dosage, optimal formulations to improve bioavailability, as well as better control for the overall diet, and correct target population.

Neuropharmacological studies of ethanolic extract of Vaccinium corymbosum on Alzheimer’s type dementia and catatonia in Swiss albino mice

Introduction: Neuroactive herbal drugs enriched with antioxidants are valuable in treating neurocognitive dysfunction and Vaccinium corymbosum, enriched with antioxidant phytochemicals, is used for treating memory disorders. Hence, the present study evaluated the neuroprotective effects of ethanolic extract of Vaccinium corymbosum (EEVC) on aluminium chloride(AlCl3)-induced Alzheimer’s type of dementia and haloperidol-induced catalepsy-associated behavioural changes. Methods:In vitro antioxidant potential was evaluated using 1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS). The total phenolic content (TPC) was quantified. For in vivo studies, AlCl3 (100 mg/kg) was orally administered for 42 days, whereas the EEVC was administered on the 21st day until the 42nd day in two doses (200 mg/kg and 400 mg/kg). In the haloperidol-induced group, EEVC was treated for 21 days, and haloperidol (1 mg/kg) was administered to induce behavioural changes. Open-field, Y-Maze and traction tests were performed, and the mice brain acetylcholinesterase (AChE) enzyme was determined. Results: IC50 values in DPPH and ABTS assays were 85.5 μg/mL and 80 μg/mL, respectively and the total phenolic content of EEVC was found to be 0.166 mg. In a behavioral study, animals treated with 200 mg/kg and 400 mg/kg of EEVC exhibited a neuroprotective impact on AlCl3-induced neurodegeneration and haloperidol-induced behavioral changes with significant inhibition (P < 0.05 and P < 0.01, respectively) in acetylcholinesterase enzyme. Conclusion: The neuroprotection by EEVC postulated that it is a promising therapeutic agent for treating behavioral and cognitive dysfunctions. Further investigations on pro-inflammatory cytokine and neuroendocrine regulation in transgenic Alzheimer’s disease (AD)models complement the therapeutic value of V. corymbosum.

The Anti-Neuroinflammatory Role of Anthocyanins and Their Metabolites for the Prevention and Treatment of Brain Disorders

Anthocyanins are naturally occurring polyphenols commonly found in fruits and vegetables. Numerous studies have described that anthocyanin-rich foods may play a crucial role in the prevention and treatment of different pathological conditions, which have encouraged their consumption around the world. Anthocyanins exhibit a significant neuroprotective role, mainly due to their well-recognized antioxidant and anti-inflammatory properties. Neuroinflammation is an intricate process relevant in both homeostatic and pathological circumstances. Since the progression of several neurological disorders relies on neuroinflammatory process, targeting brain inflammation has been considered a promising strategy in those conditions. Recent data have shown the anti-neuroinflammatory abilities of many anthocyanins and of their metabolites in the onset and development of several neurological disorders. In this review, it will be discussed the importance and the applicability of these polyphenolic compounds as neuroprotective agents and it will be also scrutinized the molecular mechanisms underlying the modulation of neuroinflammation by these natural compounds in the context of several brain diseases.

Blueberry Counteracts BV-2 Microglia Morphological and Functional Switch after LPS Challenge

Microglia, the innate immune cells of the CNS, respond to brain injury by activating and modifying their morphology. Our study arises from the great interest that has been focused on blueberry (BB) for the antioxidant and pharmacological properties displayed by its components. We analyzed the influence of hydroalcoholic BB extract in resting or lipopolysaccharide (LPS)-stimulated microglia BV-2 cells. BB exerted a protective effect against LPS-induced cytotoxicity, as indicated by cell viability. BB was also able to influence the actin cytoskeleton organization, to recover the control phenotype after LPS insult, and also to reduce LPS-driven migration. We evaluated the activity of Rho and Rac1 GTPases, which regulate both actin cytoskeletal organization and migratory capacity. LPS caused an increase in Rac1 activity, which was counteracted by BB extract. Furthermore, we demonstrated that, in the presence of BB, mRNA expression of pro-inflammatory cytokines IL-1β, IL-6 and TNF-α decreased, as did the immunofluorescence signal of iNOS, whereas that of Arg-1 was increased. Taken together, our results show that, during the inflammatory response, BB extract shifts the M1 polarization towards the M2 phenotype through an actin cytoskeletal rearrangement. Based on that, we might consider BB as a nutraceutical with anti-inflammatory activities.

Butiá fruit extract (Butia eriospatha) protects against oxidative damage and increases lifespan on Caenorhabditis elegans

Butiá (Butia eriospatha) is a fruit of a palm tree belonging to the family Arecaceae, native to South America. The aim of this study was to evaluate the antioxidant potential of butiá extract using Caenorhabditis elegans as animal model. Initially, we performed survival experiments, reproduction, resistance to oxidative stress (post or pre-treatment with paraquat or hydrogen peroxide), longevity, superoxide dismutase, and catalase GFP reporters' expression. We observed that butiá extract did not affect the worms' survival. Similarly, egg laying also showed no significant difference between treatments. None of the extract concentrations tested was able to significantly protect or reverse paraquat-induced oxidative stress. However, they were able to reverse the oxidative damage induced by hydrogen peroxide. In addition, butiá extract increased C. elegans lifespan under stress and not per se. Our results demonstrate that the Butiá is able to extend the lifespan of the nematode C. elegans and that this effect may be mediated by an induced resistance to oxidative stress. PRACTICAL APPLICATIONS: The practical applications of this research are to expand and bring scientific knowledge to the population about the benefits of the consumption of this native fruit from the southern region of Brazil. Many fruits and other plant foods are consumed and spread with benefits without proper scientific proof of these benefits. This fruit is widely cultivated and its production and consumption can be expanded from these results. Still, we point out that this is the first time that the benefits of this fruit are studied.

Biochemical Properties and Neuroprotective Effects of Compounds in Various Species of Berries

Several species of berries, such as blueberries (Vaccinium angustifolium) and lingonberries (Vaccinium vitis-idaea L.), have attracted much scientific attention in recent years, especially due to their reported antioxidant and anti-inflammatory properties. Berries, as with other types of plants, have developed metabolic mechanisms to survive various environmental stresses, some of which involve reactive oxygen species. In addition, the fruits and leaves of berries have high amounts of polyphenols, such as flavonoids, which act as potent antioxidants. These compounds could potentially be beneficial for brain aging and neurodegenerative disorders. There are now several studies documenting the beneficial effects of various berries in cell models of neurotoxicity as well as in vivo models of neurodegenerative disease. In the current review, we discuss the metabolic strategies that plants and animals have developed in order to combat reactive oxygen species. We then discuss issues of bioavailability of various compounds in mammals and provide a synopsis of studies demonstrating the neuroprotective ability of berries and polyphenols. We also summarize findings from our own research group. For example, we have detected various polyphenols in samples of blueberries and lingonberries and have found that the leaves have a much higher antioxidant capacity than the fruits. Extracts from these species have also demonstrated neuroprotective effects in cellular models of toxicity and inflammation, which are being further pursued in animal models.