An assessment of the rescue action of resveratrol in parkin loss of function-induced oxidative stress in Drosophila melanogaster

Resveratrol Inhibits VDAC1-Mediated Mitochondrial Dysfunction to Mitigate Pathological Progression in Parkinson's Disease Model

An increase in α-synuclein (α-syn) levels and mutations in proteins associated with mitochondria contribute to the development of familial Parkinson's disease (PD); however, the involvement of α-syn and mitochondria in idiopathic PD remains incompletely understood. The voltage-dependent anion channel I (VDAC1) protein, which serves as a crucial regulator of mitochondrial function and a gatekeeper, plays a pivotal role in governing cellular destiny through the control of ion and respiratory metabolite flux. The ability of resveratrol (RES), which is a potent phytoalexin with antioxidant and anti-inflammatory properties, to regulate VDAC1 in PD is unknown. The objective of this study was to evaluate the role of VDAC1 in the pathological process of PD and to explore the mechanism by which resveratrol protects dopaminergic neurons by regulating VDAC1 to maintain the mitochondrial permeability transition pore (mPTP) and calcium ion balance. The effects of RES on the motor and cognitive abilities of A53T mice were evaluated by using small animal behavioral tests. Various techniques, including immunofluorescence staining, transmission electron microscopy, enzyme-linked immunoadsorption, quantitative polymerase chain reaction (PCR), and Western blotting, among others, were employed to assess the therapeutic impact of RES on neuropathy associated with PD and its potential in regulating mitochondrial VDAC1. The findings showed that RES significantly improved motor and cognitive dysfunction and restored mitochondrial function, thus reducing oxidative stress levels in A53T mice. A significant positive correlation was observed between the protein expression level of VDAC1 and mitochondrial α-syn expression, as well as disease progression, whereas no such correlation was found in VDAC2 and VDAC3. Administration of RES resulted in a significant decrease in the protein expression of VDAC1 and in the protein expression of α-syn both in vivo and in vitro. In addition, we found that RES prevents excessive opening of the mPTP in dopaminergic neurons. This may prevent the abnormal aggregation of α-syn in mitochondria and the release of mitochondrial apoptosis signals. Furthermore, the activation of VDAC1 reversed the resveratrol-induced decrease in the accumulation of α-syn in the mitochondria. These findings highlight the potential of VDAC1 as a therapeutic target for PD and identify the mechanism by which resveratrol alleviates PD-related pathology by modulating mitochondrial VDAC1.

Antioxidant responses driven by Hesperetin and Hesperidin counteract Parkinson's disease-like phenotypes in Drosophila melanogaster

The study investigated the protective effects of Hesperetin (HSP) and Hesperidin (HSD) on 1 methyl, 4 phenyl, 1,2,3,6 tetrahydropyridine hydrochloride (MPTP)-induced Parkinsonism in Drosophila melanogaster (D. melanogaster). After a lifespan study to select exposure time and concentrations, flies were co-exposed to MPTP (0.4 mg/g diet), Hesperetin (0.2 and 0.4 mg/g diet), and Hesperidin (0.1 and 0.4 mg/g) for 7 days. In addition to in vivo parameters, we assayed some markers of oxidative stress and antioxidant status (lipid peroxidation, protein carbonylation, thiol content, hydrogen peroxide, and nitrate/nitrite levels, mRNA expression of Keap-1 (Kelch-like ECH associated protein 1), /Nrf2 (Nuclear factor erythroid 2 related factor 2), catalase, and glutathione-S-transferase (GST) activities), and cholinergic (acetyl cholinesterase activity (AChE) and dopaminergic signaling content and the mRNA expression of tyrosine hydroxylase (TH), monoamine oxidase (MAO-like) activity). In addition to increasing the lifespan of flies, we found that both flavonoids counteracted the adverse effects of MPTP on survival, offspring emergence, and climbing ability of flies. Both flavonoids also reduced the oxidative damage on lipids and proteins and reestablished the basal levels of pro-oxidant species and activities of antioxidant enzymes in MPTP-exposed flies. These responses were accompanied by the normalization of the mRNA expression of Keap1/Nrf2 disrupted in flies exposed to MPTP. MPTP exposure also elicited changes in mRNA expression and content of TH as well as in MAO and AChE activity, which were reversed by HST and HSD. By efficiently hindering the oxidative stress in MPTP-exposed flies, our findings support the promising role of Hesperetin and Hesperidin as adjuvant therapy to manage Parkinsonism induced by chemicals such as MPTP.

Therapeutic potential of stilbenes in neuropsychiatric and neurological disorders: A comprehensive review of preclinical and clinical evidence

Neuropsychiatric disorders are anticipated to be a leading health concern in the near future, emphasizing an outstanding need for the development of new effective therapeutics to treat them. Stilbenes, with resveratrol attracting the most attention, are an example of multi-target compounds with promising therapeutic potential for a broad array of neuropsychiatric and neurological conditions. This review is a comprehensive summary of the current state of research on stilbenes in several neuropsychiatric and neurological disorders such as depression, anxiety, schizophrenia, autism spectrum disorders, epilepsy, traumatic brain injury, and neurodegenerative disorders. We describe and discuss the results of both in vitro and in vivo studies. The majority of studies concentrate on resveratrol, with limited findings exploring other stilbenes such as pterostilbene, piceatannol, polydatin, tetrahydroxystilbene glucoside, or synthetic resveratrol derivatives. Overall, although extensive preclinical studies show the potential benefits of stilbenes in various central nervous system disorders, clinical evidence on their therapeutic efficacy is largely missing.

Exploring the Efficient Natural Products for the Therapy of Parkinson's Disease via Drosophila Melanogaster (Fruit Fly) Models

Parkinson's disease (PD) is a severe neurodegenerative disorder, partly attributed to mutations, environmental toxins, oxidative stress, abnormal protein aggregation, and mitochondrial dysfunction. However, the precise pathogenesis of PD and its treatment strategy still require investigation. Fortunately, natural products have demonstrated potential as therapeutic agents for alleviating PD symptoms due to their neuroprotective properties. To identify promising lead compounds from herbal medicines' natural products for PD management and understand their modes of action, suitable animal models are necessary. Drosophila melanogaster (fruit fly) serves as an essential model for studying genetic and cellular pathways in complex biological processes. Diverse Drosophila PD models have been extensively utilized in PD research, particularly for discovering neuroprotective natural products. This review emphasizes the research progress of natural products in PD using the fruit fly PD model, offering valuable insights into utilizing invertebrate models for developing novel anti-PD drugs.

Senolytic and senomorphic secondary metabolites as therapeutic agents in Drosophila melanogaster models of Parkinson's disease

Drosophila melanogaster is a valuable model organism for a wide range of biological exploration. The well-known advantages of D. melanogaster include its relatively simple biology, the ease with which it is genetically modified, the relatively low financial and time costs associated with their short gestation and life cycles, and the large number of offspring they produce per generation. D. melanogaster has facilitated the discovery of many significant insights into the pathology of Parkinson's disease (PD) and has served as an excellent preclinical model of PD-related therapeutic discovery. In this review, we provide an overview of the major D. melanogaster models of PD, each of which provide unique insights into PD-relevant pathology and therapeutic targets. These models are discussed in the context of their past, current, and future potential use for studying the utility of secondary metabolites as therapeutic agents in PD. Over the last decade, senolytics have garnered an exponential interest in their ability to mitigate a broad spectrum of diseases, including PD. Therefore, an emphasis is placed on the senolytic and senomorphic properties of secondary metabolites. It is expected that D. melanogaster will continue to be critical in the effort to understand and improve treatment of PD, including their involvement in translational studies focused on secondary metabolites.

Drosophila melanogaster as a Translational Model System to Explore the Impact of Phytochemicals on Human Health

Fruits, vegetables, and spices are natural sources of bioactive phytochemicals, such as polyphenols, carotenoids, flavonoids, curcuminoids, terpenoids, and capsaicinoids, possessing multiple health benefits and relatively low toxicity. These compounds found in the diet play a central role in organism development and fitness. Given the complexity of the whole-body response to dietary changes, invertebrate model organisms can be valuable tools to examine the interplay between genes, signaling pathways, and metabolism. Drosophila melanogaster, an invertebrate model with its extensively studied genome, has more than 70% gene homology to humans and has been used as a model system in biological studies for a long time. The notable advantages of Drosophila as a model system, such as their low maintenance cost, high reproductive rate, short generation time and lifespan, and the high similarity of metabolic pathways between Drosophila and mammals, have encouraged the use of Drosophila in the context of screening and evaluating the impact of phytochemicals present in the diet. Here, we review the benefits of Drosophila as a model system for use in the study of phytochemical ingestion and describe the previously reported effects of phytochemical consumption in Drosophila.

Resveratrol, a Multitasking Molecule That Improves Skeletal Muscle Health

Resveratrol is a natural polyphenol utilized in Chinese traditional medicine and thought to be one of the determinants of the "French Paradox". More recently, some groups evidenced its properties as a calorie-restriction mimetic, suggesting that its action passes through the modulation of skeletal muscle metabolism. Accordingly, the number of studies reporting the beneficial effects of resveratrol on skeletal muscle form and function, in both experimental models and humans, is steadily increasing. Although studies on animal models confer to resveratrol a good potential to ameliorate skeletal muscle structure, function and performance, clinical trials still do not provide clear-cut information. Here, we first summarize the effects of resveratrol on the distinct components of the skeletal muscle, such as myofibers, the neuromuscular junction, tendons, connective sheaths and the capillary bed. Second, we review clinical trials focused on the analysis of skeletal muscle parameters. We suggest that the heterogeneity in the response to resveratrol in humans could depend on sample characteristics, treatment modalities and parameters analyzed; as well, this heterogeneity could possibly reside in the complexity of skeletal muscle physiology. A systematic programming of treatment protocols and analyses could be helpful to obtain consistent results in clinical trials involving resveratrol administration.

Vitellaria paradoxa Inhibits Arsenic-induced Toxicity in Drosophila melanogaster Via the Augmentation of Antioxidant System

The Ethyl Acetate Fraction (EACF) of Ethanol Leaf Extract of Vitellaria paradoxa (ELVp) was assessed against Sodium Arsenite (SA)-induced toxicity in Drosophila melanogaster. The Gas Chromatography-Mass Spectrometry (GC-MS) analysis of EACF was carried out. The molecular docking of the compounds obtained from GC-MS was performed against D. melanogaster glutathione-S-transferase-2 (GST-2). Firstly, D. melanogaster (Harwich strain) was treated with EACF to determine its effect on longevity. Secondly, D. melanogaster was fed with EACF (1.0 and 3.0 mg/5 g diet) and/or SA (0.0625 mM) for 5 days. Thereafter, the ameliorative role of EACF in SA-induced toxicity was evaluated using the fly's emergence rate, locomotor activity, oxidative stress and antioxidant biomarkers. The in-silico study revealed varying degrees of binding affinity of the twelve active compounds of EACF against GST-2 which was comparable with the co-crystalized ligand (glutathione). The EACF increased the longevity of D. melanogaster by 20.0% compared with control and ameliorated SA-induced reduction of emergence rate and locomotor performance by 178.2 and 20.5%, respectively. Additionally, EACF ameliorated SA-induced reduction of total thiol and non-protein thiols and inhibition of catalase and GST activities (p < 0.05). These results corroborated with histological data obtained in the fat body of D. melanogaster. Overall, EACF augmented the antioxidant system of D. melanogaster and prevented sodium arsenite-induced oxidative stress due to its high antioxidant property.

Antidiabetes study of Spondias mombin (Linn) stem bark fractions in high-sucrose diet-induced diabetes in Drosophila melanogaster

Objective

The onset of insulin resistant diabetes has been associated with a high-sucrose diet in vertebrates and invertebrates. However, various parts of Spondias mombin reportedly possess antidiabetic potential. However, the antidiabetic efficacy of S. mombin stem bark in high-sucrose diet-induced Drosophila melanogaster model has not been explored. In this study, the antidiabetic and antioxidant effects of the solvent fractions of S. mombin stem bark were evaluated using in vitro, in vivo, and in silico methods.

Methods

Successive fractionation of S. mombin stem bark ethanol extract was performed; the resulting fractions were subjected to in vitro antioxidant and antidiabetic assays using standard protocols. The active compounds identified from the high-performance liquid chromatography (HPLC) study of the n-butanol fraction were docked against the active site of Drosophila α-amylase using AutoDoc Vina. The n-butanol and ethyl acetate fractions of the plant were incorporated into the diet of diabetic and nondiabetic flies to study the in vivo antidiabetic and antioxidant properties.

Results

The results obtained revealed that n-butanol and ethyl acetate fractions had the highest in vitro anti-oxidant capacity by inhibiting 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power, and hydroxyl radical followed by significant inhibition of α-amylase. HPLC analysis revealed the identification of eight compounds with quercetin having the highest peak followed by rutin, rhamnetin, chlorogenic acid, zeinoxanthin, lutin, isoquercetin, and rutinose showing the lowest peak. The fractions restored the glucose and antioxidant imbalance in diabetic flies, which is comparable with the standard drug (metformin). The fractions were also able to upregulate the mRNA expression of insulin-like peptide 2, insulin receptor, and ecdysone-inducible gene 2 in diabetic flies. The in silico studies revealed the inhibitory potential of active compounds against α-amylase with isoquercetin, rhamnetin, rutin, quercetin, and chlorogenic acid having higher binding affinity than the standard drug (acarbose).

Conclusion

Overall, the butanol and ethyl acetate fractions of S. mombin stem bark ameliorate type 2 diabetes in Drosophila. However, further studies are needed in other animal models to confirm the antidiabetes effect of the plant.

Parkin coregulates glutathione metabolism in adult mammalian brain

We recently discovered that the expression of PRKN, a young-onset Parkinson disease-linked gene, confers redox homeostasis. To further examine the protective effects of parkin in an oxidative stress model, we first combined the loss of prkn with Sod2 haploinsufficiency in mice. Although adult prkn-/-//Sod2± animals did not develop dopamine cell loss in the S. nigra, they had more reactive oxidative species and a higher concentration of carbonylated proteins in the brain; bi-genic mice also showed a trend for more nitrotyrosinated proteins. Because these redox changes were seen in the cytosol rather than mitochondria, we next explored the thiol network in the context of PRKN expression. We detected a parkin deficiency-associated increase in the ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG) in murine brain, PRKN-linked human cortex and several cell models. This shift resulted from enhanced recycling of GSSG back to GSH via upregulated glutathione reductase activity; it also correlated with altered activities of redox-sensitive enzymes in mitochondria isolated from mouse brain (e.g., aconitase-2; creatine kinase). Intriguingly, human parkin itself showed glutathione-recycling activity in vitro and in cells: For each GSSG dipeptide encountered, parkin regenerated one GSH molecule and was S-glutathionylated by the other (GSSG + P-SH [Formula: see text] GSH + P-S-SG), including at cysteines 59, 95 and 377. Moreover, parkin's S-glutathionylation was reversible by glutaredoxin activity. In summary, we found that PRKN gene expression contributes to the network of available thiols in the cell, including by parkin's participation in glutathione recycling, which involves a reversible, posttranslational modification at select cysteines. Further, parkin's impact on redox homeostasis in the cytosol can affect enzyme activities elsewhere, such as in mitochondria. We posit that antioxidant functions of parkin may explain many of its previously described, protective effects in vertebrates and invertebrates that are unrelated to E3 ligase activity.

Resveratrol-Mediated Regulation of Mitochondria Biogenesis-associated Pathways in Neurodegenerative Diseases: Molecular Insights and Potential Therapeutic Applications

Neurodegenerative disorders include different neurological conditions that affect nerve cells, causing the progressive loss of their functions and ultimately leading to loss of mobility, coordination, and mental functioning. The molecular mechanisms underpinning neurodegenerative disease pathogenesis are still unclear. Nonetheless, there is experimental evidence to demonstrate that the perturbation of mitochondrial function and dynamics play an essential role. In this context, mitochondrial biogenesis, the growth, and division of preexisting mitochondria, by controlling mitochondria number, plays a vital role in maintaining proper mitochondrial mass and function, thus ensuring efficient synaptic activity and brain function. Mitochondrial biogenesis is tightly associated with the control of cell division and variations in energy demand in response to extracellular stimuli; therefore, it may represent a promising therapeutic target for developing new curative approaches to prevent or counteract neurodegenerative disorders. Accordingly, several inducers of mitochondrial biogenesis have been proposed as pharmacological targets for treating diverse central nervous system conditions. The naturally occurring polyphenol resveratrol has been shown to promote mitochondrial biogenesis in various tissues, including the nervous tissue, and an ever-growing number of studies highlight its neurotherapeutic potential. Besides preventing cognitive impairment and neurodegeneration through its antioxidant and anti-inflammatory properties, resveratrol has been shown to be able to enhance mitochondria biogenesis by acting on its main effectors, including PGC-1α, SIRT1, AMPK, ERRs, TERT, TFAM, NRF-1 and NRF-2. This review aims to present and discuss the current findings concerning the impact of resveratrol on the machinery and main effectors modulating mitochondrial biogenesis in the context of neurodegenerative diseases.

New Insights on the Role of Bioactive Food Derivatives in Neurodegeneration and Neuroprotection

Over the last three decades, neurodegenerative diseases have received increasing attention due to their frequency in the aging population and the social and economic burdens they are posing. In parallel, an era's worth of research in neuroscience has shaped our current appreciation of the complex relationship between nutrition and the central nervous system. Particular branches of nutrition continue to galvanize neuroscientists, in particular the diverse roles that bioactive food derivatives play on health and disease. Bioactive food derivatives are nowadays recognized to directly impact brain homeostasis, specifically with respect to their actions on cellular mechanisms of oxidative stress, neuroinflammation, mitochondrial dysfunction, apoptosis and autophagy. However, ambiguities still exist regarding the significance of the influence of bioactive food derivatives on human health. In turn, gut microbiota dysbiosis is emerging as a novel player in the pathogenesis of neurodegenerative diseases. Currently, several routes of communication exist between the gut and the brain, where molecules are either released in the bloodstream or directly transported to the CNS. As such, bioactive food derivatives can modulate the complex ecosystem of the gut-brain axis, thus, targeting this communication network holds promises as a neuroprotective tool. This review aims at addressing one of the emerging aspects of neuroscience, particularly the interplay between food bioactive derivatives and neurodegeneration. We will specifically address the role that polyphenols and omega-3 fatty acids play in preventing neurodegenerative diseases and how dietary intervention complements available pharmacological approaches.