Ameliorative effects of flavonoids and polyketides on the rotenone induced Drosophila model of Parkinson's disease

Syagrus coronata fixed oil prevents rotenone-induced movement disorders and oxidative stress in Drosophila melanogaster

One prominent aspect of Parkinson's disease (PD) is the presence of elevated levels of free radicals, including reactive oxygen species (ROS). Syagrus coronata (S. coronata), a palm tree, exhibits antioxidant activity attributed to its phytochemical composition, containing fatty acids, polyphenols, and flavonoids. The aim of this investigation was to examine the potential neuroprotective effects of S. coronata fixed oil against rotenone-induced toxicity using Drosophila melanogaster. Young Drosophila specimens (3-4 d old) were exposed to a diet supplemented with rotenone (50 µM) for 7 d with and without the inclusion of S. coronata fixed oil (0.2 mg/g diet). Data demonstrated that rotenone exposure resulted in significant locomotor impairment and increased mortality rates in flies. Further, rotenone administration reduced total thiol levels but elevated lipid peroxidation, iron (Fe) levels, and nitric oxide (NO) levels while decreasing the reduced capacity of mitochondria. Concomitant administration of S. coronata exhibited a protective effect against rotenone, as evidenced by a return to control levels of Fe, NO, and total thiols, lowered lipid peroxidation levels, reversed locomotor impairment, and enhanced % cell viability. Molecular docking of the oil lipidic components with antioxidant enzymes showed strong binding affinity to superoxide dismutase (SOD) and glutathione peroxidase (GPX1) enzymes. Overall, treatment with S. coronata fixed oil was found to prevent rotenone-induced movement disorders and oxidative stress in Drosophila melanogaster.

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.

Polyvinylpyrrolidone-Capped Copper Oxide Nanoparticles-Anchored Pramipexole Attenuates the Rotenone-Induced Phenotypes in a Drosophila Parkinson's Disease Model

Parkinson's disease (PD) is a progressive, age-related neurodegenerative disease. The disease is characterized by the loss of dopaminergic neurons in the substantia nigra, pars compacta of the midbrain. Pramipexole (PPX) is a novel drug used for the treatment of PD. It has a high affinity for the dopamine (DA) D2 receptor subfamily and acts as a targeted mitochondrial antioxidant. It is less effective in the treatment of PD due to its short half-life, highly inconvenient dosing schedule, and long-term side effects. In recent years, PPX-loaded nanoformulations have been actively reported to overcome these limitations. In the current study, we focused on increasing the effectiveness of PPX by minimizing the dosing frequency and improving the treatment strategy for PD. Herein, we report the synthesis of biodegradable polyvinylpyrrolidone (PVP)-capped copper oxide nanoparticles (PVP-CuO NPs), followed by PPX anchoring on the surface of the PVP-CuO NPs (PPX-PVP-CuO NC), in a simple and inexpensive method. The newly formulated PPX-PVP-CuO NC complex was analyzed for its chemical and physical properties. The PPX-PVP-CuO NC was tested to protect against rotenone (RT)-induced toxicity in the Drosophila PD model. The in vivo studies using the RT-induced Drosophila PD model showed significant changes in negative geotaxis behavior and the level of DA and acetylcholinesterase. In addition, oxidative stress markers such as glutathione-S-transferase, total glutathione, thiobarbituric acid reactive species, and protein carbonyl content showed significant amelioration. The positive changes of PPX-PVP-CuO NC treatment in behavior, neurotransmitter level, and antioxidant level suggest its potential role in mitigating the PD phenotype. The formulation can be used for treatment or pharmacological intervention against PD.

Therapeutic Potential of Green-Engineered ZnO Nanoparticles on Rotenone-Exposed D. melanogaster (Oregon R+): Unveiling Ameliorated Biochemical, Cellular, and Behavioral Parameters

Nanotechnology holds significant ameliorative potential against neurodegenerative diseases, as it can protect the therapeutic substance and allow for its sustained release. In this study, the reducing and capping agents of Urtica dioica (UD), Matricaria chamomilla (MC), and Murraya koenigii (MK) extracts were used to synthesize bio-mediated zinc oxide nanoparticles (ZnO-NPs) against bacteria (Staphylococcus aureus and Escherichia coli) and against rotenone-induced toxicities in D. melanogaster for the first time. Their optical and structural properties were analyzed via FT-IR, DLS, XRD, EDS, SEM, UV-Vis, and zeta potential. The antioxidant and antimicrobial properties of the fabricated ZnO-NPs were evaluated employing cell-free models (DPPH and ABTS) and the well diffusion method, respectively. Rotenone (500 µM) was administered to Drosophila third instar larvae and freshly emerged flies for 24-120 h, either alone or in combination with plant extracts (UD, MC, an MK) and their biogenic ZnO-NPs. A comparative study on the protective effects of synthesized NPs was undertaken against rotenone-induced neurotoxic, cytotoxic, and behavioral alterations using an acetylcholinesterase inhibition assay, dye exclusion test, and locomotor parameters. The findings revealed that among the plant-derived ZnO-NPs, MK-ZnO NPs exhibit strong antimicrobial and antioxidant activities, followed by UD-ZnO NPs and MC-ZnO NPs. In this regard, ethno-nano medicinal therapeutic uses mimic similar effects in D. melanogaster by suppressing oxidative stress by restoring biochemical parameters (AchE and proteotoxicity activity) and lower cellular toxicity. These findings suggest that green-engineered ZnO-NPs have the potential to significantly enhance outcomes, with the promise of effective therapies for neurodegeneration, and could be used as a great alternative for clinical development.

Neurotoxic and behavioral deficit in Drosophila melanogaster co-exposed to rotenone and iron

Exposure to environmental toxicants has been linked with the onset of different neurodegenerative diseases in animals and humans. Here, we evaluated the toxic effects of co-exposure to iron and rotenone at low concentrations in Drosophila melanogaster. Adult wild-type flies were orally exposed to rotenone (50.0 µM) and ferrous sulfate (FeSO₄; 1.0 and 10.0 µM) through the diet for 10 days. Thereafter, we evaluated markers of oxidative damage (Hydrogen Peroxide (H₂O₂), Nitric Oxide (NO), Protein Carbonyl, and malondialdehyde (MDA)), antioxidant status (catalase, Glutathione S-Transferase (GST), Total Thiol (T-SH) and Non-protein Thiol (NPSH), neurotransmission (monoamine oxidase; MAO and acetylcholinesterase, AChE) and mitochondrial respiration. The results indicated that flies fed rotenone and FeSO₄ had impaired locomotion, reduced survival rate, and AChE activity with a corresponding increase in MAO activity when compared with the control (p < 0.05). Furthermore, rotenone and FeSO₄ significantly decreased the antioxidant status with a concurrent accumulation of NO, MDA, and H₂O₂. Additionally, the activity of complex 1 and mitochondria bioenergetic capacity was compromised in the flies. These findings suggest that the combination of rotenone and FeSO₄ elicited a possible synergistic toxic response in the flies and therefore provided further insights on the use of D. melanogaster in toxicological studies.

Uncovering the pharmacology of Ginkgo biloba folium in the cell-type-specific targets of Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disease with a fast-growing prevalence. Developing disease-modifying therapies for PD remains an enormous challenge. Current drug treatment will lose efficacy and bring about severe side effects as the disease progresses. Extracts from Ginkgo biloba folium (GBE) have been shown neuroprotective in PD models. However, the complex GBE extracts intertwingled with complicated PD targets hinder further drug development. In this study, we have pioneered using single-nuclei RNA sequencing data in network pharmacology analysis. Furthermore, high-throughput screening for potent drug-target interaction (DTI) was conducted with a deep learning algorithm, DeepPurpose. The strongest DTIs between ginkgolides and MAPK14 were further validated by molecular docking. This work should help advance the network pharmacology analysis procedure to tackle the limitation of conventional research. Meanwhile, these results should contribute to a better understanding of the complicated mechanisms of GBE in treating PD and lay the theoretical ground for future drug development in PD.

Phytochemicals of Avocado Residues as Potential Acetylcholinesterase Inhibitors, Antioxidants, and Neuroprotective Agents

Avocado (Persea americana) is a widely consumed fruit and a rich source of nutrients and phytochemicals. Its industrial processing generates peels and seeds which represent 30% of the fruit. Environmental issues related to these wastes are rapidly increasing and likely to double, according to expected avocado production. Therefore, this work aimed to evaluate the potential of hexane and ethanolic peel (PEL-H, PEL-ET) and seed (SED-H, SED-ET) extracts from avocado as sources of neuroprotective compounds. Minerals, total phenol (TPC), total flavonoid (TF), and lipid contents were determined by absorption spectroscopy and gas chromatography. In addition, phytochemicals were putatively identified by paper spray mass spectrometry (PSMS). The extracts were good sources of Ca, Mg, Fe, Zn, ω-6 linoleic acid, and flavonoids. Moreover, fifty-five metabolites were detected in the extracts, consisting mainly of phenolic acids, flavonoids, and alkaloids. The in vitro antioxidant capacity (FRAP and DPPH), acetylcholinesterase inhibition, and in vivo neuroprotective capacity were evaluated. PEL-ET was the best acetylcholinesterase inhibitor, with no significant difference (p > 0.05) compared to the control eserine, and it showed neither preventive nor regenerative effect in the neuroprotection assay. SED-ET demonstrated a significant protective effect compared to the control, suggesting neuroprotection against rotenone-induced neurological damage.

Anti-Parkinson's Disease Activity of Sanghuangprous vaninii Extracts in the MPTP-Induced Zebrafish Model

Parkinson's disease (PD) is a devastating disease of the central nervous system that occurs mainly in the elderly age group, affecting their quality of life. The PD pathogenesis is not yet fully understood and lacks the disease-modifying treatment strategies. Sanghuangprous vaninii (S. vaninii) is a perennial fungus with a plethora of pharmacological activities including anti-cancer and antioxidant activity and so on. However, no study till date has reported its neuroprotective effect against symptoms that are similar to PD in pre-clinical investigation. In the current study, we investigated anti-PD-like effects of S. vaninii mycelium extracts (SvMEs) on MPTP-induced PD in zebrafish. We observed that the loss of dopaminergic neurons and neurovascular reduction were reversed by using SvMEs in the zebrafish brain in a concentration-independent manner. Moreover, it also relieved locomotor impairments in MPTP-induced PD zebrafish. In addition, SvMEs exerted significant antioxidant activity in vitro, which was also demonstrated in vivo on ktr4:NTR-hKikGR zebrafish. Upon investigating the underlying mechanism, we found that SvMEs may alleviate oxidant stress and accelerate α-synuclein degradation and then alleviate PD-like symptoms. Antioxidant-related genes (sod1, gss, gpx4a, gclm, and cat) implied that the SvMEs exhibited anti-PD activity due to the antioxidation mechanism. Finally, upon analysis of chemical composition of SvMEs by liquid chromatography-mass spectrometry, we identified 10 compounds that are plausibly responsible for the anti-PD-like effect of SvMEs. On the limiting part, the finding of the study would have been more robust had we investigated the protein expression of genes related to PD and oxidative stress and compared the effects of SvMEs with any standard anti-PD therapy. Despite this, our results indicated that SvMEs possess anti-PD effects, indicating SvMEs as a potential candidate that is worth exploring further in this avenue.

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.

Emerging Novel Approaches for the Enhanced Delivery of Natural Products for the Management of Neurodegenerative Diseases

Neurodegenerative diseases (NDs) such as Alzheimer's disease, Parkinson's disease, Huntington disease, amyotrophic lateral sclerosis, and prion disease affect any part of the brain. The complete mechanism of ND is unknown, but there are some molecular mechanism and chemical process. Natural compounds have better compatibility with the human body along with lesser side effects. Moreover, several studies showed that various natural compounds have significant neuroprotective, potent antioxidant, and anti-inflammatory properties, which are effective for treating the different type of ND. In ND, natural compounds act by various mechanisms such as preventing the generation of reactive oxygen species (ROS), eliminating destructed biomolecules before their accumulation affects cell metabolism, and improving the disease conditions. But due to the presence of the blood-brain barrier (BBB) layer and unfavorable pharmacokinetic properties of natural compounds, their delivery into the brain is limited. To minimize this problem and enhance drug delivery into the brain with an effective therapeutic dose, there is a need to develop a practical novel approach. The various studies showed that nanoformulations and microneedles (MN) containing natural compounds such as quercetin, curcumin, resveratrol, chrysin, piperine, ferulic acid, huperzine A, berberine, baicalein, hesperetin, and retinoic acid effectively improved many ND. In this review, the effect of such natural drug-loaded nanoformulation and MN patches on ND management is discussed, along with their merits and demerits. This review aims to introduce different novel approaches for enhancing natural drug delivery into the brain to manage various neurodegenerative diseases.