Garcinol protects SH-SY5Y cells against MPP+-induced cell death by activating DJ-1/SIRT1 and PGC-1α mediated antioxidant pathway in sequential stimulation of p-AMPK mediated autophagy

Garcinol promotes wound healing in diabetic mice by regulating inflammation and NLRP3 inflammasome-mediated pyroptosis via the PI3K/Akt/NF-κB pathway

Diabetic wounds, characterized by chronic inflammation and impaired angiogenesis, often lead to severe complications such as persistent infections and an elevated risk of amputation, significantly affecting a patient's quality of life. Garcinol, a polyisoprenylated benzophenone derived from the rind of Garcinia indica, exhibits potent anti-inflammatory, angiogenic, and antioxidant effects in various disease models. However, its potential to enhance diabetic wound healing remains unclear. In this research, we firstly used network pharmacology analysis to identify the potential targets of Garcinol in treating diabetic wounds. Cellular study results revealed that Garcinol therapy alleviated high glucose-induced cellular dysfunction and increased the angiogenic potential of human umbilical vein endothelial cells (HUVECs). Additionally, Garcinol substantially downregulated the levels of inflammatory cytokines secreted by macrophages through inhibiting the PI3K/Akt/NF-κB signaling pathway, which was further validated using the PI3K/Akt agonist 740 YP. Furthermore, inhibiting PI3K signaling also resulted in a marked reduction of NLRP3 inflammasome-mediated pyroptosis in macrophages compared to control. In vivo study using a full-thickness diabetic wound model confirmed that Garcinol treatment promoted diabetic wound healing by improving angiogenesis, inhibiting inflammation and pyroptosis, whereas the addition of 740 YP reduced the beneficial effects of Garcinol. Overall, our findings suggested that Garcinol enhanced diabetic wound healing via its anti-inflammatory ability, suppression of pyroptosis, and enhancement of angiogenesis. These results highlight the potential of Garcinol as a therapeutic agent for diabetic wounds.

Curcumin protects against MPP+-induced neurotoxicity in SH-SY5Y cells by modulating the TRPV4 channel

BACKGROUND

It is well acknowledged that neuroinflammation, mitochondrial dysfunction, and oxidative stress (OS) play a role in the etiology of Parkinson's disease (PD). Curcumin (CUR) protect neuronal cells by interfering with the production of reactive oxygen species (ROS) in neuronal cells and suppressing OS. In this study, we investigated the role of the TRPV4 channel under CUR stimulation in the PD model induced by MPP+ in SH-SY5Y cells.

METHODS

The cells were divided into four groups: control, CUR, MPP+ and MPP++CUR. In addition, incubations were performed with TRPV4 channel agonist GSK1016790A (GSK) and its antagonist Ruthenium red (Rr) to follow the Ca2+ current induced through the TRPV4 channel.

RESULTS

MPP+ exposure increased mitochondrial and intracellular ROS production and mitochondrial membrane potential in the cell, while decreasing GSH levels. During CUR and Rr incubation, MPP+ exposure and TRPV4 agonist GSK-induced TRPV4 overstimulation were down-regulated. The effects of MPP+ on intracellular damage were changed by CUR treatment, as seen in changes in GSH levels, mROS, iROS, JC/1, apoptosis, and TRPV4 expression value compared to the MPP+ group.

CONCLUSIONS

The CUR treatment in the in vitro PD model created with MPP+ reduced cellular damage by regulating mitochondrial dysfunction, OS and TRPV4 channel activation in MPP+-induced neurotoxicity with the antioxidant properties of CUR.

Utilizing alternative in vivo animal models for food safety and toxicity: A focus on thermal process contaminant acrylamide

Rodent models have traditionally been used to assess the toxicity of food chemicals, but this approach is costly, time-consuming, and raises ethical concerns. Alternatively, non-mammalian models such as Drosophila melanogaster, Danio rerio, and Caenorhabditis elegans have been shown to be suitable for studying the toxicity of food hazards. Their advantages include low cost, short life cycles, adaptability to high-throughput screening, and adherence to the 3R principles of replacement, reduction, and refinement. These models have been extensively studied in the context of acrylamide toxicity, a common food contaminant. This article comprehensively reviews the biological characteristics of non-mammalian models, recent advances and challenges in acrylamide toxicity research using these models, and explores the potential of natural plant compounds in ameliorating acrylamide toxicity. The review aims to guide research using non-mammalian models for food safety assessment.

Study insights in the role of PGC-1α in neurological diseases: mechanisms and therapeutic potential

Peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), which is highly expressed in the central nervous system, is known to be involved in the regulation of mitochondrial biosynthesis, metabolic regulation, neuroinflammation, autophagy, and oxidative stress. This knowledge indicates a potential role of PGC-1α in a wide range of functions associated with neurological diseases. There is emerging evidence indicating a protective role of PGC-1α in the pathogenesis of several neurological diseases. As such, a deeper and broader understanding of PGC-1α and its role in neurological diseases is urgently needed. The present review provides a relatively complete overview of the current knowledge on PGC-1α, including its functions in different types of neurons, basic structural characteristics, and its interacting transcription factors. Furthermore, we present the role of PGC-1α in the pathogenesis of various neurological diseases, such as intracerebral hemorrhage, ischemic stroke, Alzheimer's disease, Parkinson's disease, Amyotrophic lateral sclerosis, Huntington's disease, and other PolyQ diseases. Importantly, we discuss some compounds or drug-targeting strategies that have been studied to ameliorate the pathology of these neurological diseases and introduce the possible mechanistic pathways. Based on the available studies, we propose that targeting PGC-1α could serve as a promising novel therapeutic strategy for one or more neurological diseases.

Cyclopiazonic acid suppresses the function of Leydig cells in prepubertal male rats by disrupting mitofusin 1-mediated mitochondrial function

This research investigated the impact of cyclopiazonic acid (CPA), a mycotoxin, on the function of progenitor Leydig cells (PLCs) in prepubertal male rats, focusing on its potential disruption of mitochondrial integrity through mitofusin 1 (MFN1) modulation. In vivo, Sprague Dawley rats received CPA (0.2, 1, 5 mg/kg/day) via gavage from postnatal days 21-28 to evaluate PLC function and mitochondrial morphology using serum hormone levels, histology, qPCR, and Western blot analyses. In vitro, rat R2C cells were treated with CPA (0.1, 1, 10 μM) alone or in combination with 100 μM leflunomide to assess PLC development through testosterone measurements, Western blotting, flow cytometry, and Mito-Tracker Green Staining. The findings from in vivo experiments showed that CPA reduced serum testosterone and progesterone levels at 1 mg/kg/day. The qPCR and Western blotting analyses revealed significant alterations in the expression of genes and proteins pertinent to PLC function, such as Scarb1, Star, Cyp11a1, and Cyp17a1. Immunofluorescence staining further revealed a reduction in MFN1 expression following exposure to CPA. In vitro experiments corroborated these observations, demonstrating that CPA induced mitochondrial fragmentation by downregulating SIRT1, PGC1-α, MFN1, and OPA1, increase reactive oxygen species, and inhibit testosterone synthesis in R2C cells. The administration of leflunomide was shown to mitigate the detrimental effects of CPA on PLCs. In conclusion, this research sheds new light on the deleterious effects of CPA on the reproductive development of prepubertal males.

Unveiling the interplay of AMPK/SIRT1/PGC-1α axis in brain health: Promising targets against aging and NDDs

The escalating prevalence of neurodegenerative diseases (NDDs) within an aging global population presents a pressing challenge. The multifaceted pathophysiological mechanisms underlying these disorders, including oxidative stress, mitochondrial dysfunction, and neuroinflammation, remain complex and elusive. Among these, the AMPK/SIRT1/PGC-1α pathway emerges as a pivotal network implicated in neuroprotection against these destructive processes. This review sheds light on the potential therapeutic implications of targeting this axis, specifically emphasizing the promising role of flavonoids in mitigating NDD-related complications. Expanding beyond conventional pharmacological approaches, the exploration of non-pharmacological interventions such as exercise and calorie restriction (CR), coupled with the investigation of natural compounds, offers a beacon of hope. By strategically elucidating the intricate connections within these pathways, this review aims to pave the ways for novel multi-target agents and interventions, fostering a renewed optimism in the quest to combat and manage the debilitating impacts of NDDs on global health and well-being.

Neurotrophic Natural Products

Neurotrophins (NGF, BDNF, NT3, NT4) can decrease cell death, induce differentiation, as well as sustain the structure and function of neurons, which make them promising therapeutic agents for the treatment of neurodegenerative disorders. However, neurotrophins have not been very effective in clinical trials mostly because they cannot pass through the blood-brain barrier owing to being high-molecular-weight proteins. Thus, neurotrophin-mimic small molecules, which stimulate the synthesis of endogenous neurotrophins or enhance neurotrophic actions, may serve as promising alternatives to neurotrophins. Small-molecular-weight natural products, which have been used in dietary functional foods or in traditional medicines over the course of human history, have a great potential for the development of new therapeutic agents against neurodegenerative diseases such as Alzheimer's disease. In this contribution, a variety of natural products possessing neurotrophic properties such as neurogenesis, neurite outgrowth promotion (neuritogenesis), and neuroprotection are described, and a focus is made on the chemistry and biology of several neurotrophic natural products.

Molecular aspects of optic nerve autophagy in glaucoma

The optic nerve consists of the glia, vessels, and axons including myelin and axoplasm. Since axonal degeneration precedes retinal ganglion cell death in glaucoma, the preceding axonal degeneration model may be helpful for understanding the molecular mechanisms of optic nerve degeneration. Optic nerve samples from these models can provide information on several aspects of autophagy. Autophagosomes, the most typical organelles expressing autophagy, are found much more frequently inside axons than around the glia. Thus, immunoblot findings from the optic nerve can reflect the autophagy state in axons. Autophagic flux impairment may occur in degenerating optic nerve axons, as in other central nervous system neurodegenerative diseases. Several molecular candidates are involved in autophagy enhancement, leading to axonal protection. This concept is an attractive approach to the prevention of further retinal ganglion cell death. In this review, we describe the factors affecting autophagy, including nicotinamide riboside, p38, ULK, AMPK, ROCK, and SIRT1, in the optic nerve and propose potential methods of axonal protection via enhancement of autophagy.

Therapeutic considerations of bioactive compounds in Alzheimer's disease and Parkinson's disease: Dissecting the molecular pathways

Leading neurodegenerative diseases Alzheimer's disease (AD) and Parkinson's disease (PD) are characterized by the impairment of memory and motor functions, respectively. Despite several breakthroughs, there exists a lack of disease-modifying treatment strategies for these diseases, as the available drugs provide symptomatic relief and bring along side effects. Bioactive compounds are reported to bear neuroprotective properties with minimal toxicity, however, a detailed elucidation of their modes of neuroprotection is lacking. The review elucidates the neuroprotective mechanism(s) of some of the major phyto-compounds in pre-clinical and clinical studies of AD and PD to understand their potential in combating these diseases. Curcumin, eugenol, resveratrol, baicalein, sesamol and so on have proved efficient in countering the pathological hallmarks of AD and PD. Curcumin, resveratrol, caffeine and so on have reached the clinical phases of these diseases, while aromadendrin, delphinidin, cyanidin and xanthohumol are yet to be extensively explored in pre-clinical phases. The review highlights the need for extensive investigation of these compounds in the clinical stages of these diseases so as to utilize their disease-modifying abilities in the real field of treatment. Moreover, poor pharmacokinetic properties of natural compounds are constraints to their therapeutic yields and this review suggests a plausible contribution of nanotechnology in overcoming these limitations.

Syringin Prevents 6-Hydroxydopamine Neurotoxicity by Mediating the MiR-34a/SIRT1/Beclin-1 Pathway and Activating Autophagy in SH-SY5Y Cells and the Caenorhabditis elegans Model

Defective autophagy is one of the cellular hallmarks of Parkinson's disease (PD). Therefore, a therapeutic strategy could be a modest enhancement of autophagic activity in dopamine (DA) neurons to deal with the clearance of damaged mitochondria and abnormal protein aggregates. Syringin (SRG) is a phenolic glycoside derived from the root of Acanthopanax senticosus. It has antioxidant, anti-apoptotic, and anti-inflammatory properties. However, whether it has a preventive effect on PD remains unclear. The present study found that SRG reversed the increase in intracellular ROS-caused apoptosis in SH-SY5Y cells induced by neurotoxin 6-OHDA exposure. Likewise, in C. elegans, degeneration of DA neurons, DA-related food-sensitive behaviors, longevity, and accumulation of α-synuclein were also improved. Studies of neuroprotective mechanisms have shown that SRG can reverse the suppressed expression of SIRT1, Beclin-1, and other autophagy markers in 6-OHDA-exposed cells. Thus, these enhanced the formation of autophagic vacuoles and autophagy activity. This protective effect can be blocked by pretreatment with wortmannin (an autophagosome formation blocker) and bafilomycin A1 (an autophagosome-lysosome fusion blocker). In addition, 6-OHDA increases the acetylation of Beclin-1, leading to its inactivation. SRG can induce the expression of SIRT1 and promote the deacetylation of Beclin-1. Finally, we found that SRG reduced the 6-OHDA-induced expression of miR-34a targeting SIRT1. The overexpression of miR-34a mimic abolishes the neuroprotective ability of SRG. In conclusion, SRG induces autophagy via partially regulating the miR-34a/SIRT1/Beclin-1 axis to prevent 6-OHDA-induced apoptosis and α-synuclein accumulation. SRG has the opportunity to be established as a candidate agent for the prevention and cure of PD.