Antioxidant Effects of Resveratrol in Intervertebral Disk

Resveratrol suppresses NSCLC cell growth, invasion and migration by mediating Wnt/β-catenin pathway via downregulating SIX4 and SPHK2

Resveratrol (RSV) has been found to have a cancer-suppressing effect in a variety of cancers, including non-small cell lung cancer (NSCLC). Studies have shown that sine oculis homeobox 4 (SIX4) and sphingosine kinase 2 (SPHK2) are tumour promoters of NSCLC. However, whether RSV regulates SIX4 and SPHK2 to mediate NSCLC cell functions remains unclear. NSCLC cell functions were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, flow cytometry, transwell assay and wound healing assay. Protein expression levels were detected by western blot. SIX4 and SPHK2 mRNA levels in NSCLC tumour tissues were examined using quantitative real-time PCR. In addition, mice xenograft models were built to explore the impact of RSV on NSCLC tumour growth. RSV inhibited NSCLC cell proliferation, invasion and migration, while facilitated apoptosis. SIX4 and SPHK2 were up-regulated in NSCLC tissues and cells, and their expression was reduced by RSV. Knockdown of SIX4 and SPHK2 suppressed NSCLC cell growth, invasion and migration, and the regulation of RSV on NSCLC cell functions could be reversed by SIX4 and SPHK2 overexpression. RSV inactivated Wnt/β-catenin pathway via decreasing SIX4 and SPHK2 levels. In animal experiments, RSV reduced NSCLC tumour growth in vivo. RSV repressed NSCLC malignant process by decreasing SIX4 and SPHK2 levels to restrain the activity of Wnt/β-catenin pathway.

Emerging antioxidant therapies in Friedreich's ataxia

Friedreich's ataxia (FRDA) is a rare childhood neurologic disorder, affecting 1 in 50,000 Caucasians. The disease is caused by the abnormal expansion of the GAA repeat sequence in intron 1 of the FXN gene, leading to the reduced expression of the mitochondrial protein frataxin. The disease is characterised by progressive neurodegeneration, hypertrophic cardiomyopathy, diabetes mellitus and musculoskeletal deformities. The reduced expression of frataxin has been suggested to result in the downregulation of endogenous antioxidant defence mechanisms and mitochondrial bioenergetics, and the increase in mitochondrial iron accumulation thereby leading to oxidative stress. The confirmation of oxidative stress as one of the pathological signatures of FRDA led to the search for antioxidants which can be used as therapeutic modality. Based on this observation, antioxidants with different mechanisms of action have been explored for FRDA therapy since the last two decades. In this review, we bring forth all antioxidants which have been investigated for FRDA therapy and have been signed off for clinical trials. We summarise their various target points in FRDA disease pathway, their performances during clinical trials and possible factors which might have accounted for their failure or otherwise during clinical trials. We also discuss the limitation of the studies completed and propose possible strategies for combinatorial therapy of antioxidants to generate synergistic effect in FRDA patients.

Machine learning algorithm predicts fibrosis-related blood diagnosis markers of intervertebral disc degeneration

BACKGROUND

Intervertebral disc cell fibrosis has been established as a contributing factor to intervertebral disc degeneration (IDD). This study aimed to identify fibrosis-related diagnostic genes for patients with IDD.

METHODS

RNA-sequencing data was downloaded from Gene Expression Omnibus (GEO) database. The diagnostic genes was identified using Random forest based on the differentially expressed fibrosis-related genes (DE-FIGs) between IDD and control samples. The immune infiltration states in IDD and the regulatory network as well as potential drugs targeted diagnostic genes were investigated. Quantitative Real-Time PCR was conducted for gene expression valifation.

RESULTS

CEP120 and SPDL1 merged as diagnostic genes. Substantial variations were observed in the proportions of natural killer cells, neutrophils, and myeloid-derived suppressor cells between IDD and control samples. Further experiments indicated that AC144548.1 could regulate the expressions of SPDL1 and CEP120 by combininghsa-miR-5195-3p and hsa-miR-455-3p, respectively. Additionally, transcription factors FOXM1, PPARG, and ATF3 were identified as regulators of SPDL1 and CEP120 transcription. Notably, 56 drugs were predicted to target these genes. The down-regulation of SPDL1 and CEP120 was also validated.

CONCLUSION

This study identified two diagnostic genes associated with fibrosis in patients with IDD. Additionally, we elucidated their potential regulatory networks and identified target drugs, which offer a theoretical basis and reference for further study into fibrosis-related genes involved in IDD.

Hyaluronic Acid Hydrogel Containing Resveratrol-Loaded Chitosan Nanoparticles as an Adjuvant in Atopic Dermatitis Treatment

Atopic dermatitis (AD) is a common disease-causing skin inflammation, redness, and irritation, which can eventually result in infection that drastically impacts patient quality of life. Resveratrol (Res) is a natural phytochemical famed for its excellent anti-inflammatory and antioxidant activities. However, it is poorly bioavailable. Thus, a drug delivery system is needed to enhance in vivo bioactivity. Herein, we report the preparation of hyaluronic acid (HA) hydrogels containing resveratrol-loaded chitosan (CS) nanoparticles, their physicochemical analysis, and their potential therapeutic effects in the treatment of AD. Positively charged CS nanoparticles prepared by tripolyphosphate (TPP) gelation showed sizes ranging from 120 to around 500 nm and Res encapsulation efficiency as high as 80%. Embedding the nanoparticles in HA retarded their hydrolytic degradation and also slowed resveratrol release. Resveratrol released from nanoparticle-loaded hydrogel counteracted the oxidative damage induced by ROS generation in TNF-α/INF-γ-treated human keratinocytes (HaCaT) used as an AD in vitro model. Moreover, pre-treatment with Res@gel reduced secretion and gene expression of proinflammatory cytokines in HaCaT cells. The physicochemical analysis and in vitro assay confirmed that the formulated hydrogel could be considered an efficient and sustained resveratrol delivery vector in AD treatment.

Sulforaphane Delays Intervertebral Disc Degeneration by Alleviating Endoplasmic Reticulum Stress in Nucleus Pulposus Cells via Activating Nrf-2/HO-1

Intervertebral disc degeneration (IVDD) is one of the main causes of low back pain, which brings heavy burdens to individuals and society. The mechanism of IVDD is complex and diverse. One of the important reasons is that the abnormal accumulation of reactive oxygen species (ROS) in nucleus pulposus cells (NPCs) leads to endoplasmic reticulum stress (ERS), which causes increased apoptosis of NPCs. Nuclear factor E2-related factor 2 (Nrf-2) and its downstream antioxidant proteins are key molecular switches for sensing oxidative stress and regulating antioxidant responses in cells. Sulforaphane (SFN), a natural compound derived from Brassicaceae plants, is a Nrf-2 agonist that displays potent antioxidant potential in vitro and in vivo. Here, we used advanced glycation end products (AGEs) to construct an in vitro degeneration model of NPCs, and we found that AGEs elevated ROS level in NPCs and caused severe ERS and apoptosis. While SFN can promote the entry of Nrf-2 into the nucleus and increase the expression level of heme oxygenase 1 (HO-1) in vitro, thus clearing the accumulated ROS in cells and alleviating ERS and cell apoptosis. Moreover, the protection of SFN on NPCs was greatly attenuated after HO-1 was inhibited. We also used AGEs to construct a rat IVDD model. Consistent with the in vitro experiments, SFN could attenuate ERS in NPCs in vivo and delay disc degeneration in rats. This study found that SFN can be used as a new and promising agent for the treatment of IVDD.

Targeting the Nrf2 signaling pathway using phytochemical ingredients: A novel therapeutic road map to combat neurodegenerative diseases

BACKGROUND

Nuclear factor erythroid 2-related factor 2 (Nrf2) is a classical nuclear transcription factor that regulates the system's anti-oxidative stress response. The activation of Nrf2 induces the expression of antioxidant proteins and improves the system's anti-oxidative stress ability. Accumulating evidence suggests that Nrf2-centered signaling pathways may be a key pharmacological target for the treatment of neurodegenerative diseases (NDDs). However, phytochemicals as new therapeutic agents against NDDs have not been clearly delineated.

PURPOSE

To review the therapeutic effects of phytochemical ingredients on NDDs by activating Nrf2 and reducing oxidative stress injury.

METHODS

A comprehensive search of published articles was performed using various literature databases including PubMed, Google Scholar, and China National Knowledge Infrastructure. The search terms included "Nrf2", "phytochemical ingredients", "natural bioactive agents", "neurodegenerative diseases", "Antioxidant", "Alzheimer's disease", "Parkinson's disease", "Huntington's disease", "amyotrophic lateral sclerosis" "multiple sclerosis", "toxicity", and combinations of these keywords. A total of 769 preclinical studies were retrieved until August 2022, and we included 39 of these articless on phytochemistry, pharmacology, toxicology and other fields.

RESULTS

Numerous in vivo and in vitro studies showed that phytochemical ingredients could act as an Nrf2 activator in the treatment of NDDs through the antioxidant defense mechanism. These phytochemical ingredients, such as salidroside, naringenin, resveratrol, sesaminol, ellagic acid, ginsenoside Re, tanshinone I, sulforaphane, curcumin, naringin, tetramethylpyrazine, withametelin, magnolol, piperine, and myricetin, had the potential to improve Nrf2 signaling, thereby combatting NDDs.

CONCLUSION

As Nrf2 activators, phytochemical ingredients may provide a novel potential strategy for the treatment of NDDs. Here, we reviewed the interaction between phytochemical ingredients, Nrf2, and its antioxidant damaging pathway in NDDs and explored the advantages of phytochemical ingredients in anti-oxidative stress, which provides a reliable basis for improving the treatment of NDDs. However, further clinical trials are needed to determine the safety and efficacy of Nrf2 activators for NDDs.

Procyanidin B2 alleviates oxidative stress-induced nucleus pulposus cells apoptosis through upregulating Nrf2 via PI3K-Akt pathway

Oxidative stress can lead to nucleus pulposus cell (NPC) apoptosis, which is considered to be one of the main contributors to intervertebral disc degeneration (IVDD). Procyanidin B2 is a natural antioxidant that protects against oxidative stress. However, whether procyanidin B2 protects NPCs from oxidative stress remains unknown. In this study, we demonstrated that procyanidin B2 could reduce tert-butyl hydroperoxide-induced reactive oxygen species in rat NPCs and attenuate rat NPC apoptosis. Further experiments revealed that procyanidin B2 upregulated the expression of both nuclear factor erythroid 2-related factor 2 (Nrf2) and phosphorylation of protein kinase B (Akt). We then used silencing of Nrf2 and LY294002 to silence Nrf2 expression and block the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, respectively, and found that the protective roles of procyanidin B2 in NPCs were inhibited. Therefore, we demonstrated that procyanidin B2 alleviated rat NPC apoptosis induced by oxidative stress by upregulating Nrf2 via activation of the PI3K/Akt signaling pathway. This study provides a potential therapeutic approach for procyanidin B2 in IVDD, which might help in the development of new drugs for IVDD treatment.

Cleistocalyx nervosum var. paniala Berry Promotes Antioxidant Response and Suppresses Glutamate-Induced Cell Death via SIRT1/Nrf2 Survival Pathway in Hippocampal HT22 Neuronal Cells

Excessive glutamate neurotransmitters result in oxidative neurotoxicity, similar to neurodegeneration. An indigenous berry of Thailand, Cleistocalyx nervosum var. paniala (CNP), has been recognized for its robust antioxidants. We investigated the effects and mechanisms of CNP fruit extracts on antioxidant-related survival pathways against glutamate-induced neurotoxicity. The extract showed strong antioxidant capability and had high total phenolic and flavonoid contents, particularly resveratrol. Next, the protective effects of the CNP extract or resveratrol on the glutamate-induced neurotoxicity were examined in HT22 hippocampal cells. Our investigation showed that the pretreatment of cells with the CNP extract or resveratrol attenuated glutamate-induced neuronal death via suppression of apoptosis cascade by inhibiting the levels of cleaved- and pro-caspase-3 proteins. The CNP extract and resveratrol suppressed the intracellular ROS by increasing the mRNA expression level of antioxidant enzymes (SODs, GPx1, and CAT). We found that this extract and resveratrol significantly increased SIRT1 expression as a survival-related protein. Moreover, they also promoted the activity of the Nrf2 protein translocation into the nucleus and could bind to the promoter containing the antioxidant response element, inducing the expression of the downstream GPx1-antioxidant protein. Our data illustrate that the CNP extract and resveratrol inhibit apoptotic neuronal death via glutamate-induced oxidative neurotoxicity in HT22 cells through the activation of the SIRT1/Nrf2 survival mechanism.

Recent Advances in Managing Spinal Intervertebral Discs Degeneration

Low back pain (LBP) represents a frequent and debilitating condition affecting a large part of the global population and posing a worldwide health and economic burden. The major cause of LBP is intervertebral disc degeneration (IDD), a complex disease that can further aggravate and give rise to severe spine problems. As most of the current treatments for IDD either only alleviate the associated symptoms or expose patients to the risk of intraoperative and postoperative complications, there is a pressing need to develop better therapeutic strategies. In this respect, the present paper first describes the pathogenesis and etiology of IDD to set the framework for what has to be combated to restore the normal state of intervertebral discs (IVDs), then further elaborates on the recent advances in managing IDD. Specifically, there are reviewed bioactive compounds and growth factors that have shown promising potential against underlying factors of IDD, cell-based therapies for IVD regeneration, biomimetic artificial IVDs, and several other emerging IDD therapeutic options (e.g., exosomes, RNA approaches, and artificial intelligence).

Resveratrol and neuroprotection: an insight into prospective therapeutic approaches against Alzheimer's disease from bench to bedside

Alzheimer's disease (AD) is the most common cause of dementia and cognitive impairment; yet, there is currently no treatment. A buildup of Aβ, tau protein phosphorylation, oxidative stress, and inflammation in AD is pathogenic. The accumulation of amyloid-beta (Aβ) peptides in these neurocognitive areas is a significant characteristic of the disease. Therefore, inhibiting Aβ peptide aggregation has been proposed as the critical therapeutic approach for AD treatment. Resveratrol has been demonstrated in multiple studies to have a neuroprotective, anti-inflammatory, and antioxidant characteristic and the ability to minimize Aβ peptides aggregation and toxicity in the hippocampus of Alzheimer's patients, stimulating neurogenesis and inhibiting hippocampal degeneration. Furthermore, resveratrol's antioxidant effect promotes neuronal development by activating the silent information regulator-1 (SIRT1), which can protect against the detrimental effects of oxidative stress. Resveratrol-induced SIRT1 activation is becoming more crucial in developing novel therapeutic options for AD and other diseases that have neurodegenerative characteristics. This review highlighted a better knowledge of resveratrol's mechanism of action and its promising therapeutic efficacy in treating AD. We also highlighted the therapeutic potential of resveratrol as an AD therapeutic agent, which is effective against neurodegenerative disorders.