Piceatannol promotes neuroprotection by inducing mitophagy and mitobiogenesis in the experimental diabetic peripheral neuropathy and hyperglycemia-induced neurotoxicity

Low-intensity pulsed ultrasound relieved the diabetic peripheral neuropathy in mice via anti-oxidative stress mechanism

Diabetic peripheral neuropathy (DPN), as one of the most prevalent complications of diabetes, leads to significant pain and financial burden to patients. Currently, there was no effective treatment for DPN since the glucose control was just a prevention and the drug therapy only relieved the DPN pain. As a non-invasive physical therapy, low-intensity pulsed ultrasound (LIPUS) is utilized in the musculoskeletal and nerve injuries therapy. Studies revealed that LIPUS could regenerate nerves by the mechanical stimulation via oxidative stress pathway, which was thought as the important factor for DPN, and might have potential in the DPN therapy. This study aimed to identify a new therapeutic strategy for DPN using LIPUS. We analyzed the therapy effect and explored the therapeutic mechanism of LIPUS on DPN in mice. This study involved animal experiments and C57BL/6J mice were randomly assigned to DPN model and Sham groups. The DPN model group was fed a high-fat chow diet and injected with streptozotocin (STZ) for 3 consecutive days (40 mg/kg/d), whereas the Sham group was fed a normal diet and injected with an equal volume of sodium citrate buffer. After the DPN model confirmed with the 84-day modeling process, the DPN mice were randomly allocated into the DPN group and the LIPUS group. The LIPUS group underwent ultrasound treatments with a center frequency of 1 MHz, a duty cycle of 20 %, and a spatial average temporal average intensity (ISATA) of 200 mW/cm2 for 20 min/d, 5 d/w. After the 56-day treatment, all mice were euthanized. LIPUS therapeutic effects were evaluated through measurements of fasting blood glucose (FBG), behavioral tests, oxidative stress tests, morphological analysis, immunofluorescence, and western blot analysis. The results indicated that DPN mice had significantly higher FBG levels (28.77 ± 2.95 mmol/L) compared with sham mice (10.31 ± 1.49 mmol/L). Additionally, DPN mice had significantly lower mechanical threshold (4.13 ± 0.92 g) and higher thermal latency (16.20 ± 2.39 s) compared with the sham mice (7.31 ± 0.83 g, 11.67 ± 1.21 s). After receiving LIPUS treatment, the glucose tolerance tests (GTT) suggested that LIPUS treatment improved glucose tolerance, which was shown by a decrease in the area under the curve (AUC) for glucose in the LIPUS group (AUC = 2452 ± 459.33 min*mmol/L) compared with the DPN group (AUC = 3271 ± 420.90 min*mmol/L). Behavioral tests showed that LIPUS treatment significantly alleviated DPN-induced abnormalities by improving the mechanical threshold from 2.79 ± 0.79 g in the DPN group to 5.50 ± 1.00 g in the LIPUS group, and significantly decreasing thermal latency from 12.38 ± 1.88 s in the DPN group to 9.49 ± 2.31 s in the LIPUS group. Morphological observations revealed that DPN mice had a thinning and irregularly shaped myelin sheath, with 61.04 ± 5.60 % of abnormal nerve fibers in the sciatic nerve in LIPUS group, compared with 49.76 ± 4.88 % of abnormal nerve fibers in the LIPUS-treated group. Additionally, LIPUS treatment increased the mean fluorescence intensity of the associated nerve regeneration protein (i.e., Nf200) from 27.81 ± 0.32 arbitrary units in the DPN group to 37.62 ± 0.36 arbitrary units in the LIPUS group. Western blot and immunofluorescence analysis showed that LIPUS treatment significantly reduced Keap1 expression to 0.04 ± 0.06 relative units, compared with 0.17 ± 0.30 in the DPN group. Furthermore, immunofluorescence analysis revealed that LIPUS treatment promoted the production of its downstream antioxidant protein, heme oxygenase-1 (HO-1), with an increase in the fluorescence intensity from 27.81 ± 0.32 arbitrary units in the DPN group to 37.62 ± 0.36 arbitrary units in the LIPUS-treated group. The fluorescence intensity of Nrf2 was significantly higher in the LIPUS group, increasing from 4.90 ± 0.25 arbitrary units in the DPN group to 15.18 ± 2.13 arbitrary units in the LIPUS-treated group. Additionally, the malondialdehyde (MDA) levels, an indicator of oxidative stress, were significantly reduced in the serum, from 5.40 ± 0.48 nmol/ml in the DPN group to 4.64 ± 0.16 nmol/ml in the LIPUS-treated group, and in the sciatic nerve, from 16.17 ± 5.88 nmol/mg protein to 4.67 ± 2.10 nmol/mg protein, suggesting the oxidative stress was inhibited by LIPUS. This study demonstrated for the first time that LIPUS could relive DPN through anti-oxidative stress process. This study suggests that LIPUS might be a new therapy strategy for DPN.

Defective PINK1-dependent mitophagy is involved in high glucose-induced neurotoxicity

Neuropathic pain often complicates diabetes progression, yet the pathogenic mechanisms are poorly understood. Defective mitophagy is linked to various diabetic complications like nephropathy, cardiomyopathy, and retinopathy. To investigate the molecular basis of hyperglycemia-induced painful diabetic neuropathy (PDN), we examined the effect of high glucose on the PTEN-induced kinase 1 (PINK1)/Parkin RBR E3 ubiquitin protein ligase (Parkin)-mediated mitophagy pathway in ND7/23 cells. Cells were treated with different glucose concentrations (25, 50, 75 mM) for various durations (24, 48, 72 h). Additionally, cells were exposed to high glucose (50 mM) with or without 100 nM rapamycin (a mitophagy enhancer) for 48 h, or transfected with PINK1 siRNA. We assessed protein levels of mitophagy-related genes (PINK1, Parkin, P62, LC3B) and apoptotic markers (cleaved-Caspase3) via Western blotting. High glucose significantly reduced the expression of autophagy-related proteins PINK1 and Parkin in a time- and concentration-dependent manner compared to controls. Rapamycin counteracted the inhibitory effects of high glucose on PINK1/Parkin-mediated mitophagy, while PINK1 siRNA transfection showed similar outcomes, confirming the inhibitory impact of high glucose on mitophagy. Moreover, high glucose induced apoptosis by suppressing PINK1/Parkin-mediated mitophagy, causing cytotoxic effects in ND7/23 cells which is derived from the fusion of mouse neuroblastoma cells and rat dorsal root ganglion (DRG) cells. Our findings suggest that hyperglycemia-induced disruption of the PINK1/Parkin mitophagy pathway impairs mitochondrial homeostasis, leading to apoptosis. Therefore, targeting PINK1 pathway activation or restoring mitophagy might be a promising therapeutic strategy for PDN treatment.

The Interplay Between Autophagy and Apoptosis in the Mechanisms of Action of Stilbenes in Cancer Cells

Plant-based stilbenes are low-molecular-weight polyphenolic compounds that exhibit anti-oxidant, anti-microbial, anti-fungal, anti-inflammatory, anti-diabetic, cardioprotective, neuroprotective, and anti-cancer activities. They are phytoalexins produced in diverse plant species in response to stress, such as fungal and bacterial infections or excessive UV irradiation. Plant-derived dietary products containing stilbenes are common components of the human diet. Stilbenes appear to be promising chemopreventive and chemotherapeutic agents. Accumulating evidence indicates that stilbenes are able to trigger both apoptotic and autophagic molecular pathways in many human cancer cell lines. Of note, the molecular crosstalk between autophagy and apoptosis under cellular stress conditions determines the cell fate. The autophagy and apoptosis relationship is complex and depends on the cellular context, e.g., cell type and cellular stress level. Apoptosis is a type of regulated cell death, whereas autophagy may act as a pro-survival or pro-death mechanism depending on the context. The interplay between autophagy and apoptosis may have an important impact on chemotherapy efficiency. This review focuses on the in vitro effects of stilbenes in different human cancer cell lines concerning the interplay between autophagy and apoptosis.

Important regulatory role of mitophagy in diabetic microvascular complications

Microvascular complications of diabetes pose a significant threat to global health, mainly including diabetic kidney disease (DKD), diabetic retinopathy (DR), diabetic peripheral neuropathy (DPN), and diabetic cardiomyopathy (DCM), which can ultimately lead to kidney failure, blindness, disability, and heart failure. With the increasing prevalence of diabetes, the search for new therapeutic targets for diabetic microvascular complications is imminent. Mitophagy is a widespread and strictly maintained process of self-renewal and energy metabolism that plays an important role in reducing inflammatory responses, inhibiting reactive oxygen species accumulation, and maintaining cellular energy metabolism. Hyperglycemia results in impaired mitophagy, which leads to mitochondrial dysfunction and ultimately exacerbates disease progression. This article summarizes the relevant molecular mechanisms of mitophagy and reviews the current status of research on regulating mitophagy as a potential treatment for diabetic microvascular complications, attempting to give new angles on the treatment of diabetic microvascular complications.

Mitochondrial Dysfunction in Diabetes: Shedding Light on a Widespread Oversight

Diabetes mellitus represents a complicated metabolic condition marked by ongoing hyperglycemia arising from impaired insulin secretion, inadequate insulin action, or a combination of both. Mitochondrial dysfunction has emerged as a significant contributor to the aetiology of diabetes, affecting various metabolic processes critical for glucose homeostasis. This review aims to elucidate the complex link between mitochondrial dysfunction and diabetes, covering the spectrum of diabetes types, the role of mitochondria in insulin resistance, highlighting pathophysiological mechanisms, mitochondrial DNA damage, and altered mitochondrial biogenesis and dynamics. Additionally, it discusses the clinical implications and complications of mitochondrial dysfunction in diabetes and its complications, diagnostic approaches for assessing mitochondrial function in diabetics, therapeutic strategies, future directions, and research opportunities.

Unlocking Gut Health: The Potent Role of Stilbenoids in Intestinal Homeostasis

Stilbenoids are a class of naturally occurring phenolic compounds found in various plant species, characterized by a stilbene backbone with diverse substituents that confer a range of biological activities. These compounds exhibit antioxidant, anti-inflammatory, and antimicrobial properties, making them promising candidates for improving intestinal health. The intestinal tract plays a critical role in nutrient digestion, absorption, and immune defense, and maintaining its integrity is vital for animal growth. Stilbenoids contribute to gut health by enhancing intestinal morphology, supporting mucosal immune responses, regulating gut microbiota composition, modulating metabolic pathways, and maintaining mitochondrial health. This review provides a comprehensive analysis of key stilbenoids, including resveratrol, pterostilbene, piceatannol, and oxyresveratrol, focusing on their biological effects and regulatory mechanisms. By highlighting their roles in mitigating intestinal inflammation and promoting gut function, this review provides a basis for the practical application of stilbenoids in animal health and husbandry.

β-Caryophyllene attenuates oxidative stress and inflammatory response in LPS induced acute lung injury by targeting ACE2/MasR and Nrf2/HO-1/NF-κB axis

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), is a clinical syndrome that can cause pulmonary edema, inflammation, oxidative stress, and immunological dysregulations. β-Caryophyllene (BCP), a natural bicyclic sesquiterpene, possesses a variety of pharmacological properties and has the potential to be a therapeutic agent. This study aimed to comprehend the effect of BCP on Nrf2/HO-1/NF-κB and ACE2/MasR axis in a rat model of ALI by lipopolysaccharide (LPS) and the underlying mechanisms during this process. The study also examined pulmonary edema, BALF, and cytokine production to investigate inflammation and oxidative stress. In the LPS group, Western blot analysis showed decreased Nrf2/HO-1 and ACE2/MasR, including increased lung edema, elevated vascular permeability, neutrophil infiltration in BALF, increased cytokine levels, and histological changes. In comparison to the LPS group, BCP dramatically reduced lung edema, vascular permeability, and histological changes. Additionally, by lowering malondialdehyde and myeloperoxidase activity in lung tissues, it also reduced oxidative stress. BCP boosted IL-10 production and decreased the levels of pro-inflammatory cytokines and neutrophil infiltration. BCP administration decreased VEGF-A and SP-D expression, subsequently lowering NF-κB activation and cytokine production. Further, BCP altered ACE2 expression, indicating its involvement by activating the ACE2/Angiotensin (1-7)/MasR axis. In addition, BCP could stimulate the Nrf2/HO-1 anti-oxidant axis to suppress NF-κB and reduce inflammation. BCP modulation of the ACE2/MasR and Nrf2/HO-1/NF-κB axis impedes the course of ALI by influencing immunological response including but not limited to oxidative stress, the influx of neutrophils, and cytokine production. Hence, BCP may act as a potential candidate for management of ALI.

Nanoparticle-enhanced delivery of resveratrol for targeted therapy of glioblastoma: Modulating the Akt/GSK-3β/NF-kB pathway in C6 glioma cells

OBJECTIVE

The study aims to explore Resveratrol (RES) as a potential therapeutic agent for Glioblastoma multiforme (GBM), a challenging brain cancer. RES, a polyphenolic compound with known benefits in various diseases including cancer, has shown promise in inhibiting glioma progression through its effects on the AKT signaling pathways. However, its limited ability to cross the blood-brain barrier restricts its clinical application in GBM treatment. This study seeks to enhance efficacy of RES by developing RES-loaded nanoparticles designed to improve penetration into glioma cells and potentially overcome the blood-brain barrier, thereby enhancing therapeutic outcomes.

METHODS

Albumin nanoparticles were prepared and characterized using FT-IR, X-RD, and SEM to determine particle size. In vitro experiments were conducted using the C6 glioma cell line, employing MTT assays, Immunofluorescence, DC-FDA staining, and western blot analysis. Molecular docking studies were also performed to assess ability of RES to inhibit the AKT/GSK-3β/NF-kB pathway.

RESULTS

In vitro results demonstrated that RES-loaded nanoparticles induced apoptosis and reduced proliferation of C6 glioma cells compared to controls. Molecular docking studies confirmed RES's potential as an inhibitor targeting the AKT/GSK-3β/NF-kB pathway. Western blot analysis revealed downregulation of AKT and GSK-3β expression in cells treated with RES-loaded nanoparticles, accompanied by increased caspase 1 levels and decreased bcl2 expression, indicative of apoptosis.

CONCLUSION

The findings suggest that RES effectively targets the AKT/GSK-3β/NF-kB signaling pathway in glioma cells. Furthermore, RES-loaded albumin nanoparticles significantly enhance therapeutic efficacy by improving cellular penetration, highlighting their potential in advancing GBM treatment strategies.

The impact of endogenous N/OFQ on DPN: Insights into lower limb blood flow regulation in rats

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes, often accompanied by impaired vascular endothelial function in the lower limbs. This dysfunction is characterized by a reduced vasodilatory response, leading to decreased blood flow in the lower limbs and ultimately contributing to the development of diabetic peripheral neuropathy. To delve deeper into this pathological process, the study employed bioinformatics to identify and analyze genes highly active in DPN. The investigation revealed that Membrane metallo-endopeptidase (MME) was effectively mitigated by its antagonist. Male Sprague-Dawley (SD) rats served as the model to systematically explore the intrinsic connection among the nociceptible/orphanin FQ-N/OFQ receptor (N/OFQ-NOP) system, femoral artery blood flow in the lower extremities, MME, and DPN. The rats were randomized into two groups: a control group and a DPN group induced by a single intraperitoneal injection of 55 mg/kg streptozotocin (STZ), with 6 rats in each group. The findings indicated that compared to the control group, the DPN group exhibited a significant reduction in femoral artery blood flow. This was accompanied by a notable increase in serum N/OFQ concentration, heightened expression of opioid-related nociceptive protein receptor 1 (OPRL1) and MME in femoral artery tissues of the lower limbs, and an elevated sciatic nerve stimulation threshold. These results suggest that the serum N/OFQ level in DPN rats is increased, which may promote the occurrence of peripheral neuropathy by up regulating MME and reducing peripheral flow distribution.

Impact of fluorosis on molecular predictors in pathogenesis of type 2 diabetes associated microvascular complications

AIM

This review presents specific insights on the molecular underpinnings of the connection between fluorosis, type 2 diabetes, and microvascular complications, along with the novel biomarkers that are available for early detection.

SUMMARY

Fluoride is an essential trace element for the mineralization of teeth and bones in humans. Exposure to higher concentrations of fluoride has harmful effects that significantly outweigh its advantageous ones. Dental fluorosis and skeletal fluorosis are the common side effects of exposure to fluoride, which affect millions of individuals globally. Alongside, it also causes non-skeletal fluorosis, which affects the population suffering from non-communicable diseases like diabetes by impacting the soft tissues and causing diabetic microvascular complications. Previous studies reported the prevalence range of these diabetic complications of neuropathy (3-65 %), nephropathy (1-63 %), and retinopathy (2-33 %). Fluoride contributes to the development of these complications by causing oxidative stress, cellular damage, degrading the functioning capability of mitochondria, and thickening the retinal vein basement.

CONCLUSION

Early diagnosis is a prompt way of prevention, and for that, biomarkers have emerged as an innovative and useful technique. This allows healthcare practitioners and policymakers in endemic areas to comprehend the molecular complexities involved in the advancement of diabetic microvascular problems in the context of high fluoride exposure.

Atractylenolide-I Attenuates MPTP/MPP+‑Mediated Oxidative Stress in Parkinson's Disease Through SIRT1/PGC‑1α/Nrf2 Axis

Parkinson's disease (PD) is typically marked by motor dysfunction accompanied by loss of dopaminergic (DA) neurons and aggravated oxidative stress in the substantia nigra pars compacta (SNpc). Atractylenolide-I (ATR-I) is a potent antioxidant sesquiterpene with neuroprotective properties. However, whether ATR-I plays a neuroprotective role against oxidative stress in PD remains unclear. The objective of this study was to explore the mechanism of antioxidant action of ATR-I in PD models both in vivo and in vitro. Here, we show that ATR-I alleviated motor deficits in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mice. Moreover, ATR-I treatment effectively reduced DA neuron loss and increased tyrosine hydroxylase expression in the SNpc of MPTP-induced mice. Additionally, ATR-I inhibited oxidative stress (as manifested by elevated superoxide dismutase and glutathione peroxidase activities, and reduced malondialdehyde content) in MPTP-induced mice and attenuated reactive oxygen species levels in 1-methyl-4-phenylpyridinum (MPP+)-treated SH-SY5Y cells. Finally, ATR-I upregulated expressions of silent information regulator 1 (SIRT1), peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), NF-E2-related factor-2 (Nrf2), and heme oxygenase-1 in MPTP-induced mice and MPP+-treated SH-SY5Y cells, but had little effect on these factors in the presence of the SIRT1 inhibitor EX527. Taken together, these findings indicated that the important antioxidant role of ATR-I in MPTP/MPP+-mediated oxidative stress and the pathogenesis of PD through the SIRT1/PGC-1α/Nrf2 axis, highlighting its potential as a therapeutic option for PD.

Investigating the interplay between mitophagy and diabetic neuropathy: Uncovering the hidden secrets of the disease pathology

Mitophagy, the cellular process of selectively eliminating damaged mitochondria, plays a crucial role in maintaining metabolic balance and preventing insulin resistance, both key factors in type 2 diabetes mellitus (T2DM) development. When mitophagy malfunctions in diabetic neuropathy, it triggers a cascade of metabolic disruptions, including reduced energy production, increased oxidative stress, and cell death, ultimately leading to various complications. Thus, targeting mitophagy to enhance the process may have emerged as a promising therapeutic strategy for T2DM and its complications. Notably, plant-derived compounds with β-cell protective and mitophagy-stimulating properties offer potential as novel therapeutic agents. This review highlights the intricate mechanisms linking mitophagy dysfunction to T2DM and its complications, particularly neuropathy, elucidating potential therapeutic interventions for this debilitating disease.

Experimental Type 2 diabetes and lipotoxicity-associated neuroinflammation involve mitochondrial DNA-mediated cGAS/STING axis: implication of Type-1 interferon response in cognitive impairment

Type-1 IFN (interferon)-associated innate immune response is increasingly getting attention in neurodegenerative and metabolic diseases like type 2 diabetes (T2DM). However, its significance in T2DM/lipotoxicity-induced neuroglia changes and cognitive impairment is missing. The present study aims to evaluate the involvement of cGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon gene), IRF3 (interferon regulatory factor-3), TBK (TANK binding kinase)-mediated Type-1 IFN response in the diabetic brain, and lipotoxicity (palmitate-bovine serum albumin conjugate/PA-BSA)-induced changes in cells (neuro2a and BV2). T2DM was induced in C57/BL6 mice by feeding on a high-fat diet (HFD, 60% Kcal) for 16 weeks and injecting a single dose of streptozotocin (100 mg/kg, i.p) in the 12th week. Plasma biochemical parameter analysis, neurobehavioral assessment, protein expression, and quantitative polymerase chain reaction study were carried out to decipher the hypothesis. T2DM-associated metabolic and lipotoxic stress led to mitochondrial impairment causing leakage of mtDNA to the cytoplasm further commencing cGAS activation and its downstream signaling. The diseased hippocampus and cortex showed decreased expression of synaptophysin (p < 0.01) and PSD-95 (p < 0.01, p < 0.05) with increased expression of cGAS (p < 0.001), p-STING (p < 0.001), p-STAT1 (signal transducer and activator of transcription) (p < 0.01), and IFN-β (p < 0.001) compared to normal control. The IFN-β/p-STAT1-mediated microglia activation was executed employing a conditioned media approach. C-176, a selective STING inhibitor, alleviated cGAS/p-STING/IFN-β expression and proinflammatory microglia/M1-associated markers (CD16 expression, CXCL10, TNF-α, IL-1β mRNA fold change) in the diabetic brain. The present study suggests Type-1IFN response may result in neuroglia dyshomeostasis affecting normal brain function. Alleviating STING signaling has the potential to protect T2DM-associated central ailment.

Systematic review of translational insights: Neuromodulation in animal models for Diabetic Peripheral Neuropathy

Diabetic Peripheral Neuropathy (DPN) is a prevalent and debilitating complication of diabetes, affecting a significant proportion of the diabetic population. Neuromodulation, an emerging therapeutic approach, has shown promise in the management of DPN symptoms. This systematic review aims to synthesize and analyze the current advancements in neuromodulation techniques for the treatment of DPN utilizing studies with preclinical animal models. A comprehensive search was conducted across multiple databases, including PubMed, Scopus, and Web of Science. Inclusion criteria were focused on studies utilizing preclinical animal models for DPN that investigated the efficacy of various neuromodulation techniques, such as spinal cord stimulation, transcranial magnetic stimulation, and peripheral nerve stimulation. The findings suggest that neuromodulation significantly alleviated pain symptoms associated with DPN. Moreover, some studies reported improvements in nerve conduction velocity and reduction in nerve damage. The mechanisms underlying these effects appeared to involve modulation of pain pathways and enhancement of neurotrophic factors. However, the review also highlights the variability in methodology and stimulation parameters across studies, highlighting the need for standardization in future research. Additionally, while the results are promising, the translation of these findings from animal models to human clinical practice requires careful consideration. This review concludes that neuromodulation presents a potentially effective therapeutic strategy for DPN, but further research is necessary to optimize protocols and understand the underlying molecular mechanisms. It also emphasizes the importance of bridging the gap between preclinical findings and clinical applications to improve the management of DPN in diabetic patients.

Cannabidiol and Beta-Caryophyllene Combination Attenuates Diabetic Neuropathy by Inhibiting NLRP3 Inflammasome/NFκB through the AMPK/sirT3/Nrf2 Axis

BACKGROUND

In this study, we investigated in detail the role of cannabidiol (CBD), beta-caryophyllene (BC), or their combinations in diabetic peripheral neuropathy (DN). The key factors that contribute to DN include mitochondrial dysfunction, inflammation, and oxidative stress.

METHODS

Briefly, streptozotocin (STZ) (55 mg/kg) was injected intraperitoneally to induce DN in Sprague-Dawley rats, and we performed procedures involving Randall Sellito calipers, a Von Frey aesthesiometer, a hot plate, and cold plate methods to determine mechanical and thermal hyperalgesia in vivo. The blood flow to the nerves was assessed using a laser Doppler device. Schwann cells were exposed to high glucose (HG) at a dose of 30 mM to induce hyperglycemia and DCFDA, and JC1 and Mitosox staining were performed to determine mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides in vitro. The rats were administered BC (30 mg/kg), CBD (15 mg/kg), or combination via i.p. injections, while Schwann cells were treated with 3.65 µM CBD, 75 µM BC, or combination to assess their role in DN amelioration.

RESULTS

Our results revealed that exposure to BC and CBD diminished HG-induced hyperglycemia in Schwann cells, in part by reducing mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides. Furthermore, the BC and CBD combination treatment in vivo could prevent the deterioration of the mitochondrial quality control system by promoting autophagy and mitochondrial biogenesis while improving blood flow. CBD and BC treatments also reduced pain hypersensitivity to hyperalgesia and allodynia, with increased antioxidant and anti-inflammatory action in diabetic rats. These in vivo effects were attributed to significant upregulation of AMPK, sirT3, Nrf2, PINK1, PARKIN, LC3B, Beclin1, and TFAM functions, while downregulation of NLRP3 inflammasome, NFκB, COX2, and p62 activity was noted using Western blotting.

CONCLUSIONS

the present study demonstrated that STZ and HG-induced oxidative and nitrosative stress play a crucial role in the pathogenesis of diabetic neuropathy. We find, for the first time, that a CBD and BC combination ameliorates DN by modulating the mitochondrial quality control system.

Targeting autophagy with natural products as a potential therapeutic approach for diabetic microangiopathy

As the quality of life improves, the incidence of diabetes mellitus and its microvascular complications (DMC) continues to increase, posing a threat to people's health and wellbeing. Given the limitations of existing treatment, there is an urgent need for novel approaches to prevent and treat DMC. Autophagy, a pivotal mechanism governing metabolic regulation in organisms, facilitates the removal of dysfunctional proteins and organelles, thereby sustaining cellular homeostasis and energy generation. Anomalous states in pancreatic β-cells, podocytes, Müller cells, cardiomyocytes, and Schwann cells in DMC are closely linked to autophagic dysregulation. Natural products have the property of being multi-targeted and can affect autophagy and hence DMC progression in terms of nutrient perception, oxidative stress, endoplasmic reticulum stress, inflammation, and apoptosis. This review consolidates recent advancements in understanding DMC pathogenesis via autophagy and proposes novel perspectives on treating DMC by either stimulating or inhibiting autophagy using natural products.

Roles of Sirt1 and its modulators in diabetic microangiopathy: A review

Diabetic vascular complications include diabetic macroangiopathy and diabetic microangiopathy. Diabetic microangiopathy is characterised by impaired microvascular endothelial function, basement membrane thickening, and microthrombosis, which may promote renal, ocular, cardiac, and peripheral system damage in diabetic patients. Therefore, new preventive and therapeutic strategies are urgently required. Sirt1, a member of the nicotinamide adenine dinucleotide-dependent histone deacetylase class III family, regulates different organ growth and development, oxidative stress, mitochondrial function, metabolism, inflammation, and aging. Sirt1 is downregulated in vascular injury and microangiopathy. Moreover, its expression and distribution in different organs correlate with age and play critical regulatory roles in oxidative stress and inflammation. This review introduces the background of diabetic microangiopathy and the main functions of Sirt1. Then, the relationship between Sirt1 and different diabetic microangiopathies and the regulatory roles mediated by different cells are described. Finally, we summarize the modulators that target Sirt1 to ameliorate diabetic microangiopathy as an essential preventive and therapeutic measure for diabetic microangiopathy. In conclusion, targeting Sirt1 may be a new therapeutic strategy for diabetic microangiopathy.

The potential of therapeutic strategies targeting mitochondrial biogenesis for the treatment of insulin resistance and type 2 diabetes mellitus

Type 2 diabetes mellitus (T2DM) is a persistent metabolic disorder marked by deficiencies in insulin secretion and/or function, affecting various tissues and organs and leading to numerous complications. Mitochondrial biogenesis, the process by which cells generate new mitochondria utilizing existing ones plays a crucial role in energy homeostasis, glucose metabolism, and lipid handling. Recent evidence suggests that promoting mitochondrial biogenesis can alleviate insulin resistance in the liver, adipose tissue, and skeletal muscle while improving pancreatic β-cell function. Moreover, enhanced mitochondrial biogenesis has been shown to ameliorate T2DM symptoms and may contribute to therapeutic effects for the treatment of diabetic nephropathy, cardiomyopathy, retinopathy, and neuropathy. This review summarizes the intricate connection between mitochondrial biogenesis and T2DM, highlighting the potential of novel therapeutic strategies targeting mitochondrial biogenesis for T2DM treatment and its associated complications. It also discusses several natural products that exhibit beneficial effects on T2DM by promoting mitochondrial biogenesis.

Phytostilbenes in lymphoma: Focuses on the mechanistic and clinical prospects of resveratrol, pterostilbene, piceatannol, and pinosylvin

Lymphoma is a cancer affecting the lymphatic system that fights infections and diseases. In addition to surgery, radiotherapy, and chemotherapy, novel approaches have recently been investigated, such as phytostilbenes in treating lymphoma. Phytostilbenes are natural compounds present in various plants and have been shown to have different therapeutic effects, including anticancer properties. Resveratrol is a main phytostilbene with various derivates followed by pterostilbene and piceatannol. Studies have revealed that phytostilbenes can suppress the growth and proliferation of lymphoma cells by inducing apoptosis and inhibiting specific enzyme activity in cancer cell survival. The compounds also have antiinflammatory effects contributing to reducing lymphoma-associated inflammation. Additionally, phytostilbenes have been shown to increase the immune system's ability to fight cancer cells by activating immune cells (T-cells and natural killer cells). This review investigates the potential therapeutic effects of phytostilbenes, including resveratrol, pterostilbene, piceatannol, and pinosylvin, against lymphoma.

Investigation of the protective effects of piceatannol on experimental subarachnoid hemorrhage in rats

BACKGROUND

Subarachnoid hemorrhage (SAH) is one of the most prevalent brain injuries in humans which has poor prognosis and high mortality rates. Due to several medical or surgical treatment methods, a gold standard method doesn't exist for SAH treatment. Piceatannol (PCN), a natural analog of resveratrol, was reported to reduce inflammation and apoptosis promising a wide range of therapeutic alternatives. In this study, we aimed to investigate the effects of PCN in an experimental SAH model. The alleviating effects of PCN in the hippocampus in an experimental SAH model were investigated for the first time.

METHODS AND RESULTS

In this study, 27 Wistar Albino male rats (200-300 g; 7-8 week) were used. Animals were divided into three groups; SHAM, SAH, and SAH + PCN. SAH model was created with 120 µl of autologous arterial tail blood to prechiasmatic cisterna. 30 mg/kg PCN was administered intraperitoneally at 1st h after SAH. Neurological evaluation was performed with Garcia's score. RT-PCR was performed for gene expression levels in the hippocampus. Pyknosis, edema, and apoptosis were evaluated by H&E and TUNEL staining. Our results indicated that PCN administration reduced apoptosis (P < 0.01), cellular edema, and pyknosis (P < 0.05) in the hippocampus after SAH. Moreover, PCN treatment significantly decreased the expression levels of TNF-α (P < 0.01), IL-6 (P < 0.05), NF-κB (P < 0.05), and Bax (P < 0.05) in the hippocampus.

CONCLUSIONS

Our results demonstrated that PCN might be a potential therapeutic adjuvant agent for the treatment of early brain injury (EBI) following SAH. Further studies are required to clarify the underlying mechanisms and treatment options of SAH.

E-Stilbenes: General Chemical and Biological Aspects, Potential Pharmacological Activity Based on the Nrf2 Pathway

Stilbenes are phytoalexins, and their biosynthesis can occur through a natural route (shikimate precursor) or an alternative route (in microorganism cultures). The latter is a metabolic engineering strategy to enhance production due to stilbenes recognized pharmacological and medicinal potential. It is believed that in the human body, these potential activities can be modulated by the regulation of the nuclear factor erythroid derived 2 (Nrf2), which increases the expression of antioxidant enzymes. Given this, our review aims to critically analyze evidence regarding E-stilbenes in human metabolism and the Nrf2 activation pathway, with an emphasis on inflammatory and oxidative stress aspects related to the pathophysiology of chronic and metabolic diseases. In this comprehensive literature review, it can be observed that despite the broad number of stilbenes, those most frequently explored in clinical trials and preclinical studies (in vitro and in vivo) were resveratrol, piceatannol, pterostilbene, polydatin, stilbestrol, and pinosylvin. In some cases, depending on the dose/concentration and chemical nature of the stilbene, it was possible to identify activation of the Nrf2 pathway. Furthermore, the use of some experimental models presented a challenge in comparing results. In view of the above, it can be suggested that E-stilbenes have a relationship with the Nrf2 pathway, whether directly or indirectly, through different biological pathways, and in different diseases or conditions that are mainly related to inflammation and oxidative stress.

Quality by design fostered fabrication of cabazitaxel loaded pH-responsive Improved nanotherapeutics against prostate cancer

Cabazitaxel has been approved for the treatment of prostate cancer since 2010. However, its poor solubility and permeability pitfalls prevent its accumulation at the target site and promote severe adverse effects. About 90% of prostate cancer (PCa) patients suffer from bone metastasis. This advent reports the development of CBZ-loaded pH-responsive polydopamine nanoparticles (CBZ NP) against metastatic PCa cells. Quality by design (QbD) and multivariate analysis tools were employed for the optimization of CBZ NP. Amorphisation of CBZ along with metastatic microenvironment responsive release was observed thereby imparting spatial release and circumventing solubility pitfalls. CBZ NP retained its cytotoxic potential, with a significant increase in quantitative cellular uptake. Apoptotic markers observed from nuclear staining with elevated reactive oxygen species (ROS) and mitochondrial damage revealed by JC-1 staining demonstrated the efficacy of CBZ NP against PC-3 cells with good serum stability and diminished hemolysis. Cell cycle analysis revealed substantial S and G2/M phase arrest with enhancement in apoptosis was observed. Western blot studies revealed an elevation in caspase-1 and suppression in Bcl-2 indicating enhanced apoptosis compared to the control group. Substantial reduction in the diameter of 3D-Tumoroid and enhanced cell proliferation inhibition indicated the efficacy of CBZ NP in PCa. Thus, we conclude that CBZ NP could be a promising Nanotherapeutic approach for PCa.

Combined Role of Interleukin-15 Stimulated Natural Killer Cell-Derived Extracellular Vesicles and Carboplatin in Osimertinib-Resistant H1975 Lung Cancer Cells with EGFR Mutations

In this study, we evaluated IL-15 stimulated natural killer cell-derived EVs (NK-EVs) as therapeutic agents in vitro and in vivo in Osimertinib-resistant lung cancer (H1975R) with EGFR mutations (L858R) in combination with carboplatin (CBP). NK-EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis, and atomic force microscopy imaging revealed vesicles with a spherical form and sizes meeting the criteria of exosomal EVs. Further, Western blot studies demonstrated the presence of regular EV markers along with specific NK markers (perforin and granzyme). EVs were also characterized by proteomic analysis, which demonstrated that EVs had proteins for natural killer cell-mediated cytotoxicity (Granzyme B) and T cell activation (perforin and plastin-2). Gene oncology analysis showed that these differentially expressed proteins are involved in programmed cell death and positive regulation of cell death. Further, isolated NK-EVs were cytotoxic to H1975R cells in vitro in 2D and 3D cell cultures. CBP's IC50 was reduced by approximately in 2D and 3D cell cultures when combined with NK-EVs. The EVs were then combined with CBP and administered by i.p. route to H1975R tumor xenografts, and a significant reduction in tumor volume in vivo was observed. Our findings show for the first time that NK-EVs target the PD-L1/PD-1 immunological checkpoint to induce apoptosis and anti-inflammatory response by downregulation of SOD2, PARP, BCL2, SET, NF-κB, and TGF-ß. The ability to isolate functional NK-EVs on a large scale and use them with platinum-based drugs may lead to new clinical applications. The results of the present study suggest the possibility of the combination of NK-cell-derived EVs and CBP as a viable immunochemotherapeutic strategy for resistant cancers.

S1PR2 inhibition mitigates cognitive deficit in diabetic mice by modulating microglial activation via Akt-p53-TIGAR pathway

Cognitive deficit is one of the challenging complications of type 2 diabetes. Sphingosine 1- phosphate receptors (S1PRs) have been implicated in various neurodegenerative and metabolic disorders. The association of S1PRs and cognition in type 2 diabetes remains elusive. Microglia-mediated neuronal damage could be the thread propagating cognitive deficit. The effects of S1PR2 inhibition on cognition in high-fat diet and streptozotocin-induced diabetic mice were examined in this work. We further assessed microglial activation and putative microglial polarisation routes. Cognitive function loss was observed after four months of diabetes induction in Type 2 diabetes animal model. JTE013, an S1PR2 inhibitor, was used to assess neuroprotection against cognitive decline and neuroinflammation in vitro and in vivo diabetes model. JTE013 (10 mg/kg) improved synaptic plasticity by upregulating psd95 and synaptophysin while reducing cognitive decline and neuroinflammation. It further enhanced anti-inflammatory microglia in the hippocampus and prefrontal cortex (PFC), as evidenced by increased Arg-1, CD206, and YM-1 levels and decreased iNOS, CD16, and MHCII levels. TIGAR, TP53-induced glycolysis and apoptosis regulator, might facilitate the anti-inflammatory microglial phenotype by promoting oxidative phosphorylation and decreasing apoptosis. However, since p53 is a TIGAR suppressor, inhibiting p53 could be beneficial. S1PR2 inhibition increased p-Akt and TIGAR levels and reduced the levels of p53 in the PFC and hippocampus of type 2 diabetic mice, thereby decreasing apoptosis. In vitro, palmitate was used to imitate sphingolipid dysregulation in BV2 cells, followed by conditioned media exposure to Neuro2A cells. JTE013 rescued the palmitate-induced neuronal apoptosis by promoting the anti-inflammatory microglia. In the present study, we demonstrate that the inhibition of S1PR2 improves cognitive function and skews microglia toward anti-inflammatory phenotype in type 2 diabetic mice, thereby promising to be a potential therapy for neuroinflammation.

The activation of SIRT1 by resveratrol reduces breast cancer metastasis to lung through inhibiting neutrophil extracellular traps

Neutrophil extracellular traps (NETs) play a crucial role in breast cancer metastasis. However, the therapeutic target of NETs in breast cancer metastasis is still unknown. Using a natural metabolite library and single-cell sequencing data analysis, we identified resveratrol (RES), a polyphenolic natural phytoalexin, and agonist of silent information regulator-1 (SIRT1) that suppressed NETs formation after cathepsin C (CTSC) treatment. In vivo, RES significantly hindered breast cancer metastasis in a murine orthotopic 4T1 breast cancer model. Serum levels of myeloperoxidase-DNA and neutrophil elastase-DNA in mouse breast cancer model were significantly lower after RES treatment. Correspondingly, the tumour infiltrated CD8+T cells in the lungs increased after the treatment. Mechanistically, RES targets SIRT1 in neutrophils and significantly inhibits the citrullination of histones H3, which is essential for chromatin decondensation and NETs formation. Furthermore, we identified that the NETs were suppressed by RES in bone marrow neutrophils after CTSC treatment, while specific deficiency of SIRT1 in neutrophils promoted NETs formation and breast cancer to lung metastasis. Thus, our results revealed that RES could be potentially identified as a viable therapeutic drug to prevent neutrophil cell death and breast cancer metastasis.

Sphingosine 1 phosphate lyase inhibition rescues cognition in diabetic mice by promoting anti-inflammatory microglia

Sphingosine-1-phosphate (S1P) is emerging as a crucial sphingolipid modulating neuroinflammation and cognition. S1P levels in the brain have been found to be decreased in cognitive impairment. S1P lyase (S1PL) is the key enzyme in metabolizing S1P and has been implicated in neuroinflammation. This study evaluated the effect of S1PL inhibition on cognition in type 2 diabetic mice. Fingolimod (0.5mg/kg and 1mg/kg) rescued cognition in high-fat diet and streptozotocin-induced diabetic mice, as evident in the Y maze and passive avoidance test. We further evaluated the effect of fingolimod on the activation of microglia in the pre-frontal cortex (PFC) and hippocampus of diabetic mice. Our study revealed that fingolimod inhibited S1PL and promoted anti-inflammatory microglia in both PFC and hippocampus of diabetic mice as it increased Ym-1 and arginase-1. The levels of p53 and apoptotic proteins (Bax and caspase-3) were elevated in the PFC and hippocampus of type 2 diabetic mice which fingolimod reversed. The underlying mechanism promoting anti-inflammatory microglial phenotype was also explored in this study. TIGAR, TP53-associated glycolysis and apoptosis regulator, is known to foster anti-inflammatory microglia and was found to be downregulated in the brain of type 2 diabetic mice. S1PL inhibition decreased the levels of p53 and promoted TIGAR, thereby increasing anti-inflammatory microglial phenotype and inhibiting apoptosis in the brain of diabetic mice. Our study reveals that S1PL inhibition could be beneficial in mitigating cognitive deficits in diabetic mice.

GSK-3β: An exuberating neuroinflammatory mediator in Parkinson's disease

Neuroinflammation is a critical degradative condition affecting neurons in the brain. Progressive neurodegenerative conditions such as Alzheimer's disease and Parkinson's disease (PD) have been strongly linked to neuroinflammation. The trigger point for inflammatory conditions in the cells and body is the physiological immune system. The immune response mediated by glial cells and astrocytes can rectify the physiological alterations occurring in the cell for the time being but prolonged activation leads to pathological progression. The proteins mediating such an inflammatory response, as per the available literature, are undoubtedly GSK-3β, NLRP3, TNF, PPARγ, and NF-κB, along with a few other mediatory proteins. NLRP3 inflammasome is undeniably a principal instigator of the neuroinflammatory response, but the regulatory pathways controlling its activation are still unclear, besides less clarity for the interplay between different inflammatory proteins. Recent reports have suggested the involvement of GSK-3β in regulating NLRP3 activation, but the exact mechanistic pathway remains vague. In the current review, we attempt to provide an elaborate description of crosstalk between inflammatory markers and GSK-3β mediated neuroinflammation progression, linking it to regulatory transcription factors and posttranslational modification of proteins. The recent clinical therapeutic advances targeting these proteins are also discussed in parallel to provide a comprehensive view of the progress made in PD management and lacunas still existing in the field.