Neuroprotective effect of Dictyopteris divaricata extract-capped gold nanoparticles against oxygen and glucose deprivation/reoxygenation

Revolutionizing Stroke Care: Nanotechnology-Based Brain Delivery as a Novel Paradigm for Treatment and Diagnosis

Stroke, a severe medical condition arising from abnormalities in the coagulation-fibrinolysis cycle and metabolic processes, results in brain cell impairment and injury due to blood flow obstruction within the brain. Prompt and efficient therapeutic approaches are imperative to control and preserve brain functions. Conventional stroke medications, including fibrinolytic agents, play a crucial role in facilitating reperfusion to the ischemic brain. However, their clinical efficacy is hampered by short plasma half-lives, limited brain tissue distribution attributed to the blood-brain barrier (BBB), and lack of targeted drug delivery to the ischemic region. To address these challenges, diverse nanomedicine strategies, such as vesicular systems, polymeric nanoparticles, dendrimers, exosomes, inorganic nanoparticles, and biomimetic nanoparticles, have emerged. These platforms enhance drug pharmacokinetics by facilitating targeted drug accumulation at the ischemic site. By leveraging nanocarriers, engineered drug delivery systems hold the potential to overcome challenges associated with conventional stroke medications. This comprehensive review explores the pathophysiological mechanism underlying stroke and BBB disruption in stroke. Additionally, this review investigates the utilization of nanocarriers for current therapeutic and diagnostic interventions in stroke management. By addressing these aspects, the review aims to provide insight into potential strategies for improving stroke treatment and diagnosis through a nanomedicine approach.

AuNPs with Cynara scolymus leaf extracts rescue arsenic-induced neurobehavioral deficits and hippocampal tissue toxicity in Balb/c mice through D1R and D2R activation

The present study was designed to evaluate whether AuNPs (gold nanoparticles) synthesized with the Cynara scolymus (CS) leaf exert protective and/or alleviative effects on arsenic (As)-induced hippocampal neurotoxicity in mice. Neurotoxicity in mice was developed by orally treating 10 mg/kg/day sodium arsenite (NaAsO2) for 21 days. 10 µg/g AuNPs, 1.6 g/kg CS, and 10 µg/g CS-AuNPs were administered orally simultaneously with 10 mg/kg As. CS and CS-AuNPs treatments showed down-regulation of TNF-α and IL-1β levels. CS and CS-AuNPs also ameliorated apoptosis and reduced the alterations in the expression levels of D1 and D2 dopamine receptors induced by As. Simultaneous treatment with CS and CS-AuNPs improved As-induced learning, memory deficits, and motor coordination in mice assessed by water maze and locomotor tests, respectively. The results of this study provide evidence that CS-AuNPs demonstrated neuroprotective roles with antioxidant, anti-inflammatory, and anti-apoptotic effects, as well as improving D1 and D2 signaling, and eventually reversed neurobehavioral impairments.

The Ethanolic Extract of Dictyopteris Divaricata Induces Apoptosis in Non-Small Cell Lung Cancer Cells by Inhibiting STAT3 Activity

Dictyopteris divaricata (DD) has been reported to exert diverse pharmacological activities, including anti-inflammatory, antioxidant, and anticancer effects. In this study, we aimed to investigate the anticancer potential of the ethanolic extract of DD (EDD) in non-small cell lung cancer (NSCLC) cells and to explore the underlying mechanism. EDD significantly suppressed cell proliferation in H1299, PC9, and H1975 NSCLC cells. EDD treatment increased the proportion of Annexin V-positive cells and cells in sub-G1 phase, indicating the induction of apoptosis. This observation was further supported by the presence of fragmented nuclei and increased expression of cleaved PARP and cleaved caspase-3 in NSCLC cells following EDD treatment. Mechanistically, EDD decreased the phosphorylation levels of signal transducer and activator of transcription 3 (STAT3) and Src. Transfection of constitutively activated STAT3 into H1975 cells partially attenuated EDD-induced apoptosis, highlighting the contribution of STAT3 inhibition to the anticancer activity of EDD. In addition, we identified fucosterol as a major constituent of EDD that exhibited similar anticancer potential in NSCLC cells. Taken together, our results demonstrate that EDD induces apoptosis in NSCLC cells by inhibiting STAT3 activity. We propose EDD as a potential candidate for the development of therapies targeting NSCLC.

Traditional Chinese medicines treat ischemic stroke and their main bioactive constituents and mechanisms

Ischemic stroke (IS) remains one of the leading causes of death and disability in humans. Unfortunately, none of the treatments effectively provide functional benefits to patients with IS, although many do so by targeting different aspects of the ischemic cascade response. The advantages of traditional Chinese medicine (TCM) in preventing and treating IS are obvious in terms of early treatment and global coordination. The efficacy of TCM and its bioactive constituents has been scientifically proven over the past decades. Based on clinical trials, this article provides a review of commonly used TCM patent medicines and herbal decoctions indicated for IS. In addition, this paper also reviews the mechanisms of bioactive constituents in TCM for the treatment of IS in recent years, both domestically and internationally. A comprehensive review of preclinical and clinical studies will hopefully provide new ideas to address the threat of IS.

Ligand-Modified Gold Nanoparticles as Mitochondrial Modulators: Regulation of Intestinal Barrier and Therapy for Constipation

Intestinal metabolism-related diseases, such as constipation, inflammatory bowel disease, irritable bowel syndrome, and colorectal cancer, could be associated with the dysfunction of intestinal mitochondria. The mitochondria of intestinal epithelial cells are of great significance for promoting intestinal motility and maintaining intestinal metabolism. It is necessary for the prophylaxis and therapy of intestinal metabolism-related diseases to improve mitochondrial function. We investigated the effect of 4,6-diamino-2-pyrimidinethiol-modified gold nanoparticles (D-Au NPs) on intestinal mitochondria and studied the regulatory role of D-Au NPs on mitochondria metabolism-related disease. D-Au NPs improved the antioxidation capability of mitochondria, regulated the mitochondrial metabolism, and maintained intestinal cellular homeostasis via the activation of AMPK and regulation of PGC-1α with its downstream signaling (UCP2 and DRP1), enhancing the intestinal mechanical barrier. D-Au NPs improved the intestinal mitochondrial function to intervene in the emergence of constipation, which could help develop drugs to treat and prevent mitochondrial metabolism-related diseases. Our findings provided an in-depth understanding of the mitochondrial effects of Au NPs for improving human intestinal barriers.

Rapeseed peptide inhibits HepG2 cell proliferation by regulating the mitochondrial and P53 signaling pathways

BACKGROUND

Rapeseed peptide, extracted from rapeseed protein, is known to have a variety of biological activities. In this study, the anti-proliferation effect and molecular mechanism of rapeseed peptide on HepG2 cells were investigated.

RESULTS

In vitro anticancer experiments showed that the rapeseed peptide NDGNQPL could inhibit HepG2 cell proliferation in a concentration-dependent manner [half maximal inhibitory concentration (IC₅₀ ), 1.56 mmol L^-1 ). HepG2 cells were induced by NDGNQPL at a 0.5 mmol L^-1 concentration and exhibited a 28.39 ± 0.80% apoptosis rate and a cell cycle arrest in the G0/G1 phase. Meanwhile, rapeseed peptide induced a decrease in mitochondrial membrane potential, an increase in reactive oxygen species (ROS) release, and changes in the nuclear morphology of HepG2 cells, indicating that rapeseed peptide could induce cell apoptosis through the mitochondrial pathway. In addition, rapeseed peptide activated the proliferation-related P53 signaling pathway, in which the expression levels of P53, P21, and cleaved-caspase3 were up-regulated, while the expression levels of murine double minute 2 (MDM2) were down-regulated. In molecular docking simulations, NDGNQPL exhibited a good affinity for the MDM2 molecule, which supported the notion that the rapeseed peptide is able to inhibit MDM2, a negative regulator of P53.

CONCLUSION

The current results indicate that the rapeseed-derived NDGNQPL peptide has the potential to inhibit the proliferation of HepG2 cells and promote human health. © 2022 Society of Chemical Industry.

The initiator of neuroexcitotoxicity and ferroptosis in ischemic stroke: Glutamate accumulation

Glutamate plays an important role in excitotoxicity and ferroptosis. Excitotoxicity occurs through over-stimulation of glutamate receptors, specifically NMDAR, while in the non-receptor-mediated pathway, high glutamate concentrations reduce cystine uptake by inhibiting the System Xc-, leading to intracellular glutathione depletion and resulting in ROS accumulation, which contributes to increased lipid peroxidation, mitochondrial damage, and ultimately ferroptosis. Oxidative stress appears to crosstalk between excitotoxicity and ferroptosis, and it is essential to maintain glutamate homeostasis and inhibit oxidative stress responses in vivo. As researchers work to develop natural compounds to further investigate the complex mechanisms and regulatory functions of ferroptosis and excitotoxicity, new avenues will be available for the effective treatment of ischaemic stroke. Therefore, this paper provides a review of the molecular mechanisms and treatment of glutamate-mediated excitotoxicity and ferroptosis.

Effect of crude polysaccharide from seaweed, Dictyopteris divaricata (CDDP) on gut microbiota restoration and anti-diabetic activity in streptozotocin (STZ)-induced T1DM mice

Type-1 Diabetes Mellitus (T1DM) is regarded as a multifunctional, immune-related disease which causes massive destruction of islet β-cells in pancreas resulting in hyperglycemic, hypoinsulinemia and hyperlipidimic conditions. The aim of the present study, was to investigate the hypothesis that streptozotocin (STZ)-induced T1DM in Balb/c mice when treated with crude polysaccharide from seaweed, Dictyopteris divaricata (CDDP) depicts improvement in diabetes-related symptoms. Treatment with CDDP resulted in decreased body weight loss, improved food consumption and water intake disbalances. The CDDP effectively improved fasting blood glucose, oral glucose tolerance (OGTT), serum insulin, insulin secretion, rejuvenation of β-cells mass, serum lipid profile and pro-inflammatory cytokines levels. Additionally, treatment with CDDP increased the population of beneficial bacteria such as Firmicutes, Bacteroidetes and Lactobacillus at phylum, family and genus levels by 16S rRNA sequencing. Furthermore, immunohistological examination confirmed that CDDP reduces the inflammation and restored the structural morphology of colon and upraised the levels of insulin receptor substrate-1 (IRS-1), Mucin-2 (MUC-2) and tight-junction proteins (TJs) whereby maintaining the gut structures and barrier permeability. Thus, the above presented data, highlights the safe and therapeutic effects of crude polysaccharide (CDDP) from D. divaricata in the treatment and restoration of T1DM disorders and can be used as a food supplement alternative to diabetes medicine.

Gold Nanoparticles Using Ecklonia stolonifera Protect Human Dermal Fibroblasts from UVA-Induced Senescence through Inhibiting MMP-1 and MMP-3

The effect of gold nanoparticles (GNPs) synthesized in marine algae has been described in the context of skin, where they have shown potential benefit. Ecklonia stolonifera (ES) is a brown algae that belongs to the Laminariaceae family, and is widely used as a component of food and medicine due to its biological activities. However, the role of GNPs underlying cellular senescence in the protection of Ecklonia stolonifera gold nanoparticles (ES-GNPs) against UVA irradiation is less well known. Here, we investigate the antisenescence effect of ES-GNPs and the underlying mechanism in UVA-irradiated human dermal fibroblasts (HDFs). The DPPH and ABTS radical scavenging activity of ES extracts was analyzed. These analyses showed that ES extract has potent antioxidant properties. The facile and optimum synthesis of ES-GNPs was established using UV-vis spectra. The surface morphology and crystallinity of ES-GNPs were demonstrated using high resolution transmission electron microscopy (HR-TEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FT-IR). ES-GNPs presented excellent photocatalytic activity, as shown by the photo-degradation of methylene blue and rhodamine B. A cellular senescence model was established by irradiating HDFs with UVA. UVA-irradiated HDFs exhibited increased expression of senescence-associated β-galactosidase (SA-β-galactosidase). However, pretreatment with ES-GNPs resulted in reduced SA-β-galactosidase activity in UVA-irradiated HDFs. Intracellular ROS levels and G1 arrest in UVA-irradiated HDFs were checked against the background of ES-GNP treatment to investigate the antisenescence effects of ES-GNPs. The results showed that ES-GNPs significantly inhibit UVA-induced ROS levels and G1 arrest. Importantly, ES-GNPs significantly downregulated the transcription and translation of MMP (matrix metalloproteinases)-1/-3, which regulate cellular senescence in UVA-irradiated HDFs. These findings indicate that our optimal ES-GNPs exerted an antisenescence effect on UVA-irradiated HDFs by inhibiting MMP-1/-3 expression. Collectively, we posit that ES-GNPs may potentially be used to treat photoaging of the skin.

Petatewalide B alleviates oxygen‑glucose deprivation/reoxygenation‑induced neuronal injury via activation of the AMPK/Nrf2 signaling pathway

Neuronal injury is a common, and critical, occurrence in clinical ischemic strokes, and can cause irreversible brain damage. However, the precise pathological mechanisms underlying this condition and effective treatment remain unclear. Increasing evidence shows that the nuclear factor erythroid 2‑related factor 2 (Nrf2)/activated protein kinase (AMPK) signaling pathway serves a significant role in neuronal injury and is involved in neuroprotection. The present study demonstrated that petatewalide B, the active constituent of Petasites japonicus, otherwise known as butterbur, can alleviate oxygen‑glucose deprivation/reoxygenation (OGD/R)‑induced neuronal death via the adenosine monophosphate‑AMPK/glycogen synthase kinase (GSK)‑3/β/Nrf2/antioxidant response element (ARE) signaling pathways in human neuroblastoma SH‑SY5Y cells. A neuronal injury model was established by depriving SH‑SY5Y cells of oxygen and glucose for 8 h, followed by 24 h of reoxygenation (OGD/R). The results indicated that the OGD/R model exhibited reduced cell viability but increased lactate dehydrogenase (LDH) release, reactive oxygen species (ROS) production and apoptosis. These were accompanied by increased levels of cleaved PARP, cleaved caspase‑9, cleaved caspase‑3, p53, Bax and p21, as well as decreased Bcl‑2 levels. Treatment with petatewalide B was able to strengthen cell viability but reduced LDH release, ROS production and the expression levels of apoptosis‑related proteins. Additionally, treatment with petatewalide B activated AMPK in the OGD/R‑exposed SH‑SY5Y cells and upregulated activation of the downstream transcription factor Nrf2, which accompanied heme oxygenase 1 (HO‑1) and NAD(P)H quinone dehydrogenase 1 (NQO1) expression. Furthermore, silencing AMPK, Nrf2, HO‑1 and NQO1 expression inhibited petatewalide B's protective effect against apoptosis in the OGD/R‑exposed SH‑SY5Y cells. Therefore, petatewalide B protected human neuroblastoma cells against OGD/R‑induced injury by downregulating apoptosis and oxidative stress via upregulation of the AMPK/Nrf2 signaling pathway, suggesting that petatewalide B may be a prospective protector against neuronal injury, having possible therapeutic and medical implications.

Pre-Treatment with Laminarin Protects Hippocampal CA1 Pyramidal Neurons and Attenuates Reactive Gliosis Following Transient Forebrain Ischemia in Gerbils

Transient brain ischemia triggers selective neuronal death/loss, especially in vulnerable regions of the brain including the hippocampus. Laminarin, a polysaccharide originating from brown seaweed, has various pharmaceutical properties including an antioxidant function. To the best of our knowledge, few studies have been conducted on the protective effects of laminarin against ischemic injury induced by ischemic insults. In this study, we histopathologically investigated the neuroprotective effects of laminarin in the Cornu Ammonis 1 (CA1) field of the hippocampus, which is very vulnerable to ischemia-reperfusion injury, following transient forebrain ischemia (TFI) for five minutes in gerbils. The neuroprotective effect was examined by cresyl violet staining, Fluoro-Jade B histofluorescence staining and immunohistochemistry for neuronal-specific nuclear protein. Additionally, to study gliosis (glial changes), we performed immunohistochemistry for glial fibrillary acidic protein to examine astrocytes, and ionized calcium-binding adaptor molecule 1 to examine microglia. Furthermore, we examined alterations in pro-inflammatory M1 microglia by using double immunofluorescence. Pretreatment with 10 mg/kg laminarin failed to protect neurons in the hippocampal CA1 field and did not attenuate reactive gliosis in the field following TFI. In contrast, pretreatment with 50 or 100 mg/kg laminarin protected neurons, attenuated reactive gliosis and reduced pro-inflammatory M1 microglia in the CA1 field following TFI. Based on these results, we firmly propose that 50 mg/kg laminarin can be strategically applied to develop a preventative against injuries following cerebral ischemic insults.

Calycosin-7-O-β-D-glucoside Attenuates OGD/R-Induced Damage by Preventing Oxidative Stress and Neuronal Apoptosis via the SIRT1/FOXO1/PGC-1α Pathway in HT22 Cells

Neuronal apoptosis induced by oxidative stress is a major pathological process that occurs after cerebral ischemia-reperfusion. Calycosin-7-O-β-D-glucoside (CG) is a representative component of isoflavones in Radix Astragali (RA). Previous studies have shown that CG has potential neuroprotective effects. However, whether CG alleviates neuronal apoptosis through antioxidant stress after ischemia-reperfusion remains unknown. To investigate the positive effects of CG on oxidative stress and apoptosis of neurons, we simulated the ischemia-reperfusion process in vitro using an immortalized hippocampal neuron cell line (HT22) and oxygen-glucose deprivation/reperfusion (OGD/R) model. CG significantly improved cell viability and reduced oxidative stress and neuronal apoptosis. In addition, CG treatment upregulated the expression of SIRT1, FOXO1, PGC-1α, and Bcl-2 and downregulated the expression of Bax. In summary, our findings indicate that CG alleviates OGD/R-induced damage via the SIRT1/FOXO1/PGC-1α signaling pathway. Thus, CG maybe a promising therapeutic candidate for brain injury associated with ischemic stroke.