Huperzine A-Liposomes Efficiently Improve Neural Injury in the Hippocampus of Mice with Chronic Intermittent Hypoxia

New natural protein tyrosine phosphatase 1B inhibitors from Gynostemma pentaphyllum

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease mainly caused by insulin resistance, which can lead to a series of complications such as cardiovascular disease, retinopathy, and its typical clinical symptom is hyperglycaemia. Glucosidase inhibitors, including Acarbose, Miglitol, are commonly used in the clinical treatment of hypoglycaemia. In addition, Protein tyrosine phosphatase 1B (PTP1B) is also an important promising target for the treatment of T2DM. Gynostemma pentaphyllum is a well-known oriental traditional medicinal herbal plant, and has many beneficial effects on glucose and lipid metabolism. In the present study, three new and nine known dammarane triterpenoids isolated from G. pentaphyllum, and their structures were elucidated by spectroscopic methods including HR-ESI-MS,1H and 13C NMR and X-ray crystallography. All these compounds were evaluated for inhibitory activity against α-glucosidase, α-amylase and PTP1B. The results suggested that compounds 7∼10 were potential antidiabetic agents with significantly inhibition activity against PTP1B in a dose-dependent manner.

Neuronal ferroptosis and ferroptosis-mediated endoplasmic reticulum stress: Implications in cognitive dysfunction induced by chronic intermittent hypoxia in mice

Obstructive sleep apnea, typically characterized by chronic intermittent hypoxia (CIH), is linked to cognitive dysfunction in children. Ferroptosis, a novel form of cell death characterized by lethal iron accumulation and lipid peroxidation, is implicated in neurodegenerative diseases and ischemia-reperfusion injuries. Nevertheless, its contribution to CIH-induced cognitive dysfunction and its interaction with endoplasmic reticulum stress (ERS) remain uncertain. In this study, utilizing a CIH model in 4-week-old male mice, we investigated ferroptosis and its potential involvement in ERS regulation during cognitive dysfunction. Our findings indicate ferroptosis activation in prefrontal cortex neurons, leading to neuron loss, mitochondrial damage, decreased levels of GPX4, SLC7A11, FTL, and FTH, increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), Fe2+, ACSL4, TFRC, along with the activation of ERS-related PERK-ATF4-CHOP pathway. Treatment with the ferroptosis inhibitor liproxstatin-1 (Lip-1) and the iron chelator deferoxamine (DFO) effectively mitigated the neuron injury and cognitive dysfunction induced by CIH, significantly reducing Fe2+ and partly restoring expression levels of ferroptosis-related proteins. Furhermore, the use of Lip-1 and DFO downregulated p-PERK, ATF4 and CHOP, and upregulated Nrf2 expression, suggesting that inhibiting ferroptosis reduce ERS and that the transcription factor Nrf2 is involved in the process. In summary, our findings indicate that cognitive impairment in CIH mice correlates with the induction of neuronal ferroptosis, facilitated by the System xc - GPX4 functional axis, lipid peroxidation, and the iron metabolism pathway, along with ferroptosis-mediated ERS in the prefrontal cortex. Nrf2 has been identified as a potential regulator of ferroptosis and ERS involved in the context of CIH.

Rosmarinic acid liposomes suppress ferroptosis in ischemic brain via inhibition of TfR1 in BMECs

BACKGROUND

Iron deposition and ferroptosis are involved in ischemic stroke injury, but the choice of drugs for treatment is limited.

PURPOSE

To investigate the potential neuroprotective effects of Rosmarinic acid (RosA) encapsulated within nanoliposomes (RosA-LIP) on ischemic stroke.

METHODS

Wild-type (WT) and TfR1EC cKO (specific knockout of the TfR1 gene in BMECs) mice used to establish a dMCAO model, with simultaneous administration of RosA-LIP (20 mg/kg/d, i.p.) or RosA (20 mg/kg/d, i.p.).

RESULTS

The successful synthesis of RosA-LIP resulted in enhanced stability and precise delivery in both the serum and brain. The administration of RosA-LIP effectively mitigated ischemia-induced behavioral abnormalities and pathological damage. RosA-LIP inhibited ferroptosis by ameliorating mitochondrial abnormalities, increasing GPX4 levels, and decreasing ACSL4/LPCAT3/Lox-dependent lipid peroxidation. RosA-LIP effectively improved blood‒brain barrier (BBB) permeability, increased tight junctions (TJs) protein expression and reduced iron levels in ischemic tissue and brain microvascular endothelial cells (BMECs) by modulating FPN1 and TfR1 levels. Furthermore, RosA-LIP suppressed TfR1 to attenuate ACSL4/LPCAT3/Lox-mediated ferroptosis in TfR1EC cKO mice subjected to dMCAO.

CONCLUSION

RosA-LIP effectively increased the brain level of RosA and protected against ferroptosis through the regulation of TfR1 in BMECs.

The development of nanocarriers for natural products

Natural bioactive compounds from plants exhibit substantial pharmacological potency and therapeutic value. However, the development of most plant bioactive compounds is hindered by low solubility and instability. Conventional pharmaceutical forms, such as tablets and capsules, only partially overcome these limitations, restricting their efficacy. With the recent development of nanotechnology, nanocarriers can enhance the bioavailability, stability, and precise intracellular transport of plant bioactive compounds. Researchers are increasingly integrating nanocarrier-based drug delivery systems (NDDS) into the development of natural plant compounds with significant success. Moreover, natural products benefit from nanotechnological enhancement and contribute to the innovation and optimization of nanocarriers via self-assembly, grafting modifications, and biomimetic designs. This review aims to elucidate the collaborative and reciprocal advancement achieved by integrating nanocarriers with botanical products, such as bioactive compounds, polysaccharides, proteins, and extracellular vesicles. This review underscores the salient challenges in nanomedicine, encompassing long-term safety evaluations of nanomedicine formulations, precise targeting mechanisms, biodistribution complexities, and hurdles in clinical translation. Further, this study provides new perspectives to leverage nanotechnology in promoting the development and optimization of natural plant products for nanomedical applications and guiding the progression of NDDS toward enhanced efficiency, precision, and safety. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Decoding active compounds and molecular targets of herbal medicine by high-throughput metabolomics technology: A systematic review

Clinical experiences of herbal medicine (HM) have been used to treat a variety of human intractable diseases. As the treatment of diseases using HM is characterized by multi-components and multi-targets, it is difficult to determine the bio-active components, explore the molecular targets and reveal the mechanisms of action. Metabolomics is frequently used to characterize the effect of external disturbances on organisms because of its unique advantages on detecting changes in endogenous small-molecule metabolites. Its systematicity and integrity are consistent with the effective characteristics of HM. After HM intervention, metabolomics can accurately capture and describe the behavior of endogenous metabolites under the disturbance of functional compounds, which will be used to decode the bioactive ingredients of HM and expound the molecular targets. Metabolomics can provide an approach for explaining HM, addressing unclear clinical efficacy and undefined mechanisms of action. In this review, the metabolomics strategy and its applications in HM are systematically introduced, which offers valuable insights for metabolomics methods to characterizing the pharmacological effects and molecular targets of HM.

Rosmarinic Acid Liposomes Downregulate Hepcidin Expression via BMP6-SMAD1/5/8 Pathway in Mice with Iron Overload

The objective of this study is to examine the potential protective effect of rosmarinic acid (RosA) encapsulated within nanoliposomes (RosA-LIP) on hepatic damage induced by iron overload. The characteristics, stability, and release of RosA-LIP in vitro were identified. The mice were randomly assigned to five groups: Control, Model, Model+DFO (DFO), Model+RosA (RosA), and Model+RosA-LIP (RosA-LIP). The iron overload model was induced by administering iron dextran (i.p.). The DFO, RosA, and RosA-LIP groups received iron dextran and were subsequently treated with DFO, RosA, and RosA-LIP for 14 days. We developed a novel formulation of RosA-LIP that exhibited stability and controlled release properties. Firstly, RosA-LIP improved liver function and ameliorated pathological changes in a mouse model of iron overload. Secondly, RosA-LIP demonstrated the ability to enhance the activities of T-SOD, GSH-Px, and CAT, while reducing the levels of MDA and 4-HNE, thereby effectively mitigating oxidative stress damage induced by iron overload. Thirdly, RosA-LIP reduced hepatic iron levels by downregulating FTL, FTH, and TfR1 levels. Additionally, RosA-LIP exerted a suppressive effect on hepcidin expression through the BMP6-SMAD1/5/8 signaling pathway. Furthermore, RosA-LIP upregulated FPN1 expression in both the liver and duodenum, thereby alleviating iron accumulation in these organs in mice with iron overload. Notably, RosA exhibited a comparable iron chelation effect, and RosA-LIP demonstrated superior efficacy in mitigating liver damage induced by excessive iron overload. RosA-LIP exhibited favorable sustained release properties, targeted delivery, and efficient protection against iron overload-induced liver damage. A schematic representation of the proposed protective mechanism of rosmarinic acid liposome during iron overload. Once RosA-LIP is transported into cells, RosA is released. On the one hand, RosA attenuates the BMP6-SMAD1/5/8-SMAD4 signaling pathway activation, leading to inhibiting hepcidin transcription. Then, the declined hepcidin contacted the inhibitory effect of FPN1 in hepatocytes and duodenum, increasing iron mobilization. On the other hand, RosA inhibits TfR1 and ferritin expression, which decreases excessive iron and oxidative damage.

Summary of drug therapy to treat cognitive impairment-induced obstructive sleep apnea

Obstructive sleep apnea (OSA) is a severe sleep disorder associated with intermittent hypoxia and sleep fragmentation. Cognitive impairment is a signifi- cant and common OSA complication often described in such patients. The most commonly utilized methods in clinical OSA treatment are oral appliances and continuous positive airway pressure (CPAP). However, the current therapeutic methods for improving cognitive function could not achieve the expected efficacy in same patients. Therefore, further understanding the molecular mechanism behind cognitive dysfunction in OSA disease will provide new treatment methods and targets. This review briefly summarized the clinical manifestations of cognitive impairment in OSA disease. Moreover, the pathophysiological molecular mechanism of OSA was outlined. Our study concluded that both SF and IH could induce cognitive impairment by multiple signaling pathways, such as oxidative stress activation, inflammation, and apoptosis. However, there is a lack of effective drug therapy for cognitive impairment in OSA. Finally, the therapeutic potential of some novel compounds and herbal medicine was evaluated on attenuating cognitive impairment based on certain preclinical studies.