Total Glycosides of Cistanche deserticola Promote Neurological Function Recovery by Inducing Neurovascular Regeneration via Nrf-2/Keap-1 Pathway in MCAO/R Rats

Iridoid glycosides in kidney-tonifying Chinese medicinal herbs: Mechanisms and implications for Alzheimer's disease therapy

ETHNOPHARMACOLOGICAL RELEVANCE

Alzheimer's disease (AD) is an incurable and irreversible type of dementia. Existing drugs cannot meet clinical needs; thus, developing new treatments is necessary. Traditional Chinese medicine (TCM) has been used in the prevention and treatment of AD. TCM holds the theory that "the kidney support brain function" and believes that dementia can be addressed from a kidney-based perspective. Kidney-tonifying herbs are a class of medicines that have the effect of tonifying the kidney and benefiting the brain. Some of these herbs have been shown to have anti-AD effects. Iridoid glycosides (IGs), which are important components of kidney-tonifying herbs, may have the potential to prevent and treat AD. However, their effects on AD have not yet been reviewed.

AIM OF THE REVIEW

This literature review provides a comprehensive summary of the potential of IGs in the prevention and treatment of AD. It also sets the foundation for future studies that will make the use of such drugs in clinical practice possible.

MATERIAL AND METHODS

Kidney-tonifying Chinese herbs were selected with reference to the Chinese Pharmacopoeia (2020 edition) and the textbook of Chinese Materia Medica (5th edition). Literature survey was conducted using PubMed, Web of Science, Google Scholar, and CNKI, with "Alzheimer's disease," "kidney-tonifying Chinese medicinal herbs," and "Iridoid Glycosides" as the primary keywords.

RESULTS

Kidney-tonifying herbal IGs include loganin, morroniside, verbenalin, cornuside, catalpol, rehmannioside A, geniposidic acid, and aucubin. These IGs have shown multiple pharmacological effects, including anti-AD effects. The effective mechanisms of IGs for AD treatment include anti-oxidative stress, inhibiting neuronal apoptosis, antagonizing amyloid neurotoxicity and tau protein hyperphosphorylation, regulating immune function, anti-inflammation, normalizing the function of the cholinergic nervous system, recuperating neurobiochemical, and regulating AD-related genes. Consequently, IGs can combat AD by modulating multiple targets and pathways.

CONCLUSION

Kidney-tonifying herbal IGs have great potential to combat AD.

Traditional Chinese medicine as a viable option for managing vascular cognitive impairment: A ray of hope

Vascular cognitive impairment (VCI) is a prevalent cognitive disorder resulting from cerebrovascular disease and encompasses a spectrum of cognitive deficits, ranging from mild impairment to vascular dementia (VD). VCI is responsible for a minimum of 20% to 40% of all cases of dementia, with its prevalence ranking second only to Alzheimer's disease on a global scale. The pathogenesis of VCI is complex and includes a lack of cholinergic nerve cells, inflammation, oxidative stress, alterations in the blood-brain barrier, and cell apoptosis. Current guideline-recommended drugs have unsatisfactory therapeutic effects. However, traditional Chinese medicine (TCM) has long been associated with treating dementia, and numerous studies regarding treating dementia with TCM have been conducted. The etiology and pathogenesis of VaD are linked to deficiencies in the spleen and kidney, as well as phlegm turbidity. Treatment involves benefiting the spleen and kidney, improving blood circulation, removing blood stasis, and dispelling phlegm. Moreover, TCM presents benefits such as few adverse effects, low cost, long-term use suitability, and preventive effects. This review outlines the pathogenesis of VCI in both modern medicine and TCM, examines traditional prescriptions and single-agent ingredients with their pharmacological effects, emphasizes TCM's unique features, and explores its multi-targeted approach to treating VCI.

Evaluation of the Neuroprotective Effect of Total Glycosides of Cistanche deserticola and Investigation of Novel Brain-Targeting Natural MAO-B Inhibitors

In this study, we investigated the role of total glycosides of Cistanche deserticola (TC) in MPTP-induced neuronal injury. Further, we screened potential inhibitory components of monoamine oxidase B (MAO-B). The study results indicate that TC may improve movement disorders and apoptosis of dopamine (DA) neurons by inhibiting MAO-B activity while reducing the number of glial cells, adjusting the metabolism level of monoamine neurotransmitters, and lowering inflammation and oxidative stress levels. Subsequently, a rapid screening method for drug-containing brain tissue was further constructed, and five candidate components that can cross the blood-brain barrier and bind to MAO-B were screened and submitted for biological activity evaluation and inhibition mechanism research. In summary, we discovered 2'-acetylacteoside as a promising and reversible mixed natural MAO-B inhibitor in TC and developed a rapid screening method for screening central nervous system drugs with blood-brain barrier permeability characteristics, providing potential candidates and an effective screening strategy for neurodegenerative diseases.

Neuroprotective effect of sulforaphane on hyperglycemia-induced cognitive dysfunction through the Nrf2/HO-1 pathway

OBJECTIVES

Sulforaphane (SFN), an isothiocyanate in cruciferous plants, has been reported to be effective in treating central nervous system diseases. However, how SFN protects the central nervous system needs further study. The aim of this study was to investigate the neuroprotective effect of SFN and its possible mechanism of action.

METHODS

Sprague-Dawley rats were used to develop a cognitive impairment model. The Morris water maze (MWM) was used to evaluate the effect of SFN on learning and memory, and haematoxylin-eosin (H&E) staining and terminal transferase deoxyuridine nick-end labelling (TUNEL) were used to observe morphologic changes in neurons and neuronal apoptosis in the hippocampus and cortex. An oxidative stress marker kit was used to detect the content and activity of SFN, and the expressions of nuclear factor drythroid-2 related Factor 2 (Nrf2), heme oxygenase 1 (HO-1), and NAD(P)H quinone oxidoreductase 1 (NQO-1) were measured by RT-PCR.

RESULTS

SFN treatment significantly improved cognition, increased the number of neurons, and suppressed neuronal apoptosis. In addition, SFN significantly decreased the content of malondialdehyde (MDA) and enhanced the antioxidant activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the hippocampus and cortex. Furthermore, SFN elevated the expression of Nrf-2, HO-1, and NQO-1.

CONCLUSIONS

SFN ameliorated diabetes-induced cognitive dysfunction by activating the Nrf2/HO-1 pathway, providing a new perspective for SFN therapy to delay cognitive impairment in diabetes patients.

Celastrol ameliorates hypoxic-ischemic brain injury in neonatal rats by reducing oxidative stress and inflammation

BACKGROUND

Hypoxic-ischemic encephalopathy (HIE) is caused by perinatal hypoxia and subsequent reductions in cerebral blood flow and is one of the leading causes of severe disability or death in newborns. Despite its prevalence, we currently lack an effective drug therapy to combat HIE. Celastrol (Cel) is a pentacyclic triterpene extracted from Tripterygium Wilfordi that can protect against oxidative stress, inflammation, and cancer. However, whether Cel can alleviate neonatal hypoxic-ischemic (HI) brain damage remains unclear.

METHODS

Here, we established both in vitro and in vivo models of HI brain damage using CoCl2-treated PC12 cells and neonatal rats, respectively, and explored the neuroprotective effects of Cel in these models.

RESULTS

Analyses revealed that Cel administration reduced brain infarction size, microglia activation, levels of inflammation factors, and levels of oxidative stress markers by upregulating levels of p-AMPKα, Nrf2, HO-1, and by downregulating levels of TXNIP and NLRP3. Conversely, these beneficial effects of Cel on HI brain damage were largely inhibited by AMPKα inhibitor Compound C and its siRNA.

CONCLUSIONS

We present compelling evidence that Cel decreases inflammation and oxidative stress through the AMPKα/Nrf2/TXNIP signaling pathway, thereby alleviating neonatal HI brain injury. Cel therefore represents a promising therapeutic agent for treating HIE.

IMPACT

We firstly report that celastrol can ameliorate neonatal hypoxic-ischemic brain injury both in in vivo and in vitro, which represents a promising therapeutic agent for treating related brain injuries. Celastrol activates the AMPKα/Nrf2/TXNIP signaling pathway to relieve oxidative stress and inflammation and thereby alleviates neonatal hypoxic-ischemic brain injury.

Activation of the Nrf2/Keap1 signaling pathway mediates the neuroprotective effect of Perillyl alcohol against cerebral hypoxic-ischemic damage in neonatal rats

Neonatal hypoxic-ischemic encephalopathy (HIE) is a severe disease with a poor prognosis, whose clinical treatment is still limited to therapeutic hypothermia with limited efficacy. Perillyl alcohol (POH), a natural monoterpene found in various plant essential oils, has shown neuroprotective properties, though its effects on HIE are not well understood. This study investigates the neuroprotective effects of POH on HIE both in vitro and in vivo. We established an in vitro model using glucose deprivation and hypoxia/reperfusion (OGD/R) in PC12 cells, alongside an in vivo model via the modified Rice-Vannucci method. Results indicated that POH acted as an indirect antioxidant, reducing inducible nitric oxide synthase and malondialdehyde production, maintaining content of antioxidant molecules and enzymes in OGD/R-induced PC12 cells. In vivo, POH remarkably lessened infarct volume, reduced cerebral edema, accelerated tissue regeneration, and blocked reactive astrogliosis after hypoxic-ischemic brain injury. POH exerted antiapoptotic activities through both the intrinsic and extrinsic apoptotic pathways. Mechanistically, POH activated Nrf2 and inactivated its negative regulator Keap1. The use of ML385, a Nrf2 inhibitor, reversed these effects. Overall, POH mitigates neuronal damage in HIE by combating oxidative stress, reducing inflammation, and inhibiting apoptosis via the Nrf2/Keap1 pathway, suggesting its potential for HIE treatment.

2-Acetylacteoside improves recovery after ischemic stroke by promoting neurogenesis via the PI3K/Akt pathway

Ischemic stroke induces adult neurogenesis in the subventricular zone (SVZ), even in elderly patients. Harnessing of this neuroregenerative response presents the therapeutic potential for post-stroke recovery. We found that phenylethanoid glycosides (PhGs) derived from Cistanche deserticola aid neural repair after stroke by promoting neurogenesis. Among these, 2-acetylacteoside had the most potent on the proliferation of neural stem cells (NSCs) in vitro. Furthermore, 2-acetylacteoside was shown to alleviate neural dysfunction by increase neurogenesis both in vivo and in vitro. RNA-sequencing analysis highlighted differentially expressed genes within the PI3K/Akt signaling pathway. The candidate target Akt was validated as being regulated by 2-acetylacteoside, which, in turn, enhanced the proliferation and differentiation of cultured NSCs after oxygen-glucose deprivation/reoxygenation (OGD/R), as evidenced by Western blot analysis. Subsequent analysis using cultured NSCs from adult subventricular zones (SVZ) confirmed that 2-acetylacteoside enhanced the expression of phosphorylated Akt (p-Akt), and its effect on NSC neurogenesis was shown to be dependent on the PI3K/Akt pathway. In summary, our findings elucidate for the first time the role of 2-acetylacteoside in enhancing neurological recovery, primarily by promoting neurogenesis via Akt activation following ischemic brain injury, which offers a novel strategy for long-term cerebrological recovery in ischemic stroke.

The chemometrics analysis and integrated pharmacology approach to decipher the effect and mechanism between raw and processed cistanche tubulosa

ETHNOPHARMACOLOGICAL RELEVANCE

Cistanche tubulosa (CT) is the dried fleshy stem with scaly leaves of Cistanche tubiflora (Schenk) Wight, which has the effects of tonifying the kidney-yang, benefiting the vital essence and blood, and moisturizing the intestines and laxatives. There are differences in the activity of CT before and after processing, but the mechanism of processing is not clear.

AIM OF THE STUDY

The study aimed to compare the strength of action of CT before and after yellow-wine processing in the treatment of constipation and kidney yang deficiency and to identify the active ingredients responsible for the differences in activity before and after yellow-wine processing.

MATERIALS AND METHODS

This study established the fingerprints of CT and PCT using HPLC to identify their shared components. Then efficacy of KYDS and FC were carried out to compare the differences between CT and PCT in terms of efficacy. Next, this study established the spectrum-effect relationship between the shared chemical components and the medical effects of CT and PCT using the gray correlation analysis and entropy methods. Ultimately, the activity of the analyzed chemical components was verified using the zebrafish model.

RESULTS

CT was more effective than PCT in promoting intestinal peristalsis, regulating gastrointestinal hormone levels, and thus treating FC. PCT was more effective than CT in improving the level of hormone indexes of the hypothalamus-pituitary-target gland axis, replenishing blood, and enhancing immunity. Through the analysis of the spectrum-effect relationship, it was finally found that 5, 6, 12 (tubuloside A), and 13 (isoacteoside) might be more closely related to the activity of tonifying kidney yang, and peaks 9, 10, and 11 (acteoside) are more closely associated with the treatment of constipation, and peaks 3 (salidroside), 4, 1, 2 (geniposidic acid), and 8 (echinacoside) were associated with both kidney yang tonic and treatment of constipation. At the same time, an activity verification experiment showed that echinacoside, geniposidic acid, and salidroside were effective in the treatment of FC and KYDS, while acteoside was very effective in the treatment of FC, and tubuloside A was significant in supplementing the blood, which validated the spectrum-effect relationship analysis.

CONCLUSION

This study proved that the raw CT had a better laxative effect, while the yellow-wine processed CT had a better kidney-yang tonic effect; moreover, spectrum-effect relationships were established to analyze the chemical components leading to changes in the activity of CT before and after yellow-wine processing.

The protective effect and mechanism of glycosides of cistanche deserticola on rats in middle cerebral artery occlusion (MCAO) model

Cerebral ischemia-reperfusion injury (CIRI) occurs frequently clinically as a complication following cardiovascular resuscitation resulting in neuronal damage specifically to the hippocampal CA1 region with consequent cognitive impairment. Apoptosis and oxidative stress were proposed as major risk factors associated with CIRI development. Previously, glycosides obtained from Cistanche deserticola (CGs) were shown to play a key role in counteracting CIRI; however, the underlying mechanisms remain to be determined. This study aimed to investigate the neuroprotective effect of CGs on subsequent CIRI in rats. The model of CIRI was established for 2 hr and reperfusion for 24 hr by middle cerebral artery occlusion (MCAO) model. The MCAO rats were used to measure the antioxidant and anti-apoptotic effects of CGs on CIRI. Neurological function was evaluated by the Longa neurological function score test. 2,3,5-Triphenyltetrazolium chloride (TTC) staining was used to detect the area of cerebral infarction. Nissl staining was employed to observe neuronal morphology. TUNEL staining was used to detect neuronal apoptosis, while Western blot determined protein expression levels of factors for apoptosis-related and PI3K/AKT/Nrf2 signaling pathway. Data demonstrated that CGs treatment improved behavioral performance, brain injury, and enhanced antioxidant and anti-apoptosis in CIRI rats. In addition, CGs induced activation of PI3K/AKT/Nrf2 signaling pathway accompanied by inhibition of the expression of apoptosis-related factors. Evidence indicates that CGs amelioration of CIRI involves activation of the PI3K/AKT/Nrf2 signaling pathway associated with increased cellular viability suggesting these glycosides may be considered as an alternative compound for CIRI treatment.

Revealing the pharmacological mechanisms of nao-an dropping pill in preventing and treating ischemic stroke via the PI3K/Akt/eNOS and Nrf2/HO-1 pathways

Nao-an Dropping Pill (NADP) is a Chinese patent medicine which commonly used in clinic for ischemic stroke (IS). However, the material basis and mechanism of its prevention or treatment of IS are unclear, then we carried out this study. 52 incoming blood components were resolved by UHPLC-MS/MS from rat serum, including 45 prototype components. The potential active prototype components hydroxysafflor yellow A, ginsenoside F1, quercetin, ferulic acid and caffeic acid screened by network pharmacology showed strongly binding ability with PIK3CA, AKT1, NOS3, NFE2L2 and HMOX1 by molecular docking. In vitro oxygen-glucose deprivation/reperfusion (OGD/R) experimental results showed that NADP protected HA1800 cells from OGD/R-induced apoptosis by affecting the release of LDH, production of NO, and content of SOD and MDA. Meanwhile, NADP could improve behavioral of middle cerebral artery occlusion/reperfusion (MCAO/R) rats, reduce ischemic area of cerebral cortex, decrease brain water and glutamate (Glu) content, and improve oxidative stress response. Immunohistochemical results showed that NADP significantly regulated the expression of PI3K, Akt, p-Akt, eNOS, p-eNOS, Nrf2 and HO-1 in cerebral ischemic tissues. The results suggested that NADP protects brain tissues and ameliorates oxidative stress damage to brain tissues from IS by regulating PI3K/Akt/eNOS and Nrf2/HO-1 signaling pathways.

FGF17 protects cerebral ischemia reperfusion-induced blood-brain barrier disruption via FGF receptor 3-mediated PI3K/AKT signaling pathway

Maintaining blood-brain barrier (BBB) integrity is critical components of therapeutic approach for ischemic stroke. Fibroblast growth factor 17 (FGF17), a member of FGF8 superfamily, exhibits the strongest expression throughout the wall of all major arteries during development. However, its molecular action and potential protective role on brain endothelial cells after stroke remains unclear. Here, we observed reduced levels of FGF17 in the serum of patients with ischemic stroke, as well as in the brains of mice subjected to middle cerebral artery occlusion (MCAO) injury and oxygen-glucose deprivation/reoxygenation (OGD/R)-induced brain microvascular endothelial cells (bEnd.3) cells. Moreover, treatment with exogenous recombinant human FGF17 (rhFGF17) decreased infarct volume, improved neurological deficits, reduced Evans Blue leakage and upregulated the expression of tight junctions in MCAO-injured mice. Meanwhile, rhFGF17 increased cell viability, enhanced trans-endothelial electrical resistance, reduced sodium fluorescein leakage, and alleviated reactive oxygen species (ROS) generation in OGD/R-induced bEnd.3 cells. Mechanistically, the treatment with rhFGF17 resulted in nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear accumulation and upregulation of heme oxygenase-1 (HO-1) expression. Additionally, based on in-vivo and in-vitro research, rhFGF17 exerted protective effects against ischemia/reperfusion (I/R) -induced BBB disruption and endothelial cell apoptosis through the activation of the FGF receptor 3/PI3K/AKT signaling pathway. Overall, our findings indicated that FGF17 may hold promise as a novel therapeutic strategy for ischemic stroke patients.

Herbal medicine and gut microbiota: exploring untapped therapeutic potential in neurodegenerative disease management

The gut microbiota that exists in the human gastrointestinal tract is incredibly important for the maintenance of general health as it contributes to multiple aspects of host physiology. Recent research has revealed a dynamic connection between the gut microbiota and the central nervous system, that can influence neurodegenerative diseases (NDs). Indeed, imbalances in the gut microbiota, or dysbiosis, play a vital role in the pathogenesis and progression of human diseases, particularly NDs. Herbal medicine has been used for centuries to treat human diseases, including NDs. These compounds help to relieve symptoms and delay the progression of NDs by improving intestinal barrier function, reducing neuroinflammation, and modulating neurotransmitter production. Notably, herbal medicine can mitigate the progression of NDs by regulating the gut microbiota. Therefore, an in-depth understanding of the potential mechanisms by which herbal medicine regulates the gut microbiota in the treatment of NDs can help explain the pathogenesis of NDs from a novel perspective and propose novel therapeutic strategies for NDs. In this review, we investigate the potential neuroprotective effects of herbal medicine, focusing on its ability to regulate the gut microbiota and restore homeostasis. We also highlight the challenges and future research priorities of the integration of herbal medicine and modern medicine. As the global population ages, access to this information is becoming increasingly important for developing effective treatments for these diseases.

Knockdown of Smox protects the integrity of the blood-brain barrier through antioxidant effect and Nrf2 pathway activation in stroke

Once an ischemic stroke occurs, reactive oxygen species (ROS) and oxidative stress degrade the tight connections between cerebral endothelial cells resulting in their damage. The expression of antioxidant genes may be enhanced, and ROS formation may be reduced following Nrf2 activation, which is associated with protection against ischemic stroke. Overexpression of spermine oxidase (Smox) in the neocortex led to increased H2O2 production. However, how Smox impacts the regulation of the blood-brain barrier (BBB) through antioxidants has not been examined yet. We conducted experiments both in the cell level and in the transient middle cerebral artery occlusion (tMCAO) model to evaluate the effect of Smox siRNA lentivirus (si-Smox) knockdown on BBB protection against ischemic stroke. Mice treated with si-Smox showed remarkably decreased BBB breakdown and reduced endothelial inflammation following stroke. The treatment with si-Smox significantly elevated the Bcl-2 to Bax ratio and decreased the production of cleaved caspase-3 in the tMCAO model. Further investigation revealed that the neuroprotective effect was the result of the antioxidant properties of si-Smox, which reduced oxidative stress and enhanced CD31+ cells in the peri-infarct cortical areas. Of significance, si-Smox activated Nrf2 in both bEnd.3 cells and tMCAO animals, and blocking Nrf2 with brusatol diminished the protective effects of si-Smox. The study findings suggest that si-Smox exerts neuroprotective effects and promotes angiogenesis by activating the Nrf2 pathway, thus decreasing oxidative stress and apoptosis caused by tMCAO. As a result, si-Smox may hold potential as a therapeutic candidate for preserving BBB integrity while treating ischemic stroke.

Inhibition of SIRT1 promotes ultraviolet B induced cataract via downregulation of the KEAP1/NFE2L2 signaling pathway

Due to continuous exposure to ultraviolet B(UVB) radiation, eye lenses are constantly subjected to oxidative stress that induces lens epithelial cell (LEC) apoptosis, which has been associated with the inactivation of Sirtuin1 (SIRT1). It is well-established that NFE2L2 has a major protective effect on UVB-induced oxidative stress and damage. However, whether UVB radiation affects oxidative/antioxidative imbalance and damages LECs by inactivating the protective NFE2L2-mediated antioxidative stress pathway through inhibition of SIRT1 is unknown. In our research, we established in vivo and in vitro UVB exposure models in Sprague Dawley rats and SRA01/04 cells, respectively, to investigate the effect of UVB radiation on the NFE2L2/ KEAP1 pathway and the role of SIRT1 in this process. The in vivo findings revealed that UVB radiation exposure decreased Sirt1 and Nfe2l2 levels, upregulated Keap1 expression, led to an oxidative/antioxidative imbalance and increased LEC apoptosis in the eye lens. Sirt1 downregulated Keap1 expression levels, but activated Nfe2l2 and its downstream target proteins. The in vitro findings showed that UVB inhibited the deacetylation of SIRT1 target proteins and increased the acetylation levels of KEAP1 and NFE2L2. We also found that UVB radiation exposure led to a significant decrease in both co-localization levels and protein interaction between SIRT1 and KEAP1. In addition, the inhibition of SIRT1 increased KEAP1 levels, inhibited the activity of NFE2L2 and decreased co- localization levels and protein interactions between NFE2L2 and KEAP1. These results suggested that UVB radiation decreased SIRT1 levels and inhibited the KEAP1/NFE2L2 pathway, thereby reducing its antioxidant effect, which might be an important mechanism of UVB-induced cataract.

Cistanche tubulosa alleviates ischemic stroke-induced blood-brain barrier damage by modulating microglia-mediated neuroinflammation

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke (IS) has both high morbidity and mortality. Previous research conducted by our group demonstrated that the bioactive ingredients of the traditional medicinal and edible plant Cistanche tubulosa (Schenk) Wight (CT) have various pharmacological effects in treating nervous system diseases. However, the effect of CT on the blood-brain barrier (BBB) after IS are still unknown.

AIM OF THE STUDY

This study aimed to identify CT's curative effect on IS and explore its underlying mechanism.

MATERIALS AND METHODS

IS injury was established in a rat model of middle cerebral artery occlusion (MCAO). Gavage administration of CT at dosages of 50, 100, and 200 mg/kg/day was carried out for seven consecutive days. Network pharmacology was used for predicting the pathways and potential targets of CT against IS, and subsequent studies confirmed the relevant targets.

RESULTS

According to the results, both neurological dysfunction and BBB disruption were exacerbated in the MCAO group. Moreover, CT improved BBB integrity and neurological function and protected against cerebral ischemia injury. Network pharmacology revealed that IS might involve neuroinflammation mediated by microglia. Extensive follow-up studies verified that MCAO caused IS by stimulating the production of inflammatory factors and microglial infiltration. CT was found to influence neuroinflammation via microglial M1-M2 polarization.

CONCLUSION

These findings suggested that CT may regulate microglia-mediated neuroinflammation by reducing MCAO-induced IS. The results provide theoretical and experimental evidence for the efficacy of CT therapy and novel concepts for the prevention and treatment of cerebral ischemic injuries.

Downregulated PGK1 attenuates cerebral ischemia-reperfusion injury by reversing neuroinflammation and oxidative stress through the Nrf2/ARE pathway

Understanding the role and mechanism of astrocytes in inflammation and oxidative response is crucial for developing therapeutic strategies to reduce inflammation and oxidative injury in cerebral ischemia-reperfusion injury (CIRI). In this study, we investigated the regulatory effects of phosphoglycerate kinase 1 (PGK1) on inflammation and oxidative response after CIRI in male adult Sprague-Dawley (SD) rats and using primary astrocytes obtained from neonatal SD rats, and explored its related mechanisms. We established a rat model of middle cerebral artery occlusion-reperfusion (MCAO/R) by suture occlusion, and an oxygen-glucose deprivation/reoxygenation model of astrocytes using oxygen-free, glucose-free, and serum-free cultures. AAV8-PGK1-GFP was injected into the left ventricle 24 h before modeling. Real-time quantitative polymerase chain reaction, enzyme-linked immunosorbent assay, co-immunoprecipitation (CoIP) assay, fluorescence in situ hybridization (FISH), and western blotting were used to elucidate the in-depth mechanisms of PGK1 in CIRI. PGK1 overexpression significantly exacerbated neurological deficits, increased cerebral infarct volume, and aggravated nerve cell injury in rats after MCAO/R. Using FISH and CoIP assays, we verified the localization of PGK1 and Nrf2 in primary astrocytes. Further rescue experiments showed that Nrf2 knockdown eliminated the protective effect of CBR-470-1 (a PGK1 inhibitor) on CIRI. Lastly, we confirmed that PGK1 aggravates CIRI by inhibiting the Nrf2/ARE pathway. In conclusion, our findings suggest that inhibiting PGK1 attenuates CIRI by reducing the release of inflammatory and oxidative factors from astrocytes by activating the Nrf2/ARE signaling pathway.

Mechanism of ERK/CREB pathway in pain and analgesia

Research has long centered on the pathophysiology of pain. The Transient Receiver Potential (TRP) protein family is well known for its function in the pathophysiology of pain, and extensive study has been done in this area. One of the significant mechanisms of pain etiology and analgesia that lacks a systematic synthesis and review is the ERK/CREB (Extracellular Signal-Regulated Kinase/CAMP Response Element Binding Protein) pathway. The ERK/CREB pathway-targeting analgesics may also cause a variety of adverse effects that call for specialized medical care. In this review, we systematically compiled the mechanism of the ERK/CREB pathway in the process of pain and analgesia, as well as the potential adverse effects on the nervous system brought on by the inhibition of the ERK/CREB pathway in analgesic drugs, and we suggested the corresponding solutions.

Effect of total glycosides of Cistanche deserticola on the energy metabolism of human HepG2 cells

To study the anti-tumor effect of Cistanche deserticola Y. Ma, HepG2 cells were treated with 0, 3.5, 10.5, 21, 31.5, and 42 μg/ml of total glycosides (TG) from Cistanche deserticola. The HepG2 cell survival rate and 50% inhibition concentration (IC50) were detected using the CCK-8 method, and the level of reactive oxygen species (ROS) was detected by using a DCFH-DA fluorescence probe. Finally, a Seahorse XFe24 energy analyzer (Agilent, United States) was used to detect cell mitochondrial pressure and glycolytic pressure. The results showed that TG could reduce the survival rate of HepG2 cells and that the IC50 level was 35.28 μg/ml. With increasing TG concentration, the level of ROS showed a concentration-dependent upward trend. Energy metabolism showed that each dose group of TG could significantly decline the mitochondrial respiratory and glycolytic functions of HepG2 cells. In conclusion, TG could significantly inhibit the mitochondrial respiration and glycolysis functions of HepG2 cells, increase the level of ROS, and inhibit cell proliferation. Thus, this experiment pointed out that Cistanche deserticola can be used as a source of anti-cancer foods or drugs in the future. However, further studies on its mechanisms and clinical applications are needed.

Folic acid ameliorates synaptic impairment following cerebral ischemia/reperfusion injury via inhibiting excessive activation of NMDA receptors

Folic acid, a water-soluble B-vitamin, has been demonstrated to decrease the risk of first stroke and improve its poor prognosis. However, the molecular mechanisms responsible for the beneficial effect of folic acid on recovery from ischemic insult remain largely unknown. Excessive activation of the N-methyl-d-aspartate receptors (NMDARs) has been shown to trigger synaptic dysfunction and excitotoxic neuronal death in ischemic brains. Here, we hypothesized that the effects of folic acid on cognitive impairment may involve the changes in synapse loss and NMDAR expression and function following cerebral ischemia/reperfusion injury. The ischemic stroke models were established by middle cerebral artery occlusion/reperfusion (MCAO/R) and by oxygen-glucose deprivation and reperfusion (OGD/R)-treated primary neurons. The results showed that folic acid supplemented diets (8.0 mg/kg for 28 days) improved cognitive performances of rats after MCAO/R. Folic acid also caused a reduction in the number of neuronal death, an increase in the number of synapses and the expressions of synapse-related proteins including SNAP25, Syn, GAP-43 and PSD95, and a decrease in p-CAMKII expression in ischemic brains. Similar changes in synaptic functions were observed in folic acid (32 µM)-treated OGD/R neurons. Furthermore, NMDA treatment reduced folic acid-induced upregulations of synapse-associated proteins and Ca²⁺ influx, whereas downregulations of NMDARs by NR1 or both NR2A and NR2B siRNA further enhanced the expressions of synapse-related proteins raised by folic acid in OGD/R neurons. Our findings suggest that folic acid improves cognitive dysfunctions and ameliorates ischemic brain injury by strengthening synaptic functions via the NMDARs.

Neuroprotective effect of Dl-3-n-butylphthalide against ischemia-reperfusion injury is mediated by ferroptosis regulation via the SLC7A11/GSH/GPX4 pathway and the attenuation of blood-brain barrier disruption

Background

Stroke is one of the most severe diseases worldwide, resulting in physical and mental problems. Dl-3-n-butylphthalide, a compound derived from celery seed, has been approved for treating ischemic stroke in China. No study has evaluated how Dl-3-n-butylphthalide affects the ferroptosis SLC7A11/GSH/GPX4 signal pathway and blood-brain barrier (BBB) PDGFRβ/PI3K/Akt signal pathways in the rat middle cerebral artery occlusion/reperfusion (MCAO/R) model of ischemic stroke.

Methods

Sprague-Dawley rats were used to develop the MCAO/R model. Our study used three incremental doses (10, 20, and 30) of Dl-3-n-butylphthalide injected intraperitoneally 24 h after MCAO/R surgery. The neuroprotective effect and success of the model were evaluated using the neurofunction score, brain water content determination, and triphenyl-tetrazolium chloride-determined infarction area changes. Pathological changes in the brain tissue and the degree of apoptosis were examined by hematoxylin and eosin, Nissl, and terminal deoxynucleotidyl transferase dUTP nick end labeling staining. In addition, pathway proteins and RNA expression levels were studied to verify the effects of Dl-3-n-butyphthalide on both pathways. At the same time, commercial kits were used to detect glutathione, reactive oxygen species, and malondialdehyde, to detect oxidative stress in brain tissues.

Results

The middle dose of Dl-3-n-butylphthalide not only improved MCAO-induced brain dysfunction and alleviated pathological damage, brain inflammatory response, oxidative stress, and apoptosis but also protected against ferroptosis and reduced BBB damage. These changes resulted in improved neurological function in the cerebral cortex.

Conclusion

We speculate that Dl-3-n-butylphthalide has a neuroprotective effect on focal cerebral ischemia/reperfusion, which may be mediated through ferroptosis-dependent SLC7A11/GSH/GPX4 signal pathway and PDGFRβ/PI3/Akt signal pathway.

The Role of Nrf2 in Relieving Cerebral Ischemia-Reperfusion Injury

Ischemic stroke includes two related pathological damage processes: brain injury caused by primary ischemia and secondary ischemia reperfusion (I/R) injury. I/R injury has become a worldwide health problem. Unfortunately, there is still a lack of satisfactory drugs for ameliorating cerebral I/R damage. Nrf2 is a vital endogenous antioxidant protein, which combines with Keap1 to maintain a dormant state under physiological conditions. When pathological changes such as I/R occurs, Nrf2 dissociates from Keap1 and activates the expression of downstream antioxidant proteins to exert a protective effect. Recent research have shown that the activated Nrf2 not only effectively inhibits oxidative stress, but also performs the ability to repair the function of compromised mitochondria, alleviate endoplasmic reticulum stress, eliminate inflammatory response, reduce blood-brain barrier permeability, inhibit neuronal apoptosis, enhance the neural network remolding, thereby exerting significant protective effects in alleviating the injuries caused by cell oxygen-glucose deprivation, or animal cerebral I/R. However, no definite clinical application report demonstrated the efficacy of Nrf2 activators in the treatment of cerebral I/R. Therefore, further efforts are needed to elaborate the role of Nrf2 activators in the treatment of cerebral I/R. Here, we reviewed the possible mechanisms underlying its potential pharmacological benefits in alleviating cerebral I/R injury, so as to provide a theoretical basis for studying its mechanism and developing Nrf2 activators.

Considering the protective effect of exendin-4 against oxidative stress in spiral ganglion neurons

Objectives

The protection of spiral ganglion neurons (SGNs) is crucial for hearing loss. Exendin-4 has been shown to have neuroprotective effects in several neurological disorders. Therefore, this study aimed to investigate the effect of the glucagon-like protein-1 receptor (GLP-1R) agonist exendin-4 on kanamycin-induced injury in mouse SGNs in vitro.

Materials and Methods

In this study, GLP-1R expression in SGNs was verified by immunofluorescence and immunohistochemical staining. In vitro-cultured SGNs and the organ of Corti were exposed to kanamycin with or without exendin-4 treatment. The cell survival rate was measured using the cell counting kit-8 assay, and the damage to auditory nerve fibers (ANF) projecting radially from the SGNs was evaluated using immunofluorescence staining. Reactive oxygen species (ROS) content was determined by flow cytometry, and glutathione peroxidase (GSH-Px) content, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were determined by spectrophotometry. Protein expression of nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) was detected using western blotting.

Results

GLP-1R was expressed in SGNs. Treatment with 1 mM kanamycin for 24 hr induced SGN damage. Exendin-4 (100 nM) had a protective effect against kanamycin-induced SGN cell injury, improved cell survival rate, reduced nerve fiber injury, increased SOD activity and GSH-Px level, and reduced MDA and ROS contents. The Nrf2/HO-1 pathway was activated.

Conclusion

Exendin-4 alleviates oxidative damage and exerts neuroprotective effects in kanamycin-induced SGN injury through the Nrf2/HO-1 signaling pathway. Exendin-4 has the potential to prevent or treat hearing loss due to SGN damage.

Clinical Study on Blood Pressure Variability, Montreal Cognitive Assessment and Arteriosclerosis Index in Patients with Cerebral Small Vessel Disease Treated with Integrated Traditional Chinese and Western Medicine by Invigorating Kidney and Removing Blood Stasis

Objective

To explore the clinical improvement in blood pressure variability, Montreal Cognitive Assessment, and angiosclerosis index in patients with cerebral small vessel disease treated with integrated traditional Chinese and Western medicine.

Methods

A randomized controlled study of patients with cerebral small vessel disease who were treated in our hospital from November 1, 2018, to January 31, 2022. The enrolled patients were randomized into 2 groups according to the random numbers: an observation group treated with integrated traditional Chinese and Western medicine and a control group treated with Western medicine only. Blood pressure variability, Montreal Cognitive Assessment (MoCA), and angiosclerosis index were compared between the two groups.

Results

There were 71 qualified cases in the observation group and 58 qualified cases in the control group. Before treatment, the indicators between the two groups were comparable (P > 0.05). After treatment, the mean values of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly decreased (P < 0.05); the decrease of 24hSBP-coefficient of variation (CV), daytime SBP (dSBP)-CV, 24hSBP-standard deviation (SD), and dSBP-SD in the observation group was significantly better than that in the control group; the MoCA scores of the observation group were significantly higher than those of the control group ((P < 0.05); the ABI and PWV were significantly different between the two groups (P < 0.05); TC, TG, HDL-C, and LDL-C in observation group decreased after treatment, and HDL-C increased significantly (P < 0.05).

Conclusion

Integrative traditional Chinese and Western medicine treatment can further reduce the blood pressure variability, especially systolic blood pressure; improve the MoCA score and cognitive function, increase the ankle-brachial index, reduce pulse wave velocity and the degree of arteriosclerosis; and improve lipid metabolism a comprehensive intervention role.

Application of natural antioxidants from traditional Chinese medicine in the treatment of spinal cord injury

Spinal cord injury (SCI) is a devastating central nervous system disease, caused by physical traumas. With the characteristic of high disability rate, catastrophic dysfunction, and enormous burden on the patient’s family, SCI has become a tough neurological problem without efficient treatments. Contemporarily, the pathophysiology of SCI comprises complicated and underlying mechanisms, in which oxidative stress (OS) may play a critical role in contributing to a cascade of secondary injuries. OS substantively leads to ion imbalance, lipid peroxidation, inflammatory cell infiltration, mitochondrial disorder, and neuronal dysfunction. Hence, seeking the therapeutic intervention of alleviating OS and appropriate antioxidants is an essential clinical strategy. Previous studies have reported that traditional Chinese medicine (TCM) has antioxidant, anti-inflammatory, antiapoptotic and neuroprotective effects on alleviating SCI. Notably, the antioxidant effects of some metabolites and compounds of TCM have obtained numerous verifications, suggesting a potential therapeutic strategy for SCI. This review aims at investigating the mechanisms of OS in SCI and highlighting some TCM with antioxidant capacity used in the treatment of SCI.

miR-29c-5p knockdown reduces inflammation and blood–brain barrier disruption by upregulating LRP6

Blood–brain barrier participates in the pathological process of ischemic stroke. MicroRNA-29c-5p was highly expressed in clinical samples from patients with ischemic stroke. In this study, oxygen-glucose deprivation (OGD) treatment of astrocytes enhanced the permeability of brain microvascular endothelial cells (BMECs), and the miR-29c-5p expression was elevated in clinical samples from patients with ischemic stroke. For the function of miR-29c-5p in ischemic stroke, the miR-29c-5p knockdown decreased the permeability and the tight junction protein (TJP) destruction of BMECs and ameliorated the inflammation induced by OGD-treated astrocytes. Mechanistically, miR-29c-5p interacted with lipoprotein receptor-related protein 6 (LRP6) and negatively regulated the LRP6 expression in astrocytes. Moreover, the rescue assays indicated that the interference with miR-29c-5p ameliorated the TJP destruction of BMECs and inflammation caused by OGD-treated astrocytes by increasing the LRP6 expression. Together, miR-29c-5p knockdown decreased the high permeability and the TJP destruction of BMECs and ameliorated the inflammation induced by OGD-treated astrocytes by elevating LRP6 expression.

Deoxyhypusine hydroxylase as a novel pharmacological target for ischemic stroke via inducing a unique post-translational hypusination modification

Ischemic stroke remains one of the leading causes of death worldwide, thereby highlighting the urgent necessary to identify new therapeutic targets. Deoxyhypusine hydroxylase (DOHH) is a fundamental enzyme catalyzing a unique posttranslational hypusination modification of eukaryotic translation initiation factor 5A (eIF5A) and is highly involved in the progression of several human diseases, including HIV-1 infection, cancer, malaria, and diabetes. However, the potential therapeutic role of pharmacological regulation of DOHH in ischemic stroke is still poorly understood. Our study first discovered a natural small-molecule brazilin (BZ) with an obvious neuroprotective effect against oxygen-glucose deprivation/reperfusion insult. Then, DOHH was identified as a crucial cellular target of BZ using HuProt™ human proteome microarray. By selectively binding to the Cys232 residue, BZ induced a previously undisclosed allosteric effect to significantly increase DOHH catalytic activity. Furthermore, BZ-mediated DOHH activation amplified mitophagy for mitochondrial function and morphology maintenance via DOHH/eIF5A hypusination signaling pathway, thereby protecting against ischemic neuronal injury in vitro and in vivo. Collectively, our study first identified DOHH as a previously unreported therapeutic target for ischemic stroke, and provided a future drug design direction for DOHH allosteric activators using BZ as a novel molecular template.

Combination of Systems Pharmacology and Experimental Evaluation to Explore the Mechanism of Synergistic Action of Frankincense-Myrrh in the Treatment of Cerebrovascular Diseases

Frankincense-Myrrh is a classic drug pair that promotes blood circulation, and eliminates blood stasis. The combination of the two drugs has a definite clinical effect on the treatment of cerebrovascular diseases (CBVDs), but its mechanism of action and compatibility have not been elucidated. In this study, the bioactive components, core targets, and possible synergistic mechanisms of Frankincense-Myrrh in the treatment of CBVDs are explored through systems pharmacology combined with in vivo and in vitro experiments. Comparing target genes of components in Frankincense and Myrrh with CBVD-related genes, common genes were identified; 15 core target genes of Frankincense-Myrrh for the treatment of CBVDs were then identified using protein-protein interaction (PPI) analysis. It was also predicted through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis that the molecular mechanism of Frankincense-Myrrh action on CBVDs was mainly related to the regulation of neurotrophic factors and inflammatory responses. Frankincense-Myrrh significantly improved neurological function, decreased infarct volume, alleviated histopathological damage, inhibited microglial expression, and promoted the expression of neurons in middle cerebral artery occlusion (MCAO)-induced rats. The results of this study not only provide important theoretical support and experimental basis for the synergistic effect of Frankincense-Myrrh, but also provide new ideas for the prevention and treatment of cerebral ischemic injuries.

Sea Cucumber-Derived Peptide Attenuates Scopolamine-Induced Cognitive Impairment by Preventing Hippocampal Cholinergic Dysfunction and Neuronal Cell Death

The incidence of neurodegenerative diseases related to cognitive decline and memory loss is on the rise as the global elderly population increases. In this study, we evaluated the effect of the sea cucumber-derived peptide Phe-Tyr-Asp-Trp-Pro-Lys (FYDWPK) on scopolamine-induced neurotoxicity in an animal model. The Morris water maze, passive avoidance apparatus, and shuttle box test were used to assess learning and memory abilities. In behavioral tests, FYDWPK effectively alleviated learning and memory impairment. FYDWPK also alleviated cholinergic dysfunction in mice with dementia. Furthermore, FYDWPK significantly improved oxidative imbalance by increasing superoxide dismutase activity and decreasing malondialdehyde levels (P < 0.05). The pathological results showed that FYDWPK alleviated neuronal loss, blurred caryotheca, and pyknotic nuclei in the hippocampus, and a high dose of FYDWPK had the best effect. In conclusion, FYDWPK alleviated cognitive and memory impairments by regulating oxidative imbalance, reducing cholinergic dysfunction, and relieving pathological alterations.

Effect of Pericytes on Cerebral Microvasculature at Different Time Points of Stroke

Pericyte, as an important component of the blood-brain barrier, has received increasing attention in the study of cerebrovascular diseases. However, the mechanism of pericytes after the occurrence of cerebral ischemia is controversial. On the one hand, the expression of pericytes increases after cerebral ischemia, constricting the blood vessels to restrict blood supply and aggravating the damage caused by ischemia; on the other hand, pericytes participate in capillary angiogenesis in the ischemic area, which facilitates the repair of the ischemic injury area. The multifunctionality of pericytes is an important reason for this phenomenon, but the different time points of observation for the outcome indicators in each study are also an important factor that leads to the controversy of pericytes. Based on the review of a large database of original studies, the authors' team summarized the effects of pericytes on cerebral microvasculature at different time points after stroke, searched the possible markers, and explored possible therapeutic.

Hepatic Injury Induced by Dietary Energy Level via Lipid Accumulation and Changed Metabolites in Growing Semi-Fine Wool Sheep

Liver injury threatens the overall health of an organism, as it is the core organ of the animal body. Liver metabolism is affected by numerous factors, with dietary energy level being a crucial one. Therefore, the present study aimed to evaluate hepatic injury and to describe its metabolic mechanism in ruminants fed diets with different dietary energy levels. A total of 25 Yunnan semi-fine wool sheep were fed diets with five dietary metabolic energy levels and were randomly assigned to five groups as follows: low energy (LE), medium–low energy (MLE), medium energy (ME), medium–high energy (MHE), and high energy (HE). The results revealed that the average optical density (AOD) of lipid droplets in the LE, MLE, and HE groups was higher than that in the ME and MHE groups. The enzyme activity of alanine aminotransferase (ALT) was the lowest in the ME group. An increase in dietary energy level promoted the superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity and altered the malondialdehyde (MDA) and protein carbonyl (PCO) concentration quadratically. In addition, both high and low dietary energy levels upregulated the mRNA abundance of proinflammatory cytokine interleukin (IL)-1β, nuclear factor-kappa B (NF-κB), and tumor necrosis factor (TNF)-α. Metabonomic analysis revealed that 142, 77, 65, and 108 differential metabolites were detected in the LE, MLE, MHE, and HE groups, compared with ME group respectively. These metabolites were involved in various biochemical pathways, such as glycolipid, bile acid, and lipid metabolism. In conclusion, both high and low dietary energy levels caused hepatic injury. Section staining and metabonomic results revealed that hepatic injury might be caused by altered metabolism and lipid accumulation induced by lipid mobilization.

The Nrf2 Pathway in Ischemic Stroke: A Review

Ischemic stroke, characterized by the sudden loss of blood flow in specific area(s) of the brain, is the leading cause of permanent disability and is among the leading causes of death worldwide. The only approved pharmacological treatment for acute ischemic stroke (intravenous thrombolysis with recombinant tissue plasminogen activator) has significant clinical limitations and does not consider the complex set of events taking place after the onset of ischemic stroke (ischemic cascade), which is characterized by significant pro-oxidative events. The transcription factor Nuclear factor erythroid 2-related factor 2 (Nrf2), which regulates the expression of a great number of antioxidant and/or defense proteins, has been pointed as a potential pharmacological target involved in the mitigation of deleterious oxidative events taking place at the ischemic cascade. This review summarizes studies concerning the protective role of Nrf2 in experimental models of ischemic stroke, emphasizing molecular events resulting from ischemic stroke that are, in parallel, modulated by Nrf2. Considering the acute nature of ischemic stroke, we discuss the challenges in using a putative pharmacological strategy (Nrf2 activator) that relies upon transcription, translation and metabolically active cells in treating ischemic stroke patients.

Total glycosides and polysaccharides of Cistanche deserticola prevent osteoporosis by activating Wnt/β-catenin signaling pathway in SAMP6 mice

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese medicine Cistanche deserticola Y. C. Ma has effect of "tonifying kidney and strengthening bone". However, the specific active extracts of C. deserticola and mechanisms for treatment of osteoporotic are not clear.

AIM OF THE STUDY

We wanted to identify the effective component extracts of C. deserticola for the treatment of osteoporosis and the potential mechanisms.

MATERIALS AND METHODS

Our group researched the extracts of C. deserticola with anti-osteoporotic activity, including total glycosides (TGs), polysaccharides (PSs), and oligosaccharides (OSs) in senescence accelerated mouse prone 6 (SAMP6) mice. The Goldner's Trichrome, Van Gieson's (VG), Safranin O-Fast Green staining and Von Kossa staining were performed to investigate the bone structure formation and calcium deposits. Serum was collected for detecting biochemical markers. Bone micro-architecture was detected by micro-CT. Expressions of bone morphogenetic protein-2 (BMP-2), osteocalcin (OCN), osteoprotegerin (OPG), receptor activator of nuclear factor-κ B ligand (RANKL), p-glycogen synthetase kinase-3β (p-GSK-3β), and p-β-catenin were analyzed by western blotting and immunohistochemistry.

RESULTS

TGs and PSs ameliorated bone histopathological damages, promoted the formation of new bone, collagenous fiber, and chondrocytes, and accelerated the calcium deposits. Moreover, they remarkable altered the biomarkers of bone turnover and effectively ameliorated bone microarchitecture. The further mechanisms study showed that TGs and PSs significantly decreased the expressions of RANKL, p-β-catenin, as well as up-regulated the expression of BMP-2, OCN, OPG, and p-GSK-3β (Ser9).

CONCLUSION

The findings of this study suggest that TGs and PSs can promote osteoblastogenic bone formation and improve bone microstructure damage in SAMP6 mice, and their therapeutic effect on osteoporosis is via activating Wnt/β-catenin signaling pathway.

Total glycosides from stems of Cistanche tubulosa alleviate depression-like behaviors: bidirectional interaction of the phytochemicals and gut microbiota

BACKGROUND

As the most frequently used kidney-yang tonifying herb in traditional Chinese medicine, dried succulent stems of Cistanche tubulosa (Schenk) Wight (CT) have been shown to be effective in the treatment of depression. However, the antidepressant components and their underlying mechanism remain unclear.

PURPOSE

To explore the active components of CT against depression, as well as the potential mechanisms.

STUDY DESIGN AND METHODS

Behavioral despair tests were used to assess the antidepressant activities of polysaccharides, oligosaccharides and different glycoside-enriched fractions separated from CT, as well as the typical gut microbiota metabolites including 3-hydroxyphenylpropionic acid (3-HPP) and hydroxytyrosol (HT). Furthermore, the effects of bioactive fractions and metabolites on chronic unpredictable mild stress (CUMS) model were explored with multiple pharmacodynamics and biochemical analyses. Changes in colonic histology and the intestinal barrier were observed by staining and immunohistochemical analysis. Gut microbial features and tryptophan-kynurenine metabolism were explored using 16S rRNA sequencing and western-blotting, respectively.

RESULTS

Total glycosides (TG) dramatically alleviated depression-like behaviors compared to different separated fractions, reflecting in the synergistic effects of phenylethanoid and iridoid glycosides on the hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, severe neuro- and peripheral inflammation, and deficiencies in 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor in the hippocampus. Moreover, TG mitigated low-grade inflammation in the colon and intestinal barrier disruption, and the abundances of several bacterial genera highly correlated with the HPA axis and inflammation in CUMS rats. Consistently, the expression of indoleamine 2, 3-dioxygenase 1 (IDO1) in the colon was significantly reduced after TG administration, accompanied by the suppression of tryptophan-kynurenine metabolism. On the other hand, HT also exerted a marked antidepressant effect by ameliorating HPA axis function, pro-inflammatory cytokine release, and tryptophan-kynurenine metabolism, while it was unable to largely adjust the disordered gut microbiota in the same manner as TG. Surprisingly, superior to fluoxetine, TG and HT could further improve dysfunction of the hypothalamic-pituitary-gonadal axis and abnormal cyclic nucleotide metabolism.

CONCLUSION

TG are primarily responsible for the antidepressant activity of CT; its effect might be achieved through the bidirectional interaction of the phytochemicals and gut microbiota, and reflect the advantage of CT in the treatment of depression.

Cistanches Herba, from an endangered species to a big brand of Chinese medicine

Cistanches Herba (CH, Chinese name: Roucongrong), is a very precious, tonic Chinese medicine. Cistanche deserticola and Cistanche tubulosa are the two commonly used species and authenticated in Chinese Pharmacopoeia. Due to the parasitic nature of Cistanche plants, the wild source was once endangered and listed in the Appendix II of Convention on International Trade in Endangered Species of Wild Fauna and Flora. However, after continuously struggling in the past decades, CH has grown up to a big brand of Chinese medicine featured with the cultivation area as 1.26 million mu, the annual output as 6000 tons, and the related industrial output value as more than 20 billion China Yuan, attributing to large-scale cultivation and in-depth phytochemical and pharmacological investigations. Noteworthily, great achievements have reached concerning the research and development of relevant products, such as modern drugs, traditional Chinese medicine prescriptions, and dietary supplements. The current review summarizes the research progresses concerning the distribution and cultivation, phytochemistry, pharmacology, metabolism and product development of CH in the past decades, and the emerging challenges and developing prospects are discussed as well.

Nrf2 mediates the neuroprotective effect of isoflurane preconditioning in cortical neuron injury induced by oxygen-glucose deprivation

OBJECTIVE

To investigate how nuclear factor-E2-related factor 2 (Nrf2) involved in the protective effect of isoflurane (Iso) preconditioning in oxygen glucose deprivation (OGD)-induced cortical neuron injury.

METHODS

Primary mouse cortical neurons were divided into Control, ML385 (an Nrf2 inhibitor), Iso, Iso + ML385, OGD, ML385 + OGD, Iso + OGD, and Iso + ML385 + OGD groups. Lactate dehydrogenase activity (LDH) release and oxidative stress indexes were quantified. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect cell viability, Annexin V-FITC/propidium iodide (PI) staining to measure cell apoptosis, dichloro-dihydro-fluorescein diacetate (DCFH-DA) method to test reactive oxygen species (ROS), and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) and Western blotting to evaluate genes and protein expression.

RESULTS

Iso preconditioning reduced LDH release and inhibited cell cytotoxicity in OGD-induced cortical neurons, which was abolished by ML385. Iso preconditioning increased the Nrf2 nuclear translocation in cortical neurons. Meanwhile, Iso decreased the OGD-induced apoptosis with the down-regulations of Bax and Caspase-3 and the up-regulation of Bcl-2, which was reversed by ML385. OGD enhanced the level of ROS and malondialdehyde (MDA) in cortical neurons, but reduced the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), which were aggravated in ML385 + OGD group and mitigated in Iso + OGD group. No observable difference was found between OGD group and Iso + ML385 + OGD group regarding apoptosis-related proteins and oxidative stress-related indexes.

CONCLUSION

Iso preconditioning up-regulated Nrf2 level to play its protective role in OGD-induced mouse cortical neuron injury.

Lycopene Exerts Neuroprotective Effects After Hypoxic-Ischemic Brain Injury in Neonatal Rats via the Nuclear Factor Erythroid-2 Related Factor 2/Nuclear Factor-κ-Gene Binding Pathway

Neonatal hypoxic-ischemic encephalopathy (HIE) is a brain injury caused by perinatal asphyxia and is the main cause of neonatal death and chronic neurological diseases. Protection of neuron after hypoxic-ischemic (HI) brain injury is considered as a potential therapeutic target of HI brain injury. To date, there are no effective medicines for neonatal HI brain injury. Lycopene (Lyc), a member of the carotenoids family, has been reported to have anti-oxidative and anti-inflammatory effects. However, its effects and potential mechanisms in HI brain injury have not yet to be systematically evaluated. In this study, we investigated whether Lyc could ameliorate HI brain injury and explored the associated mechanism both in vivo and in vitro experiments. In vivo study, Lyc significantly reduced infarct volume and ameliorated cerebral edema, decreased inflammatory response, promoted the recovery of tissue structure, and improved prognosis following HI brain injury. In vitro study, results showed that Lyc reduced expression of apoptosis mediators in oxygen-glucose deprivation (OGD)-induced primary cortical neurons. Mechanistically, we found that Lyc-induced Nrf2/NF-κB pathway could partially reversed by Brusatol (an Nrf2 inhibitor), indicated that the Nrf2/NF-κB pathway was involved in the therapy of Lyc. In summary, our findings indicate that Lyc can attenuated HI brain injury in vivo and OGD-induced apoptosis of primary cortical neurons in vitro through the Nrf2/NF-κB signaling pathway.

Activation of Nrf2 by Natural Bioactive Compounds: A Promising Approach for Stroke?

Stroke represents one of the main causes of disability and death worldwide. The pathological subtypes of stroke are ischemic stroke, the most frequent, and hemorrhagic stroke. Nrf2 is a transcription factor that regulates redox homeostasis. In stress conditions, Nrf2 translocates inside the nucleus and induces the transcription of enzymes involved in counteracting oxidative stress, endobiotic and xenobiotic metabolism, regulators of inflammation, and others. Different natural compounds, including food and plant-derived components, were shown to be able to activate Nrf2, mediating an antioxidant response. Some of these compounds were tested in stroke experimental models showing several beneficial actions. In this review, we focused on the studies that evidenced the positive effects of natural bioactive compounds in stroke experimental models through the activation of Nrf2 pathway. Interestingly, different natural compounds can activate Nrf2 through multiple pathways, inducing a strong antioxidant response associated with the beneficial effects against stroke. According to several studies, the combination of different bioactive compounds can lead to a better neuroprotection. In conclusion, natural bioactive compounds may represent new therapeutic strategies against stroke.