Hydroxysafflor yellow A acutely attenuates blood-brain barrier permeability, oxidative stress, inflammation and apoptosis in traumatic brain injury in rats1

Hydroxysafflor yellow a confers neuroprotection against acute traumatic brain injury by modulating neuronal autophagy to inhibit NLRP3 inflammasomes

ETHNOPHARMACOLOGICAL RELEVANCE

Hydroxysafflor yellow A (HSYA) is the principal bioactive compound isolated from the plant Carthamus tinctorius L. and has been reported to exert neuroprotective effects against various neurological diseases, including traumatic brain injury (TBI). However, the specific molecular and cellular mechanisms underlying HSYA-mediated neuroprotection against TBI are unclear.

AIM OF THE STUDY

This study explored the effects of HSYA on autophagy and the NLRP3 inflammasome in mice with TBI and the related mechanisms.

MATERIALS AND METHODS

Mice were subjected to TBI and treated with or without HSYA. Neurological severity scoring, LDH assays and apoptosis detection were first performed to assess the effects of HSYA in mice with TBI. RNA-seq was then conducted to explore the mechanisms that contributed to HSYA-mediated neuroprotection. ELISA, western blotting, and immunofluorescence were performed to further investigate the mechanisms of neuroinflammation and autophagy. Moreover, 3-methyladenine (3-MA), an autophagy inhibitor, was applied to determine the connection between autophagy and the NLRP3 inflammasome.

RESULTS

HSYA significantly decreased the neurological severity score, serum LDH levels and apoptosis in mice with TBI. A total of 921 differentially expressed genes were identified in the cortices of HSYA-treated mice with TBI and were significantly enriched in the inflammatory response and autophagy. Furthermore, HSYA treatment markedly reduced inflammatory cytokine levels and astrocyte activation. Importantly, HSYA suppressed neuronal NLRP3 inflammasome activation, as indicated by decreased levels of NLRP3, ASC and cleaved caspase-1 and a reduced NLRP3⁺ neuron number. It increased autophagy and ameliorated autophagic flux dysfunction, as evidenced by increased LC3 II/LC3 I levels and decreased P62 levels. The effects of HSYA on the NLRP3 inflammasome were abolished by 3-MA. Mechanistically, HSYA may enhance autophagy through AMPK/mTOR signalling.

CONCLUSION

HSYA enhanced neuronal autophagy by triggering the AMPK/mTOR signalling pathway, leading to inhibition of the NLRP3 inflammasome to improve neurological recovery after TBI.

Protective potential of hydroxysafflor yellow A in cerebral ischemia and reperfusion injury: An overview of evidence from experimental studies

Ischemic stroke, mostly caused by thromboembolic or thrombotic arterial occlusions, is a primary leading cause of death worldwide with high morbidity and disability. Unfortunately, no specific medicine is available for the treatment of cerebral I/R injury due to its limitation of therapeutic window. Hydroxysafflor yellow A, a natural product extracted from Carthamus tinctorius, has been extensively investigated on its pharmacological properties in cerebrovascular diseases. However, review focusing on the beneficial role of HSYA against cerebral I/R injury is still lacking. In this paper, we reviewed the neuroprotective effect of HSYA in preclinical studies and the underlying mechanisms involved, as well as clinical data that support the pharmacological activities. Additionally, the sources, physicochemical properties, biosynthesis, safety and limitations of HSYA were also reviewed. As a result, HSYA possesses a wide range of beneficial effects against cerebral I/R injury, and its action mechanisms include anti-excitotoxicity, anti-oxidant stress, anti-apoptosis, anti-inflammation, attenuating BBB leakage and regulating autophagy. Collectively, HSYA might be applied as one of the promising alternatives in ischemic stroke treatment.

Hydroxysafflor yellow A attenuates oxidative stress injury-induced apoptosis in the nucleus pulposus cell line and regulates extracellular matrix balance via CA XII

Intervertebral disc degeneration (IVDD) is the main cause of lower back pain. Oxidative stress injury and degradation of the extracellular matrix (ECM) are important factors causing IVDD, while hydroxysafflor yellow A (HSYA) has significant anti-oxidative stress and anti-apoptotic effects. The present study aimed to investigate the protective role of HSYA in IVDD using nucleus pulposus (NP) cells. A Cell Counting Kit-8 assay was used to detect cell viability following HSYA and tert-Butyl hydroperoxide (TBHP) treatment. Cellular reactive oxygen species levels and the level of apoptosis were measured using flow cytometry. The concentration of superoxide dismutase (SOD), malondialdehyde (MDA), catalase (CAT) and glutathione peroxidase GSH-Px were detected using ELISA. DAPI staining was performed for nuclear morphology analysis, while western blot analysis was used to detect apoptotic- and ECM-related protein expression levels. Bioinformatics analysis was used to predict the binding site between HSYA and carbonic anhydrase 12 (CA12; CA XII). NP cells were transfected withsmall interference RNA (siRNA) for CA XII downregulation. Following TBHP treatment, the level of ROS increased significantly, and the concentrations of SOD, CAT and GSH-Px were decreased. In addition, the apoptosis level of the NP cell line significantly increased following TBHP treatment. Furthermore, the expression levels of ECM-related proteins, collagen II and aggrecan were significantly decreased, and the protein expression level of MMP-13 was significantly increased. HSYA (10 µM) could effectively alleviate the effects of TBHP on NP cell apoptosis, oxidative stress damage and the expression level of ECM-related proteins. A binding site was found between HSYA and CA XII. In addition, CA XII-siRNA significantly reduced the increase in the expression level of collagen II and aggrecan proteins and decrease in the expression level of MMP-13 induced by HSYA in the NP cell line. In conclusion, HSYA could attenuate oxidative stress injury and apoptosis induced by TBHP in the NP cell line, and could improve the regulation of ECM balance.

Pharmacological Actions, Molecular Mechanisms, Pharmacokinetic Progressions, and Clinical Applications of Hydroxysafflor Yellow A in Antidiabetic Research

Hydroxysafflor yellow A (HSYA), a nutraceutical compound derived from safflower (Carthamus tinctorius), has been shown as an effective therapeutic agent in cardiovascular diseases, cancer, and diabetes. Our previous study showed that the effect of HSYA on high-glucose-induced podocyte injury is related to its anti-inflammatory activities via macrophage polarization. Based on the information provided on PubMed, Scopus and Wanfang database, we currently aim to provide an updated overview of the role of HSYA in antidiabetic research from the following points: pharmacological actions, molecular mechanisms, pharmacokinetic progressions, and clinical applications. The pharmacokinetic research of HSYA has laid foundations for the clinical applications of HSYA injection in diabetic nephropathy, diabetic retinopathy, and diabetic neuropathy. The application of HSYA as an antidiabetic oral medicament has been investigated based on its recent oral delivery system research. In vivo and in vitro pharmacological research indicated that the antidiabetic activities of HSYA were based mainly on its antioxidant and anti-inflammatory mechanisms via JNK/c-jun pathway, NOX4 pathway, and macrophage differentiation. Further anti-inflammatory exploration related to NF-κB signaling, MAPK pathway, and PI3K/Akt/mTOR pathway might deserve attention in the future. The anti-inflammatory activities of HSYA related to diabetes and diabetic complications will be a highlight in our following research.

Neuroprotective effects of Pinus eldarica in a mouse model of pentylenetetrazole-induced seizures

Objective:

Oxidative stress has pernicious effects on the brain. Pinus eldarica has antioxidant properties. We explored neuroprotective effect of P. eldarica against pentylenetetrazole (PTZ)-induced seizures.

Materials and Methods:

Male mice (BALB/c) were grouped as control, PTZ, Soxhlet (Sox) 100, Sox 200, Macerated (Mac) 100 and Mac 200 groups. Sox and Mac extracts (100 and 200 mg/kg) were injected during 7 days. Delay in onset of minimal clonic seizure (MCS) and generalized tonic- clonic seizure (GTCS) was measured. Number of dark neurons (DN) and levels of oxidative stress indicators in the hippocampus were evaluated.

Results:

Onset of MCS and GTCS was later in groups treated with the extracts than the PTZ group (p<0.01 and p<0.001). Number of DN in the hippocampus in the PTZ group was higher than the control group (p<0.001) while in the extract groups, was lower than the PTZ group (p<0.05, p<0.01 and p<0.001). MDA level was higher whereas total thiol level and activity of SOD and CAT were lower (p<0.001) in the PTZ group than the control group. MDA level in the Sox 100 (p<0.01), Sox 200 (p<0.001) and Mac 200 (p<0.01) groups was less than the PTZ group. Total thiol level in the Sox 200 (p<0.001), SOD in the Sox 100 (p<0.05), Sox 200, and Mac 200 and CAT in the Sox 200 (p<0.001) groups were higher than the PTZ group.

Conclusion:

P. eldarica prevented neuronal death and reduced seizures caused by PTZ via improving brain oxidative stress.

Mung Bean Protein Suppresses Undernutrition-Induced Growth Deficits and Cognitive Dysfunction in Rats via Gut Microbiota-TLR4/NF-kB Pathway

Early undernutrition has been found to be closely associated with subsequent neurodevelopment. However, studies examining crude growth in terms of body weight/tail length cannot clarify how diets might mediate associations between the gut microbiota and cognitive dysfunction. In the present study, Sprague-Dawley (SD) rats were fed a 7% protein diet and mung bean protein diet (MBPD) for 6 weeks to assess central nervous system functions. Bifidobacterium longum subsp, Alloprevotella, and Lactobacillus were significantly altered after supplementary MBPD. Additionally, tryptophan, tyrosine, and glycine significantly restored in the brain, and the choline system also improved. Moreover, mung bean supplementation also upregulated expression of the brain-derived neurotrophic factor, postsynaptic density 95 protein (PSD95), synaptosome-associated protein 25 (SNAP25), downregulated toll-like receptor 4 (TLR4), and nuclear factor kB (NF-kB). Metabolites in the serum also underwent changes. Together, these results showed that malnutrition perturbed neurodevelopment, while MBPD reversed this trend.