scholarly journals Effects of rhodioloside on the neurological functions of rats with total cerebral ischemia/reperfusion and cone neuron injury in the hippocampal CA1 region

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10056
Author(s):  
Yue Zhang ◽  
Xinqing Guo ◽  
Guohua Wang ◽  
Jidan Liu ◽  
Peiyu Liang ◽  
...  

Rhodioloside, the main effective constituent of Rhodiola rosea, demonstrates antiaging and antioxidative stress functions and inhibits calcium overloading in cells. These functions imply that rhodioloside may exert protective effects on hippocampal neurons after total cerebral ischemia/reperfusion injury. In this study, male Wistar rat models of total cerebral ischemia were constructed and randomly divided into four groups: sham-operation, ischemia/reperfusion, low-dosage, and high-dosage groups. The result showed that rhodioloside treatment reduced the apoptosis rates of hippocampal neurons and the histological grades of cone cells in the hippocampal CA1 region, but neuronal density was significantly increased. Besides, the protein expressions of Bcl-2/Bax and p53 were measured and found Bcl-2/Bax was increased and p53 protein level was reduced. Therefore, rhodioloside might have protective effects on rats with ischemia/reperfusion brain injury.

2021 ◽  
Vol 15 ◽  
Author(s):  
Sihan Guo ◽  
Ruimin Wang ◽  
Jiewei Hu ◽  
Liping Sun ◽  
Xinru Zhao ◽  
...  

Our recent study revealed that photobiomodulation (PBM) inhibits delayed neuronal death by preserving mitochondrial dynamics and function following global cerebral ischemia (GCI). In the current study, we clarified whether PBM exerts effective roles in endogenous neurogenesis and long-lasting neurological recovery after GCI. Adult male rats were treated with 808 nm PBM at 20 mW/cm2 irradiance for 2 min on cerebral cortex surface (irradiance ∼7.0 mW/cm2, fluence ∼0.8 J/cm2 on the hippocampus) beginning 3 days after GCI for five consecutive days. Cognitive function was evaluated using the Morris water maze. Neural stem cell (NSC) proliferation, immature neurons, and mature neurons were examined using bromodeoxyuridine (BrdU)-, doublecortin (DCX)-, and NeuN-staining, respectively. Protein expression, such as NLRP3, cleaved IL1β, GFAP, and Iba1 was detected using immunofluorescence staining, and ultrastructure of astrocyte and microglia was observed by transmission electron microscopy. The results revealed that PBM exerted a markedly neuroprotective role and improved spatial learning and memory ability at 58 days of ischemia/reperfusion (I/R) but not at 7 days of reperfusion. Mechanistic studies revealed that PBM suppressed reactive astrocytes and maintained astrocyte regeneration at 7 days of reperfusion, as well as elevated neurogenesis at 58 days of reperfusion, as evidenced by a significant decrease in the fluorescence intensity of GFAP (astrocyte marker) but unchanged the number of BrdU-GFAP colabeled cells at the early timepoint, and a robust elevation in the number of DCX-NeuN colabeled cells at the later timepoint in the PBM-treated group compared to the GCI group. Notably, PBM treatment protected the ultrastructure of astrocyte and microglia cells at 58 days but not 7 days of reperfusion in the hippocampal CA1 region. Furthermore, PBM treatment significantly attenuated the GCI-induced immunofluorescence intensity of NLRP3 (an inflammasome component), cleaved IL1β (reflecting inflammasome activation) and Iba1, as well as the colocalization of NLRP3/GFAP or cleaved IL-1β/GFAP, especially in animals subjected to I/R at 58 days. Taken together, PBM treatment performed postischemia exerted a long-lasting protective effect on astrocytes and promoted endogenous neurogenesis in the hippocampal CA1 region, which might contribute to neurological recovery after GCI.


2016 ◽  
Vol 86 (5-6) ◽  
pp. 228-234 ◽  
Author(s):  
Arash Sarveazad ◽  
Asrin Babahajian ◽  
Abazar Yari ◽  
Farjam Goudarzi ◽  
Mansoureh Soleimani ◽  
...  

Abstract. Cerebral ischemia is worldwide the third largest cause of mortality and disability in old people, and oxidative stress plays a considerable role in this process. In this study, for the fi rst time, we evaluated the effects of Trolox as an antioxidative agent in ischemia induced by reperfusion. Twenty-four Syrian male mice were randomly divided into the 3 groups. Both common carotid arteries of Syrian mice were ligated bilaterally for 20 min, blood fl ow was restored and Trolox (50 mg/kg) was immediately injected after induced ischemia. Shuttle box results showed an improvement in memory in the Trolox group compared to the ischemia group, however, these improvements were not signifi cant. Histopathological results showed a signifi cant increase in the number of healthy cells in the hippocampal CA1 region in the Trolox group compared to the ischemia group (p < 0.001). Also, caspase-3, as an apoptosis marker, was signifi cantly decreased in the Trolox group compared to the ischemia group (p < 0.01). Ultimately, as an anti-apoptotic factor, c-JUN was increased statistically in the Trolox group compared to the ischemia group (p < 0.01). Our study showed that after cerebral ischemia reperfusion, Trolox prescription increased anti-apoptotic proteins and decreased proapoptotic proteins thus protects neurons of the hippocampus and caused improvement of memory. Ultimately, these results would suggest some important treatment strategies after cerebral ischemia reperfusion.


Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Rui-li Wei ◽  
Yan Xu ◽  
Jing-ye Wang ◽  
Ben-yan Luo

Background and Purpose: Probenecid (PROB) has been used for decades to treat gouty arthritis with few side effects and recent studies revealed that it is also a specific inhibitor of pannexin-1 channel. Panx1 channel was activated by ischemic injury and inhibition of the panx1 channel maybe efficacious in stroke treatment. However, the role of PROB in cerebral ischemia /reperfusion (I/R) injury remains unclear. The aim of this study was to investigate the role of PROB in the transient global cerebral I/R injury in rats and its protective mechanisms. Methods: Twenty minutes of transient global cerebral I/R was induced using the four-vessel occlusion (4-VO) method in rats. PROB was given in the different dose, time and administration routes to verify its neuroprotective effects. Neuronal death in the hippocampal CA1 region was observed using H & E staining 7 days after ischemia. Molecular mechanisms of activation of calpain-cathepsin pathway and inflammatory cells by I/R injury were also investigated. Results: Treatment with PROB (0.1, 1 and 10 mg/kg ) 10 min before ischemia protected against I/R-induced hippocampal CA1 neuronal death significantly, and 1 mg/kg has best protective effect. Post-insult treatment 2h after reperfusion also protected against neuronal death and prolonged use for continuous 7 days could improve its protective effects compared to the single use 6h after reperfusion.Furthermore,oral administration also had protective effect. Cathepsin B expression was inceased significantly in CA-1 region after ischemia and PROB treatment could inhibit its expression. Expression of both calpain-1 and hsp70 at 1d ,2d and 3d after reperfusion were upregulated, whereas the expression of calpain-1 was inhibited and hsp70 was strengthened by pre-treatment with PROB. Prolonged PROB treatment suppressed the activation of microglia and astrocytes, reduced the number of microglia in CA1 region. Conclusions: Our study indicates that PROB protects against transient global cerebral I/R injury administrated before ischemia and even 6h after reperfusion by reducing calpain-1 expression , inhibiting lysosomal rupture and the activation of the glia, which suggests RPOB may be a promising therapeutic drug for clinical treatment of ischemic cerebral injury.


2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bing Wang ◽  
Zhongkuan Lyu ◽  
Yuanjin Chan ◽  
Qiyue Li ◽  
Li Zhang ◽  
...  

Amyloid-β peptide (Aβ) accumulation is a detrimental factor in cerebral ischemia/reperfusion (I/R) injuries accounting for dementia induced by ischemic stroke. In addition to blood brain barrier (BBB), the glymphatic system mediated by aquaporin-4 (AQP-4) on astrocytic endfeet functions as an important pathway for the clearance of Aβ in the brain. Cerebral I/R induced astrocytic pyroptosis potentially causes the AQP-4 polarization loss and dysfunctional BBB-glymphatic system exacerbating the accumulation of Aβ. Furthermore, Aβ toxicity has been identified as a trigger of pyroptosis and BBB damage, suggesting an amplified effect of Aβ accumulation after cerebral I/R. Therefore, based on our previous work, this study was designed to explore the intervention effects of Tongxinluo (TXL) on astrocytic pyroptosis and Aβ accumulation after cerebral I/R in rats. The results showed that TXL intervention obviously alleviated the degree of pyroptosis by downregulating expression levels of cleaved caspase-11/1, N-terminal gasdermin D, nucleotide-binding oligomerization domain-like receptors pyrin domain containing 3 (NLRP3), interleukin-6 (IL-6), and cleaved IL-1β and abated astrocytic pyroptosis after cerebral I/R. Moreover, TXL intervention facilitated to restore AQP-4 polarization and accordingly relieve Aβ accumulation around astrocytes in ischemic cortex and hippocampus as well as the formation of toxic Aβ (Aβ1–42 oligomer). Our study indicated that TXL intervention could exert protective effects on ischemic brain tissues against pyroptotic cell death, inhibit astrocytic pyroptosis, and reduce toxic Aβ accumulation around astrocytes in cerebral I/R injuries. Furthermore, our study provides biological evidence for the potential possibility of preventing and treating poststroke dementia with TXL in clinical practice.


Sign in / Sign up

Export Citation Format

Share Document