Salvianolic Acids for Injection alleviates cerebral ischemia/reperfusion injury by switching M1/M2 phenotypes and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia in vivo and in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: After cerebral ischemia/reperfusion injury, pro-inflammatory M1 and anti-inflammatory M2 phenotypes of microglia are involved in neuroinflammation, in which activation of NLRP3 inflammasome and subsequent pyroptosis play essential roles. Salvianolic Acids for Injection (SAFI) is Chinese medicine injection which composed of multiple phenolic acids extracted from Radix Salviae Miltiorrhizae, and has been reported to generate neuroprotective effects after cerebral ischemic insult in clinical and animal studies. AIM OF THE STUDY: The present study was designed to investigate whether SAFI exerts neuroprotective effects by switching microglial phenotype and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia. MATERIALS AND METHODS: The middle cerebral artery occlusion/reperfusion (MCAO/R) model in rats and oxygen-glucose deprivation/reoxygenation (OGD/R) model in co-cultured primary neurons and primary microglia were utilized. The neuroprotective effect of SAFI was evaluated through measuring neurological deficit scores, neuropathological changes, inflammatory factors, cell phenotype markers, and related proteins of NLRP3 inflammasome/pyroptosis axis. RESULTS: The results showed that SAFI treatment was able to: (1) produce a significant increase in neurological deficit scores and decrease in infarct volumes, and alleviate histological injury and neuronal apoptosis in cerebral cortex in MCAO/R model; (2) increase neuronal viability and reduce neuronal apoptosis in the OGD model; (3) reshape microglial polarization patterns from M1-like phenotype to M2-like phenotype; (4) inhibit the activation of the NLRP3 inflammasome and the expression of proteins related to NLRP3 inflammasome/pyroptosis axis in vivo and in vitro. CONCLUSION: These findings indicate that SAFI exert neuroprotective effect, probably via reducing neuronal apoptosis, switching microglial phenotype from M1 towards M2, and inhibiting NLRP3 inflammasome/pyroptosis axis in microglia.

Concomitant memantine and Lactobacillus plantarum treatment attenuates cognitive impairments in APP/PS1 mice.

Trimethylamine-N-oxide (TMAO) is a gut microbial metabolite that promotes Alzheimer's disease (AD) progression. Given that probiotics can alleviate AD symptoms by inhibiting the synthesis of TMAO, here we investigated the correlation between TMAO and cognitive deterioration by measuring TMAO levels in the plasma of choline-treated APP/PS1 mice (an AD mouse model) with and without probiotic treatments. We found that declines in L.plantarum in the gut were associated with cognitive impairment. Moreover, 12-weeks of treatment with memantine plus L. plantarum ameliorated cognitive deterioration, decreased Αß levels in the hippocampus, and protected neuronal integrity and plasticity. These effects were accompanied by reductions in TMAO synthesis and neuroinflammation. These experiments demonstrate that L. plantarum augments the beneficial therapeutic effects of memantine treatment in APP/PS1 mice by remodeling the intestinal microbiota, inhibiting the synthesis of TMAO, and reducing clusterin levels. Our results thus highlight intestinal microbiota as a potential therapeutic target to decrease the risk of AD.

Astragalosides promote angiogenesis via vascular endothelial growth factor and basic fibroblast growth factor in a rat model of myocardial infarction.

The aim of the present study was to evaluate the effect of astragalosides (ASTs) on angiogenesis, as well as the expression of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) following myocardial infarction (MI). MI was induced in rats by ligation of the left coronary artery. Twenty­four hours after surgery, the rats were divided into low­dose, high­dose, control and sham surgery groups (n=8 per group). The low­ and high­dose groups were treated with ASTs (2.5 and 10 mg/kg/day, respectively, via intraperitoneal injection), while, the control and sham surgery group rats received saline. Serum levels, and mRNA and protein expression levels of VEGF and bFGF, as well as the microvessel density (MVD) were determined four weeks post­treatment. Twenty­four hours post­surgery, VEGF and bFGF serum levels were observed to be comparable between the groups; while at four weeks, the VEGF and bFGF levels were higher in the AST­treated rats (P<0.01). Similarly, VEGF and bFGF mRNA and protein expression levels were higher following AST treatment (P<0.05). No difference in VEGF mRNA expression between the low­ and high­dose groups was noted, however, an increase in the bFGF expression levels was detected in the high­dose group. Newly generated blood vessels were observed following MI, with a significant increase in MVD observed in the AST­treated groups (P<0.05). AST promotes angiogenesis of the heart and increases VEGF and bFGF expression levels. Thus, it is hypothesized that increased VEGF and bFGF levels may contribute to the AST­induced increase in angiogenesis in rat models of MI.

[Effects of resveratrol on isolated thoracic aorta rings of rats].

OBJECTIVE: To investigate the relaxative characteristics of resveratrol on thoracic aortic artery in the rat and its mechanism. METHOD: We perfused the isolated rings and observed the response of NA-induced artery contraction to resveratrol under the Ca2+-contained and Ca2+-free bath solutions. In the same way were the effect of reveratrol on the vascular smooth muscle observed by adding two different concentration of KCl (30 and 80 mmol x L(-1)), and the effect on the contraction of the vascular smooth muscle depending on the intracellular calcium and extracellular calcium were also observed by adding NA. We also observed the effect of resveratrol on the contraction of rings induced by NA in the presence of L-NNA and Glibenclamide. RESULT: Resveratrol relaxed rat aorta rings precontracted by NA in a dose-dependent manner. The relaxant effect of resveratrol on the rat rings of endothelium-denuded group was reduced compared with that of endothelium-intact group; the relaxant effect of resveratrol on rat rings was higher under the condition of Ca2+-free bath solution than that under the condition of Ca2+-contained bath solution. Resveratrol had a repressive effect on the aorta's contraction induced by intracellular calcium, but had no effect induced by extracellular calcium. Resveratrol relaxed the contractions induced by KCl 30 mmol x L(-1) as well as KCl 80 mmol x L(-1), but the contraction curve of KCl 80 mmol x L(-1) was shifted upward significantly. In the L-NNA group, the relaxant effect was attenuated by (26.0 +/- 4.6) %; but there was no change in the group of Glibenclamide ( P > 0.05). CONCLUSION: The results indicate that resveratrol relaxes vascular smooth muscle in an endothelium dependent manner. The mechanisms for this phenomenon seem to be related with promoting synthesis and release of NO, opening Ca2+ activated K+ channel (KCa channel) as well as the inhibition of Ca2+ influx and release of Ca2+ from intracellular stores.