Efficacy and safety of naotaifang capsules for hypertensive cerebral small vessel disease: Study protocol for a multicenter, randomized, double-blind, placebo-controlled clinical trial

Crosstalk between ferroptosis and necroptosis in cerebral ischemia/reperfusion injury and Naotaifang formula exerts neuroprotective effect via HSP90-GCN2-ATF4 pathway

BACKGROUND

Cerebral ischemia/reperfusion injury (CIRI) is a sequence of pathophysiological processes after blood recanalization in the patients with ischemic stroke, and has become the hinder for the rehabilitation. Naotaifang formula (NTF) has exhibited the clinical effectiveness for this disease. However, its action effects and molecular mechanisms against CIRI are not fully elucidated.

PURPOSE

The research was to clarify the crosstalk between ferroptosis and necroptosis in CIRI, and uncover the mechanism underlying the neuroprotection of NTF.

METHODS

This study established MCAO/R rat models with various reperfusion times. Western blot, transmission electron microscope, laser speckle imaging, immunofluorescence, immunohistochemistry and pathological staining were conducted to detect and analyze the obtained results. Subsequently, various NTF doses were used to intervene in MCAO/R rats, and biology experiments, such as western blot, Evans blue, immunofluorescence and immunohistochemistry, were used to analyze the efficacy of NTF doses. The effect of NTF was further clarified through in vitro experiments. Eventually, HT22 cells that suffered OGD/R were subjected to pre-treatment with plasmids overexpressing HSP90, MLKL, and GPX4 to indicate the interaction among ferroptosis and necroptosis.

RESULTS

There was a gradual increase in the Zea Longa score and cerebral infarction volume following CIRI with prolonged reperfusion. Furthermore, the expression of factors associated with pro-ferroptosis and pro-necroptosis was upregulated in the cortex and hippocampus. NTF alleviated ferroptosis and necroptosis in a dose-dependent manner, downregulated HSP90 levels, reduced blood-brain barrier permeability, and thus protected nerve cells from CIRI. The results in vitro research aligned with those of the in vivo research. HSP90 and MLKL overexpression promoted necroptosis and ferroptosis while activating the GCN2-ATF4 pathway. GPX4 overexpression had no effect on necroptosis or the associated signaling pathway. The administration of NTF alone, as well as its combination with the overexpression of HSP90, MLKL, or GPX4 plasmids, decreased the expression levels of factors associated with pro-ferroptosis and pro-necroptosis and reduced the protein levels of the HSP90-GCN2-ATF4 pathway. Moreover, the regulatory effects of the NTF alone group on GSH, ferrous iron, and GCN2 were more significant compared with those of the HSP90 overexpression combination group.

CONCLUSION

Ferroptosis and necroptosis were gradually aggravated following CIRI with prolonged reperfusion. MLKL overexpression may promote ferroptosis and necroptosis, while GPX4 overexpression may have little effect on necroptosis. HSP90 overexpression accelerated both forms of cell death via the HSP90-GCN2-ATF4 pathway. NTF alleviated ferroptosis and necroptosis to attenuate CIRI by regulating the HSP90-GCN2-ATF4 pathway. Our research provided evidence for the potential of drug development by targeting HSP90, MLKL, and GPX4 to protect against ischemic stroke.

Evidence-based evaluation of adjuvant therapy with Chinese medicine for cerebral small vessel disease: A systematic review and meta-analysis

BACKGROUND

As the population ages, the prevalence of cerebral small vessel disease (CSVD) steadily increases, resulting in a significant economic burden on society. In East Asian nations, Chinese medicine has been used extensively to teat CSVD and has been reported to improve the cognitive function of patients. The present study aimed to comprehensively assess the efficacy and safety of Chinese medicine as adjuvant therapy for CSVD.

METHODS

A literature search of the CNKI, Wanfang, VIP, SinoMed, Medline, Cochrane Library, and ChiCTR databases were searched for RCTs investigating the use of TCM as an adjuvant in the treatment of CSVD, published up to July 27, 2023, was performed. Based on the Cochrane Collaboration Network bias risk assessment criteria, Review Manager version 5.3 was used to perform a meta-analysis.

RESULTS

Meta-analysis of 27 RCTs, including 2554 subjects, revealed that the majority of the RCTs exhibited risk for ambiguous bias. The findings demonstrated that the use of Chinese medicine as an adjuvant treatment for CSVD effectively enhanced the cognitive function, as evidenced by improvements in the MMSE score (mean difference (MD) = 2.42, 95% confidence interval (CI) [1.79,3.17], P < .00001), MoCA score (MD = 2.39, 95% CI [1.78,2.99], P < .00001) and ADL score (MD = 4.13, 95% CI [1.74,6.51], P = .0007). Furthermore, the study also demonstrated the advantages of Chinese medicine adjuvant therapy in enhancing the Chinese medicine syndrome score (MD = -2.57, 95% CI [-3.31, -1.83], P < .00001), CRP (MD = -1.35, 95% CI [-2.27, -0.43], P = .004), Hcy (MD = -3.44,95% CI [-4.05, -2.83], P < .00001), and blood flow velocity (CBV) (MD = 1.37,95% CI [0.24,2.50], P = .02). Moreover, there was no statistical difference in the incidence of adverse reactions between the 2 groups.

CONCLUSION

Findings of the present study indicate that the Chinese medicine, as an adjuvant to conventional treatment, appeared to be efficacious in enhancing cognitive function, reducing Chinese medicine syndrome score, improving blood biochemical markers, and improving cerebral blood flow perfusion in patients with CSVD, without any notable adverse reactions. However, it is imperative to validate these conclusions in future high-quality investigations.