CZ2HF mitigates β-amyloid 25-35 fragment-induced learning and memory impairment through inhibition of neuroinflammation and apoptosis in rats

Zuoguiwan Ameliorates Cognitive Deficits and Neuro-Inflammation in Streptozotocin-Induced Alzheimer's Disease Rats

INTRODUCTION

Alzheimer's disease is the most popular neurodegenerative disorder with no effective drugs to stop the progression. Zuoguiwan (ZGW), a traditional Chinese herbal medicine, has been applied in many diseases. Our study aimed to detect the function and mechanisms of ZGW in Alzheimer's disease (AD).

METHODS

The rat models of AD were established by streptozotocin (STZ), and the function of ZGW on cognitive dysfunction was measured with the Morris water maze test. The concentration of pro-inflammatory mediators was accessed by enzyme-linked immunosorbent assay. The relative mRNA expression of ERβ was detected by real-time quantitative PCR.

RESULTS

The treatment with ZGW could suppress the cognitive impairment by the findings of escape latency and time spent in the target quadrant and the increased concentration of IL-1β, IL-6, and TNF-α induced by STZ. STZ might repress the mRNA levels of ERβ, and ZGW management weakened the declined mRNA expression of ERβ. ZGW might play a protective role in AD rats against the injury of STZ on cognition and neuro-inflammation by improving the mRNA expression of ERβ.

CONCLUSION

The results indicated that ZGW might be a novel therapeutic strategy to slow the process of AD by modulating ERβ.

Neuroprotective Effects of OMO within the Hippocampus and Cortex in a D-Galactose and Aβ 25-35-Induced Rat Model of Alzheimer's Disease

Morinda officinalis F.C. How. (Rubiaceae) is a herbal medicine. It has been recorded that its oligosaccharides have neuroprotective properties. In order to understand the oligosaccharides extracted from Morinda officinalis (OMO), a systematic study was conducted to provide evidence that supports its use in neuroprotective therapies for Alzheimer's disease (AD). AD rat models were prepared with D-galactose and Aβ_25–35. The following groups were used in the present experiment: normal control group, sham-operated group, model group, Aricept group, OMO low-dose group, OMO medium-dose group, and OMO high-dose group. The effects on behavioral tests, antioxidant levels, energy metabolism, neurotransmitter levels, and AD-related proteins were detected with corresponding methodologies. AD rats administered with different doses of OMO all exhibited a significant (P < 0.05) decrease in latency and an increase (P < 0.05) in the ratio of swimming distance to total distance in a dose-dependent manner in the Morris water maze. There was a significant (P < 0.05) increase in antioxidant enzyme activities (SOD, GSH-Px, and CAT), neurotransmitter levels (acetylcholine, γ-GABA, and NE and DA), energy metabolism (Na⁺/K⁺-ATPase), and relative synaptophysin (SYP) expression levels in AD rats administered with OMO. Furthermore, there was a significant (P < 0.05) decrease in MDA levels and relative expression levels of APP, tau, and caspase-3 in AD rats with OMO. The present research suggests that OMO protects against D-galactose and Aβ_25–35-induced neurodegeneration, which may provide a novel strategy for improving AD in clinic.

CZYH Alleviates β-Amyloid-Induced Cognitive Impairment and Inflammation Response via Modulation of JNK and NF-κB Pathway in Rats

Cu-Zhi-Yi-Hao (CZYH), an empirical formula of traditional Chinese medicine (TCM), has been used for amnesia treatment in clinical practice. However, its underlying pharmacological mechanism has not been fully illuminated. The current study was designed to investigate the neuroprotective effect of CZYH on a β-amyloid 25-35- (Aβ_25-35-) induced learning and memory deficit rat model. CZYH (200, 400, or 800 mg/kg), donepezil (1.0 mg/kg), or distilled water was given to Aβ_25-35-stimulated animals for 17 days consecutively. The Morris water maze test revealed that CZYH (400 or 800 mg/kg) administration improved the Aβ_25-35-induced cognitive impairments in rats, and Nissl staining demonstrated that CZYH mitigated the Aβ-caused neuron loss. In addition, CZYH treatment markedly inhibited the activation of microglia as evidenced by a decreased level of IBA-1 and increased YM-1/2 protein expression. The protein expression levels of TNF-α, IL-1β, and COX-2 were also repressed by CZYH. Besides, CZYH treatment alleviated Aβ-induced IκB-α degradation and NF-κB p65 phosphorylation, as well as reduced the JNK phosphorylation level. In conclusion, the present study suggests that CZYH could improve learning and memory abilities and relieve neuron loss in Aβ_25-35-induced rats, at least partly through inhibition of the neuroinflammatory response via inhibiting the JNK-dependent NF-κB activation, indicating that CZYH might be a promising formula for the treatment of AD.