Neuroprotective Effects of OMO within the Hippocampus and Cortex in a D‐Galactose and Aβ_25–35‐Induced Rat Model of Alzheimer’s Disease

Abstract

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 Aβ25–35. 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 Aβ25–35-induced neurodegeneration, which may provide a novel strategy for improving AD in clinic.

Traditional Chinese Medicine as a Promising Strategy for the Treatment of Alzheimer’s Disease Complicated With Osteoporosis

“…After the administration of MO aqueous extracts for 4 weeks, it was observed that MO significantly improved the learning and memory ability in a water maze test, significantly reduced the activity of aldose reductase, decreased the serum advanced glycosylation end products (AGEs) and receptor for advanced glycosylation end products (RAGEs), and then decreased the damage to brain cells ( Ye et al, 2015 ). In D-galactose and Aβ 25-35 -induced AD rats, different doses of MO also significantly increased the antioxidant enzyme activities (SOD, GSH-Px, and CAT), neurotransmitter levels (acetylcholine, gamma-aminobutyric, and dopamine), energy metabolism (Na + /K + -ATPsae), and relative synaptophysin expression levels ( Deng et al, 2020 ). Furthermore, there was a significant decrease in MDA levels and relative expression levels of APP, tau, and caspase-3 in AD rats after treatment with MO.…”

Neuroprotective effects of Morinda officinalis How.: Anti-inflammatory and antioxidant roles in Alzheimer’s disease

“…A recent study revealed that OMOs can significantly enhance learning and memory abilities and alleviate symptoms of dementia ( Chen et al, 2013b ). Deng et al (2020) further explored the pharmacological effects of these oligosaccharides in a D -galactose- and Aβ 25–35-induced rat model of AD and found that OMOs exerted neuroprotective effects via antioxidant-related mechanisms in the hippocampus and cortex of AD rats. Furthermore, in a rat model of AD, OMOs were shown to alleviate oxidative damage in the brain, and oligosaccharides significantly increased in the activities of CAT, SOD, and glutathione peroxidase in the hippocampus, while decreasing the content of malondialdehyde.…”

“…Furthermore, in a rat model of AD, OMOs were shown to alleviate oxidative damage in the brain, and oligosaccharides significantly increased in the activities of CAT, SOD, and glutathione peroxidase in the hippocampus, while decreasing the content of malondialdehyde. In addition to protecting brain tissues from oxidative damage, OMOs may protect against D -galactose- and Aβ25–35-induced AD by increasing neurotransmitter levels and relative synaptophysin expression levels in AD model rats; thus, OMOs may represent a novel strategy for alleviating symptoms of AD in the clinical setting ( Deng et al, 2020 ).…”

“…A recent study revealed that OMOs can significantly enhance learning and memory abilities and alleviate symptoms of dementia (Chen et al, 2013b). Deng et al (2020) further explored the pharmacological effects of these oligosaccharides in a D-galactose-and Aβ 25-35-induced rat model of AD Antioxidative and Anti-inflammatory activities of Morinda officinalis How. (MO) and its main components.…”

Tenuifolin in the prevention of Alzheimer's disease‐like phenotypes: Investigation of the mechanisms from the perspectives of calpain system, ferroptosis, and apoptosis

“…The combined AD model based on d ‐galactose ( d ‐gal)‐induced aging and Aβ 1–42 toxicity can simulate the multifactorial pathogenic characteristics of AD, which has become a hot spot in current AD model research (Deng et al, 2020; Ye et al, 2020). In the present study, we adopted a systematic exploration of the multi‐scale mechanism to investigate the treatment effect of Ten on AD, which combined the target prediction, network pharmacology, and functional bioinformatics analysis.…”