Prophylactic Melatonin Attenuates Isoflurane‐Induced Cognitive Impairment in Aged Rats through Hippocampal Melatonin Receptor 2 – cAMP Response Element Binding Signalling

Liu, Huan; Ni, Cheng; Li, Zhengqian; Yang, Ning; Zhou, Yang; Rong, Xiaoying; Qian, Min; Chui, Dehua; Guo, Xiangyang

doi:10.1111/bcpt.12652

Cited by 20 publications

(16 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Melatonin is a potent antioxidant with no side effects even in the case of large-scale use. The neural injury models, such as cognitive impairment, exhibited neuroprotective effects (Liu Y. et al, 2013; Liu et al, 2017). Our experimental results also showed that melatonin reduces the cognitive impairment induced by isoflurane exposure.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice

Yuan

Zhai

et al. 2019

Front. Aging Neurosci.

View full text Add to dashboard Cite

Melatonin exerts neuroprotective effects on isoflurane-induced cognitive impairment. However, the underlying mechanism has yet to be elucidated. The present study sought to determine if melatonin confers its beneficial effects by acting on mammalian target of rapamycin (mTOR) and attenuates the neuroinflammation in the hippocampus of aged mice. A total of 72 male C57BL/6 mice, 16-month-old, were randomly and equally divided into six groups: (1) the control group (CON); (2) the rapamycin group (RAP); (3) the melatonin group (MEL); (4) the isoflurane group (ISO); (5) the rapamycin + isoflurane group (RAP + ISO); and (6) the melatonin + isoflurane group (MEL + ISO). RAP, RAP + ISO, MEL, MEL + ISO groups received 1 mg/kg/day mTOR inhibitor rapamycin solution or 10 mg/kg/day melatonin solution, respectively, intraperitoneally at 5:00 p.m. for 14 days consecutively. Mice in the CON and ISO groups were administered an equivalent volume of saline. Subsequently, ISO, RAP + ISO, and MEL + ISO groups were exposed to inhale 2% isoflurane for 4 h; the CON, RAP, and MEL mice received only the vehicle gas. Then, the memory function and spatial learning of the mice were examined via the Morris water maze (MWM) test. mTOR expression was detected via Western blot, whereas the concentration of inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6 and that of melatonin was quantified with enzyme-linked immunosorbent assay (ELISA). Melatonin and rapamycin significantly ameliorated the isoflurane-induced cognitive impairment and also led to a decrease in the melatonin levels as well as the expression levels of TNF-α, IL-1β, IL-6, and p-mTOR in the hippocampus. In conclusion, these results showed that melatonin and rapamycin attenuates mTOR expression while affecting the downstream proinflammatory cytokines. Thus, these molecular findings could be associated with an improved cognitive function in mice exposed to isoflurane.

show abstract

Section: Discussionmentioning

confidence: 99%

“…et al, 2013; Zhang S. et al, 2016). A recent study showed that the level of melatonin in the hippocampus could be increased by the intraperitoneal injection of exogenous melatonin, thereby reducing the degree of cognitive dysfunction (Liu et al, 2017). However, the molecular mechanism of this effect is not yet clarified.…”

Section: Introductionmentioning

confidence: 99%

Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice

Yuan

Zhai

et al. 2019

Front. Aging Neurosci.

View full text Add to dashboard Cite

show abstract

“…Melatonin is the main hormone produced by the pineal gland [ 1 ] and decreases with age in humans [ 2 , 3 ]. Melatonin also phosphorylates CREB, which is correlated with enhancements in learning and memory in mice and rats [ 4 , 5 ]. The phosphorylation of CREB by melatonin is likely mediated through the melatonin receptors, melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2), according to a study of the nervous system [ 6 ].…”

Section: Introductionmentioning

confidence: 99%

The Melatonin Signaling Pathway in a Long-Term Memory In Vitro Study

et al. 2018

View full text Add to dashboard Cite

The activation of cyclic adenosine monophosphate (cAMP) response element-binding protein (CREB) via phosphorylation in the hippocampus is an important signaling mechanism for enhancing memory processing. Although melatonin is known to increase CREB expression in various animal models, the signaling mechanism between melatonin and CREB has been unknown in vitro. Thus, we confirmed the signaling pathway between the melatonin receptor 1 (MT1) and CREB using melatonin in HT-22 cells. Melatonin increased MT1 and gradually induced signals associated with long-term memory processing through phosphorylation of Raf, ERK, p90RSK, CREB, and BDNF expression. We also confirmed that the calcium, JNK, and AKT pathways were not involved in this signaling pathway by melatonin in HT-22 cells. Furthermore, we investigated whether melatonin regulated the expressions of CREB-BDNF associated with long-term memory processing in aged HT-22 cells. In conclusion, melatonin mediated the MT1-ERK-p90RSK-CREB-BDNF signaling pathway in the in vitro long-term memory processing model and increased the levels of p-CREB and BDNF expression in melatonin-treated cells compared to untreated HT-22 cells in the cellular aged state. Therefore, this paper suggests that melatonin induces CREB signaling pathways associated with long-term memory processing in vitro.

show abstract

“…The expression of MT1 in SCN decreases with age, especially in AD [8,31,32]. Through normalizing the MT2, melatonin mediates phase advances in the SCN circadian clock of rats [33], and diminishes the isoflurane-induced cognitive impairment in aged rats [34]. The aforementioned reveals the importance of SCN, MT1, and MT2 on the normalization of the circadian rhythm.…”

Section: Discussionmentioning

confidence: 99%

A Standardized Extract of Asparagus officinalis Stem (ETAS®) Ameliorates Cognitive Impairment, Inhibits Amyloid β Deposition via BACE-1 and Normalizes Circadian Rhythm Signaling via MT1 and MT2

Chan

et al. 2019

Nutrients

View full text Add to dashboard Cite

The prevalence of cognitive impairments and circadian disturbances increases in the elderly and Alzheimer’s disease (AD) patients. This study investigated the effects of a standardized extract of Asparagus officinalis stem, ETAS® on cognitive impairments and circadian rhythm status in senescence-accelerated mice prone 8 (SAMP8). ETAS® consists of two major bioactive constituents: 5-hydroxymethyl-2-furfural (HMF), an abundant constituent, and (S)-asfural, a novel constituent, which is a derivative of HMF. Three-month-old SAMP8 male mice were divided into a control, 200 and 1000 mg/kg BW ETAS® groups, while senescence-accelerated resistant mice (SAMR1) were used as the normal control. After 12-week feeding, ETAS® significantly enhanced cognitive performance by an active avoidance test, inhibited the expressions of amyloid-beta precursor protein (APP) and BACE-1 and lowered the accumulation of amyloid β (Aβ) in the brain. ETAS® also significantly increased neuron number in the suprachiasmatic nucleus (SCN) and normalized the expressions of the melatonin receptor 1 (MT1) and melatonin receptor 2 (MT2). In conclusion, ETAS® enhances the cognitive ability, inhibits Aβ deposition and normalizes circadian rhythm signaling, suggesting it is beneficial for preventing cognitive impairments and circadian rhythm disturbances in aging.

show abstract

Prophylactic Melatonin Attenuates Isoflurane‐Induced Cognitive Impairment in Aged Rats through Hippocampal Melatonin Receptor 2 – cAMP Response Element Binding Signalling

Cited by 20 publications

References 42 publications

Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice

Melatonin and Rapamycin Attenuate Isoflurane-Induced Cognitive Impairment Through Inhibition of Neuroinflammation by Suppressing the mTOR Signaling in the Hippocampus of Aged Mice

The Melatonin Signaling Pathway in a Long-Term Memory In Vitro Study

A Standardized Extract of Asparagus officinalis Stem (ETAS®) Ameliorates Cognitive Impairment, Inhibits Amyloid β Deposition via BACE-1 and Normalizes Circadian Rhythm Signaling via MT1 and MT2

Contact Info

Product

Resources

About