Young Coconut Juice Reduces Some Histopathological Changes Associated with Alzheimer's Disease through the Modulation of Estrogen Receptors in Orchidectomized Rat Brains

Administration of Young Coconut (Cocos nucifera L.) Juice Ameliorates Memory Impairment in a Menopausal Rat Model

BACKGROUND/OBJECTIVES

In Southeast Asia, the traditional use of young coconut (Cocos nucifera L.) juice (YCJ) by women to alleviate postmenopausal symptoms suggests potential estrogenic properties. However, few studies explore the impact of YCJ on pathologies associated with estrogen deficiency in postmenopausal animal models. This study examines the impact of YCJ supplementation on memory impairment and depression-like behavior in ovariectomized (Ovx) rats.

METHODS

Ten-week-old female rats underwent either a sham operation (Sham) or bilateral Ovx. The rats in the Ovx + YCJ group received 5×-concentrated YCJ by gavage at a dose of 15 mL/kg body weight. Twelve weeks later, the Morris water maze and forced swim tests were used to evaluate hippocampus-dependent spatial memory and depression-like behavior, respectively.

RESULTS

The Ovx rats displayed significant memory impairment (p < 0.05) and depression-like behaviors (p < 0.05), while the memory performance in the rats in the Ovx + YCJ group resembled that of the Sham rats. However, the administration of YCJ did not result in the improvement of depression-like behavior.

CONCLUSIONS

These findings suggest that YCJ consumption may help ameliorate memory impairment in postmenopausal women.

Estrogen Receptors: A New Frontier in Alzheimer's Disease Therapy

Alzheimer's disease (AD) is a long-term neurodegenerative condition that leads to the deterioration of neurons and synapses in the cerebral cortex, resulting in severe dementia. AD is significantly more prevalent in postmenopausal women, suggesting a neuroprotective role for estrogen. Estrogen is now known to regulate a wide array of physiological functions in the body by interacting with three known estrogen receptors (ERs) and with the β-amyloid precursor protein, a key factor in AD pathogenesis. Recent experimental evidence indicates that new selective ER modulators and phytoestrogens may be promising treatments for AD for their neuroprotective and anti-apoptotic properties. These alternatives may offer fewer side effects compared to traditional hormone therapies, which are associated with risks such as cardiovascular diseases, cancer, and metabolic dysfunctions. This review sheds light on estrogen-based treatments that may help to partially prevent or control the neurodegenerative processes characteristic of AD, paving the way for further investigation in the development of estrogen-based treatments.

Estrogen signaling via estrogen receptor alpha and its implications for neurodegeneration associated with Alzheimer's disease in aging women

Estrogen receptor alpha (ERα) is a transcription factor activated by estrogenic hormones to regulate gene expression in certain organs, including the brain. In the brain, estrogen signaling pathways are central for maintaining cognitive functions. Herein, we review the neuroprotective effects of estrogens mediated by ERα. The estrogen/ERα pathways are affected by the reduction of estrogens in menopause, and this event may be a risk factor for neurodegeneration associated with Alzheimer's disease in women. Thus, developing a better understanding of estrogen/ERα signaling may be critical for defining new biomarkers and potential therapeutic targets for Alzheimer's disease in women.

Estrogenic hormones receptors in Alzheimer's disease

Estrogens are hormones that play a critical role during development and growth for the adequate functioning of the reproductive system of women, as well as for maintaining bones, metabolism, and cognition. During menopause, the levels of estrogens are decreased, altering their signaling mediated by their intracellular receptors such as estrogen receptor alpha and beta (ERα and ERβ), and G protein-coupled estrogen receptor (GPER). In the brain, the reduction of molecular pathways mediated by estrogenic receptors seems to favor the progression of Alzheimer's disease (AD) in postmenopausal women. In this review, we investigate the participation of estrogen receptors in AD in women during aging.