Alzheimer's disease (AD) is a progressive disorder that affects the brain and leads to cognitive decline and memory loss, with postmenopausal women being unduly affected. Estrogen is believed to exert Show more
Alzheimer's disease (AD) is a progressive disorder that affects the brain and leads to cognitive decline and memory loss, with postmenopausal women being unduly affected. Estrogen is believed to exert neuroprotective effects by influencing amyloid-beta accumulation, tau hyperphosphorylation, oxidative stress, synaptic function, neuroinflammation, and brain-derived neurotrophic factor (BDNF) signalling. This review examines the role of estrogen in AD pathogenesis among postmenopausal women. A systematic literature search was conducted using PubMed, Scopus, and Web of Science. Keywords included "estrogen", "Alzheimer's disease", "neuroprotection", "amyloid-beta," and "BDNF." Inclusion criteria were peer-reviewed studies from the past 10 years focusing on estrogen's effects on AD mechanisms, neurobiology, and therapeutic relevance. Articles were screened by title and abstract. Followed by a full-text review to ensure methodological rigour and relevance. Evidence indicates that estrogen reduces amyloid beta burden, inhibits tau phosphorylation, mitigates oxidative stress, preserves synaptic connectivity, and suppresses neuroinflammation. Estrogen also modulates ApoE-linked lipid metabolism and enhances BDNF signalling, supporting neuronal survival and cognitive resilience. Declining estrogen after menopause increases vulnerability to AD. Understanding estrogen's neuroprotective mechanisms may support targeted therapeutic strategies. Hormone replacement therapy (HRT) and selective estrogen receptor modulators (SERMs) show potential, but further research is needed to optimise timing, dosage, and patient selection in postmenopausal AD prevention and management. Show less
In the present study, a comparative global high-throughput proteomic analysis strategy was used to identify proteomic differences between estrus and diestrus stage of estrous cycle in dairy cows. Sali Show more
In the present study, a comparative global high-throughput proteomic analysis strategy was used to identify proteomic differences between estrus and diestrus stage of estrous cycle in dairy cows. Saliva was collected from cows during estrus and diestrus, and subjected to LC-MS/MS-based proteomic analysis. A total of 2842 proteins were detected in the saliva of cows, out of which, 2437 and 1428 non-redundant proteins were identified in estrous and diestrous saliva, respectively. Further, it was found that 1414 and 405 salivary proteins were specific to estrus and diestrus, respectively while 1023 proteins were common to both groups. Among the significantly dysregulated proteins, the expression of 56 proteins was down-regulated (abundance ratio <0.5) while 40 proteins were up-regulated (abundance ratio > 2) in estrous compared to diestrous saliva. The proteins, such as HSD17B12, INHBA, HSP70, ENO1, SRD5A1, MOS, AMH, ECE2, PDGFA, OPRK1, SYN1, CCNC, PLIN5, CETN1, AKR1C4, NMNAT1, CYP2E1, and CYP19A1 were detected only in the saliva samples derived from estrous cows. Considerable number of proteins detected in the saliva of estrous cows were found to be involved in metabolic pathway, PI3K-Akt signaling pathway, toll-like receptor signaling pathway, steroid biosynthesis pathway, insulin signaling pathway, calcium signaling pathway, estrogen signaling pathway, oxytocin signaling pathway, TGF-β signaling pathway and oocyte meiosis. On the other hand, proteins detected in saliva of diestrous cows were involved mainly in metabolic pathway. Collectively, these data provide preliminary evidence of a potential difference in salivary proteins at different stages of estrous cycle in dairy cows. Show less