Decreasing estrogen levels are associated with an increased risk of dementia and Alzheimer’s disease (AD) in postmenopausal women. We used ovariectomized (OVX) rats as a model for postmenopausal women. Our studies showed that a high daily dose of 100 mL/kg body weight of young coconut juice (YCJ) helped prevent AD pathologies. We investigated the optimal dose for the neuroprotective effects of YCJ that would have least side effects following prolonged consumption and the neuroprotective effects of the YCJ acted via choline acetyltransferase (ChAT) and N-methyl-D-aspartate receptors (NMDAR1). Our results showed that rats receiving YCJ at a dose of 10 mL/kg BW/d had the least side effects in their liver and kidney. The ovariectomized rats that were given 10 mL/kg BW/d (OY10) and 20 mL/kg BW/d (OY20) of YCJ demonstrated significantly (p<0.05) higher vaginal scores, as compared to the control ovariectomized (OW) group, showed proestrus and estrus stages continuously throughout the ten weeks. A significant (p<0.05) increase was observed in the number of ChAT-ir, NMDAR1-ir, ERα-ir, and ERβ-ir pyramidal neurons in CA1, CA2 and CA3 hippocampal areas (HP) and prefrontal cortex (PF) brain regions following administration of YCJ. Moreover, there was a significant positive correlation among those number of ChAT-ir, NMDAR1-ir, ERα-ir, and ERβ-ir neurons. Our study indicated that YCJ at the lowest dose of 10 mL/kg BW/day has estrogenic effects using primarily screening vaginal smear, a test of epithelial cell changes in response to alterations in the concentration of the ovarian hormone. The mechanism of YCJ on preserving neuronal cells and prevent Alzheimer’s pathologies, ChAT, and NMDAR1 antibodies were also investigated. Estrogenic effects of YCJ were also confirmed using estrogen receptor (ERα and ERβ) antibodies. In brief, YCJ has neuroprotective effects by preserving ChAT-ir and NMDAR1-ir neurons via ERα and ERβ.
Kolip Payanglee1, Albert M. Hutapea2, Nisaudah Radenahmad1
1 Division of Health and Applied Sciences, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand
2 Department of Pharmacy, Faculty of Science, Universitas Advent Indonesia, Bandung, Indonesia