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

Abstract

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.

Keywords: coconut; depression; memory impairment; menopause; ovariectomy; rat.

Figure 1

Body weight (A), ratio of uterus/body weight (B), and ratio of brain/body weight (C) among three groups: sham-operated (Sham), ovariectomized (Ovx), and Ovx rats supplemented with YCJ for 12 weeks (Ovx + YCJ). The values represent the mean ± SEM (n = 9–10 rats per group). * p < 0.05 and ** p < 0.01 compared with the Ovx group, and *** p < 0.001 compared with the Sham group (one-way ANOVA with Tukey’s multiple comparison test). Post hoc power was 0.97 (effect size 0.84) for (A), 1.00 (effect size 1.71) for (B), and 0.91 (effect size 0.74) for (C). YCJ: young coconut juice, SEM: standard error of the mean, ANOVA: analysis of variance.

Figure 2

Assessment of motility based on entry times into each virtual quadrant zone divided by latency time (A), latency time until arriving at the platform over the course of trials (B), and latency time in the final set of trials (C) among three groups: sham-operated (Sham), ovariectomized (Ovx), and Ovx rats supplemented with YCJ for 12 weeks (Ovx + YCJ). The values represent the mean ± SEM (n = 9–10 rats per group). * p < 0.05 compared with the Ovx group (one-way ANOVA with Tukey’s multiple comparison test). Post hoc power was 0.21 (effect size 0.27) for (A) and 0.47 (effect size 0.43) for (C). YCJ: young coconut juice, SEM: standard error of the mean, ANOVA; analysis of variance.

Figure 3

Accumulated immobility time over time (A) and for 5 min (B) among three groups: sham-operated (Sham), ovariectomized (Ovx), and Ovx rats supplemented with YCJ for 12 weeks (Ovx + YCJ). The values represent the SEM (n = 9–10 rats per group). * p < 0.05 compared with the Sham group (one-way ANOVA with Tukey’s multiple comparison test). Post hoc power was 0.56 (effect size 0.48). YCJ: young coconut juice, SEM: standard error of the mean, ANOVA; analysis of variance.