Abstract
Current cholinesterase inhibitors such as donepezil are limited by adverse effects including agitation and sleep disturbance. Nutmeg, Myristica fragrans Houtt., seed oil and green tea, Camellia sinensis (L.) Kuntze, infusion containing pro-cognitive constituents, have been proposed to act synergistically while balancing sedation. This study evaluated their cognitive and sedative effects, alone and combined, in scopolamine-induced dementia mice. Thirty male mice were assigned to six groups (n = 5): normal, negative control (scopolamine 1 mg/kg), positive control (donepezil 3 mg/kg), nutmeg seed oil (200 µL/kg), green tea infusion (200 mg/kg), or their combination, given 30 minutes before scopolamine. Spatial learning and memory were assessed by the Morris water maze (5-day acquisition, probe test), and locomotor activity and sedation by the open field test (ToxTrac). Data were analysed using Wilcoxon signed-rank, Kruskal-Wallis, and Mann-Whitney U tests. Nutmeg seed oil alone produced the greatest cognitive improvement (Δ = 23.33 s; 35.00% time in target quadrant), comparable to donepezil and significantly better than the negative control (P = 0.008). The combination improved memory but did not exceed nutmeg seed oil alone (P = 0.095) and remained inferior to donepezil (P = 0.032), indicating no synergy. Green tea alone was least effective, reflecting a degrading infusion procedure (90 °C, 15 min). The combination showed intermediate locomotor activity. Nutmeg seed oil alone, not combined with green tea, is the more promising pro-cognitive candidate in scopolamine-induced dementia mice. Combination re-evaluation requires optimised green tea extraction and mechanistic confirmation.