Curcuma comosa improves learning and memory function on ovariectomized rats in a long-term Morris water maze test

Aim of the studyCurcuma comosa extract and some purified compounds from this plant have been reported to have estrogenic-like effects, and estrogen improves learning in some animals and potentially in postmenopausal women; therefore, this study tested the hypothesis that Curcuma comosa and estrogen have similar beneficial effects on spatial learning and memory.Materials and methodsCurcuma comosa hexane extract, containing 0.165 mg of (4E,6E)-1,7-diphenylhepta-4,6-dien-3-one per mg of the crude extract, was orally administered to ovariectomized Wistar rats at the doses of 250 or 500 mg/kg body weight. 17β-estradiol (10 μg/kg body weight, subcutaneously) was used as a positive control. Thirty days after the initiation of treatment, animals were tested in a Morris water maze for spatial learning and memory. They were re-tested every 30 days and a final probe trial was run on day 119.ResultsCompared to control rats, OVX rats displayed significant memory impairment for locating the platform in the water maze from day 67 after the surgery, onward. In contrast, OVX rats treated with either Curcuma comosa or estrogen were significantly protected from this decline in cognitive function. Further, the protection of cognitive effects by Curcuma comosa was larger at higher dose.ConclusionsThese results suggest that long-term treatment with Curcuma comosa has beneficial effects on learning and memory function in rats.

Graphical abstractOVX rats displayed significant memory impairment for locating the platform in the water maze from day 67 after the surgery. Curcuma comosa hexane extract, containing 0.165 mg of (4E,6E)-1,7-diphenylhepta-4,6-dien-3-one per mg of the crude extract, was administered to the OVX rats at the doses of 250 and 500 mg/kg body weight. The administration significantly protected the decline in cognitive function of OVX rats. The effects were similar to the estrogen did.Figure optionsDownload full-size imageDownload as PowerPoint slide