Studies carried out on leguminous plants of the genus Pueraria showed that some species of this genus are endowed with oestrogenic properties and are able to relieve some menopausal symptoms. The aim of thiswork was to assess the potential health benefit of Pueraria phaseoloides in ovariectomized rats, an experimental model of menopause. Ovariectomized Wistar rats were treated for 3-days with aqueous (AE) and dichloromethane/methanol (DCM/MeOH) extracts of Pueraria phaseoloides, following the 14-days interval necessary for functionally perceptible oestrogen decline. Oestrogen-like effects were assessed on primary oestrogen target organs, while anxiolytic properties were evaluated with help of the elevated plus-maze (EPM) and the open field (OF) tests. Then, the effects of extracts on hot flushes were evaluated using data loggers. The DCM/MeOH extract (dose 500 mg/kg) significantly increased the uterine epithelial thickness (p < 0.05). Both AE and DCM/MeOH extracts induced the differentiation of the acini, and led to an increase in eosinophilic secretary granules in mammary gland sat all doses tested. Pueraria phaseoloides induced an increase in the percentages of time spent and number of entries in the open arms of the EPM, in the time spent at the centre of the arena in the OF test. The most pronounced anxiolytic effects were induced by AE at the doses 150 and 300 mg/kg. Instead, the DCM/MeOH extract had the strongest oestrogen-like effects and reduced significantly the total number (p < 0.05, p < 0.01), the frequency of hot flushes (at all the doses tested), and their average duration at 300 mg/kg (p < 0.01). Our results suggest that Pueraria phaseoloides has oestrogenic properties and can correct various physiological alterations related to oestrogen depletion in ovariectomized rats, possibly through oestrogenic pathway.

Abstract:On study of the effects of estrogen deficiency on anxiety disorder by using ovariectomised animals, one discrepancy was the difference in behavioral testing delay following ovariectomy and the paradigms used. Thus, the aim of this study was to evaluate the anxiogenic effects of fourteen-day estrogen decline subsequent to ovariectomy on Wistar rats using EPM (elevated plus-maze) and open field tests. As results, fourteen days of estrogens decline has induced an increase of anxiety-related behaviour by a reduction of the percentage of the number of entries into the open arm (p < 0.01) and an increase of the percentage of the number of entries into the closed arm (p < 0.01) during the elevated plus-maze test. This anxiety-like behaviour was confirmed on the open field test by a reduction of time spent in the centre of the arena (p < 0.05) as well as a reduction of crossing (p < 0.05) and an increase of the weight of faecal boli (p < 0.05) and grooming (p < 0.01). Meanwhile, the administration of diazepam or estradiol valerate (1 mg/kg BW each) has corrected the anxious-like behaviour in both tests paradigms. These results suggest that fourteen days of estrogens decline was associated with an anxiety-related behaviour. This experimental model can constitute an excellent tool for the study of anxiolytic substances in menopause-related anxiety.