Effects ofHibiscus sabdariffacalyces on spatial memory and hippocampal expression of BDNF in ovariectomized rats

Ovarian hypofunction is characterized by decay in brain-derived neurotrophic factor (BDNF), a neurotrophin associated with cognitive and memory function. Hormone replacement therapy is the most common treatment to counteract the negative effects of ovarian insufficiency; however, this therapy may increase the odds of endometrial cancer, blood clots, stroke, and breast cancer. Therefore, a safer alternative to synthetic estrogens is needed. One possible candidate may be phytoestrogens.Hibiscus sabdariffaL. (Malvaceae) is a source of natural food colorants; the calyces and leaves of the plant are consumed in drinks and culinary preparations and are recognized for several health benefits related to their high content of anthocyanins. In the present study, we used an ovariectomized rat model to assess the phytoestrogenic effect ofH. sabdariffa, and evaluated spatial memory and BDNF expression. Ninety-day-old female Wistar rats were randomly separated into six groups. Rats from four groups were ovariectomized and injected with a physiological dose of estradiol, or given, in drinking water, an extract prepared from calyces ofH. sabdariffaat doses of 50 or 100 mg/kg body weight. Both Intact and Sham groups were included as controls. At day 42, short- and long-term memories were assessed by the Barnes maze test, and hippocampal BDNF expression was evaluated by RT-qPCR and Western blot. Ovariectomy significantly decreased memory performance and BDNF expression, compared with controls. However, administration ofH. sabdariffaextract reversed the negative effect of ovariectomy on short- and long-term memory parameters and BDNF expression. A stronger effect was observed at a lower dose of the extract. In conclusion, the extract fromH. sabdariffaacted as a phytoestrogen in ovariectomized rats, improving spatial memory performance and hippocampal BDNF expression. Based on these promising results, further clinical experimentation is recommended to study the benefits ofH. sabdariffaas an alternative hormonal therapy in patients with ovarian hypofunction.

Automated summary

Ovarian hypofunction is associated with decreased levels of brain-derived neurotrophic factor (BDNF), and hormone replacement therapy is a common treatment option. However, this therapy has potential risks. Hibiscus sabdariffa may be a safer alternative, as it improves memory and BDNF expression in ovariectomized rats. Further clinical experimentation is recommended to explore the potential benefits of H. sabdariffa as an alternative hormonal therapy for ovarian hypofunction patients.