Preliminary phytochemical analysis and the effect of Agave sisalana on body weight and defensive behaviours in ovariectomized rats

摘要

Agave sisalana is a plant belonging to the Agavaceae family. Sisal juice is constituted of steroidic saponins which are precursor molecules of many pharmacologically active steroids. These precursor molecules can act in brain structures that are related to the modulation of emotional disorders. They can act on energy metabolism or directly on the absorptive process of fats. The objective of this research was to identify the biocompounds present in A. sisalana juice, and to evaluate the effect of different extracts on the expression of defensive behaviours of rats in elevated plus maze and open field tests, and body weight, in a condition that corresponds to an induced menopause. Wistar rats were subjected to bilateral ovariectomy or to a sham surgical procedure under anaesthesia. Following surgery, they were treated gavage with sisal juice - concentrated crude juice (CCJ): 500 or 1000 mg/kg; dried extract (DE): 50, 100 or 200 mg/kg; dry mucilage extract (DME): 25, 50 or 100 mg/kg; and intermediate product (IP): 25, 50 or 100 mg/kg; or distilled water. The results showed the presence of coumarins, flavonoids, condensed tannins, free anthraquinones, alkaloids and saponins in the sisal juice. Both CCJ and DE (100 mg/kg) caused weight loss without alteration of defensive behaviours related to the manifestation of anxiety. As saponins were identified in DE in significant amounts, the observed effects were attributed to this component. Such findings point to A. sisalana as a plant that could potentially be used to treat weight gain during menopause.