Abstract

Background: This study investigated the combined effects of phenolic and phytoestrogen compounds in Ochna schweinfurthianaon oral glucose tolerance in an ovariectomized rat model of menopause.
Methods: Pulverized root powder of Ochna schweinfurthiana was extracted with methanol, and the extract was partitioned into hexane, ethyl acetate, butanol, and water fractions. The total phenolic and phytoestrogen contents of the extracts and fractions were tested. Ovariectomy was performed via surgical excision of the ovaries along the upper horn. One hour after administration of the combined phytoestrogen- and phenol-rich fractions to the ovariectomized animals, they were administered 2 g/kg D-glucose (p.o). Blood samples were collected at 15, 30, 45, 60, 90, and 120 min after glucose administration to determine the blood glucose concentration. Phytoestrogen: phenol combination groups of five animals received phytoestrogen (PE) 132: Phenol (PH) 251 mg/kg and PE 160: PH 130 mg/kg phytoestrogen and phenol rich fraction combinations, respectively.
Results: The extract contained a considerable quantity of total phenol (142.16 mgGAE/g), which partitioned mostly into the ethyl acetate fraction (phenol-rich fraction), while phytoestrogens were concentrated in the water fraction. The Area under the blood glucose curve (AUC) of the vehicle control group was the highest (27645 mg x min/dl) compared to that of the treatment groups. PE 132:PH 251 mg/kg and PE 160: PH 130 mg/kg recorded 17810 and 16188 mg x min/dl respectively which were lower than the value (18804 mg x min/dl) recorded for the reference drug (estradiol). Conclusion: The combination of phenolic and phytostrogen phytocompounds in Ochna schweinfurthiana improved glucose tolerance, which was impaired by ovariectomy.

Key words: Phenolic compounds, Phytoestrogens, Ovariectomized, Glucose tolerance, Ochna swienfurthiana, Menopause, Insulin sensitivity