Effect of red rooibos tea supplementation on body composition and metabolism in ovariectomized Sprague-Dawley rats

Abstract

Through menopause, increases in visceral adipose tissue (VAT), reductions in lean mass, and decreases in energy expenditure are observed. These changes have been linked to increases in inflammation and oxidative stress that occur alongside the decline in ovarian estrogen production. The objective of this study was to determine if red rooibos (RR), a polyphenol-rich tea, can ameliorate changes to body composition and metabolic outcomes in the ovariectomized (OVX) rat model. 56 female, 6-month-old, Sprague-Dawley rats were randomly assigned to 4 groups (n=14 per group): SHAM-WATER, SHAM-RR, OVX-WATER and OVX-RR. Prior to assigned surgeries, body composition was assessed via dual energy X-ray absorptiometry (DXA) (iNSiGHT, Osteosys) and metabolic measures were recorded via Promethion metabolic caging system. The intervention (2.6 g RR/kg body mass, prepared in distilled water) was provided ad libitum for 12 weeks. As expected, OVX rats accumulated a higher whole-body fat mass %, lower lean mass %, and a higher body mass when compared to SHAM rats (p<0.05). At endpoint, OVX rats had a higher ovarian adipose depot mass (p=0.012) and inguinal adipose depot mass (p<0.001), with a trend for reduced brown adipose depot mass (p=0.072). All measures were standardized to body mass, respectively. OVX rats consumed a greater amount of food over time compared to the SHAM rats (p<0.05). SHAM rats consumed a greater quantity of fluid, regardless of whether they received water or RR (p<0.05). RR intervention did not attenuate the changes to body composition or metabolic outcomes observed in the OVX group. Moreover, this study provided a robust overview of the many physiological and metabolic changes that occur 12-weeks post-OVX.