Curcumin limits weight gain, adipose tissue growth, and glucose intolerance following the cessation of exercise and caloric restriction in rats

Abstract

Weight regain, adipose tissue growth, and insulin resistance can occur within days after the cessation of regular dieting and exercise. This phenomenon has been attributed, in part, to the actions of stress hormones as well as local and systemic inflammation. We investigated the effect of curcumin, a naturally occurring polyphenol known for its anti-inflammatory properties and inhibitory action on 11β-HSD1 activity, on preserving metabolic health and limiting adipose tissue growth following the cessation of daily exercise and caloric restriction (CR). Sprague-Dawley rats (6-7 wk old) underwent a "training" protocol of 24-h voluntary running wheel access and CR (15-20 g/day; ~50-65% of ad libitum intake) for 3 wk ("All Trained") or were sedentary and fed ad libitum ("Sed"). After 3 wk, All Trained were randomly divided into one group which was terminated immediately ("Trained"), and two detrained groups which had their wheels locked and were reintroduced to ad libitum feeding for 1 wk. The wheel locked groups received either a daily gavage of a placebo ("Detrained + Placebo") or curcumin (200 mg/kg) ("Detrained + Curcumin"). Cessation of daily CR and exercise caused an increase in body mass, as well as a 9- to 14-fold increase in epididymal, perirenal, and inguinal adipose tissue mass, all of which were attenuated by curcumin ( P < 0.05). Insulin area under the curve (AUC) during an oral glucose tolerance test, HOMA-IR, and C-reactive protein (CRP) were elevated 6-, 9-, and 2-fold, respectively, in the Detrained + Placebo group vs. the Trained group (all P < 0.05). Curcumin reduced insulin AUC, HOMA-IR, and CRP vs. the placebo group (all P < 0.05). Our results indicate that curcumin has a protective effect against weight regain and impaired metabolic control following a successful period of weight loss through diet and exercise, perhaps via inhibition of glucocorticoid action and inflammation. NEW & NOTEWORTHY Weight regain after dieting and exercise is a common phenomenon plaguing many individuals. The biological mechanisms underlying weight regain are incompletely understood and are likely multifactorial. In this paper, we examined the metabolic implications of curcumin, a compound known for its anti-inflammatory properties and inhibitory action on the enzyme 11β-HSD1, in a rodent model of adiposity rebound after the cessation of diet and exercise.

Skeletal muscle ceramides do not contribute to physical inactivity-induced insulin resistance

“…Using this model in mice, we observed that 10 days of physical inactivity are sufficient to induce hyperinsulinemia and to increase the HOMA-IR, both considered as hallmarks of insulin resistance (Singh and Saxena, 2010). These results are in accordance with previous studies conducted in Sprague-Dawley or OLETF rats after 7 days of wheel lock (Rector et al, 2010, 2008; Teich et al, 2017). Few data are available about the effects of the wheel lock model on glucose tolerance.…”

Skeletal muscle ceramides do not contribute to physical-inactivity-induced insulin resistance

“…Using this model in mice, we observed that 10 days of physical inactivity are sufficient to induce hyperinsulinemia and to increase the HOMA-IR, both considered as hallmarks of insulin resistance (Singh and Saxena, 2010). These results are in accordance with previous studies conducted in Sprague-Dawley or OLETF rats after 7 days of wheel lock (Rector et al, 2010(Rector et al, , 2008Teich et al, 2017). Few data are available about the effects of the wheel lock model on glucose tolerance.…”

“…Few data are available about the effects of the wheel lock model on glucose tolerance. Teich and colleagues recently observed that 7 days of wheel lock were sufficient to affect glucose tolerance in young Sprague-Dawley male rats (Teich et al, 2017). In the present study, we did not report an effect on glucose tolerance after 10 days of wheel lock.…”

Curcumin reduces inflammation in knee osteoarthritis rats through blocking TLR4 /MyD88/NF‐κB signal pathway

“…Two weeks after injection with MIA, 200 mg/kg curcumin (Sigma, St. Louis, USA) dissolved in 1 mL saline were intraperitoneally injected in OA + curcumin group for 14 consecutive days. The duration time and doses of curcumin were based on previous studies (Cai et al, ; Kelany, Hakami, & Omar, ; Teich, Pivovarov, Porras, Dunford, & Riddell, ). The OA + PBS group was intraperitoneally injected with equal volume of saline.…”