Effects of blueberry anthocyanidin on dyslipidemia, proinflammatory cytokines and insulin sensitivity in high-fat-diet induced obese rats

Objective To investigate the effect of blueberry anthocyanidin on serum lipid profiles, proinflammatory cytokines and insulin sensitivity in high-fat-diet induced obese rats. Methods Male Sprague-Dawley rats were randomly grouped to receive a standard chow diet(control group, 7 cases) or high-fat-diet(23 cases). Six weeks later, high-fat-diet induced obese rats were divided into the 2 groups.Then, rats received a standard chow diet, a high-fat-diet, or a high-fat-diet supplemented with anthocyanidin extracted from blueberry at 200 mg/(kg·d) for 4 weeks, and were then euthanized.Parameters of body weight, visceral adipose tissue, serum glucose, insulin, total cholesterol(TC), triglyceride(TG), low-density lipoprotein(LDL), high-density lipoprotein(HDL), tumor necrosis factor-α(TNF-α), interleukin-6(IL-6), high sensitive C-reactive protein(hs-CRP) and homeostasis model assessment insulin resistance(HOMR-IR) were measured. Results The levels of glucose [(9.15±1.10) mmol/L], TC[(462.5±81.5) mg/L], TG[(152.5±19.1) mg/L], LDL[(203.7±31.1) mg/L], TNF-α[(4.03±1.03) ng/L], IL-6[(1.81±0.31) ng/L], hs-CRP[(106.62±15.52) ng/L] and HOMA-IR(3.94±0.78)in blueberry anthocyanidin group were lower than those in the obese rats [(11.38±1.50)mmol/L, (566.2±113.2) mg/L, (192.5±24.9) mg/L, (253.7±58.3) mg/L, (5.74±1.61) ng/L, (3.85±0.93) ng/L, (132.62±17.18) ng/L, 5.09±0.90], and the differences were significant(all P 0.05). The level of HOMA-IR index was positively correlated with serum glucose, TC, TG, LDL, TNF-α, IL-6, and hs-CRP(r=0.733, 0.668, 0.602, 0.607, 0.683, 0.728, 0.784, 0.907 and 0.743, all P<0.01). The level of HOMA-IR index was negatively correlated with HDL(r=-0.581, P<0.01). Conclusions Blueberry anthocyanidin enhances insulin sensitivity, which may be associated with the amelioration of the dyslipidemia and the less severe inflammation in high-fat-diet induced obese rats. Key words: Anthocyanidin; Insulin resistance; Dyslipidemia; Inflammation; Obesity; Rat