Triglyceride accumulation: inhibitory effects of tangzhiqing formula.

The tangzhiqing formula (TZQ-F) is a traditional antidiabetic prescription that includes red peony root, mulberry leaf, lotus leaf, danshen root, and hawthorn leaf. The research team's previous study showed that the TZQ-F had beneficial effects on abnormal glucose and lipid metabolism.This study was aimed at investigating TZQ-F's mechanism of lipid metabolism to evaluate its inhibitory effect on triglyceride (TG) accumulation.This study included both an in vivo and an in vitro component. For the in vivo study, C57BL/6 mice were used as the normal control group, and KK-A(y) mice were divided into five groups: (1) model control group, (2) positive control group (10 mg/kg/d rosiglitazone), (3) 500 mg/kg/d TZQ-F treated KK-A(y) mice, (4) 200 mg/kg/d TZQ-F treated KK-A(y) mice, and (5) 100 mg/kg/d TZQ-F treated KK-A(y) mice. For the in vitro study, 3T3-L1 cells were divided into the following: (A) red peony total saponins, (B) danshen total polyphenols, (C) lotus leaf total flavonoids, (D) lotus leaf total alkaloids, (E) mulberry leaf total flavonoids, (F) mulberry leaf total alkaloids, (G) mulberry leaf polysaccharide, and (H) hawthorn leaf total flavonoids, and (I) tangzhiqing formula, including a normal group (NG) and a model control group (CG).This study occurred at Tianjin University of Traditional Chinese Medicine (TUTCM), Tianjin, China.TZQ-F, suspended either in a 5% acacia solution and a vehicle (5% acacia solution) were given orally to the KK-A(y) mice once/d (16:00-17:00) for 4 wk.RT-PCR and a Western blot analysis were used to detect gene and protein expression respectively.The in vivo study showed that TZQ-F significantly reduced body weight without changing food intake in KK-A(y) mice and significantly decreased the levels of serum glucose (GLU), triglycerides (TG), and free fatty acids (FFA). TZQ-F significantly increased expression of AMP-activated protein kinase (AMPK) and phosphorylation of AMPK in the liver and muscle tissues of the KK-A(y) mice. TZQ-F significantly decreased expression of acetyl-CoA carboxylase (ACC), fatty-acid synthase (FAS), hormone-sensitive lipase (HSL), and tumor necrosis factor-α (TNF-α) in the liver and muscles. It also significantly decreased expression of sterol regulatory element binding protein-1c (SREBP-1c) while it significantly increased expression of glucose transporter type 4 (GLUT-4). The in vitro study showed that TZQ-F significantly suppressed the accumulation of TG and FFA in mature adipocytes and similarly increased expression of AMPK and peroxisome proliferator-activated receptors-α (PPAR-α) and phosphorylation of AMPK, while it decreased expression of ACC, FAS, HSL, and SREBP-1c.The findings partly clarified the inhibitory effects of TZQ-F on TG accumulation related to the AMPK signaling pathway.