To investigate the effect of hawthorn procyanidins (HPC) on lipid metabolism and its mechanism by regulating the AMP-activated protein kinase/sterol regulatory element binding protein-1c (AMPK/SREBP-1c) signaling pathway.

Sixty rats were randomly divided into six groups (n = 10) blank control (BC), hyperlipidemia model (HM), low-, medium-, and high-dose HPC (HPC-LD, HPC-MD, and HPC-HD) and fenofibrate positive control (FP). The contents of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in the serum and liver homogenate were measured by commercial kits. Hematoxylin eosin (HE) staining was used to observe hepatic histopathological changes. The mRNA expression levels of AMPK, SREBP-1c, glycerol-3-phosphate acyltransferase-1 (GPAT1), acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), carnitine palmitoyltransterase-1 (CPT1) and peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α) in the liver were measured by quantitative real-time polymerase chain reaction (PCR). Western blotting was used to detect the protein expression of p-AMPK, SREBP-1c, GPAT1, ACC, FAS, CPT1 and PGC-1α in the liver.

After seven weeks of feeding on a high-fat diet, body mass, liver mass and liver index significantly increased compared with the control group fed on a basal diet (P < 0.05 or < 0.01). Compared with the HM group, the contents of TG, TC and LDL-C in serum and liver homogenate in the HPC-HD and FP groups significantly decreased, and the content of HDL-C significantly increased (P < 0.01); the effect of HPC on lipid content in serum and liver homogenate was dose-dependent. After prophylactic intervention with HPC, the steatosis of hepatocytes was gradually improved with an increase in the dosage of HPC. Compared with the HM group, the AMPK mRNA expression and p-AMPK protein expression in liver tissues in the HPC-HD and FP groups significantly increased (P < 0.01), and the mRNA and protein expression of SREBP-1c, GPAT1, ACC and FAS significantly decreased (P < 0.01), and the mRNA and protein expression of CPT1 and PGC-1α significantly increased in the liver (P < 0.01).

HPC can effectively improve lipid metabolism in hyperlipidemic rats, which may be related to the regulation of the AMPK/SREBP-1c signaling pathway.

To investigate the molecular mechanism underlying the protective effect of Solanum tuberosum anthocyanin (STA) on radiation-induced hematopoietic stem/progenitor cell senescence.

C57BL/6 mice were randomly divided into three groups: control, model, STA treatment and STA prevention, and the cell senescence model was constructed by X-ray irradiation. The hemogram of mice in each group were examined using a hematology analyzer after drug administration. Stem cell antigen 1 positive hematopoietic stem/progenitor cells (Sca-1⁺HSC/HPCs) were isolated and purified from each group by immunomagnetic cell sorting and were stained using a senescence-associated β-galactosidase (SA-β-Gal) kit to calculate the proportion of SA-β-Gal positive cells. The number of mixed lineage colony forming unit (CFU-Mix) was used to evaluate the colony-forming capacity and differentiation potential of hematopoietic stem/progenitor cells. Cell cycle was analyzed by flow cytometry. The mRNA and protein expression of p53 and p21^Waf1/Cip1 were detected by quantitative real-time polymerase chain reaction (qPCR) and Western blot.

The numbers of red blood cells (RBCs), white blood cells (WBCs) and platelets in the peripheral blood were significantly lower in the model group than in the control group (P < 0.01). In addition, compared with the control group, the proportion of SA-β-Gal positive cells significantly increased (P < 0.01), the number of CFU-Mix significantly fell (P < 0.01), the proportion of G0/G1 phase cells significantly increased, the proportions of G2/M and S phase cells significantly dropped (P < 0.01), and the relative mRNA and protein expression levels of p53 and p21^Waf1/Cip1 significantly increased in the model group (P < 0.01). STA could significantly restore the above parameters of mice in the model group irrespective of whether it was administered before or after X-ray radiation, with more pronounced effect being observed in the former case.

STA can protect hematopoietic stem/progenitor cells against radiation by regulating the p53-p21^Waf1/Cip1 pathway.