Platelet-rich plasma (PRP) has become an important regenerative therapy. However, the preparation method of PRP has not been standardized, and the optimal platelet concentration for PRP used in skin wound repair is unclear, leading to inconsistent clinical efficacy of PRP. Therefore, the development of standardized preparation methods for PRP and the investigation of the dose-response relationship between PRP with different platelet concentrations and tissue regeneration plays an important role in the development and clinical application of PRP technology. This study has developed an integrated blood collection device from blood drawing to centrifugation. Response surface methodology was employed to optimize the preparation conditions, ultimately achieving a platelet recovery rate as high as 95.74% for PRP (with optimal parameters: centrifugation force 1730× g, centrifugation time 10 min, and serum separation gel dosage 1.4 g). Both in vitro and in vivo experimental results indicate that PRP with a (2×) enrichment ratio is the most effective in promoting fibroblast proliferation and skin wound healing, with a cell proliferation rate of over 150% and a wound healing rate of 78% on day 7.

It has been demonstrated in some studies that triterpenoid acid extract fromEriobotrya japonica leaf is beneficial to prevent hyperlipidemia or insulin resistance. However, the effect of triterpenoid acids in Eriobotrya japonica leaf on a series of typical symptoms of metabolic syndrome (MetS) has been rarely studied systematically. Therefore, the present study aims to systematically evaluate the effect of Eriobotrya japonica leaf triterpenoid acids (ELTA) on MetS and explore its potential mechanism. ELTA (HPLC purity 95.2 %) was prepared and administered orally (200 mg/kg) to C57BL/6 J mice fed with a high-fat diet (HFD) for 12 weeks. Pioglitazone (30 mg/kg) was used as a positive control drug. Food intake, body weight, total lipid in feces, lipid profiles, inflammatory factors in serum, hepatic glutathione, and lipid peroxide were measured. Oral glucose tolerance test (OGTT) and insulin tolerance test (ITT) were performed to evaluate insulin sensitivity. RT-qPCR and molecular docking were performed to explore the potential mechanism. ELTA administration reduced body weight gain, relative liver weight, and relative visceral adipose weight. The levels of serum total cholesterol, triglycerides, low-density lipoprotein cholesterol, hepatic total cholesterol, and hepatic triglycerides were also reduced. ELTA reduced the area under curve (AUC) of blood glucose curves in OGTT and ITT. Relative mRNA level analysis of genes related to MetS showed that ELTA can effectively increase the transcriptional levels of Nrf2, HO-1, PPAR-γ, GluT2, GK, FXR, while effectively decrease those of PTP1B, p65, TNF-α, IL-6, SREBP, 11βHSD-1. Molecular docking showed that the ligands in ELTA can bind to 11βHSD-1, GK, PPAR-γ, and JNK, the important targets involved in MetS. ELTA can effectively alleviate visceral central obesity, insulin resistance, dyslipidemia, oxidative stress, and inflammation of HFD-induced MetS in C57BL/6 J mice. This is possibly achieved by acting on 11βHSD-1, GK, PPAR-γ, and JNK.