β-caryophyllene promotes white fat browning in obese mice through up-regulation of the PPARγ/PGC-1α/UCP1 pathway

Acta Universitatis Medicinalis Anhui 2024 09 v.59 1591-1598     font:big middle small

Found programs: Natural Science Foundation of Guangdong Province(No.2017A030313856)

Authors:Jiang Haoran; Tang Xiaofei; Wu Jielin; Wang Jiaoling; Huang Chengyu; Zhu Shuguang ;Zang Linquan

Keywords:β-caryophyllene;white adipose browning;white adipose tissue;epididymis white adipose tissue;peroxisome proliferator-activated receptor γ;peroxisome proliferator-activated receptor γ coactivator 1-α;uncoupling protein 1

DOI:10.19405/j.cnki.issn1000-1492.2024.09.014

〔Abstract〕 Objective To investigate the effects of β-caryophyllene(BCP) on the browning of white adipose tissue in obese mice and the related mechanisms. Methods An obese mouse model was establishedviaintraperitoneal injection of a high-fat diet supplemented with propylthiouracil saline solution [14.4 mg/(kg·d)] in male Kunming mice. Obesity model mice were randomly divided into a model group(Model group) and a BCP administration group(BCP-50 group); normal diet mice were set up as a control group(Control group), with 8 mice in each group. BCP administration was given by gavage at a dose of 50 mg/kg once in the morning and once in the evening in the BCP-administered group, while the rest of the group was administered by gavage with aqueous solution of Tween 80 for 4 weeks. The oral glucose tolerance test was performed at the end of 4-week administration, and mice were executed after overnight fasting at the end of the experiment, and blood samples and adipose tissues were rapidly collected for subsequent experimental tests. The kit was used to detect serological-related indexes; hematoxylin-eosin staining was conducted to observe the morphology of adipose tissue; immunohistochemical staining was carried out to observe the expression of uncoupling protein 1(UCP1) in adipose tissue; Western blot was employed to detect expression of peroxisome proliferator-activated receptor γ coactivator1-α(PGC1α), peroxisome proliferator-activated receptor γ(PPARγ), UCP1 and cannabinoid receptor 2(CNR2) proteins in epididymal white adipose(eWAT). Results Compared with the model group, the body mass of obese mice in the BCP-50 group was significantly reduced(P<0.05), food intake was decreased(P<0.01), insulin resistance was improved(P<0.000 1), and the serum content of low-density lipoprotein cholesterol(LDL-C) and nonesterified fatty acid(NEFA) in the obese mice was significantly reduced(P<0.000 1 andP<0.01). Total cholesterol(TC), triglyceride(TG), and high-density lipoprotein cholesterol(HDL-C) contents did not change significantly. In addition, the adiposity coefficient and eWAT specific gravity of obese mice in the BCP-50 group were significantly decreased(P<0.05); the adipocytes in eWAT and BAT were reduced; and the expression of the UCP1 protein was significantly elevated(P<0.01 andP<0.05). In addition to UCP1, the expression levels of PGC1α, PPARγ, and CNR2 proteins in the eWAT of obese mice in the BCP-50 group were also significantly elevated(P<0.01,P<0.05, andP<0.001). Conclusion β-caryophyllene promotes white adipose tissue browning through up-regulating PPARγ/PGC-1α/UCP1 pathway expression, thus improving obesity.