Pomegranate flower extract bidirectionally regulates the proliferation, differentiation and apoptosis of 3T3-L1 cells through regulation of PPARγ expression mediated by PI3K-AKT signaling pathway

• Published in: Biomedicine & pharmacotherapy 2020-11, Vol.131, p.110769, Article 110769
• Main Authors: Li, Tong, Zhang, Ling, Jin, Chen, Xiong, Yao, Cheng, Yu-Yao, Chen, Kang
• Format: Article
• Language: English
• Subjects: 3T3-L1 Cells; Active component; Adipocytes - cytology; Adipocytes - drug effects; Akt-PI3K signaling pathway; Animals; Apoptosis; Apoptosis - drug effects; Cell Differentiation - drug effects; Cell Proliferation - drug effects; Dose-Response Relationship, Drug; Flowers; Lipid accumulation; Lipid Metabolism - drug effects; Mice; Phosphatidylinositol 3-Kinases - metabolism; Plant Extracts - administration & dosage; Plant Extracts - chemistry; Plant Extracts - pharmacology; Pomegranate - chemistry; Pomegranate flowers; PPAR gamma - metabolism; PPARγ; Proto-Oncogene Proteins c-akt - metabolism; Time Factors
• ISSN: 0753-3322; 1950-6007
• DOI: 10.1016/j.biopha.2020.110769

[Display omitted] •Pomegranate flower extract regulates the PI3K-Akt signaling pathway bidirectionally.•Different doses of pomegranate flowers have the opposite effect on preadipocyte.•Pomegranate flower extract inhibits adipocyte differentiation.•The components in the pomegranate flower act synergistically in cell differentiation. Pomegranate flower is a kind of uygur medicine with anti - type 2 diabetes, anti - lipid, anti - inflammation, anti - oxidation. We investigated the effect of pomegranate flower extract (PFE) on the proliferation, differentiation and apoptosis of 3T3-L1 preadipocytes, as well as the effects of five compounds in PF on cell differentiation. 3T3-L1 preadipocytes were treated with PFE (0.5, 1, 2, 5, 10, 20, 50, 100 μg/mL), quercetin, luteolin, ursolic acid, apigenin and kaempferol (5, 10, 20, 40, 80 μM), and cell viability was measured at 24, 48 and 72 h by Cell Counting Kit-8. The modified cocktail induction method induced the differentiation of 3T3-L1 preadipocytes, and treated them with PFE and the compounds. The lipid accumulation was determined by oil red O staining, and the intracellular triglyceride content was determined by commercial kit. The expressions of PPARγ, C/EBP, LPL, DGAT and aP2 mRNA in mature adipocyte were determined by q-PCR, and the expressions of PPARγ, Akt, p-akt and PI3K protein were determined by western blot. 3T3-L1 preadipocytes were treated with PFE (5, 10, 20 μg/mL) while induced apoptosis by palmitate (300 μM), Hoechst staining to observe apoptosis morphology, Annexin Ⅴ- FITC/PI staining with flow cytometry instrument to detect the number of early and late apoptosis cells, the q-PCR and western blot for determining the Bcl-2, Bax, caspase 3 mRNA and protein expression. PFE (5, 10, 20 μg/mL) promoted or did not affect the proliferation and differentiation of 3T3-L1 preadipocytes, and reduced the number of early and late apoptotic cells, increased the expression of Bcl-2 mRNA and protein, and inhibited the expression of Bax and caspase-3 mRNA and protein. Furthermore, PFE (40, 60 μg/mL), quercetin (10, 20, 40 μM), luteolin (5, 10, 20 μM), apigenin(20,40 μM), kaempferol (20, 40 μM) significantly restrain the 3T3-L1 different extent proliferation and differentiation of preadipocyte, reduce the accumulation of lipids in adipocyte, reduce expression of adipogenesis factor, PFE(40, 60 μg/mL) inhibited the activation of the PI3K-Akt pathway by inhibiting the expression of PI3K and p-Akt proteins, and inhibite