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• EGCG inhibits early and terminal adipocyte differentiation via targeting MCE phase. • EGCG regulates cell cycle in sequential order at the MCE phase of adipogenesis. • EGCG inhibits MCE and terminal adipogenesis via STAT3 (Tyr705) inactivation. • HFD induces a signature change of cell cycle regulators in mouse adipose tissues. • EGCG inhibits adipogenesis and p-STAT3/cell cycle regulator expressions in vivo. Mitotic clonal expansion (MCE) is a prerequisite for preadipocyte differentiation and adipogenesis. Epigallocatechin gallate (EGCG) has been shown to inhibit preadipocyte differentiation. However, the exact molecular mechanisms are still elusive. This study investigated whether EGCG could inhibit adipogenesis and lipid accumulation by regulating the cell cycle in the MCE phase of adipogenesis and its underlying molecular mechanisms. 3T3-L1 preadipocytes were induced to differentiate by a differentiation cocktail (DMI) and were treated with EGCG (25–100 μM) for 9, 18, and 24 h to examine the effect on MCE, or eight days to examine the effect on terminal differentiation. C57BL/6 mice were fed a high-fat diet (HFD) for three months to induce obesity and were given EGCG (50 or 100 mg/kg) daily by gavage. We showed that EGCG significantly inhibited terminal adipogenesis and lipid accumulation in 3T3-L1 cells and decreased expressions of PPARγ, C/EBPα, and FASN. Notably, at the MCE phase, EGCG regulated the cell cycle in sequential order, induced G0/G1 arrest at 18 h, and inhibited the G2/M phase at 24 h upon DMI treatment. Meanwhile, EGCG regulated the expressions of cell cycle regulators (cyclin D1, cyclin E1, CDK4, CDK6, cyclin B1, cyclin B2, p16, and p27), and decreased C/EBPβ, PPARγ, and C/EBPα expressions at MCE. Mechanistic studies using STAT3 agonist Colivelin and antagonist C188–9 revealed that EGCG-induced cell cycle arrest in the MCE phase and terminal adipocyte differentiation was mediated by the inhibition of JAK2/STAT3 signaling cascades and STAT3 (Tyr705) nuclear translocation. Furthermore, EGCG significantly protected mice from HFD-induced obesity, reduced body weight and lipid accumulations in adipose tissues, reduced hyperlipidemia and leptin levels, and improved glucose intolerance and insulin sensitivity. Moreover, RNA sequencing (RNA-seq) analysis showed that the cell cycle changes in epididymal white adipose tissue (eWAT) were significantly enriched upon EGCG treatment. We further verified that EGCG treatment significantly reduced expressions of adipogenic factors, cell cycle regulators, and p-STAT3 in eWAT. EGCG inhibits MCE, resulting in the inhibition of early and terminal adipocyte differentiation and lipid accumulation, which were mediated by inhibiting p-STAT3 nucleus translocation and activation. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Fruit and vegetable byproducts were evaluated as media and carbon sources for Euglena. • When used as media, Euglena cultivated with orange peel showed the highest beta-glucan production. • When used as a carbon source, Euglena cultivated with apple pomace showed the highest beta-glucan production. • Fruit and vegetable byproducts were effective for beta-glucan production when used as a single carbon source. • It is expected to contribute to the circular economy of waste. Five fruit and vegetable byproducts were evaluated as carbon sources and media for beta-glucan production from Euglena gracilis. Orange peel showed the highest beta-glucan concentration (6.5 g/L) and productivity (1.9 g/L/day) when used as a medium. However, when employed as carbon sources, apple pomace showed the highest beta-glucan concentration (10.6 g/L) and productivity (3.5 g/L/day). The appropriate chemical oxygen demand/nitrogen ratio (71.1) and favorable carbon sources of apple contributed to beta-glucan production. Increasing sugar concentrations in apple pomace and orange peel from 10 to 30 g/L raised the beta-glucan concentration to 11.6 g/L. Using apple pomace and orange peel individually proved more effective than mixing them for beta-glucan production. Therefore, apple as a carbon source is the most effective fruit and vegetables byproduct for beta-glucan production. This is expected to reduce the cost of E. gracilis cultivation on a large-scale and contribute to the circular economy. [ABSTRACT FROM AUTHOR]