Osakabe Naomi, Nakamura Hitomi, Yoshida Yamato, Katsuragawa Sae, Iida Naoki, Fujii Yasuyuki, Jacob Ursula M, Fritsch Tilman, Abdelhameed Ali, Calabrese Vittorio
Systems Engineering and Science, Graduate School of Engineering and Science, Shibaura Institute of Technology, Saitama, 337-8570, Japan.
Department of Bioscience and Engineering, Faculty of System Science and Engineering, Shibaura Institute of Technology, 307 Fukasaku, Minumaku, Saitama, 337-8570, Japan.
Open Med (Wars). 2025 Mar 18;20(1):20251152. doi: 10.1515/med-2025-1152. eCollection 2025.
Flavan-3-ols (FLs), astringent polyphenols, are known to have low bioavailability and induce excessive sympathetic nervous system activation. This study aimed to compare the effects of FLs on brown, subcutaneous, and visceral adipose tissue in mice.
C57BL/6J male mice fed a standard or high-fat diet were given water or 50 mg/kg FL orally by gavage for 2 weeks. Excised brown, inguinal, and epididymal fat tissues were prepared for frozen sectioning. After hematoxylin and eosin (HE) staining, the effects of FL administration on each adipose tissue were observed, and expression analysis of mitochondrial DNA genes was performed.
Repeated administration of FL had no morphological effects on brown adipose tissue or visceral fat. However, FL significantly reduced the cell size in subcutaneous fat and induced the appearance of multilocular structures. Furthermore, FL increased cytochrome B expression in subcutaneous fat. The results showed that FLs induce browning of subcutaneous fat in mice.
This study showed that FL-induced enhancement of sympathetic nerve activity increased mitochondria in subcutaneous fat and promoted browning. However, no changes were observed in other adipose tissues. Further long-term administration is required to analyze the effects of FLs on adipose tissue thoroughly.
黄烷-3-醇（FLs）是一种具有收敛性的多酚类物质，已知其生物利用度低，并会引起过度的交感神经系统激活。本研究旨在比较FLs对小鼠棕色脂肪组织、皮下脂肪组织和内脏脂肪组织的影响。
给喂食标准饮食或高脂饮食的C57BL/6J雄性小鼠经口灌胃给予水或50mg/kg FL，持续2周。将切除的棕色脂肪组织、腹股沟脂肪组织和附睾脂肪组织制备用于冷冻切片。苏木精和伊红（HE）染色后，观察FL给药对各脂肪组织的影响，并进行线粒体DNA基因的表达分析。
重复给予FL对棕色脂肪组织或内脏脂肪无形态学影响。然而，FL显著减小了皮下脂肪细胞大小，并诱导出现多房结构。此外，FL增加了皮下脂肪中细胞色素B的表达。结果表明，FLs可诱导小鼠皮下脂肪褐变。
本研究表明，FL诱导的交感神经活动增强增加了皮下脂肪中的线粒体并促进了褐变。然而，其他脂肪组织未观察到变化。需要进一步长期给药以全面分析FLs对脂肪组织的影响。
