The present study aims to explore the glucose-lowering effects of the previously characterised dark tea (Camellia sinensis L.) protein extract (DTPE) from Heimaojian on the spleen–brain axis of diabetic mice. DTPE was orally administrated (50–100 mg/kg) to alloxan-induced mice for 21 d; a biochemical assay and transcriptome profiling (RNA sequencing (RNA-Seq)) were performed. The results showed that DTPE can improve glucose tolerance. Compared with the model group, at day 21, the fasting blood glucose values were significantly (P < 0·05) decreased by 44·9 % (13·8 v. 7·6 mmol/l) and 51·4 % (13·8 v. 6·7 mmol/l) for high dose of DTPE (100 mg/kg) and drug metformin (125 mg/kg) groups, respectively. Subsequently, transcriptome profiling (RNA-Seq) was performed on the spleen and brain of diabetic mice. Totally, fifty-two spleen-derived and forty-seven brain-derived differentially expressed genes related to the synthesis, transport and metabolism of glucose were identified. The regulatory network analysis indicated that DTPE may exert glucose-lowering effects through a thirty-seven-gene sub-network related to metabolism, Parkinson’s disease, oxidative phosphorylation and immunity. In summary, for the first time, the present data revealed that dark tea-derived DTPE could exert a potential anti-hyperglycaemic effect by modulating the spleen–brain axis.

中文翻译：

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黑茶蛋白提取物调控糖尿病小鼠脾脑轴的降糖作用

本研究旨在探索先前表征的黑茶的降糖作用。茶树L.) 黑毛煎蛋白提取物 (DTPE) 对糖尿病小鼠脾脑轴的作用。给四氧嘧啶诱导的小鼠口服 DTPE (50-100 mg/kg) 21 天；进行了生化测定和转录组分析（RNA测序（RNA-Seq））。结果表明，DTPE可以提高糖耐量。与模型组比较，第21天空腹血糖值显着（磷< 0·05) 下降 44·9 % (13·8五。7·6 mmol/l) 和 51·4 % (13·8五。6·7 mmol/l) 分别用于高剂量 DTPE (100 mg/kg) 和药物二甲双胍 (125 mg/kg) 组。随后，对糖尿病小鼠的脾脏和大脑进行转录组分析（RNA-Seq）。共鉴定出52个脾源性和47个脑源性与葡萄糖合成、转运和代谢相关的差异表达基因。调控网络分析表明，DTPE可能通过与代谢、帕金森病、氧化磷酸化和免疫相关的37个基因亚网络发挥降糖作用。总之，目前的数据首次表明，黑茶衍生的 DTPE 可以通过调节脾脑轴发挥潜在的抗高血糖作用。