Table 3.
Hypoglycemic effects of different fermented tea and extracts in animal models.
| Tea | Main Components | Time, Way | Animal Type | Diabetes Induction Mode | Result/ Pathway |
References |
|---|---|---|---|---|---|---|
| Roasted GT, kung fu BT | Tea water extract | 5 weeks, free to drink | SPF C57BL/6J male mice | HSFD | It can promote liver glycogen synthesis and inhibit gluconeogenesis./ Activation of IRS-1-PI3K/AKT-GLUT2 pathway. |
[45] |
| GT | Green tea extract | 19 days, free to drink | Male Wistar/ST rats; KK-Ay mice | STZ | It can promote GLUT4 translocation in skeletal muscle; enhance glucose uptake. | [67] |
| GT | EGCG | 17 weeks, free to drink | C57BL/6 mice | HFD | It can reduce AGEs to lower plasma glucose and alleviate diabetic complications. | [68] |
| Selenium-rich BT and ordinary BT | Tea water extract | 5 weeks, free to drink | C57BL/6J mice | STZ/HFD | It can inhibit digestive enzymes, regulate glucose metabolism, and alleviate liver injury and inflammation./ Activation of PI3K/Akt pathway. |
[69] |
| Selenium-rich BT, selenium-deficient BT | Tea powder | 4 weeks, free intake | Male Sprague-Dawley rats | HFD | It can improve weight, lower total triglycerides and fasting blood glucose, enhance insulin sensitivity, relieve liver and intestinal injury, reduce inflammation, and enrich beneficial intestinal bacteria. | [70] |
| GT, YT, BT | Water extract | 25 days, free to drink | Male ICR mice | HFD | GT and BT maintain body weight in high-fat diet mice, while YT significantly lowers blood glucose. | [71] |
| BT | Theaflavins, thearubigins | 56 days, free to drink | Male Sprague Dawley rats | HSD | Theaflavins and thearubigins reduce plasma glucose and boost insulin release. | [72] |
| BT, DT | Tea water extract | 28 days, gavage (1000, 500, and 300 mg/kg). | Male SPF Kunming mice | Intraperitoneal injection of STZ | Enhances glucose transport, reduces postprandial blood glucose, and inhibits liver glycogen synthesis./ Up-regulation of PI3K, AKT, IRS1, GLUT2; down-regulation of GSK3β protein and gene expression. |
[73] |
| GT, OT, BT, DT | Tea polysaccharide | 4 weeks, gavage (0.2 mL, 150 mg/kg, 200 mg/kg, 300 mg/kg) | Male ICR mice | HSFD | BT polysaccharide is highly effective in inhibiting α-glucosidase and reducing triglyceride, total cholesterol, LDL cholesterol, creatinine, alanine aminotransferase, and aspartate aminotransferase. | [44] |
| GT, WT, OT, BT, purple tea | Tea water extract | Gavage, Samples were taken once every 30 min for two hours (500 mg/kg). | Normal male Swiss mice | Normal male Swiss mice | Purple tea shows the highest starch digestion inhibition. BT shows the most significant improvement in glucose tolerance. | [47] |
| BT | Theaflavins | 7 weeks, oral | Male C5BL mice | HFD | It can reduce blood glucose, improve IR, alleviate liver injury, and lower serum triglycerides, total cholesterol, LDL cholesterol, as well as alanine aminotransferase and aspartate aminotransferase levels./ Activation of SIRT6/AMPK/SREBP-1/FASN pathway. |
[74] |
| Raw Pu‘er tea, cooked Pu‘er tea | Theabrownin | 24 weeks, gavage (400 mg/kg) | C57BL/6J male mice | HFD | Both inhibit weight gain and maintain glucose homeostasis./ Up-regulation of GLUT4 and IRS1. |
[75] |
| DT | Tea protein | 21 days, gavage (50 mg/kg, 100 mg/kg, 125 mg/kg) | SPF C6BL/8 male mice | alloxan | It can inhibit weight, enhance glucose tolerance, and reduce fasting blood glucose. Activation of spleen–brain axis to alleviate hyperglycemia. |
[76] |
| GT | Tea polysaccharide | 3 weeks, gavage (100 mg/kg, 200 mg/kg, 400 mg/kg) | Male Wistar rats | HFD | It can reduce blood glucose, promote SCFAs production, alleviate IR, mitigate pancreatic and liver damage, and increase beneficial intestinal bacteria. | [77] |
| Wuyi rock tea (OT) | Tea polysaccharide | 40 days, gavage | Male Wistar rats | HFD/STZ | It can regulate gut flora, boost beneficial bacteria, lower fasting blood glucose, improve glucose tolerance, and ease liver and pancreatic damage. | [78] |
| BT | Theaflavins | 20 weeks, gavage (25 mg/kg/day) | SDT rats | SDT rats | It can improve glucose tolerance, promote incretin secretion and improve IR | [66] |
| Tea grounds | Tea dietary fiber | 28 days, gavage (250 mg/kg, 500 mg/kg, 1000 mg/kg) | Male wistar rats | HFD/STZ | It can improve hyperglycemia, enhance insulin sensitivity, ease pancreatic injury, boost SCFAs levels, and stimulate insulin secretion. | [79] |
| L-theanine | L-theanine | 28 days, gavage (200 mg/kg) | Male Wistar rats | Nicotinamide/STZ | It can reduce leptin and adiponectin levels in the hippocampus of diabetic mice, alleviate hippocampal damage, promote overall blood glucose metabolism, and maintain the glucose balance in the body. | [80] |
High-sugar and high-fat diet (HSFD), streptozotocin (STZ), high-fat diet (HFD), high-sugar diet (HSD), reduced glutathione/oxidized glutathione (GSH/GSSG), glycogen synthase kinase 3β (GSK3β).