Subacute safety and Antihyperglycemic Effects of Freeze-Dried Beetroot (Beta vulgaris) Powder in Normoglycemic Male and Female Wistar Rats

Beetroot (Beta vulgaris L.) is rich in phytochemicals with potential health benefits. This study investigated the subacute safety, hypoglycemic, hepatoprotective, and nephroprotective effects of freeze-dried beetroot powder (BR) in male and female Wistar rats. Methods: Fifty rats (25/sex) were divided into ten groups (n=5/group/sex). Groups received distilled water (control), glibenclamide (5 mg/kg), or BR at 100, 500, and 1000 mg/kg body weight orally for 28 days. Body weight was monitored, and an oral glucose tolerance test (OGTT) was performed on day 7. Upon termination, haematological, biochemical, and histological analyses of the liver and kidney were conducted. Results: BR administration did not adversely affect normal growth or cause overt signs of toxicity. In the OGTT, BR (100 and 500 mg/kg) significantly (p<0.005) reduced postprandial blood glucose levels in both sexes. Haematological and most biochemical parameters remained within normal ranges. Notably, BR treatment significantly reduced serum bilirubin and alanine aminotransferase (ALT) levels, indicating hepatoprotective activity. Furthermore, histopathological examination of the liver and kidney revealed normal tissue architecture across all BR-treated groups, corroborating its organ-protective effects. The highest dose (1000 mg/kg) showed some significant alterations in relative organ weights, but without corresponding histological damage

甜菜根（Beta vulgaris L.）富含具有潜在健康益处的植物化学物质。本研究探究了冻干甜菜根粉（BR）对雌雄Wistar大鼠的亚急性安全性、降血糖、肝保护及肾保护作用。
方法：将50只大鼠（雌雄各25只）分为10组，每组每性别各5只（n=5/组/性别）。各组分别经口给予蒸馏水（对照组）、格列本脲（5 mg/kg）或不同剂量BR（100、500、1000 mg/kg体重），连续给药28天。每日监测大鼠体重，并于第7天进行口服葡萄糖耐量试验（OGTT）。实验结束后，对大鼠进行血液学、生化指标检测以及肝、肾组织病理学分析。
结果：灌胃BR未对大鼠正常生长产生不良影响，亦未引发明显毒性体征。在OGTT中，100和500 mg/kg剂量的BR可显著（p<0.005）降低雌雄大鼠的餐后血糖水平。血液学及多数生化指标均维持在正常参考范围内。值得注意的是，BR干预可显著降低血清胆红素与丙氨酸氨基转移酶（ALT）水平，提示其具有肝保护活性。此外，肝、肾组织病理学检查显示，所有BR给药组的组织形态均保持正常，进一步证实了其器官保护作用。最高剂量组（1000 mg/kg）的脏器相对重量出现部分显著变化，但未伴随相应的组织病理学损伤。