EFFECT OF BAICALIN ON GLUCOSE AND LIPID METABOLISM AND INTESTINAL FLORA OF DIABETIC MICE

Yingni Luan*, Liangqing Guo**, #

*Department of Traditional Chinese Medicine Physiotherapy, Shandong University Hospital, Jinan, PR China - **Department of Endocrinology, Affiliated Hospital of Shandong University of Traditional Chinese Medicine, Jinan, PR China

Objective: To investigate the effect of baicalin on glucose and lipid metabolism and intestinal flora of diabetic mice. 

Methods: All mice were fed adaptively for 1 week and were then fed a high-fat diet from the second week. In the sixth week, the mice were randomly divided into either high-fat diet control or diabetic groups. The mice were given citrate buffer in the control group, whereas mice in the diabetic group were randomly divided into either diabetic model or baicalin groups. The mice were administered 80 mg/kg baicalin and 0.5% CMC saline by gavage in the baicalin group, and those were administered with 0.5% CMC saline by gavage in both control and model groups, once a day for 6 weeks. Six weeks later, the mice were killed after their eyeballs had been removed under anaesthesia. Their caecal stool was collected aseptically. Glucose content was measured using a glucose oxidase-peroxidase-4-aminoantipyrine-phenol (GOD-PAP) method. Changes in total cholesterol (TC) and triglyceride (TG) levels were determined by an oxidase method. The levels of interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α) and endotoxin were assayed using an enzyme-linked immunosorbent assay. The genomic DNA of the faecal flora was extracted and was then accurately quantified using the Qubit2.0 DNA detection kit, followed by high-throughput sequencing using the Miseq high-throughput sequencing platform. 

Results: After 6 weeks of a high-fat diet, the blood glucose and body weight were significantly lower in the baicalin group than those in the model group (P<0.01). The levels of TC and TG were significantly higher in the model group than those in the control group (P<0.01). The levels of TC and TG in the baicalin group were significantly lower than those in the model group (P<0.01). The levels of IL-6, TNF-α and endotoxin were significantly higher in the model group compared to control group values (P<0.01). The levels of IL-6, TNF-α and endotoxin were significantly lower in the baicalin group than those in the model group (P<0.01). The number of OTUs was significantly higher in the model group, but much lower in the baicalin group than that in the control group (P<0.05). The level of Shannon was significantly lower in the model group and the baicalin group than that in the control group (P<0.05). In addition, the level of Shannon was significantly lower in the baicalin group than the model group value (P<0.05). The levels of ACE and Chaol were significantly higher in the model group and baicalin group than those in the control group (P<0.05), and these levels were significantly lower in the baicalin group compared to the model group (P<0.05). The coverage index was above 0.90 in all three groups, indicating that the probability that it was not detected in the sample sequence was low. The negative bacteria/positive bacteria were significantly higher in the model group than those in the control group (P<0.05), and the negative bacteria/positive bacteria were significantly lower in the baicalin group than those in the model group (P<0.05).

Conclusions: Baicalin can substantially improve the symptoms of diabetic mice and alleviate the metabolic inflammation induced by a high-lipid diet; this compound is, therefore, associated with an ability to regulate intestinal flora.