ABSTRACT
Objective: To investigate the effect of Coptidis Rhizoma on intestinal microflora of normal and type 2 diabetic rats before and after being steamed with rice wine based on 16S rRNA sequencing technology. Method: The type 2 diabetic rat model was established by high-fat diet and streptozotocin. Normal and model rats were given the decoction of Coptidis Rhizoma or Coptidis Rhizoma steamed with rice wine every day (0.8 g·kg-1, according to raw drug quantity), the positive drug group was given metformin solution every day (0.25 g·kg-1), continuous administration for 30 d. Blood glucose was measured once a week and oral glucose tolerance was measured on the 27th day of administration. On the 30th day, feces were taken and the rats were anesthetized. Blood was taken for enzyme linked immunosorbent assay (ELISA). Colon was dissected for hematoxylin-eosin (HE) staining. Based on 16S rRNA gene sequencing technology, the alpha diversity, beta diversity, abundance and composition, and the correlation with anti-inflammatory and antioxidant activities of intestinal microflora were comprehensively analyzed and evaluated. Result: After giving normal rats Coptidis Rhizoma or Coptidis Rhizoma steamed with rice wine, there were some inflammatory reactions, imbalance of oxidation-antioxidant system, pathological damage of colon and changes of intestinal microflora, which showed some toxic and side effects, but the toxic and side effects of Coptidis Rhizoma steamed with rice wine were lower than those of Coptidis Rhizoma. Coptidis Rhizoma could reduce fasting blood glucose and improve glucose tolerance in type 2 diabetic rats before and after steaming. Although the effect of Coptidis Rhizoma steamed with rice wine had an increasing trend, there was no significant difference between before and after processing. Type 2 diabetic rats appeared mild inflammation and imbalance of oxidation-antioxidant system, characterized by significant increase of contents of interleukin (IL)-6, nuclear transcription factor (NF)-κB and malondialdehyde (MDA) (PPPConclusion: Coptidis Rhizoma can treat type 2 diabetic rats by regulating intestinal microflora before and after steaming with rice wine, and the effect of Coptidis Rhizoma steamed with rice wine is better. The toxic and side effects of Coptidis Rhizoma on intestinal flora are reduced by steamed with rice wine. The processing mechanism of increasing efficacy and decreasing toxicity of Coptidis Rhizoma steamed with rice wine is closely related to intestinal microflora.