Effect of Danggui Niantongtang on Intestinal Flora of Knee Osteoarthritis Mice Based on 16S rDNA Sequencing / 中国实验方剂学杂志

ABSTRACT

ObjectiveThis study aims to explore the potential mechanism of Danggui Niantongtang in treating knee osteoarthritis （KOA） by regulating the intestinal flora through 16S rDNA analysis. MethodThirty-six C57BL/6J mice were subjected to anterior cruciate ligament transection （ACLT） to establish a KOA model and were randomly divided into the sham surgery group， model group， low-dose Danggui Niantongtang group （0.819 g·kg-1）， medium-dose Danggui Niantongtang group （1.638 g·kg-1）， high-dose Danggui Niantongtang group （3.276 g·kg-1）， and Meloxicam group （0.975 mg·kg-1）， with 6 mice in each group. Except for the treatment groups， the sham surgery group and model group were given normal saline by gavage. After 4 weeks of continuous intervention， feces and intact knee joints of the mice were collected. Hematoxylin-eosin （HE） staining and Safranin O-Fast Green staining were performed to observe the pathological changes in knee joint tissue morphology. The 16S rDNA sequencing was used to analyze changes in the abundance and diversity of intestinal microorganisms before and after treatment， along with corresponding functional predictions. ResultHigh-dose Danggui Niantongtang and Meloxicam significantly relieved pain symptoms in KOA mice， improved the disorder of joint structure， maintained the integrity of knee articular cartilage， increased the expression of type Ⅱ collagen alpha 1 （Col2a1） in articular cartilage， and decreased the expression of matrix metalloproteinase-13 （MMP-13）. The results of 16S rDNA sequencing showed that high-dose Danggui Niantongtang could adjust the abundance and structure of intestinal microbial species. Compared with the sham surgery group， the abundance of Proteobacteria， Actinobacteria， Ruminococcus， and Bacteroides was significantly increased in the model group （P<0.05）， while in the Danggui Niantongtang group， the abundance of these four flora was significantly reduced compared with the model group. Compared with the sham surgery group， the abundance of Verrucomicrobia， Oscillospira， and Akkermansia was significantly decreased in the model group （P<0.05）， while in the Danggui Niantongtang groups， the abundance of these three flora was significantly increased compared with the model group （P<0.05）. Functional pathway prediction of differential genera revealed that species differences among groups mainly involved metabolic pathways with high abundance associated with biosynthesis and precursors， as well as energy production， including amino acid biosynthesis， nucleotide and nucleoside biosynthesis， cofactors， prosthetic groups， electron carriers， and vitamin biosynthesis. ConclusionDanggui Niantongtang can effectively protect articular cartilage and delay the progression of KOA， possibly by regulating the structure of the intestinal flora， promoting probiotics， and inhibiting the growth of harmful pathogenic bacteria.