Metabonomics study on the effects of acupuncture and moxibustion in a rat knee osteoarthritis model

For elucidating effects of acupuncture and moxibustion on the metabolism of knee osteoarthritis (KOA) in rats, A method for metabolite analysis based on high throughput liquid chromatography-tandem mass spectrometry (LC-MS) was used to investigate overall changes in serum between groups. Rats were divided into four groups: control (C), model (M), KOA plus traditional acupuncture and moxibustion (T) and KOA plus syndrome differentiation acupuncture and moxibustion (S). The paw withdrawal threshold, open-field test and Hematoxylin and eosinstaining were applied to assess the transformations of knee hyperalgesia and histopathology. The serum metabolic fingerprints were obtained by using metabonomics. Orthogonal partial least squares-discriminant analysis was evaluated to highlight the differences and identify possible biomarkers. The changing trends of potential serum biomarkers and biological pathways of differential metabolites among different groups were analyzed. The results showed that acupuncture and moxibustion alleviate hyperalgesia and cartilage degeneration in KOA rats. A total of 11 metabolites were annotated between C and M. Among the 11 metabolites, the level of 5 metabolites were reversed in group S, including Glutathione, Ornithine, Alpha-dimorphecolic acid, Carnosine, Anserine, and group T only reversed the contents of 2 metabolites, including Aminoadipic acid and Carnosine. T versus M, beta-Alanine metabolism, Histidine metabolism, Tryptophan metabolism, mTOR signaling pathway, and Chagas disease were the affected pathways. Therefore, beta-Alanine metabolism, Histidine metabolism, Tryptophan metabolism were the main differential metabolic pathways after T treatment. In the comparison of the S and M groups, beta-Alanine metabolism, mTOR signaling pathway, D-arginine and D-ornithine metabolism, PPAR signaling pathway, and Chagas disease were the affected pathways. In conclusion, acupuncture and moxibustion can ameliorate the symptoms of KOA. Compared with traditional acupuncture and moxibustion, treatment based on syndrome differentiation obviously exerted an effect on KOA-induced metabolic alterations, which is related to the improvement of oxidative damage, inflammatory, cell autophagy, and energy metabolism.