Study on the activity of Huo–Xue–Hua–Yu decoction and its drug groups in improving fracture healing using surface-enhanced Raman scattering (SERS) spectroscopy based on gold nanoparticles

The Huo-Xue-Hua-Yu decoction (HXHYD) prescription, which possesses good clinical properties for healing fractures, is made up of 12 types of traditional Chinese medicines (TCMs). According to the drug efficacy of TCM, HXHYD consists of four drug-group prescriptions. This study focused on the type of active mechanism in these drug groups and the type of interaction between them in HXHYD. Surface-enhanced Raman scattering (SERS) spectroscopy was employed to study the effect of the incorporation of calcium hydroxyapatite (CHA), protein and lipid groups on the repair of complete tibial fractures in rats treated with HXHYD and its drug-group prescriptions and without treatment to reveal the efficacy rule of the drug groups in the prescription. The rats were divided into seven groups, each of which was subdivided into three subgroups (evaluated on days 15, 21 and 30 after surgery). The six treatment groups were treated HXHYD, four drug-group prescriptions and Gu-Zhe-Cuo-Shang capsule therapy (treated control). SERS readings were taken at the fractured sites. The results showed that the medical ingredients in HXHYD were not the simple addition of four drug-group prescriptions and the efficacy of HXHYD was stronger than every other drug group prescription because it contained the highest content of CHA and highest carbonate-to-phosphate and phosphate-to-phenylalanine ratios among the treatment groups at all time points in comparison with the fractured control group (no treatment). Thus, the SERS technique has great potential to provide a novel method for effectively and accurately studying the efficacy rule of drug groups in one prescription with the aim to optimize prescriptions.