Construction and application of effect-related near-infrared spectroscopy for traditional Chinese medicines-Exemplification by rhubarb dispensing granules

Consistency in quality of traditional Chinese medicine granules is an important factor to ensure reproducible clinical efficacy. In this study rhubarb dispensing granules were utilized to construct an efficacious near-infrared spectroscopy (eNIRS) assay by combining NIRS and biopotency. A NIR method for assaying rhubarb dispensing particles was established, and information on different batches was collected. The diarrhea-inducing biopotency of rhubarb dispensing granules was determined based on a constipation model induced by diphenoxylate in mice. The animal protocol was approved by the Animal Ethic Committee of 302 Hospital of Chinese PLA People's Liberation Army (ID:IACUC-2019-0010). Ten anthraquinones were determined in rhubarb dispensing granules by UPLC. The correlation between NIR and biopotency was analyzed and five characteristic bands that correlated highly with bioactivity were identified, including 4 011-4 390, 4 859-5 461, 7 012-7 493, 10 992-11 312 and 11 871-12 489 cm^-1. There were some differences in the main bands of different chemical constituents. In summary, five active bands based on NIRS were identified and found to be able to achieve rapid on-line detection of rhubarb dispensing granule quality. This research model may also provide reference for quality control of other Chinese medicine dispensing granules.