Clinical and Cellular Evidence of Glycyrrhiza glabra and Platycodon grandiflorus for Vocal Fold Nodules Complementary Treatment

Vocal fold nodules (VFNs) are the most frequent cause of hoarseness. The management comprised medical, surgical and physical therapy but the effectiveness is not always satisfactory. In this study, we try to figure out an alternative treatment from our clinical experience summary. We retrospectively reviewed VFNs patients who received traditional Chinese medicine (TCM) treatments from July 2018 to August 2020 and traced their Chinese Voice Handicap Index-10 (VHI-C10) and multidimensional voice program (MDVP) analysis results. For further evaluation, we conducted an inflammatory response of porcine vocal fold epithelial (PVFE) cells with 50 ng/mL TNF-alpha. The inflamed PVFE cells were separately cultured in the aqueous extract of Glycyrrhiza glabra (G. glabra) and Platycodon grandifloras (P. grandifloras). In these VFNs patients (n = 22), the average VHI-C10 score decreased from 17.6 to 6.6 (p < 0.001). MDVP analysis revealed improvements in jitter, shimmer, noise-harmonic ratio, and GRBAS scoring system. Of the TCM prescription patterns, G. glabra and P. grandiflorus were used most frequently. In the MTT assay of PVFE cells, no adverse effects of our extracts were observed at doses of 1-200 µg/mL. Western blot analysis revealed downregulation of p65 and mitogen activated protein kinase pathway proteins. The results from both the clinical and in vitro aspects of this study revealed that the herbs G. glabra and P. grandiflorus may offer beneficial outcomes as alternative treatments for VFNs after precise diagnosis.