ABSTRACT
Objective: Tea polyphenols are natural extracts used widely throughout the world. However, the severe astringency of tea polyphenols has reduced patient compliance. Based on the analysis of the formation mechanism of astringency, this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect. Methods: Artificial saliva was used to prepare the tea polyphenols solution with different pH, using β-casein to imitate salivary protein, and preparing 1.2 mg/mL β-casein solution. A fluorescence quenching test was used to study the interaction between tea polyphenols and β-casein, combined with the stability test results of the compound, we can choose the pH with weak binding but good stability as the best pH for masking astringency. The taste-masking tablets were prepared under the best pH conditions, and the Xinnaojian Original Tablets were prepared according to the conventional preparation method. The disintegration time limit and solubility were tested respectively. The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale (VAS). Results: The result of the fluorescence quenching test prompted that the combination force was the weakest when the pH was 4.9. Further synchronous fluorescence analysis showed that an increase in pH resulted in a decrease of the binding sites between tea polyphenols and β-casein, and this decrease was closely related to changes in tryptophan residues in β-casein. Both original and taste-masking Xinnaojian Tablets were prepared. Volunteers’ VAS scores illustrated that the astringency improved significantly with the masking tablets (P < 0.05). Conclusion: This pH-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets. This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.
ABSTRACT
Coronavirus disease-2019 (COVID-19) belongs to the epidemic diseases of traditional Chinese medicine (TCM), which is infected by the air with disease and the initial stage of the disease is in upper energizer. TCM holds that the nose is the orifice of the lung and the gateway of the breath. WU Shang-xian, the famous external doctor in Qing dynasty, discussed in Liyue Pianwen that "for the disease in upper energizer, the most effective method is to use the medicine powder via nasal administration and sneeze to disperse". For thousands of years, ancient Chinese medical practitioners had explored and developed the TCM nasal administration method in the struggle against epidemics. Qingkailing is the basic formula for heat-clearing and detoxifying, and researches have clarified its therapeutic effect on upper respiratory tract infections. Therefore, based on TCM nasal administration, this article took Qingkailing as an example to study the feasibility of its nasal preparations for the treatment of COVID-19. On the one hand, it is helpful for the rapid development of Qingkailing nasal preparations for COVID-19. On the other hand, it can broaden the new thinking of TCM in treating epidemic diseases, and give full play to the advantages of TCM in treating epidemic diseases.