Study on the Resolving Phlegm Effect of D-Limonene in Mice with Spleen Deficiency and Phlegm-Dampness Syndrome

Abstract

Objective: According to Traditional Chinese Medicine theory, spleen deficiency and phlegm-dampness syndrome (SDPDS) are caused by abnormal water metabolism in the body because of spleen dysfunction. The purpose of this article was to evaluate the efficacy of D-limonene (DL) in resolving phlegm in mice with SDPDS from the perspective of regulating the level of aquaporin 3 (AQP3). Methods: The model of SDPDS was induced in mice using the multifactor modeling method, which combines internal and external dampness. An artificial climate box was used to create a humid environment, whereas the irregular diet was caused by different feeding methods on odd-even days. The mice were divided into blank control, model group, DL low-dose, DL high-dose, and positive groups. The mice were modeled and treated for 7 day. Levels of gastrin and amylase (AMS) in the serum, mucus secretion in the trachea, and AQP3 in the tissue near the gastric cardia. Results: DL significantly reduced mucus secretion in the trachea (P < 0.001). It also increased the level of AMS in the serum (P < 0.01) and decreased the level of AQP3 in the gastric tissue (P < 0.01). Conclusions: Mice with SDPDS exhibited disturbed water metabolism and significantly increased AQP3 levels. DL can restore the levels of AQP3 and plays an important role in resolving phlegm. This study may also help expand the efficacy of natural drugs containing DL and improve the utilization of natural drug resources.