Objective  To examine effects of Rhizoma Alismatis decoction (RAD) on hyperlipidemia and expressions of aquaporin 3 (AQP3) and aquaporin 4 (AQP4) in colon tissues in rats.

  Methods  Sixty male Sprague-Dawley rats were randomly divided into 6 groups: a blank and a model group with distilled water, a positive control group with simvastatins, and high-, moderate-, and low-dose groups with modified RAD by gavage once a day continuously for five weeks. All the rats were fed with high-fat diet except for those of the blank control with normal diet. At the end of the treatments, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) were detected and the expressions of AQP3 and AQP4 in colon tissues were detected with real-time reverse transcription PCR (RT-PCR) and Western blot.

  Results  Compared to those in the blank control rats, serum TG (2.183 ± 0.204 mmol/L), TC (2.013 ± 0.250 mmol/L), LDL-C (1.267 ± 0.087 mmol/L) were significantly elevated but serum HDL-C (0.731 ± 0.085 mmol/L) was significantly reduced in in the model rats (P < 0.05 for all). Compared to those in the blank control rats, serum TG (1.205 ± 0.139 mmol/L), TC (1.164 ± 0.197 mmol/L), LDL-C (0.787 ± 0.057 mmol/L) were decreased but serum HDL-C (0.904 ± 0.115 mmol/L) was increased significantly in the rats with high-dose modified RAD (P < 0.05 for all). The expressions of AQP3 (0.944 ± 0.052) and AQP4 (0.701 ± 0.067) in colon tissues of the model rats increased significantly compared to those of the blank control rats (both P < 0.01); while, the expressions of AQP3 (0.502 ± 0.085) and AQP4 (0.366 ± 0.061) in colon tissues of the rats treated with high-dose modified RAD decreased significantly compared to those of the model rats (both P < 0.05).

  Conclusion  Modified Rhizoma Alismatis decoction can regulate blood lipids in rats and the effect may be related to the regulated expressions of AQP3 and AQP4 in colon tissue.