Codonopsis Radix modulates water and electrolytes homeostasis in mice

Abstract

Codonopsis Radix is a traditional Chinese medicine best known for its effects in treating digestive, cardiovascular, immunological and hematopoitic diseases. It also appears in the traditional Chinese medical prescriptions against ascites. However, the physiological effect and molecular mechanism of Codonopsis Radix in water and electrolytes homeostasis have not been well studied. We found that Codonopsis Radix decoction increased water intake and the urine volume, but decreased food intake in mice. The treatment significantly reduced angiotensin II receptor (AT1R) transcription and serum aldosterone level in animals, suggested perturbed function of renin-angiotensin system. RNAseq analysis of Codonopsis Radix treated NCI-H295R cells detected suppressed AT1R, SP1, and TEF transcription as well. Thus, Codonopsis Radix may regulate water and electrolytes homeostasis by affecting AT1R expression and aldosterone biosynthesis, possibly through downregulating SP1 and TEF transcription.

Keywords: AT1R; Aldosterone; Codonopsis Radix; Polyurine; RAAS.

Figure 1

Effects of Codonopsis Radix on water-intake and food-intake. Seven-week-old mice were treated with water or Codonopsis Radix (0.1g/ml) for 4 weeks. (A–D) FSHR^PB/PB female mice; (E–H) GPR45^PB/PB male and female mice; (I–L) wild-type (WT) mice. n = 5.

Figure 2

Dosage effects of Codonopsis Radix on water-intake and food-intake. Seven-week-old mice were treated with water or different Codonopsis Radix doses (0.1 g/ml or 0.02 g/ml) for 4 weeks. (A–D) FSHR^PB/PB female mice; (E–H) GPR45^PB/PB female mice; (I–L) GPR45^PB/PB male mice. n = 5.

Figure 3

Effect of Codonopsis Radix on water homeostasis. Seven-week-old wild-type male mice were treated with Codonopsis Radix for 3 days. Food intake, water intake, urine volumes, and feces weight were measured daily. n = 5 for Codonopsis Radix group; n = 6 for H₂O group in (A), (B), (C), and (E). n = 8 for Codonopsis Radix group; n = 7 for H₂O group in (D). All data were shown as mean ± SEM. ∗P < 0.05; ∗∗P < 0.01, by student's t test.

Figure 4

Effects of Codonopsis Radix on urine osmolality, serum K⁺ concentration, and systolic pressure in wild-type male mice. (A) The urine osmolality. n = 5 for Codonopsis Radix group; n = 6 for H₂O group. (B) Urine pH. n = 8 for Codonopsis Radix group; n = 7 for H₂O group; (C) Serum K⁺ concentration, n = 4 for both groups; (D) Blood pressure. n = 4 for Codonopsis Radix group; n = 6 for H₂O group. All data were shown as mean ± SEM. ∗P < 0.05; ∗∗P < 0.01, by student's t test.

Figure 5

Effects of 4-week Codonopsis Radix treatment on serum hormone levels in wild-type male mice. ELISA results were shown for serum renin (A), AngII (B), aldosterone (C), ANP (D), Relaxin (E), and AVP (F) concentrations. n = 7 for Codonopsis Radix group; n = 8 for H₂O group. All data were shown as the mean ± SEM. ∗P < 0.05, by student's t test.

Figure 6

Effects of Codonopsis Radix on gene transcription, as measured by quantitative RT-PCR. (A) Tissue AT1R mRNA level of male mice treated by Codonopsis Radix for 4 weeks. (B) AT1R mRNA level in Codonopsis Radix treated NCI–H295R cells. (C) Hypothalamic vasopressin (AVP), kidney vasopressin receptor 2 (AVPR2), and kidney aquaporin 2 (AQP2) mRNA levels of male mice treated by Codonopsis Radix for 4 weeks. (D) Tissue ANP receptor mRNA level of male mice treated by Codonopsis Radix for 4 weeks. Ad: adrenal gland. Gapdh serves as the internal control to calculate relative expression. All data were shown as the mean ± SEM. ∗∗P < 0.01, ∗∗∗P < 0.001, by student's t test.

Figure 7

Effects of Codonopsis Radix on gene transcriptional profiles. (A) Significantly differentially expressed genes, (B) Volcano plot, and (C) KEGG pathway enrich plot of differentially expressed genes were shown based on RNAseq results from NCI–H295R cells treated with 1 mg/ml Codonopsis Radix for 24 h. Red spot: upregulated genes; Black spot: no difference genes; Blue spot: downregulated genes; LogFC: log₂ (fold change); log₁₀(FDR): log₁₀(False Discovery Rate). (D) Quantitative RT-PCR results showing transcription alterations in the adrenal gland of wild-type male mice treated by Codonopsis Radix for 3 days. Summarized results from 3 independent wells are shown, with Gapdh serving as the internal control. All data were shown as mean ± SEM. n = 5. ∗P < 0.05. ∗∗∗P < 0.001. by student's t test. (E) A working model for the effects of Codonopsis Radix on water and electrolytes homeostasis.