HuangQin Decoction Attenuates CPT-11-Induced Gastrointestinal Toxicity by Regulating Bile Acids Metabolism Homeostasis

Abstract

Irinotecan (CPT-11) is a potent chemotherapeutic agent, however, its clinical usage is often limited by the induction of severe gastrointestinal (GI) toxicity, especially late-onset diarrhea. HuangQin Decoction (HQD), commonly used for the treatment of GI ailments, has been proved could significantly ameliorate the intestinal toxicity of CPT-11. To reveal the mechanisms of CPT-11-induced toxicity and the modulation effects of HQD, a previous untargeted metabolomics study was performed and the results indicated that HQD may protect the GI tract by altering the metabolism of bile acids (BAs). Nevertheless, the untargeted assays are often less sensitive and/or efficient. In order to further confirm our previous findings, here in this paper, serum and tissues metabolic profiles of 17 BAs were analyzed using liquid chromatography-tandem mass spectrometry based targeted metabolomics. The results indicated that serum and tissues levels of most BAs were significantly decreased after CPT-11 administration, except some hydrophobic BAs. Co-treatment with HQD could markedly attenuate CPT-11-induced GI toxicity and reverse the alterations of hydrophobic BAs. Despite the fact that the BAs pool size remained unchanged, the balance of BAs had shifted leading to decreased toxicity after HQD treatment. The present study demonstrated for the first time that the precise interaction between HQD, CPT-11-induced intestinal toxicity and BAs' homeostasis.

Keywords: HuangQin Decoction; LC-MS/MS; bile acids; irinotecan (CPT-11); metabolomics.

FIGURE 1

Experimental design. Animals either received vehicle alone, CPT-11 alone, or CPT-11 and HQD. The toxicity model was constructed by treatment of animals with CPT-11 at 150 mg/kg by intravenous injection (i.v.) once a day for two consecutive days (day 1–2). HQD (10 g/kg) was given orally twice a day for 6 days beginning on day 0 (day 0–5). The mortality, weight loss and food intake of animals were monitored daily. The rats were finally euthanized on day 5. Serum and tissues (liver, jejunum, ileum, cecum, colon, and rectum) were collected for preparation and analysis. The dashed part is completed in the pilot study.

FIGURE 2

CPT-11-induced intestinal damage. Tissue sections (liver, jejunum, ileum, cecum, and colon) were dissected for routine histopathology assessment. Representative photographs of histological examination for (A–E) control, (F–J) model, and (K–O) HQD group. Bar = 50 μm.

FIGURE 3

PLS-DA models of bile acids profiles. Based on the score plots, bile acids profiles of three groups of rats were shown for (A) serum, (B) liver, (C) jejunum, (D) ileum, (E) cecum, (F) colon, and (G) rectum. (A) R²X = 0.614, R²Y = 0.806, Q² = 0.641; (B) R²X = 0.710, R²Y = 0.753, Q² = 0.575; (C) R²X = 0.530, R²Y = 0.647, Q² = 0.483; (D) R²X = 0.513, R²Y = 0.830, Q² = 0.524; (E) R²X = 0.471, R²Y = 0.709, Q² = 0.547; (F) R²X = 0.614, R²Y = 0.753, Q² = 0.540; (G) R²X = 0.711, R²Y = 0.875, Q² = 0.612.

FIGURE 4

Concentrations of hydrophobic bile acids in biological samples among different groups. Graphics represent the mean ± SD. P-values were determined by Mann–Whitney U-test. Significance compared with control group: ^∗∗∗P < 0.001, ^∗∗P < 0.01, ^∗P < 0.05. Significance compared with model group (only CPT-11-treated group): ^###P < 0.001, ^##P < 0.01, ^#P < 0.05.

FIGURE 5

The impact of CPT-11 and HQD on bile acids metabolome. The bile acids profile in the intestine shows the combined data from five segments (jejunum, ileum, cecum, colon, and rectum). Bile acids with arrow is significantly changed (↑ content increased; ↓ content decreased).