Hepatotoxicity of a Cannabidiol-Rich Cannabis Extract in the Mouse Model

Abstract

The goal of this study was to investigate Cannabidiol (CBD) hepatotoxicity in 8-week-old male B6C3F1 mice. Animals were gavaged with either 0, 246, 738, or 2460 mg/kg of CBD (acute toxicity, 24 h) or with daily doses of 0, 61.5, 184.5, or 615 mg/kg for 10 days (sub-acute toxicity). These doses were the allometrically scaled mouse equivalent doses (MED) of the maximum recommended human maintenance dose of CBD in EPIDIOLEX® (20 mg/kg). In the acute study, significant increases in liver-to-body weight (LBW) ratios, plasma ALT, AST, and total bilirubin were observed for the 2460 mg/kg dose. In the sub-acute study, 75% of mice gavaged with 615 mg/kg developed a moribund condition between days three and four. As in the acute phase, 615 mg/kg CBD increased LBW ratios, ALT, AST, and total bilirubin. Hepatotoxicity gene expression arrays revealed that CBD differentially regulated more than 50 genes, many of which were linked to oxidative stress responses, lipid metabolism pathways and drug metabolizing enzymes. In conclusion, CBD exhibited clear signs of hepatotoxicity, possibly of a cholestatic nature. The involvement of numerous pathways associated with lipid and xenobiotic metabolism raises serious concerns about potential drug interactions as well as the safety of CBD.

Keywords: cannabidiol; hepatotoxicity; liver injury; natural products; phytochemical.

Conflict of interest statement

Quick serves as a scientific consultant for Allergen. The other authors have no conflicts of interest to disclose.

Figures

Figure 1

Effects of single gavage with CBD. Mice were gavaged with 246, 738, or 2460 mg/kg of CBD in sesame oil with tissues harvested at 24 h. (A) Body weight change, (B) liver to body weight ratios, intrahepatic concentrations of (C) total glutathione (GSH), (D) reduced glutathione (GSSG), and (E) GSH/GSSG ratio. Data are presented as mean ± SEM (n = 6). * indicates a significant difference as calculated with a One-Way ANOVA and Tukey’s post-hoc test, and # indicates a significant difference as calculated with a Kruskal-Wallis test with a Dunn’s post-hoc test (p < 0.05).

Figure 2

Effects of single gavage with CBD on intrahepatic expression of cytochrome P450s and UDP-glucuronosyltransferases. Livers were collected at 24 h and gene expression was measured using the quantitative real-time (qRT) PCR. * - indicate data analyzed by One-Way ANOVA with Tukey’s post-test, and # indicate non-normal data analyzed with a Kruskal-Wallis and Dunn’s post-hoc test. Data are presented as mean ± SEM fold changed from vehicle (n = 6), with * or # as p < 0.05; ** or ## as p < 0.01; *** or ### as p < 0.001; and **** or #### as p < 0.0001.

Figure 3

Effects of 2-week administration of CBD on liver histomorphology. H&E stained liver sections from (A) vehicle mice or those gavaged with (B) 61.5 mg/kg, (C) 184.5 mg/kg, or (D) 615 mg/kg CBD in sesame oil for 2 weeks. Note that 615 mg/kg group was terminated after 2–3 doses due to overt toxicity elicited by CBD.

Figure 4

Effects of 2-week administration of CBD on: (A) Body weight dynamics, (B) Liver to body weight ratio. Intrahepatic concentrations of (C) total glutathione (GSH), (D) reduced glutathione (GSSG), and (E) GSH/GSSG ratio. Data are presented as mean ± SEM (n = 6). # indicates a significant difference as calculated with a Kruskal-Wallis test with a Dunn’s post-hoc test with # representing p < 0.05; and ###p < 0.001.

Figure 5

Effects of a two-week administration of CBD on intrahepatic expression of cytochrome P450s and UDP-glucuronosyltransferases. Livers were collected 6 h after the last gavage and gene expression was measured using the quantitative real-time (qRT) PCR. * - indicate data analyzed by One-Way ANOVA with Tukey’s post-test, and # indicate non-normal data analyzed with a Kruskal-Wallis and Dunn’s post-hoc test. Data are presented as mean ± SEM fold changed from vehicle (n = 6), with * or # as p < 0.05; ** or ## as p < 0.01; *** or ### as p < 0.001; and **** or #### as p < 0.0001.