Article Figures & Data
Figures
- Fig. 1.
Metabolic pathways and structures of major cannabinoids and their metabolites.
- Fig. 2.
Chromatograms of probe metabolites in microsomes from UGT-overexpressing HEK293 cell lines. Probe substrates (at concentrations close to their known Km; see Supplemental Table 1) were incubated in rUGTs for 60–120 minutes at 37°C, and individual corresponding metabolites were analyzed by UPLC-MS/MS as described in Supplemental Table 1 and in the Materials and Methods.
- Fig. 3.
Screening of cannabinoid inhibition of major hepatic UGTs in microsomes from UGT-overexpressing HEK293 cell lines. Probe substrates were β-estradiol for UGT1A1, chenodeoxycholic acid for UGT1A3, trifluoperazine for UGT1A4, serotonin for UGT1A6, propofol for UGT1A9, codeine for UGT2B4, zidovudine for UGT2B7, nicotine for UGT2B10, oxazepam for UGT2B15, and dihydroexemestane for UGT2B17. Incubations were performed using 10 or 100 µM of cannabinoid, with probe substrate concentrations at or close to their known Km for their corresponding enzyme (see Supplemental Table 1). Shown are the mean inhibition of two individual experiments performed for each probe substrate. Data are expressed as a percentage of metabolite formation formed in assays with cannabinoid compared with assays without cannabinoid.
- Fig. 4.
Inhibitory effects of CBD on the glucuronidation of UGT probe substrates in microsomes from UGT-overexpressing HEK293 cell lines (rUGT), HLMs, and HKMs. Shown are representative plots comparing CBD concentration with the percent glucuronidation activity against probe substrates in rUGT microsomes, HLMs, and HKMs. Incubations were performed for 60–120 minutes at 37°C using 80–90 µg of rUGT microsomes or 90–200 µg HLMs or HKMs with the following probe substrates: propofol, acetaminophen, and furosemide for UGT1A9; serotonin for UGT1A6; codeine for UGT2B4; and AZT for UGT2B7 (see Supplemental Table 1 for concentrations). Individual metabolites were analyzed by UPLC-MS/MS as described in the Materials and Methods.
Tables
- TABLE 1
IC50 values (µM) of cannabinoids against major hepatic UGT enzymes in microsomes from recombinant UGT–overexpressing cells, HLMs, or HKMs.
Probe substrate Microsomes THC CBD CBN IC50 IC50,u IC50 IC50,u IC50 IC50,u µM µM µM µM µM µM Serotonin rUGT1A6 10 ± 2.6 0.40 ± 0.10 HKM NA 17 ± 3.7 1.0 ± 0.23 NA HLM 28 ± 6.5 1.4 ± 0.33 Codeine rUGT2B4 11 ± 2.7 0.47 ± 0.11 5.8 ± 1.2 0.22 ± 0.045 HKM 55 ± 5.2 2.9 ± 0.27 39 ± 5.9 2.5 ± 0.37 NA HLM 13 ± 2.6 0.61 ± 0.13 8.0 ± 1.1 0.40 ± 0.058 AZT rUGT2B7 33 ± 8.5 1.4 ± 0.36 21 ± 3.9 0.82 ± 0.15 49 ± 12 4.2 ± 1.1 HKM 51 ± 12 2.6 ± 0.65 35 ± 3.5 2.2 ± 0.22 57 ± 7.5 6.9 ± 0.90 HLM 59 ± 6.6 2.8 ± 0.32 30 ± 4.1 1.5 ± 0.21 59 ± 8.6 5.5 ± 0.79 Propofol rUGT1A9 11 ± 3.0 0.45 ± 0.12 3.2 ± 0.52 0.12 ± 0.020 6.0 ± 0.75 0.51 ± 0.063 HKM 12 ± 3.4 0.64 ± 0.18 5.5 ± 0.56 0.34 ± 0.035 7.5 ± 1.7 0.90 ± 0.20 HLM 30 ± 6.4 1.4 ± 0.31 19 ± 4.6 1.0 ± 0.24 31 ± 4.1 2.9 ± 0.38 Furosemide rUGT1A9 8.0 ± 0.47 0.33 ± 0.020 2.4 ± 0.66 0.090 ± 0.025 9.2 ± 2.1 0.78 ± 0.18 HKM 10 ± 4.1 0.54 ± 0.22 3.6 ± 0.80 0.22 ± 0.049 15 ± 0.77 1.9 ± 0.092 HLM 32 ± 6.3 1.5 ± 0.30 29 ± 4.0 1.5 ± 0.20 34 ± 6.3 3.1 ± 0.58 Acetaminophen rUGT1A9 12 ± 3.7 0.49 ± 0.15 1.9 ± 0.29 0.073 ± 0.011 6.9 ± 0.54 0.59 ± 0.046 HKM 15 ± 3.0 0.79 ± 0.16 3.8 ± 0.82 0.24 ± 0.05 21 ± 3.4 2.6 ± 0.41 HLM 29 ± 8.9 1.4 ± 0.43 12 ± 3.2 0.64 ± 0.16 30 ± 4.5 2.8 ± 0.96 IC50 values are presented as means ± S.D. of three independent experiments. IC50,u, binding-corrected IC50; NA, not analyzed.
Data Supplement
- Supplemental Data -
Supplemental Table 1. Assay conditions used for the experiments.
Supplemental Figure 1. Inhibitory effects of THC and CBN on the glucuronidation of UGT probe substrates in microsomes from UGT-overexpressing HEK293 cell lines (rUGT), HLM and HKM.
- Supplemental Data -
In this issue
Cannabinoids and Their Metabolites as UGT Enzyme Inhibitors
