title: Cremophor EL-based nanoemulsion enhances transcellular permeation of emodin through glucuronidation reduction in UGT1A1-overexpressing MDCKII cells.
abstract: Oral emodin, a natural anthraquinone and active component of many herbal medicines, is poorly bioavailable because of extensive first-pass glucuronidation. Here we aimed to prepare emodin nanoemulsion (EMO-NE) containing cremophor EL, and to assess its potential for enhancing transcellular absorption of emodin using UGT1A1-overexpressing MDCKII cells (or MDCK1A1 cells). EMO-NE was prepared using a modified emulsification technique and subsequently characterized by particle size, morphology, stability, and drug release. MDCKII cells were stably transfected with UGT1A1 using the lentiviral transfection approach. Emodin transport and metabolism were evaluated in Transwell-cultured MDCK1A1 cells after apical dosing of EMO-NE or control solution. The obtained EMO-NE (116 ± 6.5 nm) was spherical and stable for at least 2 months. Emodin release in vitro was a passive diffusion-driven process. EMO-NE administration increased the apparent permeability of emodin by a 2.3-fold (p<0.001) compared to the pure emodin solution (1.2 × 10(-5) cm/s vs 5.3 × 10(-6) cm/s). Further, both apical and basolateral excretion of emodin glucuronide (EMO-G) were significantly decreased (≥56.5%, p<0.001) in EMO-NE group. This was accompanied by a marked reduction (57.4%, p<0.001) in total emodin glucuronidation. It was found that the reduced glucuronidation was due to inhibition of cellular metabolism by cremophor EL. Cremophor EL inhibited UGT1A1-mediated glucuronidation of emodin using the mixed-type inhibition mechanism. In conclusion, cremophor EL-based nanoemulsion greatly enhanced transcellular permeation of emodin through inhibition of UGT metabolism. This cremophor EL-based nanoformulation may be a promising strategy to improve the oral bioavailability of emodin.
authors: Division of Pharmaceutics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China.
authors: Tianpeng
authors: T
authors: Zhang
authors: Ocular Surface Research Center and Institute of Ophthalmology, Jinan University School of Medicine, Guangzhou, China.
authors: Dong
authors: D
authors: Dong
authors: Division of Pharmaceutics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China.
authors: Danyi
authors: D
authors: Lu
authors: Division of Pharmaceutics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China.
authors: Shuai
authors: S
authors: Wang
authors: Division of Pharmaceutics, College of Pharmacy, Jinan University, 601 Huangpu Avenue West, Guangzhou 510632, China. Electronic address: bj.wu@hotmail.com.
authors: Baojian
authors: B
authors: Wu
mesh_terms: D000818:Animals; D004285:Dogs; D065546:Drug Liberation; D004642:Emodin / Q000008:administration & dosage* / Q000494:pharmacology; D004655:Emulsions; D004705:Endocytosis / Q000187:drug effects; D020719:Glucuronides / Q000378:metabolism*; D014453:Glucuronosyltransferase / Q000235:genetics / Q000378:metabolism*; D005990:Glycerol / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D061985:Madin Darby Canine Kidney Cells; D049329:Nanostructures / Q000008:administration & dosage* / Q000737:chemistry; D000099148:UGT1A1 Enzyme
chemical_list: D004642:Emodin; D004655:Emulsions; D020719:Glucuronides; D014453:Glucuronosyltransferase; D005990:Glycerol; D000099148:UGT1A1 Enzyme; C000515:cremophor EL
keywords: Cremophor EL; Emodin; Glucuronidation; MDCK cells; Nanoemulsions; UGT