title: Intestinal absorption mechanisms of MTBH, a novel hesperetin derivative, in Caco-2 cells, and potential involvement of monocarboxylate transporter 1 and multidrug resistance protein 2.
abstract: Hesperetin, the aglycone of hesperidin, occurs naturally in citrus fruits. It exerts extensive pharmacological activities. However, hesperetin's poor solubility and low bioavailability limit its wide application. In order to overcome these limitations, recently a series of novel hesperitin derivatives containing Mannich base moieties were synthesized and the anti-inflammatory activity was evaluated, among which MTBH (8-methylene-tert-butylamine-3',5,7-trihydroxy-4'-methoxyflavanone) showed a significantly improved water solubility, and promising anti-inflammatory activity in vitro and in vivo compared with hesperitin. Thus, the aim of this study was to investigate the permeability and transport mechanisms of MTBH, using Caco-2 cell monolayer. MTBH was effectively absorbed by Caco-2 cells in a concentration-dependent manner in both directions at 7.5-480 μM. Moreover, MTBH showed pH dependent and TEER values independent transport in both directions. Transport of MTBH was obviously decreased in the presence of sodium azide (an ATP inhibitor) or CCCP (a proton-ionophore). MTBH transport was markedly reduced by MCT inhibitors quercetin or phloretin, and the substrate analogs l-lactate or benzoic acid. We verified MCT1, MCT3, MCT4, MCT5, and MCT6 were expressed in Caco-2 cells by western blot. Silence MCT1 with siRNA resulted in significant inhibition of MTBH uptake. The verapamil, a P-gp inhibitor, and Ko143, a BCRP inhibitor, had no effect on the transport of MTBH. However, MK-571 or probenecid, MRP2 inhibitors, led to an apparently decrease in the efflux of MTBH. In summary, MTBH was absorbed by transcellular passive diffusion and a pH dependent mechanism mediated by MCT1. MRP2 but P-gp or BCRP may be involved in the transport of MTBH.
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China. Electronic address: shchlin520@163.com.
authors.forename: Chenlin
authors.initials: C
authors.lastname: Shen
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Ruonan
authors.initials: R
authors.lastname: Chen
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Zhengyue
authors.initials: Z
authors.lastname: Qian
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Meng
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Tingting
authors.initials: T
authors.lastname: Hu
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Li
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Zhaolin
authors.initials: Z
authors.lastname: Chen
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China; Anhui Provincial Hospital, Hefei 230001, China.
authors.forename: Chaojie
authors.initials: C
authors.lastname: Hu
authors.affiliation: School of Pharmacy, Institute for Liver Diseases of Anhui Medical University (AMU), Anhui Key Laboratory of Bioactivity of Natural Products, Anhui Medical University, Hefei 230032, China. Electronic address: lj@ahmu.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Li
mesh_terms: D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D018938:Caco-2 Cells; D044950:Flavanones / Q000494:pharmacology*; D006569:Hesperidin; D006801:Humans; D007408:Intestinal Absorption; D027501:Monocarboxylic Acid Transporters / Q000378:metabolism*; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism*
chemical_list: D000893:Anti-Inflammatory Agents; D044950:Flavanones; D006569:Hesperidin; D027501:Monocarboxylic Acid Transporters; D000089762:Multidrug Resistance-Associated Protein 2; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C000608081:8-methylene-tert-butylamine-3',5,7-trihydroxy-4'-methoxyflavanone; C000715087:ABCC2 protein, human; C013015:hesperetin
keywords: Caco-2 cells; Flavonoids; MCT1; MRP2; MTBH; Passive diffusion