title: Inhibition of para-Hydroxyphenylpyruvate Dioxygenase by Analogues of the Herbicide Nitisinone As a Strategy to Decrease Homogentisic Acid Levels, the Causative Agent of Alkaptonuria.
abstract: Alkaptonuria (AKU) is a rare multisystem metabolic disease caused by deficient activity of homogentisate 1,2-dioxygenase (HGD), which leads to the accumulation of homogentisic acid (HGA). Currently, there is no treatment for AKU. The sole drug with some beneficial effects is the herbicide nitisinone (1), an inhibitor of p-hydroxyphenylpyruvate dioxygenase (4-HPPD). 1 has been used as a life-saving drug in infants with type I tyrosinemia despite severe side effects due to the buildup of tyrosine. Four clinical trials of nitisinone to treat AKU have shown that 1 consistently decreases HGA levels, but also caused the accumulation of tyrosine in blood serum. Moreover, the human preclinical toxicological data for 1 are incomplete. In this work, we performed pharmacodynamics and toxicological evaluations of 1, providing the first report of LD50 values in human cells. Intracellular tyrosinemia was also evaluated. Three additional 4-HPPD inhibitors with a more favorable profile than that of 1 in terms of IC50, LD50, and tyrosine accumulation were also identified among commercially available compounds. These may be promising starting points for the development of new therapeutic strategies for the treatment of AKU.
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Marcella
authors.identifier: http://orcid.org/0000-0002-2736-4010
authors.initials: M
authors.lastname: Laschi
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Giulia
authors.identifier: http://orcid.org/0000-0003-0016-0728
authors.initials: G
authors.lastname: Bernardini
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Elena
authors.identifier: http://orcid.org/0000-0001-8987-940X
authors.initials: E
authors.lastname: Dreassi
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Lia
authors.identifier: http://orcid.org/0000-0002-5379-8808
authors.initials: L
authors.lastname: Millucci
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Michela
authors.identifier: http://orcid.org/0000-0002-6910-0056
authors.initials: M
authors.lastname: Geminiani
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Daniela
authors.identifier: http://orcid.org/0000-0002-9657-4169
authors.initials: D
authors.lastname: Braconi
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Barbara
authors.identifier: http://orcid.org/0000-0002-4622-7054
authors.initials: B
authors.lastname: Marzocchi
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Maurizio
authors.identifier: http://orcid.org/0000-0003-0456-6995
authors.initials: M
authors.lastname: Botta
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy.
authors.forename: Fabrizio
authors.identifier: http://orcid.org/0000-0002-9598-2339
authors.initials: F
authors.lastname: Manetti
authors.affiliation: Department of Biotechnology, Chemistry and Pharmacy, Università degli Studi di Siena, Via Aldo Moro 2, 53100, Siena, Italy. annalisa.santucci@unisi.it.
authors.forename: Annalisa
authors.identifier: http://orcid.org/0000-0001-6976-9086
authors.initials: A
authors.lastname: Santucci
mesh_terms: D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000474:Alkaptonuria / Q000188:drug therapy* / Q000378:metabolism; D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D003512:Cyclohexanones / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006540:Herbicides / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D006713:Homogentisic Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D015394:Molecular Structure; D009579:Nitrobenzoates / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013329:Structure-Activity Relationship
chemical_list: D003512:Cyclohexanones; D006540:Herbicides; D009579:Nitrobenzoates; D015111:4-Hydroxyphenylpyruvate Dioxygenase; C077073:nitisinone; D006713:Homogentisic Acid
keywords: alkaptonuria; enzymes; inhibitors; nitisinone; p-hydroxyphenylpyruvate dioxygenase