title: Does the use of chitosan contribute to oxalate kidney stone formation?
abstract: Chitosan is widely used in the biomedical field due its chemical and pharmacological properties. However, intake of chitosan results in renal tissue accumulation of chitosan and promotes an increase in calcium excretion. On the other hand, the effect of chitosan on the formation of calcium oxalate crystals (CaOx) has not been described. In this work, we evaluated the antioxidant capacity of chitosan and its interference in the formation of CaOx crystals in vitro. Here, the chitosan obtained commercially had its identity confirmed by nuclear magnetic resonance and infrared spectroscopy. In several tests, this chitosan showed low or no antioxidant activity. However, it also showed excellent copper-chelating activity. In vitro, chitosan acted as an inducer mainly of monohydrate CaOx crystal formation, which is more prevalent in patients with urolithiasis. We also observed that chitosan modifies the morphology and size of these crystals, as well as changes the surface charge of the crystals, making them even more positive, which can facilitate the interaction of these crystals with renal cells. Chitosan greatly influences the formation of crystals in vitro, and in vivo analyses should be conducted to assess the risk of using chitosan.
authors.affiliation: Department of Biochemistry, Biosciences Centre, Federal University of Rio Grande do Norte, Salgado Filho avenue 3000, Natal, RN 59078-970, Brazil. moacirfqn@gmail.com.
authors.forename: Moacir
authors.initials: M
authors.lastname: Fernandes Queiroz
authors.affiliation: Department of Biochemistry, Biosciences Centre, Federal University of Rio Grande do Norte, Salgado Filho avenue 3000, Natal, RN 59078-970, Brazil. melo.krt@gmail.com.
authors.forename: Karoline Rachel Teodosio
authors.initials: KR
authors.lastname: Melo
authors.affiliation: Department of Biochemistry, Biological Sciences Centre, Federal University of Parana, Coronel Francisco H. dos Santos avenue S/N, Curitiba, PR CP 19031, Brazil. popoh_diego@hotmail.com.
authors.forename: Diego Araujo
authors.initials: DA
authors.lastname: Sabry
authors.affiliation: Department of Biochemistry, Biological Sciences Centre, Federal University of Parana, Coronel Francisco H. dos Santos avenue S/N, Curitiba, PR CP 19031, Brazil. sassaki@ufpr.br.
authors.forename: Guilherme Lanzi
authors.initials: GL
authors.lastname: Sassaki
authors.affiliation: Department of Biochemistry, Biosciences Centre, Federal University of Rio Grande do Norte, Salgado Filho avenue 3000, Natal, RN 59078-970, Brazil. hugo@cb.ufrn.br.
authors.forename: Hugo Alexandre Oliveira
authors.initials: HA
authors.lastname: Rocha
mesh_terms: D000975:Antioxidants / Q000494:pharmacology; D002129:Calcium Oxalate / Q000378:metabolism; D048271:Chitosan / Q000009:adverse effects* / Q000494:pharmacology; D003460:Crystallization; D006801:Humans; D007668:Kidney / Q000187:drug effects; D007669:Kidney Calculi / Q000209:etiology*; D009682:Magnetic Resonance Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000975:Antioxidants; D002129:Calcium Oxalate; D048271:Chitosan