title: Hydrodynamic stress induces monoterpenoid oxindole alkaloid accumulation by Uncaria tomentosa (Willd) D. C. cell suspension cultures via oxidative burst.
abstract: Uncaria tomentosa cell suspension cultures were grown in a 2-L stirred tank bioreactor operating at a shear rate gamma(.)(avg)=86 s(-1). The cultures showed an early monophasic oxidative burst measured as H2O2 production (2.15 micromol H2O2 g(-1) dw). This response was followed by a transient production of monoterpenoid oxindole alkaloids (178 +/- 40 microg L(-1) at 24 h). At the stationary phase (144 h), the increase of the shear rate gamma(.)(avg) up to 150 s(-1) and/or oxygen tension up to 85% generated H2O2, restoring oxindole alkaloid production. U. tomentosa cells cultured in Erlenmeyer flasks also exhibited the monophasic oxidative burst but the H2O2 production was 16-fold lower and the alkaloids were not detected. These cells exposed to H2O2 generated in situ produced oxindole alkaloids reaching a maximum of 234 +/- 40 microg L(-1). A positive correlation was observed between the oxindole alkaloid production and the endogenous H2O2 level. On the other hand, addition of 1 microM diphenyleneiodonium (NAD(P)H oxidase inhibitor) or 10 microM sodium azide (peroxidases inhibitor) reduced both H2O2 production and oxindole alkaloids build up, suggesting that these enzymes might play a role in the oxidative burst induced by the hydrodynamic stress.
authors.affiliation: Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del IPN (CINVESTAV-IPN), Av. Instituto Politécnico Nacional 2508, Col, San Pedro Zacatenco, 07360, México, D. F. México.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Trejo-Tapia
authors.forename: Gabriela
authors.initials: G
authors.lastname: Sepúlveda-Jiménez
authors.forename: José Luis
authors.initials: JL
authors.lastname: Trejo-Espino
authors.forename: Carlos M
authors.initials: CM
authors.lastname: Cerda-García-Rojas
authors.forename: Mayra
authors.initials: M
authors.lastname: de la Torre
authors.forename: Mario
authors.initials: M
authors.lastname: Rodríguez-Monroy
authors.forename: Ana C
authors.initials: AC
authors.lastname: Ramos-Valdivia
mesh_terms: D020948:Cat's Claw / Q000502:physiology*; D002478:Cells, Cultured; D006861:Hydrogen Peroxide / Q000378:metabolism; D018384:Oxidative Stress / Q000502:physiology*; D010100:Oxygen / Q000378:metabolism*; D011312:Pressure; D017382:Reactive Oxygen Species / Q000378:metabolism*; D016897:Respiratory Burst / Q000502:physiology*; D046948:Secologanin Tryptamine Alkaloids / Q000378:metabolism*
chemical_list: D017382:Reactive Oxygen Species; D046948:Secologanin Tryptamine Alkaloids; D006861:Hydrogen Peroxide; D010100:Oxygen