Maqui berry (Aristotelia chilensis) extract improves memory and decreases oxidative stress in male rat brain exposed to ozone

ABSTRACT

Introduction: Prolonged ozone exposure can produce a state of oxidative stress, which in turn causes alterations in the dynamics of the brain and affects memory and learning. Moreover, different investigations have shown that high flavonoid content berries show a great antioxidant activity. The relationship between the protective effect of the maqui berry extract and its antioxidant properties in the brain has not been studied in depth. Objectives: The present study evaluated whether the protection exerted by the aqueous extract of maqui berry in brain regions associated with cognitive performance is due to its antioxidant capacity. Methods: Sprague Dawley rats were exposed to 0.25 ppm ozone and administered with maqui berry extracts. At the end of the treatments, spatial learning and short- and long-term memory were evaluated, as well as oxidative stress markers. Results: The administration of 50 and 100 mg/kg of the aqueous extract of maqui berry was effective in preventing the cognitive deficit caused by chronic exposure to ozone. The antioxidant effect of the administration of maqui berry was analyzed in the prefrontal cortex, hippocampus, and amygdala. Oxidative stress markers levels decreased and the enzymatic activity of superoxide dismutase diminished in animals exposed to ozone treated with the 50 mg/kg dose of maqui berry. Discussion: These results show a relationship between protection at the cognitive level and a decrease in oxidative stress markers, which suggests that the prevention of cognitive damage is due to the antioxidant activity of the maqui berry.

KEYWORDS:

• Oxidative stress
• memory and learning
• maqui berry
• malondialdehyde
• superoxide dismutase
• ozone
• antioxidants
• neuroprotection
• hippocampus

Acknowledgments

Christian Guerra-Araiza received Beca de Excelencia en Investigación by Fundación IMSS, A. C. This paper was presented in partial compliance with the requirements for the PhD degree of Iván Bribiesca Cruz at the Doctorate in Biological Sciences Program (Universidad Nacional Autónoma de México). The sponsors had no participation in the design of the study, the obtaining and analysis of results, the decision to publish or the preparation of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was partially funded by the Spanish Ministry of Economy, Industry and Competitiveness (MEIC) through the Research Project ‘Bebesano’ (Grant number AGL2016-75332-C2-1-R) and the Fondo de Investigación en Salud (Project FIS/IMSS/PROT/G17/1664) from the Instituto Mexicano del Seguro Social.].

Notes on contributors

Iván Bribiesca-Cruz

Iván Bribiesca-Cruz is a PhD candidate in Biological Sciences (Universidad Nacional Autónoma de México, Mexico City, Mexico) and completed a B.Sc. in Biology (Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Mexico City, Mexico) and an M.Sc. in Biological Sciences (Universidad Nacional Autónoma de México, Mexico City, Mexico). Bribiesca-Cruz’s research include sex hormones, oxidative stress in neurodegenerative diseases, and natural antioxidants in ozone exposure models.

Diego A. Moreno

Diego A. Moreno holds a PhD in Biological Sciences, University of Granada, Spain. He is a scientific researcher in the Phytochemistry and Healthy Foods lab of the Food Science and Technology Department at CEBAS-CSIC – The Spanish National Research Council (2018–present), being a member of the Research Group on Quality, Safety and Bioactivity of Plant Foods (CSIC #641446) since 2005, staff scientist (2008–2018) and postdoctoral associate (‘Ramón y Cajal’ 2006–2008, and I3P-CSIC 2005-2006). Diego A. Moreno has a previous experience abroad as a postdoctoral associate in the Ilya Raskin’s Lab at Rutgers – The State University of New Jersey (New Brunswcik, NJ, US) from 2001 to 2004, and background of PhD in Plant Physiology (2000), MSc (1996), and BSc (1994), obtained in the University of Granada (Spain). Current active projects of R&D and innovation on the development of new functional foods and beverages enriched in bioactive phytochemicals to modulate the energy metabolism (inflammation, glucose and lipid metabolism).

Cristina García-Viguera

Cristina García-Viguera completed a BSc in Pharmacy (Complutense Univ. Madrid), and PhD in Chemistry (Murcia Univ.). Worked in several Institutions: Oxford Univ., Reading Univ, Kew Gardens and IFR, in UK, as well as ATO-DLO (The Netherlands). Currently is a CSIC- Research Professor, at CEBAS-CSIC (Murcia- Spain). Has 164 publications (h = 52), and 4 patents. Research: development of new plant origen foods (fresh and processed), organoleptic and nutritionally improved, through life-enhancing bioactive phytochemicals. Founding Partner of the Spin-off Aquaporins & Ingredients SL. Head of the “Phytochemistry and Healthy Food Lab” and CSIC-UPCT “Quality and Risk Assessment in Food” (Assoc Unit).

Juan Manuel Gallardo

Juan Manuel Gallardo is an MD (Universidad Autónoma de Aguascalientes), MSc in Physiology Sciences (Centro de Investigación y Estudios Avanzados –IPN). He currently works at the Unidad de Investigación Médica en Enfermedades Nefrológicas, Instituto Mexicano del Seguro Social in Mexico. He does research on oxidative stress and inflammation in nephrological and metabolic diseases.

Julia J. Segura-Uribe

Julia J. Segura-Uribe obtained a BSc in Chemistry (Universidad Nacional Autónoma de México, Mexico City, Mexico), MSc in Biochemistry (Universidad Nacional Autónoma de Mexico, Mexico City, Mexico), and is a PhD candidate in Medical Research (Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, Mexico). Has 17 publications. Research: Sex hormones and neuroprotection, Alzheimer's disease.

Rodolfo Pinto-Almazán

Rodolfo Pinto-Almazán obtained a BSc in Pharmaceutical and Biological Chemistry (Universidad La Salle, Mexico City), an MSc in Pharmacology (Instituto Politécnico Nacional [IPN], Mexico City), a PhD in Biomedical Sciences (Universidad Nacional Autónoma de Mexico [UNAM], Mexico City), and a Postdoctoral Fellow at USC-CONACYT program (Keck University of Medicine, USC/Children’s Hospital Los Angeles, CA). Currently, he works as an Associate Professor in Medical Sciences “C” (Hospital Regional de Alta Especialidad de Ixtapaluca, Secretaría de Salud, Ixtapaluca, Mexico). Has 13 publications (143 cites, h = 6), among others. Research: Sex differences on neurological effects of metabolic syndrome. Cognitive effects in children nutrition.

Christian Guerra-Araiza

Christian Guerra-Araiza obtained a BSc in Biology (Universidad Nacional Autónoma de México, Mexico City), and a PhD in Biochemistry (Universidad Nacional Autónoma de Mexico, Mexico City). He continued his research as a postdoc at DGAPA-UNAM program (Instituto Cajal. Madrid, Spain). Currently, he works as Titular Researcher B at the Instituto Mexicano del Seguro Social (IMSS), Mexico City, Mexico. Has 50 publications. Research: Sex hormones and neuroprotection, Alzheimer disease, neurological effects of pollution and metabolic syndrome.