An extract of Hibiscus sabdariffa improves short-term memory in rats with experimental diabetic hyperglycemia

ABSTRACT

Background

Calyxes of Hibiscus sabdariffa (Hs) contain anthocyanins, that normalize blood glucose levels (BGL) in diabetic patients. Diabetes also causes memory alterations, which could hypothetically decrease with the consumption of Hs.

Objectives

To investigate the effect of dietary supplementation with a Hs extract on working memory and BGL in rats.

Methods

Diabetic hyperglycemia (DHG) was induced with streptozotocin (STZ, 55 mg/kg i.p.) in Wistar rats. After 72 h DHG was confirmed, and the consumption of Hs extract began (50 mg/Kg/day). BGL and body weight (BW) were measured at 10, 20 and 30 days after DHG induction in controls and treated animals. Learning and short-term memory were evaluated after 30 days with Novel Object Recognition Test (NOR) and Barnes Maze (BM). The gross hippocampal structure was histologically analyzed.

Results

STZ-treated animals presented low BW and persistent DHG (BGL <300 mg/dL). Diabetic animals consuming the Hs extract had a dual response: some showed BGL comparable to controls, while others had levels comparable to diabetic animals not consuming extract. Diabetic animals that consumed the Hs extract had a better performance in NOR and BM than the diabetic animals not consuming the extract. At the histological level, hippocampal morphological differences were observed between diabetic animals that consumed the extract and those that did not.

Discussion

The Hs extract used here could be a good co-adjuvant in the treatment of DHG, aimed at mitigating memory deficits and high BGL. These beneficial effects could be attributed to the anthocyanin content in the extract.

KEYWORDS:

• Hibiscus sabdariffa
• hyperglycemia
• work memory
• hippocampus

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

The data of this study are available from the corresponding author upon request.

Additional information

Funding

This work was supported by Consejo Estatal de Ciencia y Tecnología de Jalisco [grant number: 8237-2019]; Departamento de Biología Celular y Molecular, CUCBA, Universidad de Guadalajara [grant number: P3E/2020/254363].

Notes on contributors

Silvia J. López-Pérez

Silvia J. López-Pérez, PhD (ORCID: 0000-0002-6467-9927). Biologist and PhD in Biomedical Sciences focus in Neuroscience from the University of Guadalajara, currently a senior researcher in the CUCBA neurochemistry laboratory, and undergraduate and graduate level professor. Her main research interest is on the mechanisms of brain damage associated with metabolic diseases, and the use of nutraceuticals as adjuvants in their treatment. She has directed projects with external government financing and with the support of the University of Guadalajara. She has directed various projects leading to undergraduate and postgraduate degrees and has presented her works in international specialized events. She is the author or co-author of 17 indexed research papers.

Mónica E. Ureña-Guerrero

Mónica E. Ureña-Guerrero, PhD (ORCID: 0000-0001-8658-4171). Biologist and PhD in Biomedical Sciences with specialty in Neurosciences from the University of Guadalajara. She has completed several training courses at various institutions in Mexico, Europe and North America, as well as a brief research stay at the University of Veterinary Medicine in Hannover, Germany. Her line of research focuses on the characterization of the cellular and molecular mechanisms involved in seizure susceptibility due to brain immaturity, excitotoxic neuronal death, and neurovascular disorders. She has taught more than 100 undergraduate, doctoral and specialization courses, and directed 14 undergraduate theses and 7 doctoral theses. In research, she has directed 5 projects with external funds and more than 10 projects with funds from the UDG, she has presented the results of her projects in more than 70 specialized events and is the author or co-author of 25 indexed research papers. She is now recognized as a Level II National Researcher by the National System of Researchers of Mexico.

Jacinto Bañuelos-Pineda

Jacinto Bañuelos-Pineda, PhD (ORCID: 0000-0002-9744-5668). Senior Research Professor with extensive experience in teaching and research in morphophysiology of the central nervous system and animal behavior. His line of research is in animal morphophysiology and the use of antioxidants to improve animal health, in which he has published 40 articles. He currently belongs to the National System of Researchers of CONAHCYT, México.