Encapsulating squalene in nanoparticles: more effective than the equivalent dose of the free drug
A collaboration between several areas of the CIBER in the area of Obesity and Nutrition (CIBEROBN) and the area of Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN) at the University of Zaragoza and the Instituto de Nanociencia y Materiales de Aragón (INMA), CSIC-University of Zaragoza, has made possible to encapsulate squalene, which is a component of virgin olive oil with large antioxidant properties, in nanoparticles. The research team, led by Jesús de la Osada, found that these particles protect the liver, being much more effective and requiring much less quantity to achieve the benefits of this substance compared to its free form.
In vitro studies
Virgin olive oil, the main source of fat in the Mediterranean diet, contains a significant amount of squalene, which has natural antioxidant properties. Squalene resists frying; it is absorbed by the body and accumulates in the liver. However, due to its highly hydrophobic nature (not miscible with water), its bioavailability outside olive oil is very low and it is easily oxidized. Hence, in order to be able to use this compound outside olive oil, new ways of efficiently administering it are required.
In this study, to increase its delivery and enhance its therapeutic action, the researchers loaded squalene onto polylactic co-glycolic acid (PLGA) nanoparticles. “Monomers based on this polymer, PGLA, are compounds that biodegrade in the body without causing toxicity because they are composed of two biological substances, lactic acid and glycolic acid, which are already used to make biodegradable suture threads. Under certain conditions, extraordinarily small capsules called nanoparticles can form encapsulating highly hydrophobic drugs and are easily taken up by cells. In this work we show that PGLA nanoparticles can be loaded with squalene,” explains Dr de la Osada.
These squalene-loaded particles stabilized this compound and were used to evaluate its effect in vitro using mouse cells. This work showed that they entered the cells with great efficacy, producing a therapeutic effect, which reduced the amount of compound required.
The role of the TXNDC5 protein
In addition, the researchers genetically engineered a mouse liver cell line (AML12) using CRISPR/cas9 techniques (which is a molecular tool used to “edit” or “correct” the genome of any cell) so that they would not have the TXNDC5 protein. This protein had been found by the group to be associated with fatty liver disease and its function is unknown. In this work, the aim was to evaluate the role of the lack of this protein in the action of squalene when encapsulated in nanoparticles.
Both types of cells (genetically modified and unmodified cells) were incubated with either hydrogen peroxide or the naturally occurring toxic compound, tapsigargin, to subject them to oxidative stress. Encapsulated squalene reduced hydrogen peroxide-induced oxidative damage and tapsigargin-induced endoplasmic reticulum damage. This was not observed in cells lacking TXNDC5 protein.
Therefore, it was concluded that squalene protects mouse hepatocytes (a type of liver cell located only in the liver and responsible for bile production) from oxidative and endoplasmic reticulum damage via molecular mechanisms that depend on TXNDC5.
The future direction of this work is to validate this therapeutic strategy to prevent and combat fatty liver disease using preclinical models.
Bibliographic reference:
Seyed Hesamoddin Bidooki, Teresa Alejo, Javier Sánchez-Marco, Roberto Martínez-Beamonte, Roubi Abuobeid, Juan Carlos Burillo, Roberto Lasheras, Víctor Sebastián, María J. Rodríguez-Yoldi, Manuel Arruebo and Jesús Osada. “Squalene Loaded Nanoparticles Effectively Protect Hepatic AML12 Cell Lines against Oxidative and Endoplasmic Reticulum Stress in a TXNDC5-Dependent Way”. Antioxidants 2022. https://doi.org/10.3390/antiox11030581
About CIBEROBN
The CIBER (Consorcio Centro de Investigación Biomédica en Red, M.P.) depends on the Instituto de Salud Carlos III -Ministerio de Ciencia e Innovación- and is co-financed by the European Regional Development Fund (ERDF). The CIBER de Fisiopatología de la Obesidad y Nutrición (CIBEROBN) is a consortium made up of 33 national working groups of proven scientific excellence, which focuses its research work on the study of obesity, nutrition and physical exercise in order to generate useful knowledge for clinical practice, the food industry and society as a whole. This institution also works on the benefits of the Mediterranean diet, the prevention of metabolic disorders, childhood and youth obesity, and the relationship between obesity and cancer.
