Free radicals?

We hear a great deal in the news about so called “free radicals”and the damage they can do to our bodies. 

A free radical is a molecule that is highly unstable and reacts easily with other molecules (technically, this is because these molecules have an unpaired electron).  Free radicals are produced by a variety of normal biological processes and can also be a result of external exposures such as radiation, pollutants, and cigarette smoke.

Reactive oxygen species

Reactive oxygen species, or ROS, are a subset of free radicals that contain oxygen. Examples of ROS include peroxides including hydrogen peroxide (H₂O₂).  Cells with high metabolic rates produce greater amounts of ROS. 

In a biological context, ROS are by-products of the normal metabolism of oxygen, and are intrinsic to cellular functioning and are present at low levels in normal cells, where they have roles in cell signalling and homeostasis.  However, ROS can cause irreversible damage to DNA as they oxidize and modify some cellular components and prevent them from performing their original functions. 

Antioxidants

Antioxidants are substances that can prevent or slow damage to cells caused by free radicals. They are sometimes called “free-radical scavengers.”

Antioxidants counteract free radicals and they work in two different ways.  Enzymatic antioxidants work by breaking down or converting harmful ROS into water.    Non-enzymatic antioxidants such as Vitamin E and Vitamin C work by reacting with the radicals directly to neutralise the free radical.

What is oxidative stress?

Oxidative stress occurs anytime there exists an imbalance between antioxidants and free radicals, resulting in an abundance of unchecked reactive free radical species. 

Oxidative stress results in damage to DNA, proteins, and lipids and can have dramatic effects.

ROS are involved in the pathogenesis of multiple inflammatory diseases such as rheumatoid arthritis, cardiac and vascular dysfunction, and cancers.  

Cerium oxide (nanoceria) as an antioxidant

In a recent paper published in Frontiers in Immunology, authors Lena M Ernst and Victor F Puntes outline how cerium oxide (CeO₂) nanoparticles (nanoceria) not only protect from oxidative stress consequence of inflammation but also modulate the immune response towards inflammation resolution.

Importantly, this paper also outlines details on the safety of nanoceria as a medical treatment, as well as the conditions under which it can be produced safely to provide the desired theraputic effects and is easily and naturally excreted from the body. 

The authors explain that cerium is affordable, as abundant as silver, and that nanoceria is easy to produce following green chemistry principles with simple reagents having recyclable basic waters as by-product. It is stable in simple storage conditions, and of universal use.

Nanoceria as a treatment for oxidative stress

Dysregulation of the immune system is associated with an overproduction of metabolic reactive oxygen species (ROS) and consequent oxidative stress. By buffering excess ROS, cerium oxide (CeO₂) nanoparticles (nanoceria) not only protect from oxidative stress consequence of inflammation but also modulate the immune response towards inflammation resolution.

In recent years, Nanoceria has received much attention, because of its widespread biomedical applications, including antibacterial, antioxidant and anticancer activity, drug/gene delivery systems, anti-diabetic property, and tissue engineering.

Properly formulated, nanoceria is highly soluble, safe, and potentially biodegradable, and it may overcome current antioxidant substances limitations and thus open a new era for human health management.

We expect to hear a lot more about Nanoceria and its potential as a treatment for a variety of ailments in the near future.