Experimental evidence showed that oxidative stress plays a major role in the ageing process. Reactive oxygen species are activated by a large number of endogenic and environmental challenges. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage cellular structural membranes, lipids, proteins, and DNA. The body possesses endogenous defense mechanisms, such as antioxidative enzymes and non-enzymatic antioxidative molecules, protecting it from free radicals by reducing and neutralizing them. With age, the production of free radicals increases, while the endogenous defense mechanisms weaken. This imbalance leads to the progressive damage of the structure of the cell, which results in the ageing phenotype.