Oxidative stress: Insights into the Pathogenesis and Treatment of Alopecia

Hairs are exposed to a host of endogenous and environmental stress by pollutants, microbial assaults, UV radiation, oxidized scalp lipids, grooming practices and cosmetic treatments which have diverse range of adverse consequences. The exposure to these environmental and cosmetic substances, leads to generation of free radicals, reactive oxygen species in particular, leading to oxidative stress. Oxidative stress generates inflammation, and/or psycho-emotional stress, and also influences the ageing process, including the hair follicle. The term alopecia signifies loss of hair owing to several factors, ultimately resulting in decreased hair density. Cell death on hair follicle (keratinocytes and its distinctive mesenchyme of dermal papilla) have been attributed to mechanisms of oxidative stress, including H2O2, nitric oxide and derivatives, ultraviolet rays, ionizing radiations, endotoxin-induced inflammation, photodynamic therapy and cigarette smoke. Persistent oxidative activities in the body, may generate antioxidant defense systems, which can prevent the attack of biological molecules. In case of androgenic alopecia, copper and zinc was discovered in the disrupted metabolism form in serum, urine and hair of the patients, and data suggests rise in oxidative stress. This review is focused on the effects of the reactive oxygenated species in disturbing the redox balance and inducing oxidative injury that leads to androgenic alopecia.