Melanin
Melanin tells the tale of how our ancestors survived from the Sun's heavy UV rays 50000 years back.
About Melanin
Melanin is a natural pigment in the body responsible for the color of human skin, hair, and eyes. Produced by specialized cells called melanocytes, its primary function is to provide protection against damage from ultraviolet (UV) radiation by absorbing and scattering UV light.
Types of Melanin
There are three main types of melanin found in humans:
- Eumelanin: This is a dark brown/black pigment and the most common type. Higher levels of eumelanin result in darker skin and hair and offer superior protection against UV damage, thus lowering the risk of skin cancer.
- Pheomelanin: This is a lighter, red/yellow pigment found in high amounts in individuals with red hair, freckles, lips, and nipples. Unlike eumelanin, pheomelanin provides minimal photoprotection and may even contribute to skin damage when exposed to UV light.
- Neuromelanin: Found in specific areas of the brain, such as the substantia nigra, this dark pigment's exact function is still being studied, but it is thought to play a role in binding metals and protecting neurons.
Function
Melanin's main roles in the human body include:
- Pigmentation: Determining an individual's unique color of skin, hair, and eyes based on the type and quantity produced.
- Photoprotection: Acting as a natural sunscreen by absorbing and dissipating harmful UV rays before they can damage the DNA in skin cells, which reduces the risk of sunburn and skin cancer.
- Antioxidant Activity: Acting as a free radical scavenger, which helps to neutralize reactive oxygen species (ROS) produced by cellular processes and UV exposure, thus preventing oxidative stress and cellular damage.
- Auditory Function: Melanocytes in the inner ear are involved in hearing and balancing functions.
Conditions Related to Melanin
Imbalances in melanin production can lead to various conditions:
- Albinism: A genetic disorder characterized by a lack or significant reduction of melanin in the skin, hair, and eyes, often resulting in vision problems and a high susceptibility to sun damage.
- Vitiligo: An autoimmune condition where melanocytes are destroyed, leading to smooth, white patches on the skin and hair.
- Hyperpigmentation: Conditions like melasma or sunspots, where there is an excess production or uneven distribution of melanin, leading to darker patches of skin.
- Parkinson's Disease: The loss of neuromelanin-producing cells in the brain is a key feature of this neurodegenerative disorder.
Download Pdf
