Don't be surprised if in a few years television commercials for skin cream start touting that they are "now formulated with methylene blue." That's because research out of the University of Maryland (UMD) has shown that the common antioxidant can reverse the effects of aging on our skin.
The dye has been used in medicine for more than 140 years for a variety of things - from staining bodily tissue during surgery to killing bacteria in urinary tract infections. It works by destroying disease-causing free radicals. Recently it's shown promise in fighting Alzheimer's disease.
And now scientists at the University of Maryland have found another use: anti-aging.
Lead author Professor Zheng-Mei Xiong said: 'Methylene blue demonstrates a great potential to delay skin aging for all ages.'
The researchers tested it for four weeks in skin cells from healthy middle-aged donors and octogenarians as well as patients diagnosed with progeria - a rare genetic disease that ages them quickly.
Methylene blue - first synthesized in 1876 - out-performed three other antioxidants N-Acetyl-L-Cysteine (NAC), MitoQ and MitoTEMPO (mTEM).
Fibroblasts - skin cells that produce the structural protein collagen - experienced a decrease in damaging reactive oxygen species, a reduced rate of death and an increase in the rate of cell division throughout the treatment.
Anything that helps maintain collagen levels in the skin will keep it looking younger as natural levels of start to fall in your mid-30s. By the age of 55 they may have fallen by 40 percent. Less collagen means skin that sags and wrinkles.
Prof Kan Cao said: 'Our work suggests methylene blue could be a powerful antioxidant for use in skin care products.
'The effects we are seeing are not temporary. Methylene blue appears to make fundamental, long-term changes to skin cells.'
Antioxidants help counteract the effects of free radicals - unstable molecules in our body's cells which help speed up the ageing process,
The expression of two genes commonly used as indicators of cellular aging - senescence-associated beta-galactosidase and p16 - were decreased in the cells from older donors.
Prof Xiong said: 'I was encouraged and excited to see skin fibroblasts, derived from individuals more than 80 years old, grow much better in methylene blue-containing medium with reduced cellular senescence markers.'
The researchers whose findings are published in Scientific Reports then used simulated human skin they themselves developed to perform several more experiments.
The 3D model made of living skin cells includes all the major layers and structures of with the exception of hair follicles and sweat glands.
Prof Cao said it could also be used in skin irritation tests required by the Food and Drug Administration for the approval of new cosmetic products.
She said: 'This system allowed us to test a range of aging symptoms that we can't replicate in cultured cells alone.
'Most surprisingly we saw model skin treated with methylene blue retained more water and increased in thickness - both of which are features typical of younger skin.'
When methylene blue was added to cosmetic creams it caused little to no irritation - even at high concentrations. The researchers plan to develop safe and effective ways for consumers to benefit from its properties.
Prof Cao said: 'We have already begun formulating cosmetics that contain methylene blue. Now we are looking to translate this into marketable products..
'Perhaps down the road we can customize the system with bioprinting, such that we might be able to use a patient's own cells to provide a tailor-made testing platform specific to their needs.'