Skin & Muscle

Japan Study Shows Pearl Extract Rejuvenates Aged Brain and Skin

Japanese scientists show that pearl oyster extract improves memory impairments and signs of skin aging, including wrinkles in prematurely aged mice.

By Yedida Bogachkov, Ph.D.

Key Points:

  • Treatment with pearl extract improves memory deficits in aged mice by preventing neurodegeneration. 
  • Pearl extract rejuvenates the fur of aged mice while reversing aspects of skin aging, such as thinning and wrinkles. 
  • Rejuvenation is attributed to elevated antioxidants and reduced cellular stress.

Pearls are often associated with a vintage look and grandmotherly vibe. However, pearls are formed by oysters to protect themselves against harmful shell invaders. And now, a new study shows that an extract from pearl oysters may in fact delay the aging process and improve our skin and memory.

The study, out of the Muroran Institute of Technology in Japan, currently under review for publication in Marine Biotechnology, focused on prematurely aged mice. When these aged mice were treated with an extract from a layer of the oyster pearl called the nacreous layer (nacre extract), their hair (or fur) looked healthier and younger while their skin was thicker, held more water, and had fewer wrinkles. The extract also served to improve memory and decrease cell death within the brain. Additionally, cellular stress – a major part of aging – was also decreased with nacre extract treatment.

“Nacre extract may be an effective antiaging agent,” the authors concluded.

Pearl Extract Reverses Brain and Skin Aging 

Premature aging was induced in young mice by injecting them with a sugar called D-galactose. The prematurely aged mice had reduced memory test scores compared to young mice, which improved upon treatment with nacre extract. Additionally, nacre extract suppressed neuronal degeneration and decreased neuronal cell death in the hippocampus – a region of the brain involved in memory and learning. These findings suggest that memory was improved in aged mice by preventing neurodegeneration, thus reversing brain aging.

Nacre extract improves spatial learning
(Yamamoto, et al., 2022 | Under Review)  Memory Improved with Nacre Extract. Aged (D-galactose) mice treated with either 40 mg/kg (Nacre40) or 80 mg/kg (Nacre80) injections of nacre extract had improved spatial learning and memory, as measured by the Y-maze test.

Looking at fur, the prematurely aged mice had coarse, dull hair, characteristic of aging. However, after receiving nacre extract treatment, their appearance improved. Nacre extract also reversed the skin water loss observed in aged mice, while rejuvenating skin (epidermis) thickness and suppressing the formation of wrinkles, perhaps due to the decreased collagen — a structural protein that keeps skin firm — destruction seen with nacre treatment. Overall, these findings suggest that nacre extract can reverse skin aging. 

Nacre extract improves hair
(Yamamoto, et al., 2022 | Under Review) Nacre Extract Improves Hair and Limits Wrinkles. Aged (D-galactose) mice treated with 80 mg/kg (Nacre80) of nacre extract had improved fur (top) and fewer wrinkles (bottom).

Cellular stress – known as oxidative stress – is a hallmark of aging and is thought to drive the aging process in many tissues and organs. D-galactose-induced cellular stress was reduced in the brain and skin of aged mice treated with nacre extract. Additionally, antioxidant proteins, which help maintain low levels of cellular stress and may stave off the aging process, were increased following nacre treatment. This means that the nacre-induced reversal of brain and skin aging could be due to alleviation of cellular stress.

The Science Behind Medicinal Pearls

The findings of this study reveal how brain and skin aging may be reversed with the use of an extract from pearls. Pearl powder — basically finely crushed pearls — which has been used for centuries in Chinese medicine, is available almost anywhere online, but the question is whether it works. Very few studies have been performed to look at its effects on humans, but a recent randomized, placebo-controlled trial showed that, in 20 participants, pearl powder had some antioxidant properties, which as mentioned above can help decrease the effects of the aging process and cellular stress. This study looked at nacre extract, essentially proteins isolated from nacre, also known as mother-of-pearl, which should be more potent than pearl powder because the proteins are purer.

Plenty of skincare products are jumping on the pearl powder train, touting pearl protein and other components from mussels as active ingredients. This study suggests that there is real science behind their claims, and perhaps nacre extract will be the next new viral skincare ingredient.

Model & Dosage

Model: ICR (institute of Cancer Research) mice

Dosage: 40 mg/kg or 80 mg/kg of nacre extract intraperitoneally injected


Yamamoto H., Shimomura, N., Oura, K., Hasegawa, Y. Nacre extract from pearl oyster shell prevents D-galactose-induced brain and skin aging. Under Review Preprint at Research Square


Chiu HF, Hsiao SC, Lu YY, Han YC, Shen YC, Venkatakrishnan K, Wang CK (2018). Efficacy of protein rich pearl powder on antioxidant status in a randomized placebo-controlled trial. J Food Drug Anal 26: 309–317.

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