Page 124 - phytochemistry I - PharmD Clinical

2. Skin pigmentation disorders
Arbutin is used for treating: Hyperpigmentation, Lentigines, Melasma,
Chloasma (brownish macules) and Freckles.
• Arbutin is used as a skin-lightening agent because it is composed
of hydroquinone with a sugar group attached. The hydroquinone
group acts as an inhibitor of tyrosinase, a key enzyme involved in
melanin (pigment) production. This inhibitory activity is due to the
structural similarity of the hydroquinone group to tyrosine, which is
the natural substrate for tyrosinase.
• In addition to its innate inhibitory effect, arbutin may also act as a
reservoir that slowly releases hydroquinone. Once absorbed into
the skin, enzymes within the body can cleave off the sugar group
from arbutin, releasing hydroquinone. This acts like a built-in safety
valve, preventing the skin from being exposed to too much
hydroquinone at once.
• Arbutin is one of the best alternatives to hydroquinone as it provides
the skin-lightening effect of hydroquinone without some of the risks.

Aldehydic glycosides

Glucovanillin

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