Vitamin P on skin dullness: Hosokawa reviews the effect of vitamin P (biofl avonoids) on skin dullness and its application to cosmetics. The color of the skin is known to refl ect the blood fl ow within it. Because the concentration of melanin is low in the lip, and the horny layer in the lip area is thin, the dullness of lip was presumed to be infl uenced easily by the color of blood. Researchers studied the physiological differences between colorful and dull-colored lips by measuring blood fl ow and oxygen saturation. They found that dull-colored lips and the corner of the lips (generally dull-colored compared to the center of lips) show relatively poor blood flow and a lower degree of oxygenation.
Vitamin P is known to enhance blood circulation. However it is poorly soluble in water and oil and its usage has been extremely limited. Recently alpha-glucosyl hesperidin made by glucosylating hesperidin, a derivative of vitamin P, was found to be easily dissolved in water. Incorporated into a lipstick, the ingredient increased blood flow 30 minutes after application, and after two weeks of daily application the lips became noticeably less dull. The investigators conclude that these fi ndings provide evidence that the decrease of blood fl ow has a close relation to the dullness of lip color.
