ascorbic-acid and Lentigo

Little is known about the anti-pigmenting effects of whitening agents on solar lentigos (SLs), which comprise ~ 60% of hyperpigmented facial lesions of Asian subjects. Lotions with or without 6% L-ascorbate-2-phosphate trisodium salt (APS) [test lotion (TL) and placebo lotion (PL), respectively] were applied twice daily for 24 weeks in a double-blind half-face study of 27 Japanese females with SLs on both sides of their faces. Pigmentation scores were evaluated using a photo-scale and the skin colors were assessed using a color difference meter and a mexameter for SLs and the non-lesional surrounding skin (NLS). Although the pigmentation scores were not significantly different between the TL and PL-treated SLs after 24 weeks, the L values of TL-treated SLs and NLS increased significantly with a significantly higher △L value in SLs than in NLS. In contrast, the L values of PL-treated SLs and NLS remained unchanged after the treatment. The number of subjects with > 2.0 △L was 7 of 27 (TL) and 0 of 27 (PL) in SLs and 3 of 27 (TL) and 0 of 27 (PS) in NLS. In contrast, the melanin index in TL-treated SLs and NLS significantly decreased with a significantly higher △melanin index in SLs than in NLS. Similarly, the melanin index of PL-treated SLs and NLS were significantly decreased with a significantly higher △melanin index in SLs than in NLS. These findings strongly indicate that APS has a weak but significant anti-pigmenting effect on SLs and a significant whitening effect even on normally pigmented healthy skin.

Topics: Administration, Cutaneous; Ascorbic Acid; Asian People; Double-Blind Method; Female; Humans; Japan; Lentigo; Melanins; Melanocytes; Skin Lightening Preparations; Skin Pigmentation; Time Factors; Treatment Outcome

Solar lentigines (SL) are benign signs of sun damage that many people find distressing.. To assess the efficacy and safety of L-ascorbic acid 10% + phytic acid 2% for treating SL.. A double-blind, vehicle-controlled trial in 30 healthy subjects with ≥2 SL. Subjects were randomly assigned to apply product to one side of the body and vehicle to the other twice daily for 3 months with follow-up of 2 months..   The pigmentation index for product-treated SL was reduced (maximum reduction 1.3 at 3 months [M3]), while that for vehicle-treated lesions remained stable. These differences were statistically significant for M1-M4 (P ≤ 0.003). Dermoscopy detected significant intergroup differences in pigmentation at M5 (P=0.011). Colorimetry results indicated a statistically significant improvement in brightness (L*) between study drug and vehicle at M5. Fifteen subjects experienced 23 adverse events; six (mostly halo depigmentation) were judged possibly related to the study drug. There were six instances of mild-to-moderate intolerance in the study drug group and five in the vehicle-treated group.. Study treatment was significantly more efficacious than vehicle in many respects and was well tolerated. Future, larger studies are needed to confirm these results and to compare the product with gold standard treatments.

Topics: Aged; Aged, 80 and over; Antioxidants; Ascorbic Acid; Colorimetry; Dermoscopy; Double-Blind Method; Drug Combinations; Female; Humans; Lentigo; Male; Middle Aged; Phytic Acid; Statistics, Nonparametric

So-called darkened age spots encompass distinct pathological processes. The efficacy of topical depigmenting agents is difficult to objectivate.. To assess the hypopigmenting effect of three cosmetic formulations using objective biometrological methods.. 50 women of South-East Asian ancestry were enrolled in this pilot study. They had solar lentigines according to dermoscopic criteria. The lesions were treated by topical hypopigmenting formulations. Products were applied twice daily for 2 or 3 months. Assessments at 1-month intervals were made using narrow-band reflectance spectrophotometry, image analysis of video-recorded ultraviolet light reflection and photodensitometry- and image-analysis-assisted corneomelametry.. A 20% azelaic acid formulation and another one containing 5% ascorbyl glucosamine, 1% kojic acid and alpha-hydroxyacid esters appeared inefficacious on solar lentigines. A stabilized soy extract showed a better although modest lightening effect when assessed by corneomelametry. The subclinical or faint mottled skin revealed by ultraviolet light examination better responded (p < 0.05) to treatments.. Focal epidermal hyperpigmentation is better controlled by topical whitening agents when the increase in melanin content reflects a modest functional hyperactivity of melanocytes.

Topics: Administration, Topical; Adult; Ascorbic Acid; Densitometry; Dermatologic Agents; Dicarboxylic Acids; Double Bind Interaction; Drug Combinations; Female; Forearm; Glucosamine; Glycine max; Hand; Humans; Image Processing, Computer-Assisted; Lentigo; Melanins; Melanocytes; Middle Aged; Pilot Projects; Plant Extracts; Pyrones; Sunlight

Objective methods of measuring skin color are needed to evaluate pigmentary lesions quantitatively. We have developed a new method of measuring skin color using a plastic bar system called the Skin Tone Color Scale based on Munsell's color space system. We have also evaluated the effectiveness of various therapies using this measurement system. Our system was designed to measure skin color in normal skin, pigmentary lesions of solar lentigo, chloasma and ephelides, and postinflammatory pigmentation. Moreover, effectiveness of various therapies for these pigmentary lesions was evaluated. The evaluations made with this system were closely related to physician assessment. This method may be useful in measuring of skin color and evaluating the effectiveness of therapies for pigmentary diseases.

Topics: Adolescent; Adult; Aged; Ascorbic Acid; Dermatologic Agents; Dermatology; Face; Female; Humans; Hyperpigmentation; Laser Therapy; Lentigo; Melanosis; Middle Aged; Phototherapy; Skin Pigmentation; Statistics, Nonparametric; Tranexamic Acid

Hydroquinone is a well known reagent used in the treatment of pigmentation disorders. The instability of the quinones and the required active concentration make topical treatment rather difficult. We tested the efficacy of an ascorbate-phytohydroquinone complex that inhibits the synthesis of melanin and promotes the degradation of the existing melanin. Lentigo senile lesions were evaluated before and after 1 month of treatment. Objective skin color evaluation was performed instrumentally. After one month of treatment, a clear depigmentation of the macules was measured. None of the volunteers reported any side effects from the prolonged treatment with the hydroquinone containing product.

Topics: Administration, Cutaneous; Aged; Aged, 80 and over; Apiaceae; Ascorbic Acid; Benzoyl Peroxide; Citrus; Colorimetry; Dermatologic Agents; Drug Combinations; Female; Follow-Up Studies; Glucosides; Humans; Hydroquinones; Lentigo; Male; Melanins; Middle Aged; Oils, Volatile; Oxyquinoline; Plant Extracts; Skin Pigmentation