arbutin and aloesin

Hyperpigmentation has traditionally been a relatively difficult condition to treat, especially in darker racial ethnic groups. Multiple topical agents available act upon different steps of the pigmentation pathway. We review these topical agents, their mechanisms of action, and their effectiveness as monotherapy and in combination with other compounds. Ultimately, combination therapy is the most efficacious when considering overall depigmentation as well as treatment time required to achieve clinical improvement.

Topics: Administration, Topical; Adrenal Cortex Hormones; Arbutin; Chromones; Drug Combinations; Free Radical Scavengers; Glucosides; Humans; Hydroquinones; Hyperpigmentation; Keratolytic Agents; Monophenol Monooxygenase; Niacinamide; Phytotherapy; Plant Preparations; Randomized Controlled Trials as Topic; Receptor, PAR-2; Retinoids; Skin Diseases; Skin Lightening Preparations; Skin Pigmentation

Skin hyperpigmentation is caused by the overproduction of melanin pigment, which is synthesized by the action of tyrosinase. We recently reported that aloesin inhibits tyrosinase activity. The present study was undertaken to test the inhibitory effect of aloesin on pigmentation in human skin after UV radiation. Experimental subjects were UV-irradiated (210 mJ) on the inner forearm. UV-irradiated regions were assigned to four groups: vehicle control, aloesin treated, arbutin treated, and aloesin and arbutin treated. Aloesin and/or arbutin were administered four times a day for 15 days. Aloesin treatment suppressed pigmentation by 34%, arbutin by 43.5%, and the cotreatment by 63.3% compared with the control (n = 15; P < 0.05). Moreover, aloesin treatment showed pigmentation suppression in a dose-dependent manner (n = 7; P < 0.05). These results raise the possibility that aloesin may be used as an agent that inhibits melanin formation induced by UV radiation.

Topics: Adult; Analysis of Variance; Arbutin; Chromones; Dose-Response Relationship, Drug; Drug Therapy, Combination; Glucosides; Humans; Hyperpigmentation; Male; Melanins; Radiation Injuries; Ultraviolet Rays

To observe the effect of aloesin, tea polyphenols, arbutin on melanocytes in the pigmented skin equivalent model.. First, we constructed the pigmented skin equivalent model in vitro. And then we detected the effect of aloesin, tea polyphenols and arbutin on the cells' shape, tyrosinase activity and formation of melanin in the constructed pigmented skin equivalent.. Three depigmenting agents showed an inhibition effect on the tyrosinase activity of melanocytes and reduced significantly melanin content in the pigmented skin equivalent model, in which the tea polyphenols had the strongest effect, and then was the aloesin. But the tea polyphenols showed the strongest toxicity, while the aloesin and arbutin had a much lower toxicity.. All the three depigmenting agents showed a concentration dependent suppression effect on the tyrosinase activity and formation of melanin, in which the tea polyphenols was the strongest effect( P <0.05). Aoesin has a good suppression effect on the tyrosinase activity and formation of melanin, but has a much lower toxicity, which could be used as a safe depigmenting agent.

Topics: Arbutin; Cells, Cultured; Chromones; Flavonoids; Foreskin; Glucosides; Humans; Male; Melanins; Melanocytes; Phenols; Pigmentation; Polyphenols; Skin; Skin Aging

To study the effects of aloesin and arbutin on normal cultured human melanocytes in synergetic method.. Building up the system of cultured human melanocytes. The cultured melanocytes in vitro were treated with the mixture of aloesin and arbutin. The cell viability and tyrosinase activity was measured by MTT assay, utilization of L-Dopa as the substrate respectively; melanin content was measured by image analysis system. Furthermore, the effects of the mixture on melanocytes were compared with that of aloesin and arbutin.. The mixture of aloesin and arbutin showed an inhibition on tyrosinase activity of human melanocytes and reduced significantly melanin content. Between the mixture and the single use of aloesin or arbutin, there is significant difference (P < 0.05). On the other hand, the mixture has little influence on melanocytes viability and there is negative significance.. The mixture of aloesin and arbutin can significantly inhibit the tyrosinase activity and melanogenesis of cultured human melanocytes. It showed the effects of aloesin and arbutin in a synergistic manner. It is worth to give farther study later.

Topics: Arbutin; Cells, Cultured; Chromones; Dose-Response Relationship, Drug; Drug Synergism; Glucosides; Humans; Melanocytes; Monophenol Monooxygenase

In this study, we present evidence that cotreatment of aloesin and arbutin inhibits tyrosinase activity in a synergistic manner by acting through a different action mechanism. Aloesin or arbutin similarly inhibited enzyme activity of human- and mushroom-tyrosinases with an IC50 value of 0.1 or 0.04 mM, respectively. Lineweaver-Burk plots of the enzyme kinetics data showed that aloesin inhibited tyrosinase activity noncompetitively with a Ki value of 5.3 mM, whereas arbutin did it competitively (Maeda, 1996). We then examined whether cotreatment of these agents inhibits the tyrosinase activity in a synergistic manner. The results showed that 0.01 mM aloesin in the presence of 0.03 mM arbutin inhibited activity of mushroom by 80% of the control value and the reverse was also true. The inhibitory effects were calculated to be synergistic according to the Bürgi method. Taken together, we suggest that aloesin along with arbutin inhibits in synergy melanin production by combined mechanisms of noncompetitive and competitive inhibitions of tyrosinase activity.

Topics: Agaricales; Arbutin; Binding, Competitive; Chromones; Dose-Response Relationship, Drug; Drug Synergism; Enzyme Inhibitors; Glucosides; Humans; Melanoma; Monophenol Monooxygenase; Tumor Cells, Cultured