Melanin biosynthesis inhibition

Lee SH, Choi SY, Kim H et al. Mulberroside F isolated from the leaves of Moms alba inhibits melanin biosynthesis. Biol Pharm Bull 2002 25 1045-8. 

Some anti-frmgal agents such as tricyclazole produce a weakening of cell walls by inhibiting melanin biosynthesis. More recently, several compounds that target the p-(l,3)-D-glucan and chitin synthases have been developed. 

These alkaloids inhibit melanin biosynthesis in B16 melanoma cells this represents a rare example of such inhibition by indole alkaloids. 

The 50% ethanolic leaf extracts of A. uva-ursi and other species inhibited melanin biosynthesis and displayed SOD-like activity, which may be useful in skin-whitening preparations."... 

Three compounds have been developed that utilise the inhibition of melanin biosynthesis as the basis of disease control (Figure 4.18). The first and most valuable of these is tricyclazole. Tricyclazole is readily absorbed by the foliage and roots of rice plants and redistributed acropetally. On treated plants, conidial germination of P. oryzae and... 

Tricyclazole is reported to inhibit the melanin biosynthesis pathway between 1,3,8 trihydoxynaphthalene and vermelone whereas chromatographic analysis of P. oryzae culture media indicates that KTU 3616 treatment stimulates the accumulation of the intermediate, scytalone. 

Another group of fungicides interferes with cell wall formation. Two examples of this group include 1) the polyoxines, which prevent chitin formation by competitively inhibiting chitin-synthase, the final enzyme involved in chitin biosynthesis, and 2) melanine biosynthesis inhibitors, especially in Pyricularia oryzae. Examples of... 

Another group of diseases with perturbed BH4 metaholism in human epidermis are skin disorders, including vitiligo and the Hermansky—Pudlak syndrome. Although the etiology for these disorders is not yet known, both involve lowered PCD/DCoH activities concomitant with 6- and 7-biopterin and H2O2 accumulation in skin, tyrosinase inhibition, and abnormal melanin biosynthesis. ... 

The naphthalene derivatives (171, 172), from Daldinia concentrica (Ascomycetes), were significantly active towards C. elegans (10, 25 (ig/ml) and also showed antimicrobial and cytotoxic activity [6]. Since the black fruiting bodies of D. concentrica are highly melanized, it is likely that these compounds arise from melanin biosynthesis. Some naphthoquinones have been found to inhibit the motility and survival of H. contortus (LI). Plumbagin ( 173) was the most potent (ED 1 ig/ml) followed by 1, 4-naphthoquinone, juglone (174) and 1, 2-naphthoquinone [281]. 

The mechanism of action of these compounds appears to involve inhibition of the enzyme tyrosinase, thus interfering with the biosynthesis of melanin. In addition, monobenzone may be toxic to melanocytes, resulting in permanent loss of these cells. Some percutaneous absorption of these compounds takes place, because monobenzone may cause hypopigmentation at sites distant from the area of application. Both hydroquinone and monobenzone may cause local irritation. Allergic sensitization to these compounds can occur. Prescription combinations of hydroquinone, fluocinolone... 

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