PURPOSE The aim of this study was to investigate acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and antityrosinase activities of extracts from ten Piper species namely; P. caninum, P. lanatum, P. abbreviatum, P. aborescens, P. porphyrophyllum, P. erecticaule, P. ribesioides, P. miniatum, P. stylosum, and P. majusculum. METHODS Anticholinesterase and antityrosinase activities were e...

Tyrosinase, a widely spread enzyme in micro-organisms, animals, and plants, participates in two rate-limiting steps in melanin formation pathway which is responsible for skin protection against UV lights' harm whose functional deficiency result in serious dermatological diseases. This enzyme seems to be responsible for neuromelanin formation in human brain as well. In plants, the enzyme leads t...

experimental autoimmune vitiligo was induced by the intradermal injection of the purified mushroom tyrosinase emulsified in complete freund’s adjuvant (cfa) in female c57bl/6 mice. the onset of vitiligo was characterized by hair hypopigmentation and total melanocyte depletion in the basal layer of the epidermis. oral administration of semipurified mushroom tyrosinase prevented experimental auto...

The catalytic oxidation of catechol by crude preparations of mushroom tyrosinase was studied by a method yielding data on initial reaction velocities. Graphical analysis of the results suggests that an excess of catechol inhibits its own oxidation by a competitive process, thus accounting for the observed optimum in the substrate concentration. However, added phenol, though itself a substrate, ...

The aim of the present study is to preliminarily investigate the antimelanogenesis effect of Inonotus obliquus extracts by cell-free mushroom tyrosinase assay. It was found that petroleum ether and n-butanol extracts might contain unknown potential tyrosinase inhibitors, while its ethyl acetate extract might contain some unknown accelerators. Six compounds were isolated and their structures wer...

polyphenol oxidase (ppo), also known as tyrosinase (ec 1.14.18.1), is a copper-containing enzyme widely distributed in microorganisms, animals, and plants. this enzyme is responsible not only for browning in plants but also for melanization in animals. thus, tyrosinase inhibitors have a huge impact on industry and the economy. in the current study, we first purified the enzyme, then evaluated i...

Experimental autoimmune vitiligo was induced by the intradermal injection of the purified mushroom tyrosinase emulsified in Complete Freund’s Adjuvant (CFA) in female C57BL/6 mice. The onset of vitiligo was characterized by hair hypopigmentation and total melanocyte depletion in the basal layer of the epidermis. Oral administration of semipurified mushroom tyrosinase prevented experimental auto...

OBJECTIVES Involvement of tyrosinase in the synthesis of melanin and cell signaling pathway has made it an attractive target in the search for therapeutic inhibitors for treatment of different skin hyperpigmentation disorders and melanoma cancers. MATERIALS AND METHODS In the present study, we conducted a comprehensive kinetic analysis to understand the mechanisms of inhibition imposed by 2-a...

Objective(s): In previous studies, antioxidant activity of Viola odorata L. has been demonstrated. In this study, we have investigated the anti-melanogenic effect of extract and fractions of the plant in B16F10 cell line. Materials and Methods: Impact of different increasing concentrations of extract and fractions of V. odorata was evaluated on cell viability, cellular tyrosinase, melanin conte...

The coordinatively unsaturated copper (II) complexes of 1,3-bis(2'-pyridyl)-1,2-diaza-2- butene with different ancillary anions were synthesized which can bind to copper centers of tyrosinase enzyme. The compounds were found to exhibit inhibitory activities against mushroom tyrosinase and the nature and extent of inhibition is modulated according to the type of ancillary anions.