Study of Mushroom Tyrosinase Inhibitory Activity Among 70 Plants from Kurdistan Provience

Tyrosinase is a multifunctional, glycosylated and copper containing oxidase, and is found in fungi, microorganisms, plants and animals. The most important function of tyrosinase in mammals is melanogenesis. Hyperpigmentation is a serious problem for beauty. It is possible to cure these diseases with inhibition of tyrosinase. There have been attempts to control the metabolism of pigmentations by means of natural chemical agents.

The aim of this study was to find new potent inhibitors for ،tyrosinase among plant extracts.  

The subject of this study was anti-tyrosinase activity of methanolic extracts of 70 plant species, using mushroom tyrosinase inhibition method. All extracts were screened for their tyrosinase inhibitory activity at 400, 100, 25, 6.2 µg/ml final concentrations in reaction mixture. Assay method was based on spectrophotometric study of absorption in 492 nm and kojic acid was used as positive controls.

The results showed that nine plant extracts including Bongardia chrysogonum (L.) Spach, Podophylaceae, Heptaptera anatolica (Boiss.) Tutin, Apiaceae, Hyoscyamus kurdicus Bornm, Solanaceaes, Hypericum scabrum, Marrubium cuneatum, Nonea hypoleia, Salvia suffruticosa, Scrophularia pruinosa Boiss, Scrophulariaceae and Verbascum phoenicum L, Scrophulariaceae, (400 µg/ml) and two plant extracts including Asperugo procumbens L, Boraginaceae and Astragalus siliquosus Boiss. subsp. siliquosus, Papilionaceae (25µg/ml) have inhibitory activity more than 60%. Saliva suffruticosa showed a considerable inhibition value, 92.62% (400 µg/ml) and low IC50 (94.77 µg/ml) and according to kinetic analysis its type of inhibition on tyrosinase is noncompetitive.

Because of its high inhibitory activity and low IC50, Saliva suffruticosa extract would be interesting for further studies.