Abstract | OBJECTIVES: MATERIALS AND METHODS: RESULTS: Kinetic analysis revealed that nicotinic acid and picolinic acid competitively restricted the monophenolase activity with inhibition constants (Ki) of 1.21 mM and 1.97 mM and the diphenolase activity with Kis of 2.4 mM and 2.93 mM, respectively. 2-aminobenzoic acid and 4-aminobenzoic acid inhibited the monophenolase activity in a non-competitive fashion with Kis of 5.15 µM and 3.8 µM and the diphenolase activity with Kis of 4.72 µM and 20 µM, respectively. CONCLUSION: Our cell-based data revealed that only the pyridine derivatives imposed cytotoxicity in melanoma cells. Importantly, the concentrations of the inhibitors leading to 50% decrease in the cell density (IC50) were comparable to those causing 50% drop in the enzyme activity, implying that the observed cytotoxicity is highly likely due to the tyrosinase inhibition. Moreover, our cell-based data exhibited that the pyridine derivatives acted as anti-proliferative agents, perhaps inducing cytotoxicity in the melanoma cells through inhibition of the tyrosinase activities.
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Authors | Nematollah Gheibi, Negar Taherkhani, Abolfazl Ahmadi, Kamahldin Haghbeen, Dariush Ilghari |
Journal | Iranian journal of basic medical sciences
(Iran J Basic Med Sci)
Vol. 18
Issue 2
Pg. 122-9
(Feb 2015)
ISSN: 2008-3866 [Print] Iran |
PMID | 25810885
(Publication Type: Journal Article)
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