Oxidative Degradation of High-Molar-Mass Hyaluronan: Effects of Some Indole Derivatives to Hyaluronan Decay

Indole derivatives such as isatin (a natural compound), cemtirestat, stobadine, and its derivatives (synthetic compounds) are known to have numerous positive effects on human health due to regulation of oxidative status. The aim of the study was to assess radical scavenging capacities of these compounds and explore their potential protective effects against reactive oxygen species formed during Cu(II) ions and ascorbate-induced degradation of high-molar-mass hyaluronan. Based on the IC(50)values determined by the ABTS assay, the most effective compound was SM1M3EC2 center dot HCl reaching the value approximate to 11 mu mol/L. The lowest IC(50)value reached in the DPPH assay was reported for cemtirestat approximate to 3 mu mol/L. Great potency of inhibition of hyaluronan degradation was shown by cemtirestat, followed by isatin even at low concentration 10 mu mol/L. On the other hand, stobadine center dot 2HCl had also a protective effect on hyaluronan degradation, however at greater concentrations compared to cemtirestat or isatin. SME1i-ProC2 center dot HCl reported to be a less effective compound and SM1M3EC2 center dot HCl can be considered almost ineffective compared to stobadine center dot 2HCl. In conclusion, our results showed that both isatin and cemtirestat were capable of attenuating the degradation of high-molar-mass hyaluronan due to their ability to complex/sequester cupric ions.