We detected potential protective effects of elderberry (Sambucus nigra) extracts against oxidative degradation of hyaluronan (HA) in vitro. To evoke free-radical-mediated HA degradation, we applied Weissberger’s biogenic oxidative system [comprising biogenic compounds in relevant pathophysiological concentrations, i.e. 100 µM ascorbate plus 1 µM Cu(II)], which mimics the situation of acute inflammation. Time- and dose- dependent changes of dynamic viscosity of the HA solutions in the presence and absence of two elderberry extracts produced in years 2006 and 2012 were recorded by rotational viscometry (RV). Radical scavenging capacity of both extracts was investigated by the ABTS assay [ABTS - 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)]. Oxygen consumption of the HA oxidative system in the absence and presence of the elderberry extracts in the HA reaction system was determined.
RV revealed that addition of the newer extract (year 2012) promoted inhibition of HA degradation more markedly compared to the older extract (year 2006). In contrast, a more effective scavenger of ABTS·+ was the older extract (year 2006). The results of oximetry are in accordance with the results of the ABTS assay.
The work was supported by the grant VEGA 2/0011/11 and APVV 0351-10.