Characterization of a Malva sylvestris L. flos preparation for beneficial properties suitable in the treatment of dry eye disease

In dry eye disease (DED), inflammation is responsible for clinical symptoms such as itching, foreign body sensation, redness and pain. The release of pro-inflammatory mediators is triggered by an hyperosmolar environment due to loss of tear volume. Leukotrienes and prostaglandins produced by 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2), respectively, are key mediators in inflammation. Visiodoron Malva^® eye drops – authorized as a medical device for the treatment of DED – contains an ethanolic extract of Malva sylvestris L. flos (MS) that accounts for a reduction of surface tension thereby facilitating the wetting of the ocular surface. We report about novel investigations in vitro to explore the putative potential of MS in DED treatment to prevent inflammation and oxidative stress and the ability to promote wound healing. MS concentration dependently inhibited 5-LOX- and COX-2 activity in vitro (IC₅₀: 22.7 and 23.3 µg/ml).

In an ORAC (oxygen radical absorbance capacity) assay the scavenging efficiency was high against peroxyl- and peroxynitrite radicals (IC₅₀: 30.3 and 23.3 µg/ml), medium against hydroxyl radicals (308 µg/ml) and low against superoxide radicals (>1.000 µg/ml). In a cell culture set-up MS significantly enhanced the regenerative response in vitro at 100 µg/ml. These data suggest that MS might exert an effective contribution in DED treatment by anti-inflammatory and radical scavenging actions. MS might be further helpful promoting regeneration following ocular damage in DED. However, further investigations are needed to study bioavailability and efficacy in vivo.

Publication History

Article published online:
13 December 2021