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Abstract ID: 24-157

Mallow extract improves the efficacy of hyaluronic acid in the treatment of dry eye disease

Johann Röhrl


Purpose

Symptoms of dry eye disease (DED) include itching, foreign body sensation, redness and pain. The hyperosmolar environment due to loss of tear volume triggers oxidative stress and the release of pro-inflammatory mediators. First line treatment for DED is mostly based on eye drops containing hyaluronic acid (HA), providing ideal properties for lubricating the corneal surface and stabilising the tear film. Here we report about in vitro investigations exploring the potential of the herbal Malva sylvestris L. flos (MS) extract to treat symptoms of DED. We show that a combination of HA and MS offers ideal physicochemical properties for tear film stabilisation and advanced corneal surface lubrication compared to HA-only treatment.


Methods

MS dry extract was prepared using ethanolic extracts of dried flowers from MS (Ø=D1 V.20, Eth. 43% m/m). In cellular antioxidant assays different concentrations of MS extracts were tested using HaCat cells to determine intracellular antioxidant uptake. Surface tension was measured in accordance to DIN EN 14370 using a commercial tensiometer with HA and MS extract at different concentrations. Mucoadhesion of HA or MS mucilage was measured using gravimetric tests on an inclined (45-degree angle) temperature-controlled mucin-coated slide.


Results

Using HA-containing eye drops in combination with MS extract, surface tension was significantly reduced compared to a HA-only product by determination of the rheological profile with concentration-dependent effects of MS extract. Additionally, the MS extract and HA demonstrated potent mucoadhesion. In a cellular antioxidant assay MS showed antioxidant activity at a concentration of 300 µg/ml, indicating its cellular uptake in vitro. In the lipid peroxidation assay the MS extract demonstrated significant concentration-dependent antioxidant activity.


Conclusion

Data suggest that the MS extract provides an effective contribution to common HA treatments in DED therapy by its beneficial physicochemical properties. Ongoing research is performed to further analyse the therapeutic efficacy.


Additional Authors

Maria-Riera Piqué-Borràs – Weleda AG

Mónica Menett-von Eiff – Weleda AG

Gerald Künstle – Weleda AG

– Weleda AG