Inhibition of key inflammatory targets by Malva sylvestris L. flos in the context of dry eye disease

Dry eye disease (DED) is an ocular disorder usually associated with inflammation of the corneal surface due to hyperosmolarity and loss of tear fluid. In this context, inflammation is characterised by activation of the nuclear factor-kappa B (NF-κB) signalling pathway and release of inflammatory mediators such as matrix metalloproteinases (MMPs). In particular, increased MMP-9 levels have been found to accelerate the process of tissue degradation in the apical corneal epithelium, contributing to its desquamation and barrier disruption, and also playing an important role as a biomarker in DED [1], [2].

Here, we report the beneficial anti-inflammatory effects of Malva sylvestris L. flos (MS) dry extracts, which may have a positive impact on the treatment of DED.

The dry extracts were prepared from the ethanolic extracts of the dried flowers of Malva sylvestris L. flos (∅ = D1 V.20, Eth. 43% m/m flos).

We have demonstrated concentration-dependent inhibition of NF-κB translocation by MS in a reporter assay using the human Jurkat cell line (IC₅₀: 34 µg/ml) indicating its down-regulation of immune responses and inflammation. In addition, we report reduced activity of several MMPs under MS treatment in enzyme inhibition assays, particularly for inhibition of MMP-9, which plays a key role in the inflammatory cascade in eye irritation by degrading inflamed tissue (IC₅₀: 30.8 µg/ml).

Overall, these mechanisms targeted by MS contribute to an overall anti-inflammatory response and may ultimately lead to a beneficial symptom relief in irritated eyes. However, further studies are needed to more precisely determine the potential therapeutic benefits of MS.

Publikationsverlauf

Artikel online veröffentlicht:
12. Dezember 2022

• References

• 1 Pflugfelder SC, de Paiva CS. The Pathophysiology of Dry Eye Disease: What We Know and Future Directions for Research. Ophthalmology 2017; 124: S4-S13
• 2 Kook KY, Jin R, Li L. et al. Tear Osmolarity and Matrix Metallopeptidase-9 in Dry Eye Associated with Sjögrenʼs Syndrome. Korean J Ophthalmol 2020; 34: 179-186