Pharmacological in vitro profiling of Buddleja officinalis flower extracts in the context of dry eye disease

Background

Dry eye disease (DED) is caused by inflammation on the ocular surface and insufficient quality or production of the tear film. Due to various harmful environmental conditions, a gradual increase of DED cases has been reported.

Hypothesis/purpose

This study aims for a comprehensive in vitro pharmacological and phytochemical profiling of two different Buddleja officinalis Maxim. extracts to assess their potential for the treatment of DED.

Methods

A hydroethanolic (BO-HE) and a lead-like enhanced (BO-LLE) B. officinalis extract were phytochemically characterized by UHPLC-UV-MS and UHPLC-ELSD analyses. Afterwards, the effects of either BO-HE or BO-LLE on in vitro dry eye models, including human corneal epithelial cell-transformed (HCE-T) cells, immortalized human meibomian gland epithelial cells (IHMGECs) and human leukemia monocytic (THP-1) cells, and Jurkat cells, were investigated.

Results

Both extracts exhibited strong anti-inflammatory properties with free radical scavenging activities and reduction of intracellular reactive oxygen species (ROS) in UVB-exposed HCE-T cells. Treatment with BO-HE or BO-LLE showed wound healing capacities. Moreover, both extracts differentially modulate mediator secretion in UVB-exposed HCE-T cells. In IHMGECs, the size of secreted lipid droplets was larger in BO-LLE treated cells. As for immune cells, a significant reduction in levels of TNF-α and IL-6 secretion by lipopolysaccharide (LPS)-exposed THP-1 cells was observed. Additionally, BO-LLE effectively inhibited intracellular calcium influx in Jurkat cells even at low concentrations.

Conclusion

The results of this study demonstrate pharmacological potential of B. officinalis flowers for the treatment of DED pathology with BO-LLE exerting a slightly more beneficial profile than BO-HE.