Artemesia annua extract prevents glyoxal-induced cell injury in retinal microvascular endothelial cells during glaucoma

Purpose: To investigate the effect of Artemesia annua extract on glyoxal-induced injury in retinal microvascular endothelial cells (HRECs).Methods: HRECs were cultured in a medium containing 500 μM glyoxal or glyoxal plus 50μM Artemesia annua extract, or in the medium alone for 24 h. Apoptosis was analysed by flow cytometry using annexin V and propidium iodide staining. Changes in mitochondrial membrane potential were determined by JC-1 staining.Results: When HRECs were cultured in a medium of 500 μM glyoxal, a significant (p < 0.05) decrease in caspase-3 expression was observed. However, treatment of HRECs with Artemesia annua extract (50 μM) inhibited the glyoxal-mediated decrease in caspase-3 expression. The extract also inhibited caspase-3 proteolysis, as was evident from the reduction in the level of cleaved caspase-3. Upregulation of ROS production by glyoxal in HRECs was inhibited by treatment with the extract. The viability of HRECs was significantly decreased by glyoxal (p < 0.05), but the decrease in viability was significantly reversed by Artemesia annua extract (p < 0.05). The extract also reduced gyloxal-induced apoptosis in HRECs from 17.3 to 2.6 % (p < 0.001). Results from JC-1 staining showed significantly (p < 0.001) higher level of green fluorescence in HRECs cultured with glyoxal. However, the glyoxal-induced increase in green fluorescence level was significantly (p < 0.01) reduced on exposure to Artemesia annua extract.Conclusion: Artemesia annua extract prevents oxidative damage to HRECs via inhibition of ROS production, up-regulation of caspase-3 expression and suppression of caspase-3 proteolysis. Therefore, Artemesia annua can potentially be used for the development of a new drug for the prevention of retinal injury in glaucoma.Keywords: Artemesia annua, Retinal injury, Glaucoma, Green fluorescence, cleaved caspase-3, ROS production