Assessing the protective effects of cryptotanshinone on CoCl₂‑induced hypoxia in RPE cells

The development of several retinal diseases is closely related to hypoxia. As a component of the Traditional Chinese medicine Salvia miltiorrhiza, the effects of cryptotanshinone (CT) on retinal cells under hypoxic conditions are not well understood. The aim of the present study was to explore how CT exerted its protective effects on retinal pigment epithelium (RPE) cells under hypoxic conditions induced by cobalt chloride (CoCl₂). The effects of CT were investigated using a Cell Counting Kit‑8 assay, Annexin V‑FITC/PI staining, reverse transcription‑quantitative PCR and western blotting in ARPE‑19 cells. CT (10 and 20 µM) reduced the CoCl₂‑induced increase in vascular endothelial growth factor expression and hypoxia‑inducible transcription factor‑1α expression in ARPE‑19 cells. Additionally, CT alleviated hypoxia‑induced apoptosis by regulating Bcl‑2 and Bax protein expression. CT treatment also reduced the increase in the mRNA levels of IL‑6, IL‑1β and TNF‑α induced by CoCl₂. In summary, CT may protect RPE cells against apoptosis and inflammation in CoCl₂‑induced hypoxia, and these results warrant further in vivo study into its value as a drug for treating hypoxic eye diseases.