Aim: To investigate the effects of a traditional Chinese medicine formula Qing Huo Yi Hao (QHYH) and its components on hydroxyl radical (HO(•)) production in vitro and the activity of QHYH against free radicals in cultured endothelial cells induced by high glucose.
Methods: Hydroxyl radicals (HO(•)) were generated through Fenton reactions in vitro, and 5,5-dimethyl-1-pyrroline N-oxide (DMPO) was used as a spin trap to form DMPO/HO(•) adducts detected using electron paramagnetic resonance (EPR). Immortalized mouse cerebral microvascular endothelial (bEnd.3) cells were treated with high glucose (35 mmol/L). The free radical scavenging ability of QHYH in the cells was evaluated using EPR. Superoxide dismutase (SOD) was used to identify the free radicals scavenged by QHYH in the cells.
Results: QHYH and its 8 components concentration-dependently reduced DMPO/HO(•) signaling. The DMPO/HO(•) adduct scavenging ability of QHYH was 82.2%, which was higher than each individual component. The free radical scavenging ability of 1% QHYH in high glucose-treated bEnd.3 cells was approximately 70%. In these cells, the free radicals were also specifically reduced by SOD (400 U/mL), implying that the free radicals were primarily superoxide anions.
Conclusion: The results demonstrate that the QHYH formula is potent antioxidant acting as scavenge of superoxide anions in high glucose-treated endothelial cells.