Abstract: BACKGROUND: Studies have shown that serum homocysteine concentration is an independent predictor of the prevalence and severity of coronary artery disease for patients with normal hypersensitivity C-reactive protein levels. 
OBJECTIVE: To investigate the protective effect of Wenban Decoction on the apoptosis of rat cardiac microvascular endothelial cells (CMECs) induced by homocysteine by regulating PI3K/Akt signaling pathway. 
METHODS: Rat CMECs were primarily cultured in vitro, and the cells were randomly divided into control group, model group and Wenban Decoction group (50 mg/L Wenban Decoction). The cells in the latter two groups were injured by 10 mmol/L homocysteine prior to the treatment. Cell counting kit-8 was used to detect the cell viability of each group. ELISA was used to determine serum lactate dehydrogenase, malondialdehyde, whole blood catalase, superoxide dismutase, glutathione peroxidase, interleukin 6, intercellular adhesion molecule 1, interleukin 1β, and tumor necrosis factor α. Flow cytometry was used to detect cell apoptosis after addition of LY294002 based on the treatment with Wenban Decoction. Western blot was used to detect the expression of PI3K, Akt, p-Akt, Bax, Bcl-2 and caspase3 protein in the cells. An ethic approval was given by the Animal Experiment Ethics Committee of Liaoning University of Traditional Chinese Medicine (approval No. 21000092018010).
RESULTS AND CONCLUSION: Compared with the control group, the survival ability of CMECs in the model group was significantly reduced, the leakage of lactate dehydrogenase was significantly increased, which caused oxidative stress and the release of inflammatory factors, and finally led to a large number of apoptosis. Compared with the model group, Wenban Decoction improved the survival ability of CMECs, reduced the leakage of lactate dehydrogenase, significantly decreased the intracellular levels of interleukin 1β, intercellular adhesion molecule 1, interleukin 6 and tumor necrosis factor α (P < 0.05), as well as reduced the number of apoptotic cells. PI3K inhibitor reversed the inhibitory effect of Wenban Decoction on homocysteine-induced apoptosis of CMECs. To conclude, Wenban Decoction can significantly improve the survival ability of CMECs, reduce the leakage of lactate dehydrogenase, inhibit the level of oxidative stress and the release of inflammatory factors, and ultimately reduce the number of apoptotic cells, which is related to the inhibition of PI3K/Akt signaling pathway.

Key words: coronary heart disease, heart, microvessel, endothelial cell, apoptosis, pathway, Chinese herb, experiment