Effects and mechanism of Pigeonpea (Cajanus cajan (L.) Millsp.) leaves on proliferation, migration, and tube formation of hypoxic human umbilical vein endothelial cells in vitro.

ETHNOPHARMACOLOGICAL RELEVANCE: Pigeonpea (Cajanus cajan (L.) Millsp) leaves (PL) are widely used for treating avascular necrosis of the femoral head. PL has an ideal effect on bone angiogenesis in patients with hormone-induced avascular necrosis of the femoral head and could promote the repair of blood vessels in the necrotic femoral head. Angiogenesis is beneficial to the treatment of myocardial ischemia. PL can be used to treat ischemic heart disease; however, no studies have examined whether it could protect the myocardium against ischemia injury via promoting angiogenesis.

AIM: The present study aimed to investigate whether PL could encourage angiogenesis on hypoxic human umbilical vein endothelial cells (HUVECs) and whether estrogen receptor (ER-α), protein kinase B (Akt), and vascular endothelial growth factor (VEGF) (the ischemia injury salvage kinase pathway, phosphoinositide-3 kinase (PI3K)) are involved in this effect.

METHODS: A hypoxic HUVEC model was established by culture in the hypoxia incubator. The proliferation ability of HUVECs was determined by the 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) method, the migration rate of HUVECs was inspected by the Transwell method, the tube formation was evaluated by the Matrigel method, and the expression of PI3K, phosphorylated Akt (p-Akt), and VEGF was detected by Western blotting.

RESULTS: The proliferation, migration, and tube formation were promoted by the PL extract on hypoxic HUVECs, and the hypoxia-induced downstream signaling was counteracted, leading to increased expression of PI3K, p-Akt, and VEGF in HUVECs.

CONCLUSIONS: The current findings showed that the PL extracts encourage angiogenesis. In addition, the above effects could be mediated via ER-α and PI3K/Akt/VEGF pathways.