Salvianolic acid B enhances in vitro angiogenesis and improves skin flap survival in Sprague-Dawley rats

Insufficient angiogenesis and microcirculatory intravascular clotting have been implicated in the pathophysiology of skin flap failure. Salvianolic acid B (Sal B), isolated from Salvia miltiorrhiza, has been reported to enhance angiogenesis in vitro. This study was aimed to determine the efficacy of Sal B on ischemia-reperfusion injury of the skin flap in Sprague-Dawley rats. Sal B was administered intraperitoneally 2 h before operation, and on the 2nd and 4th days after surgical elevation of an extended epigastric adipocutaneous flap (5 × 7 cm) in ketamine-anesthetized rats. Flap ischemia was achieved by ligating the right superficial epigastric artery and vein and clamping the left superficial epigastric artery and vein for 3 h and then released. Percentage of flap necrosis area (FNA) and plasma levels of aspartate aminotransferase, alanine aminotransferase, creatinine, and malondialdehyde were measured at 7 days after the operation. Animals were divided into six groups, including: vehicle, Sal B low dose (5 mg/kg), Sal B high dose (50 mg/kg) and each with [mesh(+)] or without mesh [mesh(-)] placement. In the three groups with mesh(+), FNA in control flaps was 53.7 ± 6.9%, whereas low-dose and high-dose Sal B significantly improved flap survival with FNA 27.4 ± 3.8% and 25.3 ± 4.3%, respectively (P < 0.05, one-way ANOVA). In the three groups with mesh(-), control flaps were 35.9 ± 4.5%, whereas high-dose Sal B also significantly improved flap survival with FNA 17.9 ± 4.7% (P < 0.05, one-way ANOVA). There were no differences in aspartate aminotransferase, alanine aminotransferase, creatinine, or malondialdehyde between groups. We conclude that Sal B attenuates ischemia-reperfusion injury of skin flap, and provides therapeutic potential in reconstructive plastic surgery.