Crocin enhances the viability of random pattern skin flaps: involvement of enhancing angiogenesis and inhibiting oxidative stress.

The random pattern skin flap has been an important procedure in plastic and reconstructive surgery to cover various challenging defects. However, distal flap necrosis is problematic. Crocin is a natural carotenoid compound, which have been reported to possess a wide spectrum of properties and induce pleiotropic anti-inflammatory, anti-oxidative and cytoprotective effects. We explored whether crocin enhanced random skin flap survival. Thirty-six male SD rats were distributed to two groups randomly: the crocin and control groups. Flap survival areas were measured 7 days after surgery. Neutrophil numbers and microvascular density were evaluated via haematoxylin and eosin staining, and blood perfusion via laser Doppler imaging. Vascular endothelial growth factor (VEGF) levels were measured by immunohistochemical staining and Western blotting. We also measured the levels of markers of ischaemia-reperfusion injury [malondialdehyde (MDA) and superoxide dismutase (SOD)]. With regard to flap survival area assay, a significant between-group difference of survival area for the experimental flap was evident. As for flap blood flow test in Area II, the crocin group was statistically better than that of the control group. And in the histological result, the mean vessel density and VEGF level were statistically higher when treated with crocin. Crocin also decreased the MDA but increased the SOD level. Crocin thus improved random skin flap viability, enhancing angiogenesis and inhibiting ischaemia-reperfusion injury.