EGF and ulcer disease: Further, sea buckthorn procyanidins (SBPC) from bark extract enhance the healing of acetic acid-induced gastric lesions by reducing ulcer size in a dose-dependent manner, increasing epidermal growth factor (EGF) levels in plasma, and up-regulating the expression of epidermal growth factor receptor (EGFR) and proliferating cell nuclear antigen (PCNA) around the ulcer site, which promotes mucosal repair and epithelial renewal (Xu et al., 2007).