Investigation into the cyto-protective and wound healing properties of cryptic peptides from bovine Achilles tendon collagen.

Many proteins have concealed regions in their amino acid sequences that when liberated or exposed by conformational changes can exhibit bioactivity. Two such cryptic bioactive peptides, C2 (with cell adhesive properties) and E1 (with cell adhesive and antioxidant properties) have been isolated from bovine tendon collagen. This investigation deals with the efficacy of these peptides in countering externally generated stress and imparting cyto-protection in mammalian cell systems. The cell survival activity was studied with two cell lines, viz., HeLa and Vero, with varying concentrations of five oxidative stress-generating agents. The activities of the peptides in supporting cell adhesion and countering stress were determined in their coated and dissolved forms. C2 and E1 coated dishes registered 8 times (p<0.01) higher rate of cell survival against oxidative stress than collagen coated dishes. E1 increased stress tolerance levels by >100 times in dissolved form and C2, by 8 times in coated form. The peptides supported faster wound closure than collagen under normal as well as stressed condition. Maximum stress tolerance was observed on C2 coated dishes in the presence of E1 in the medium suggesting that both enhanced cell adhesion and antioxidative activities significantly contribute to the cell survival during stress. The present study emphasizes that collagen peptides, apart from providing a suitable surface for cell adhesion, also confer protection to cells against oxidative stress.