Biological Activity of a Gallic Acid−Gelatin Conjugate

Goal of the present study was the characterization of the biological properties of a gelatin−gallic acid conjugate (Gel-GA) to evaluate its applicability in biomedicine and pharmacy. The macromolecular conjugate was synthesized by free radical grafting reaction between gelatin and gallic acid (GA) to form a covalent conjugate that was found to retain the antioxidant and enzymatic activities of free GA. In particular, the peroxynitrite scavenging power was found to be consistent with a IC50 value of 2.17 ± 0.4 mg mL−1. The enzymatic capacities of GA, which are regarded beneficial for cell functions, are partly retained in the Gel-GA conjugate. In particular, acetylcholinesterase inhibition (IC50 of 7.1 ± 1.3 mg mL−1) implies the conjugate’s usefulness in the chemoprevention of Alzheimer’s disease, while the inhibition of α-amylase (IC50 of 9.8 ± 1.1 mg mL−1) suggests that the conjugate can be a preferred alternative for inhibition of carbohydrate breakdown and control of glycemic index of food products. Finally, the anticancer activity of Gel-GA was proven in prostate carcinoma and renal cell carcinoma cell lines, confirming the potential of the proposed protein−polyphenol conjugate in medicine.