Short peptides having biological and therapeutic activity are disclosed. Specifically, the activity of the disclosed peptides is directed to reducing or protecting against mutagen-induced cellular/tissue toxicity (i.e., chemopreventive). For example, the disclosed peptides protect against skin toxicity and/or mutagenesis that occurs from ultraviolet (UV) light exposure. The disclosed peptides also block the activation of certain cell cycle regulatory proteins such as Chk2. An example of such a peptide is Ser-Leu-Tyr-Gln-Ser (SEQ ID NO: 10). The disclosed peptides are also useful for methods of reducing or protecting against cellular toxicity and mutation accumulation that would otherwise occur following mutagen exposure. One such method is drawn to applying a peptide to the skin to prevent or reduce mutagenic damage resulting from UV light (e.g., sunlight) exposure.
