Novel peptide identified from the skin of Kaloula pulchra frog

A novel peptide which was named Cath-KP was identified from the skin of Kaloula pulchra frog. Cath-KP belongs to the Cathelicidin family with 37 amino acid residues (GCSGRFCNLFNNRRPGRLTLIHRPGGDKRTSTGLIYV). Cath-KP possesses a favorable antioxidant capability in both in vivo and in vitro. Cath-KP succesfully across the blood-brain barrier, strengthen protection against oxidative stress by promoting the expression of antioxidant enzymes and alleviating the accumulation of mitochondrial and intracellular ROS through regulating the activation of Sirt/Nrf2, FAK, and p38 signaling pathways, thereby ameliorate the damage towards nerve cells caused by stimulus. Cath-KP also affects the apoptosis process via modulating the expression of related protein including Bax and Bcl-2. In vivo, Cath-KP exerts a promising neuroprotective properties in MPTP-induced PD mice.