Preliminary Study on the Antibacterial and Cytotoxic Effects of the Synthetic New Peptide NJP9-A

The in vitro antibacterial effect of a synthetic new peptide NJP9-A originated from natural marine invertebrates and its cytotoxicity, selectivity and one possible mechanism of action on human leukemia cells were investigated. NJP9-A showed significant bacteriostasis against Staphylococcus aureus (including methicillin-resistant S. aureus), and had a very low hemolysis efficiency on the human red blood cells. NJP9-A selectively bound to and inhibited the proliferation of leukemia cells, but had almost no inhibitory effect on the proliferation of HEK293 and HUVEC cells. The underlying mechanism of NJP9-A’s anti-leukemia cell effect may involve changing the expression of PIK3R1 (PI3K p85 regulatory subunit 1), and the corresponding PI3K signal transduction pathway. NJP9-A inhibits Gram-positive bacteria and is cytotoxic to leukemia cells. The underlying mechanism of NJP9-A’s anti-leukemia cell effect is still unclear, but it may be related to the alteration of PIK3R1 expression.