PARP1-IN-10 (compound 12c) is a highly potent and non-cytotoxic PARP1 inhibitor with an in vitro IC50 value of 50.62 nM, effectively inducing cell cycle arrest at the G2/M phase and apoptosis, while significantly augmenting the cytotoxic effects of temozolomide (TMZ) [1].

PARP1-IN-10 (compound 12c) exhibited no cytotoxicity at 10 μM over 48 hours against NCI-60 human tumor cell lines and showed an IC50 of 3.73 μM in inhibiting the MDA-MB-436 cell line. In 48-hour treatments, PARP1-IN-10 induced dose-dependent G2/M phase arrest at 1 and 3.73 μM and, at 0.5 μM, significantly enhanced temozolomide (TMZ) efficacy in A549 cell lines, reducing TMZ's IC50 from 24.2 μM to 3.64 μM. These findings, through cytotoxicity assays, cell cycle, and apoptosis analysis, underscore PARP1-IN-10’s potential as a specific and synergistic therapeutic agent with existing treatments like TMZ.