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After the publication of the above article, the authors have realized that they failed to properly acknowledge the work performed by their Center for Innovative Drug Discovery High Throughput Screening Core Facility in the paper. The Declarations section of their paper should therefore have also included the following statement: "The UT Health San Antonio Center for Innovative Drug Discovery HTS Facility was funded in part by the Cancer Prevention Research Institute of Texas (CPRIT; grant no. RP160844)". The authors regret their oversight in failing to include this information in the Declarations section of their paper. [the original article was published in International Journal of Oncology 53: 2627-2636, 2018; DOI: 10.3892/ijo.2018.4585].

Polygodial, a drimane sesquiterpenoid dialdehyde isolated as a pungent component of the water pepper Persicaria hydropiper, exhibits antifeedant, antimicrobial, anti-inflammatory and anticancer effects. Polygodial also activates transient receptor potential vanilloid subtype 1 (TRPV1) channels. Previously, we described the synthesis of a C12-Wittig derivative of polygodial, termed P3, with significant antiproliferative effects against multiple cancer types including oral squamous cell carcinoma (OSCC). In the present study, a more potent derivative, P27, with superior anti-proliferative effects in vitro and antitumor effects in Cal-27 derived xenografts is described. Polygodial, P3, and P27 all significantly decreased OSCC tumor growth, with P27 being equipotent with polygodial and P3 being the least efficacious. However, neither analog elicited the adverse effect observed with polygodial: Profound transient inflammation. Although P3 and P27 pharmacophores are based on polygodial, novel effects on OSCC cell cycle distribution were identified and shared anticancer effects that are independent of TRPV1 activity were observed. Polygodial elicits an S-phase block, whereas P3 and P27 lead to G2/M phase arrest. Pretreatment of OSCC cells with the TRPV1 antagonist capsazepine does not affect the antiproliferative activity of P3 or P27, indicating that TRPV1 interactions do not regulate OSCC cell proliferation. Indeed, calcium imaging studies identified that the analogs neither activate nor antagonize TRPV1. Behavioral studies using a rat model for orofacial pain confirmed that these analogs fail to induce nocifensive responses, indicating that they are non-noxious in vivo. All compounds induced a significant concentration-dependent decrease in the mitochondrial transmembrane potential and corresponding apoptosis. Considering that P27 is equipotent to polygodial with no TRPV1-associated adverse effects, P27 may serve as an efficacious novel therapy for OSCC.