At a strikingly low concentration of 0.1 μM — far below typical supplementation doses — resveratrol completely rescued ionizing radiation (IR)-induced DNA damage in human endothelial cells, fully restored tube-forming (vascularization) capacity, and maintained stable distribution of PECAM-1, a critical cell-adhesion protein governing vascular integrity. The finding emerged from a validated in vitro endothelial injury model using comet assays for DNA strand-break quantification, immunofluorescence for protein localization, and Western blot across at least five independent experimental replicates.
The hormetic dose-response here is the analytically interesting detail: resveratrol's protective ceiling at 0.1 μM implies that higher concentrations — common in polyphenol supplement capsules delivering micromolar-to-millimolar plasma exposures — may not confer proportionally greater, or any, benefit to the endothelium. This aligns with resveratrol's notoriously poor and highly variable oral bioavailability, where plasma concentrations rarely sustain even low-nanomolar free levels. For cancer patients undergoing radiotherapy, endothelial damage is a clinically significant driver of late cardiovascular toxicity, and a natural compound that preserves vascular architecture during treatment would be genuinely valuable. However, this is strictly an in vitro cell-culture study — no animal pharmacokinetics, no tumor-protection controls, and no mechanistic pathway (NF-κB, SIRT1, Nrf2) was conclusively identified. The work is incremental and hypothesis-generating rather than practice-changing, but the validated screening model offers a practical platform for future compound discovery.
