Chlorogenic acid (CGA) possesses various biological activities such as anti-oxidant, anti-inflammatory, and anti-diabetic activities. In the present study, we examined the effect of CGA on the transduction efficiency of PEP-1-ribosomal protein S3 (PEP-1-rpS3) into cells and brain tissues, and its neuroprotective potential against ischemia/reperfusion. We found that, in the presence of CGA, the transduction efficiency of PEP-1-rpS3 into astrocytes and the CA1 region of the hippocampus was enhanced, compared to its transduction in the absence of CGA. Also, cell viability data demonstrated that the sample treated with CGA + PEP-1-rpS3 exhibited improved cell viability against hydrogen peroxide (H₂O₂)-induced toxicity more significantly than the sample treated with PEP-1-rpS3 alone. Also, in a gerbil ischemia model, data demonstrated that following the ischemic insult, the group treated with PEP-1-rpS3 + CGA showed markedly enhanced protection of neuron cells in CA1 region of hippocampus, compared to those treated with CGA or PEP-1-rpS3 alone. Taken together, these results suggest that CGA may improve the transduction efficiency of protein transduction domain (PTD) fusion proteins into target cells or tissues, thereby enhancing their therapeutic potential against various diseases.

Keywords: chlorogenic acid, PEP-1-ribosomal protein S3, protein transduction, ischemic insult