Abstract Background Pancreatic ductal adenocarcinoma (PDAC) remains one of the most fatal malignancies. Several chemotherapies employing fluorouracil (5-FU) and gemcitabine were attempted, but the survival rate was extremely low. Resveratrol (RVT), known as a polyphenol compound and phytoalexin, was demonstrated to induce intrinsic apoptosis in cancer cells. However, its low delivery performance and efficiency at tumor sites remain an obstacle to exploit RVT as a drug. To address these problems, we bio-conjugated resveratrol with gold nanoparticles (GNPs) via polyvinylpyrrolidone as a cross-linker (RVT@PVP-GNPs) and investigated whether the fabrications could enhance the delivery performance and anti-tumor efficacy of RVT. Results The fabrication of gold nanoparticles (GNPs) and bio-conjugated with resveratrol (RVT@PVP-GNPs) was conducted firstly. TEM image, spectrophotometry and zeta-potential revealed that the GNPs and RVT@PVP-GNPs having a size of approximately 40 nm were successfully synthesized and exhibited moderate stability. GNPs alone represented no damage in PANC-1 cells and moreover diminished the cytotoxicity of RVT in Raw264.7 murine macrophage cells, demonstrating the superiority of gold nanoparticles as a drug carrier. Evaluation using dialysis showed a burst release rate of RVT within 96 h at pH 5.0, demonstrating the possibility of enhanced efficiency of RVT delivery through blood vessels to the tumor. The RVT@PVP-GNPs induced increased rates of S-phase cell cycle arrest and apoptosis compared with free RVT. Notably, RVT@PVP-GNPs diminished the proportion of necrotic cells, whereas free RVT increased it. We also demonstrated that the RVT@PVP-GNPs may induce an apoptosis via intrinsic mitochondria with higher degree compared with free RVT, indicating the possibility of enhanced anti-tumor agents. In animal studies, RVT@PVP-GNPs conjugated with AS1411 aptamer induced efficient tumor volume suppression without accumulation in or damage to the kidneys in vivo. Conclusions The results demonstrate that RVT@PVP-GNPs enhance the anti-tumor efficacy of free RVT by activating the intrinsic apoptotic pathway and could be considered as potential anti-tumor drug candidates against pancreatic cancer cells.

The major components of magnolia flower extracts (MFEs) were classified into four substances, such as flavonoids, phenylethanoid glycoside derivatives (PhGs), caffeoylquinic acids (CQAs), and others, in our previous study. The chemical components of MFEs, including the rutin of flavonoid, acteoside and isoacteoside of PhGs, and caffeyolquinic acids, are reported to have physiological effects on anti-obesity effects. The anti-obesity effect of fresh and browned Magnolia denudata flower extracts (FMFE and BMFE, respectively) was investigated in 3T3-L1 adipocytes. The treatment concentrations of FMFE and BMFE were 200 and 400 μg/mL, respectively, as determined with the WST-1 assay. Intracellular lipid accumulation in 3T3-L1 cells was inhibited with the treatment of MFEs, including FMFE and BMFE, as observed with an image of the culture plate, using an optical microscope and Oil red O staining. The expression of the adipogenic target genes involved in adipocyte differentiation, including PPARγ, C/EBPα, perilipin, FABP4, FAS, HSL, and SREBP-1, was suppressed with the treatment of MFEs. Additionally, the phosphorylation of AMPK and ACC in 3T3-L1 cells was significantly increased following treatment with the MFEs. These results suggest that both MFEs have a potential for physiological effects on anti-obesity activity.