Ardipusilloside I (ADS-I) is a natural compound that can be isolated from the Chinese medicinal herb Ardisiapusilla A.DC, and has been reported to inhibit the growth of glioblastoma cells in cultures. This study was designed to test its efficacy by the delivery using biodegradable implants against glioblastoma in vivo. ADS-I was incorporated into polymer microspheres, which were prepared by a mixture of poly (D, L-lactic acid) and poly (D, L-lactic-co-glycolic acid) polymers and then fabricated into wafers. The anti-glioma activities of ADS-I-loaded wafers were examined by methylthiazol tetrazolium (MTT) assay in cultured rat C6 glioma cells, and by magnetic resonance imaging (MRI) and survival monitoring in C6 glioma-bearing rats. Here, we showed that ADS-I-loaded wafers sustained ADS-I release in vitro for 36 days in Higuchi model of kinetics, and had the same cytotoxic activity as ADS-I in the solution against the growth of C6 glioma cells in cultures. In C6 glioma-bearing rats, ADS-I wafer implants inhibited tumor growth in a dose-dependent matter, and were more effective than the same dosage of ADS-I in the solution. The tumor suppression efficacies of ADS-I wafer implants were positively correlated with an increase in tumor cell apoptosis and prolonged animal survival, and were associated with a decrease in vascular endothelial growth factor, C-reactive protein, tumor necrosis factor-α and interleukin-6, and an increase in interleukin-2 expression. In conclusion, this study demonstrates significant efficacy of local delivery of ADS-I using polymer implants against glioma tumor growth in vivo, suggesting the potential of ADS-I-loaded wafers for glioma treatment.
Keywords: Ardipusilloside I; anti-tumor activities; glioblastoma; implant wafer; interstitial therapy.