Ent-kaurenoic acid-enriched Mikania glomerata leaves-complexed β-cyclodextrin: Pharmaceutical development and in vivo antitumor activity in a sarcoma 180 mouse model.

The extract obtained from Mikania glomerata leaves rich in ent-kaurenoic acid (ERKA) shows cytotoxic activity in vitro, but its hydrophobic nature and thermosensitivity are issues to be solved prior to in vivo antitumor studies. The purpose of this study was to investigate the antitumor activity of inclusion complexes formed between ERKA and β-cyclodextrin (ERKA:β-CD) in rodents. ERKA:β-CD complexes obtained by malaxation (MX) and co-evaporation (CE) methods were firstly characterized regarding their physical properties, encapsulation efficiency, and cytotoxicity againts L929 cells. The antitumor activity study was then performed in mice with sarcoma 180 treated with saline, 5-fluouracil (5FU) and ERKA:β-CD at 30, 100 and 300 µg/kg. The weight, volume, percentage of inhibition growth, gross and pathological features and positivity for TUNEL, ki67, NFκB and NRF2 in the tumors were assessed. Serum lactate-dehydrogenase activity (LDH), white blood cells count (WBC) and both gross and pathological features of the liver, kidneys and spleen were also evaluated. The formation of the inclusion complexes was confirmed by thermal analysis and FTIR, and they were non-toxic for L929 cells. The MX provided a better complexation efficiency. ERKA:β-CD300 promoted significant tumor growth inhibition, and attenuated the tumor mitotic activity and necrosis content, comparable to 5-fluorouracil. ERKA:β-CD300 also increased TUNEL-detected cell death, reduced Ki67 and NF-kB immunoexpression, and partially inhibited the serum LDH activity. No side effect was observed in ERKA:β-CD300-treated animals. The ERKA:β-CD inclusion complexes at 300 µg/kg displays antitumour activity in mice with low systemic toxicity, likely due to inhibition on the NF-kB signaling pathway and LDH activity.