30 secondary polyphenolic metabolites were characterised in Eucalyptus kino methanol extract using HPLC-MS/MS. The antitumor activity of the extract in combination with low level ionising radiation in female mice with solid tumors from inoculated Ehrlich ascites carcinoma cells was investigated. Tumor cell-inoculated mice received daily extract doses (100 mg/kg, 200 mg/kgBW) with or without a single exposure to 0.25 Gy γ-rays, and cis-platin as a reference anticancer drug. Changes in the tumor volume, oxidative state, levels of caspase-3, TGF-β and Nf-κB were assessed by q-PCR. Surprisingly, a dose of 200 mg/kg extract together with γ-radiation remarkably reduced the tumor volume, improved the oxidative and apoptotic biomarker levels. In conclusion, results showed that a combination of kino extract with low level γ-radiation synergistically reduced tumor progression due to the antioxidant and anti-proliferative activities of the polyphenolics in the extract.
Keywords: Caspase-3; Eucalyptus globulus; Nf-κB; TGF-β; ascites carcinoma; kino; polyphenols.