Anticancer activity of glucomoringin isothiocyanate in human malignant astrocytoma cells

Isothiocyanates (ITCs) released from their glucosinolate precursors have been shown to inhibit tumorigenesis and they have received significant attention as potential chemotherapeutic agents against cancer. Astrocytoma grade IV is the most frequent and most malignant primary brain tumor in adults without any curative treatment. New therapeutic drugs are therefore urgently required. In the present study, we investigated the in vitro antitumor activity of the glycosylated isothiocyanate moringin [4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate] produced from quantitative myrosinase-induced hydrolysis of glucomoringin (GMG) under neutral pH value. We have evaluated the potency of moringin on apoptosis induction and cell death in human astrocytoma grade IV CCF-STTG1 cells. Moringin showed to be effective in inducing apoptosis through p53 and Bax activation and Bcl-2 inhibition. In addition, oxidative stress related Nrf2 transcription factor and its upstream regulator CK2 alpha expressions were modulated at higher doses, which indicated the involvement of oxidative stress-mediated apoptosis induced by moringin. Moreover, significant reduction in 5S rRNA was noticed with moringin treatment. Our in vitro results demonstrated the antitumor efficacy of moringin derived from myrosinase-hydrolysis of GMG in human malignant astrocytoma cells.