Delphinidin enhances radio-therapeutic effects via autophagyinduction and JNK/MAPK pathway activation in non-small celllung cancer

Delphinidin is a major anthocyanidin compound found in various vegetablesand fruits. It has anti-oxidant, anti-inflammatory, and various other biologicalactivities. In this study we demonstrated the anti-cancer activity of delphinidin,which was related to autophagy, in radiation-exposed non-small cell lung cancer(NSCLC). Radiosensitising effects were assessed in vitro by treating cells with a subcytotoxicdose of delphinidin (5 M) before exposure to -ionising radiation (IR). Wefound that treatment with delphinidin or IR induced NSCLC cell death in vitro; howeverthe combination of delphinidin pre-treatment and IR was more effective thaneither agent alone, yielding a radiation enhancement ratio of 1.54 at the 50% lethaldose. Moreover, combined treatment with delphinidin and IR, enhanced apoptoticcell death, suppressed the mTOR pathway, and activated the JNK/MAPK pathway.Delphinidin inhibited the phosphorylation of PI3K, AKT, and mTOR, and increasedthe expression of autophagy-induced cell death associated-protein in radiation-exposedNSCLC cells. In addition, JNK phosphorylation was upregulated by delphinidinpre-treatment in radiation-exposed NSCLC cells. Collectively, these results show thatdelphinidin acts as a radiation-sensitizing agent through autophagy induction andJNK/MAPK pathway activation, thus enhancing apoptotic cell death in NSCLC cells.

Delphinidin enhances radio-therapeutic effects via autophagyinduction and JNK/MAPK pathway activation in non-small celllung cancer

Delphinidin is a major anthocyanidin compound found in various vegetablesand fruits. It has anti-oxidant, anti-inflammatory, and various other biologicalactivities. In this study we demonstrated the anti-cancer activity of delphinidin,which was related to autophagy, in radiation-exposed non-small cell lung cancer(NSCLC). Radiosensitising effects were assessed in vitro by treating cells with a subcytotoxicdose of delphinidin (5 M) before exposure to -ionising radiation (IR). Wefound that treatment with delphinidin or IR induced NSCLC cell death in vitro; howeverthe combination of delphinidin pre-treatment and IR was more effective thaneither agent alone, yielding a radiation enhancement ratio of 1.54 at the 50% lethaldose. Moreover, combined treatment with delphinidin and IR, enhanced apoptoticcell death, suppressed the mTOR pathway, and activated the JNK/MAPK pathway.Delphinidin inhibited the phosphorylation of PI3K, AKT, and mTOR, and increasedthe expression of autophagy-induced cell death associated-protein in radiation-exposedNSCLC cells. In addition, JNK phosphorylation was upregulated by delphinidinpre-treatment in radiation-exposed NSCLC cells. Collectively, these results show thatdelphinidin acts as a radiation-sensitizing agent through autophagy induction andJNK/MAPK pathway activation, thus enhancing apoptotic cell death in NSCLC cells.

Radioprotective effects of delphinidin on normal human lung cells against proton beam exposure

BACKGROUND/OBJECTIVES: Exposure of the normal lung tissue around the cancerous tumor during radiotherapy causes serious side effects such as pneumonitis and pulmonary fibrosis. Radioprotectors used during cancer radiotherapy could protect the patient from side effects induced by radiation injury of the normal tissue. Delphinidin has strong antioxidant properties, and it works as the driving force of a radioprotective effect by scavenging radiation-induced reactive oxygen species (ROS). However, no studies have been conducted on the radioprotective effect of delphinidin against high linear energy transfer radiation. Therefore, this study was undertaken to evaluate the radioprotective effects of delphinidin on human lung cells against a proton beam. MATERIALS/METHODS: Normal human lung cells (HEL 299 cells) were used for in vitro experiments. The 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay assessed the cytotoxicity of delphinidin and cell viability. The expression of radiation induced cellular ROS was measured by the 2′-7′-dicholordihydrofluorescein diacetate assay. Superoxide dismutase activity assay and catalase activity assay were used for evaluating the activity of corresponding enzymes. In addition, radioprotective effects on DNA damage-induced cellular apoptosis were evaluated by Western blot assay. RESULTS: Experimental analysis, including cell survival assay, MTT assay, and Western blot assay, revealed the radioprotective effects of delphinidin. These include restoring the activities of antioxidant enzymes of damaged cells, increase in the levels of pro-survival protein, and decrease of pro-apoptosis proteins. The results from different experiments were compatible with each to provide a substantial conclusion. CONCLUSION: Low concentration (2.5 µM/mL) of delphinidin administration prior to radiation exposure was radioprotective against a low dose of proton beam exposure. Hence, delphinidin is a promising shielding agent against radiation, protecting the normal tissues around a cancerous tumor, which are unintentionally exposed to low doses of radiation during proton therapy.

Therapeutic effects of dihydroartemisinin and transferrin against glioblastoma

BACKGROUND/OBJECTIVES: Artemisinin, a natural product isolated from Gaeddongssuk (artemisia annua L.) and its main active derivative, dihydroartemisinin (DHA), have long been used as antimalarial drugs. Recent studies reported that artemisinin is efficacious for curing diseases, including cancers, and for improving the immune system. Many researchers have shown the therapeutic effects of artemisinin on tumors such as breast cancer, liver cancer and kidney cancer, but there is still insufficient data regarding glioblastoma (GBM). Glioblastoma accounts for 12-15% of brain cancer, and the median survival is less than a year, despite medical treatments such as surgery, radiation therapy, and chemotherapy. In this study, we investigated the anti-cancer effects of DHA and transferrin against glioblastoma (glioblastoma multiforme, GBM). MATERIALS/METHODS: This study was performed through in vitro experiments using C6 cells. The toxicity dependence of DHA and transferrin (TF) on time and concentration was analyzed by MTT assay and cell cycle assay. Observations of cellular morphology were recorded with an optical microscope and color digital camera. The anti-cancer mechanism of DHA and TF against GBM were studied by flow cytometry with Annexin V and caspase 3/7. RESULTS: MTT assay revealed that TF enhanced the cytotoxicity of DHA against C6 cells. An Annexin V immune-precipitation assay showed that the percentages of apoptosis of cells treated with TF, DHA alone, DHA in combination with TF, and the control group were 7.15 ± 4.15%, 34.3 ± 5.15%, 66.42 ± 5.98%, and 1.2 ± 0.15%, respectively. The results of the Annexin V assay were consistent with those of the MTT assay. DHA induced apoptosis in C6 cells through DNA damage, and TF enhanced the effects of DHA. CONCLUSION: The results of this study demonstrated that DHA, the derivative of the active ingredient in Gaeddongssuk, is effective against GBM, apparently via inhibition of cancer cell proliferation by a pharmacological effect. The role of transferrin as an allosteric activator in the GBM therapeutic efficacy of DHA was also confirmed.