Intracellular Pathways and Mechanisms of Colored Secondary Metabolites in Cancer Therapy.

Despite the great advancements made in cancer treatment, there are still many unsatisfied aspects, such as the wide palette of side effects and the drug resistance. There is an obvious increasing scientific attention towards nature and what it can offer the human race. Natural products can be used to treat many diseases, of which some plant products are currently used to treat cancer. Plants produce secondary metabolites for their signaling mechanisms and natural defense. A variety of plant-derived products have shown promising anticancer properties in vitro and in vivo. Rather than recreating the natural production environment, ongoing studies are currently setting various strategies to significantly manipulate the quantity of anticancer molecules in plants. This review focuses on the recently studied secondary metabolite agents that have shown promising anticancer activity, outlining their potential mechanisms of action and pathways.

The effect of Azo-dyes on glioblastoma cells in vitro.

Despite the multidisciplinary standard treatment of glioblastoma (GB) consisting of maximal surgical resection, followed by radiotherapy (RT) plus concomitant chemotherapy with temozolomide (TMZ), the majority of patients experience tumor progression and almost universal mortality. In recent years, efforts have been made to create new agents for GB treatment, of which azo-dyes proved to be potential candidates, showing antiproliferative effects by inducing apoptosis and by inhibiting different signaling pathways. In this study we evaluated the antiproliferative the effect of six azo-dyes and TMZ on a low passage human GB cell line using MTT assay. We found that all compounds proved antiproliferative properties on GB cells. At equimolar concentrations azo-dyes induced more cytotoxic effect than TMZ. We found that Methyl Orange required the lowest IC50 for 3 days of treatment (26.4684 µM), whilst for 7 days of treatment, two azo dyes proved to have the highest potency: Methyl Orange IC50 = 13.8808 µM and Sudan I IC50 = 12.4829 µM. The highest IC50 was determined for TMZ under both experimental situations. Conclusions: Our research represents a novelty, by offering unique valuable data regarding the azo-dye cyototoxic effects in high grade brain tumors. This study may focus the attention on azo-dye agents that may represent an insufficient exploited source of agents for cancer treatment.

Combined Effects of Doxorubicin and Temozolomide in Cultured Glioblastoma Cells.

The oncological field benefits of extensive medical research and various types of cancer notice improvements, however glioblastoma multiforme remains one of the deadliest cancers in humans with virtually no advance in survival and clinical outcome. Temozolomide, the FDA approved drug for glioblastoma, faces numerous challenges such as resistance and side effects. To overcome these challenges, many combination therapies are currently studied. The present study analyses the effects of temozolomide in combination with doxorubicin on a glioblastoma cell line. Our results showed that both drugs displayed a cytotoxic effect on the studied cells in single administration (55% for 100µM temozolomide at 14 days, 53% for 100µM doxorubicin at 14 days), but without a synergistic effect in dual therapy. Although the results failed to produce the expected effect, they propose new research perspectives in the future.