Heat processing effect of luteolin on anti-metastasis activity of human glioblastoma cells U87.

Among the flavonoïds, luteolin is a flavone that has been identified in many plants. It is known for its apoptotic potential with damage to DNA and cell cycle blockage. Many studies have shown that luteolin has anti-oxidant, anti-inflammatory, and anti-cancer activities. However, it is known that heat treatment (boiling, cooking, and treating with microwaves …) can influence the structure of flavonoïds, which often leads to changes in their activities. The present study was conducted to study the effect of heated luteolin on anti-tumor activity of glioblastoma cells U87. Glioblastoma cell viability was evaluated by MTT assay. Adhesion assay was performed on different protein matrices (collagen type 1, vitronectin, fibronectin, and poly-L-lysine); migration assay was determined by modified Boyden chambers and videomicroscopy, and finally, angiogenesis was tested in vitro by capillary network formation on Matrigel™. The results obtained show that the thermal treatment significantly reduces its cytotoxic activity and ability to inhibit cell adhesion to different protein matrices. It was also found that the heat processed significantly reduced the ability of luteolin to inhibit cell migration, cell invasion, and endothelial cell angiogenesis (HMEC-1). This suggests that heat treated luteolin has a lower anti-tumor potential than native luteolin. Graphical abstract ᅟ.

Heated naringin mitigate the genotoxicity effect of Mitomycin C in BALB/c mice through enhancing the antioxidant status.

A major problem with cancer chemotherapy is its severe toxic effects on non-target tissues. Assessment of natural products for their protective effect against anticancer drugs induced toxicity is gaining importance in cancer biology. The aim of the present study was to evaluate the effect of native and thermal treated naringin on the protective effect against mitomycin C (MMC) induced genotoxicity. The genotoxicity in liver kidney and brain cells isolated from Balb/C mice were evaluated by performing the comet assay. Antioxidant and lipid peroxidation assays were carried out to understand the protective effects of these compounds. The comet assay showed that heated and native naringin were not genotoxic at the tested dose (40 mg/kg b.w) on liver, kidney and brain cells. A significant decrease in DNA damages was observed, at the tested doses (20 mg/kg b.w and 40 mg/kg b.w) suggesting a protective role of these molecules against the genotoxicity induced by mitomycin C on liver, kidney and brain cells. Moreover, administration of MMC (6 mg/kg b.w.) altered the activities of glutathione peroxidase and superoxide dismutase accompanied by a significant increase of lipid peroxidation. Pretreatment of mouse with heated and native naringin before MMC administration significantly raised the glutathione peroxidase and superoxide dismutase activities followed by a reduced MMC-induced lipid peroxidation. Our study demonstrated that heat treatment of naringin preserve activities of native naringin. The genoprotective properties of heated and native naringin against MMC could be attributed to its antioxidant activities and its inhibitory effect on lipid peroxidation.

Thermal treatment of luteolin-7-O-ß-glucoside improves its immunomodulatory and antioxidant potencies.

Phytochemicals extracted from flowers, roots and bark, leaves, and other plant sources have been used extensively throughout human history with varying levels of efficacy in prevention and treatment of disease. Recently, advanced methods for characterization and clinical use of these materials have allowed modern understanding of their properties to be used as immunomodulatory agents that act by enhancement of endogenous cytoprotective mechanisms, avoiding interference with normal physiologic signaling and highly effective medical treatment with minimal adverse side effects. Simple methods have been identified for improving their biological effects, such as thermal conditioning by heating or freezing-prominent example being heat treatment of lycopene and tetrahydrocannabinol. The present investigation shows improvement of the ability of heat to augment splenocyte proliferation, natural killer (NK) cell activities, and antioxidant capacity of the flavonoid luteolin-7-O-ß-glucoside (L7G) in comparison with the native (non heat-treated) molecule, while further demonstrating that both the native and the heat-treated variants exhibit comparable antioxidant properties, as evidenced by their effects in macrophages by inhibition of nitric oxide production and lysosomal enzyme activity in experiments that strengthen lysosomal membrane integrity. Outcomes of these studies suggest that heat-treated L7G shows promise for use in immunotherapy, including anti-cancer regimens, as shown by its improvement of NK cell cytotoxicity.

Effect of heated naringenin on immunomodulatory properties and cellular antioxidant activity.

Naringenin is one of the most popular flavonoids derived from citrus. It has been reported to be an effective anti-inflammatory compound. Citrus fruit may be used raw, cooked, stewed, or boiled. The present study was conducted to investigate the effect of thermal processes on naringenin in its immunomodulatory and cellular antioxidant activities. The effects of flavonoids on B and T cell proliferation were assessed on splenocytes stimulated or not with mitogens. However, their effects on cytotoxic T lymphocyte (CTL) and natural killer (NK) activities were assessed in splenocytes co-incubated with target cells. The amount of nitric oxide production and the lysosomal enzyme activity were evaluated in vitro on mouse peritoneal macrophages. Cellular antioxidant activity in splenocytes and macrophages was determined by measuring the fluorescence of the dichlorofluorescin (DCF). Our findings revealed that naringenin induces B cell proliferation and enhances NK activity. The highest concentration of native naringenin exhibits a significant proliferation of T cells, induces CTL activity, and inhibits cellular oxidation in macrophages. Conversely, it was observed that when heat-processed, naringenin improves the cellular antioxidant activity in splenocytes, increases the cytotoxic activity of NK cells, and suppresses the cytotoxicity of T cells. However, heat treatment maintains the anti-inflammatory potency of naringenin.