Biochemical Study of Antitumor Activity of Resveratrol in Combination with Selenium in Ehrlich Ascites Carcinoma Bearing and/or Irradiated Mice

Abstract

The understanding of the fundamental role of angiogenesis and metastasis in cancer growth has led to tremendous interest in research regarding its regulatory mechanisms in the management of cancer. The present study evaluates the influence of the angiogenic regulators on the tumor growth and the cell sensitivity to ionizing radiation (IR) targeting the improvement of cancer therapeutic protocols. It is found that, polyphenolic non-flavonoid; resveratrol, which is present in a large number of plant products, had attracted many interests with its benefits not only as phytoalexin agent but also by its anticancer, antioxidant and anti-inflammatory benefits. Accordingly, the antiangiogenic activities of Res and Sse were tested invitro as well as invivo. Alteration in Ehrlich ascites carcinoma (EAC) viability was observed in the γ-irradiated (6.5 Gy) and non-irradiated EAC cells incubated with different concentrations of Res 30, 50, 60, 80 and 100 µM and Res accompanied with 5 μg /ml Sse.The action of Res and/ or Sse was examined invivo in mice bearing Ehrlich cells and/ or γ-irradiated (single whole body dose). Solid tumor was produced by intramuscular (i.m.) inoculation with EAC cells. To fulfil the targets of this study, a total of 160 female mice weighing 20 – 25 g, were classified into 16 groups, 10 for each group, and treated with daily intraperitoneal (i.p.) injections with Res 25 mg/kg b.wt and/or Sse 5μg/mice for 14 successive days as follow:Control groups: )C(;mice received i.p. injection with DMSO in PBS, )Res, Sse & Res+Sse(; mice i.p. injected with Res, Sse ora mixture of both, respectively. Irradiated groups: (Irr(; mice exposed to a single whole body γ–irradiated dose,)Res+Irr, Sse+Irr & Res+Sse+Irr(; mice i.p. injected with Res, Sse ora mixture of both, respectively, then γ–irradiated24 hrs. after the last injected dose, Ehrlich groups:)E(;mice bearing solid tumor (i.m. inoculation), )E+Res, E+Sse &E+Res+Sse(; mice bearing solid tumor and i.p. injected with Res, Sse ora mixture of both, respectively.Ehrlich-Irradiated groups: E+Irr; mice bearing solid tumor and γ–irradiated, E+Res+Irr, E+Sse+Irr & E+Res+Sse+Irr; mice bearing solid tumor i.p. injected with Res, Sse ora mixture of both, respectively, then γ–irradiated 24 hrs. after the last injected dose. Results obtained from this studyindicated that the maximal inhibitory concentration values of Res and Sse were 100 μM and 5µg, respectively, after 24 hrs. incubation. However, when Ehrlich cells were treated with 80 μM Res and 5µg Sse simultaneously, a synergistic anti-proliferative effect had been observed. Mice bearing tumor treated with Res and/or Sse then exposed to γ-irradiationshowed marked reduction in the tumor volume on the 1st and the 2nd time intervals as compared to the corresponding non-treated mice. In addition, serum MMP-2 & -9 activities, TNF-α level and LDH activity in the Irr, E or E+Irr mice groups were significantly increased, compared to their corresponding values in the control (C) mice group. Also, the serum of (MMP-2, MMP -9 & LDH) activities and TNF-α level in the Ehrlich-Irradiated (E+Irr) mice group were significantly increased the Ehrlich (E) group. In contrast, the serum MMP-2, MMP-9 & LDH activities and TNF-α level in E or the E+ Irr mice treated with Res, Sse or Res+Sse were significantly decreasedas compared to the E group. A significant increase in the liver TBARs concentration in the Irr, E or E+Irr mice groups was observed. In contrast, the E or E+Irr treated with Res, Sse or Res+Sse showed significant decrease in the liver TBARs concentration as compared to in E group.

A significant reduction in the liver antioxidant enzymes SOD, CAT and GSHcontent of the Irr, E or E + Irr mice groups was observed as compared to the C group. On the other hand, treatment of E & E+Irr mice with Res, Sse or Res+Sse showed significant increase in the liver SOD activity as compared to the E group. While treatment of mice bearing tumor (E) with Res, Sse or Res + Sse showed significant increase in the liver CAT activity, compared to the E group on the 1st time interval and only Res+Sse on the 2nd time interval.Furthermore, the liver CAT activity had a significant increase in the E+Irr treated groups with Res+Sse, comparedto the E group on the 1st time interval. On the other hand, treatment of E & E+Irr mice with Res + Sse showed significant increase in the liver GSH content as compared to the E group. While, the treatment with Res or Sse individually showed significant increase in the liver GSH content as compared to the E group and non-significant increase for E+Irr group. Tumor antioxidant markers, SOD, CAT and GSH were significantly decreased in the E+Irr mice group, compared to the E group on the 1st and the 2nd time intervals for SOD and CAT and on the 2nd time interval for GSH. Also, E+ Irr group treated with Res, Sse or Res+Sse had a significant decrease in the tumor antioxidant markers as compared to E group. Administration of Res, Sse or Res+Sse to E group showed significant decrease in the CAT and GSH of the tumor tissues compared to the E group, while treatment of E groups with a mixture of Res and Sse showed more significant reduction in the SOD activity of the tumor tissues compared to E group.