Chemosensetizing and cardioprotective effects of resveratrol in doxorubicin- treated animals

Abstract

Background: Doxorubicin (DOX), an anthracycline antibiotic is one of the most effective anticancer drug used in the treatment of variety of cancers .Its use is limited by its cardiotoxicity. The present study was designed to assess the role of a natural product resveratrol (RSVL) on sensitization of mammary carcinoma (Ehrlich ascites carcinoma) to the action of DOX and at the same time its protective effect against DOX-induced cardiotoxicity in rats.

Methods: Ehrlich ascites carcinoma bearing mice were used in this study. Percent survival of tumor bearing mice was used for determination of the Cytotoxic activity of DOX in presence and absence of RSVL. Uptake and cell cycle effect of DOX in tumor cells in the presence of RSVL was also determined. Histopatholgical examination of heart tissues after DOX and/or RSVL therapy was also investigated.

Results: DOX at a dose level of 15 mg/kg increased the mean survival time of tumor bearing mice to 21 days compared with 15 days for non tumor-bearing control mice. Administration of RSVL at a dose level of 10 mg/kg simultaneously with DOX increased the mean survival time to 30 days with 70% survival of the tumor-bearing animals. RSVL increased the intracellular level of DOX and there was a strong correlation between the high cellular level of DOX and its cytotoxic activity. Moreover, RSVL treatment showed 4.8 fold inhibition in proliferation index of cells treated with DOX. Histopathological analysis of rat heart tissue after a single dose of DOX (20 mg/kg) showed myocytolysis with congestion of blood vessels, cytoplasmic vacuolization and fragmentation. Concomitant treatment with RSVL, fragmentation of the muscle fiber revealed normal muscle fiber.

Conclusion: This study suggests that RSVL could increase the cytotoxic activity of DOX and at the same time protect against its cardiotoxicity.

Keywords: Cardioprotection; Cell cycle disturbance; Doxorubicin; Potentiation; Resveratrol.

Figure 1

Effect of RSVL treatment (10 mg/kg,i.p.) on the cytotoxic activity of doxorubicin (10 mg/kg,i.p.) against the growth of Ehrlich ascites cells.

Figure 2

Effect of resveratrol treatment on the doxorubicin level in Ehrlich ascites cell. Doxorubicin was injected (20 mg/kg i.p.) in tumor-bearing mice treated with 10 mg /kg,i.p. RSVL in simultaneous manner (red box) or saline (blue diamond suit). Each data represents the mean ± S.D. of six mice. ^aSignificantly different from DOX after 3 hours of treatment at P-value ≤ 0.05. ^bSignificantly different from DOX after 24 hours of treatment at P-value ≤ 0.05. ^cSignificantly different from DOX after 48 hours of treatment at P-value ≤ 0.05.

Figure 3

Effect of DOX (15 mg/kg) and/or RSVL (10 mg/kg) on cell cycle phase distribution of Ehrlich ascites cells.

Figure 4

Effect of DOX and/or RSVL on the proliferation index. ^aSignificantly different from Control at P-value ≤ 0.05. ^bSignificantly different from DOX after 3 h of treatment at P-value ≤ 0.05. ^cSignificantly different from DOX after 24 h of treatment at P-value ≤ 0.05.

Figure 5

A photomicrograph of the myocardium of a normal rat showing branching cardiac muscle fibers (b) with central oval euchromatic nuclei (thick arrow). The fibroblast in the endomycium revealed deeply stained flat nuclei (thin arrows). H&E × 400.

Figure 6

A photomicrograph of the myocardium of a rat given RSVL (10 mg/kg,i.p.) showing a general architecture almost similar to group I (control) except for slight congestion of the blood vessels (arrows). H&E × 400.

Figure 7

A photomicrograph of the myocardium of a rat given DOX ( 20 mg/kg,i.p.) a :showing areas of myocytolysis(m). H&E × 400. b: showing congestion of blood vessels (arrows). H&E × 400. c: showing myocytes with cytoplasmic vacuolization (V) or fragmentation (F). Some nuclei were pyknotic (thin arrow) while others revealed chromatin margination (thick arrow). H&E × 400. d: showing hyalinization of the muscle fiber (thick arrow). Notice the congested blood vessel (thin arrow). H&E × 400. e: showing chromatin margination of some nuclei (black arrows)while others were pyknotic (white arrows). Areas empty of muscle fibers around the pyknotic nuclei were evident (thick arrow). H&E × 400.

Figure 8

A photomicrograph of the myocardium of a rat given RSVL (10 mg/kg,i.p.) concomitantly with DOX showing normal muscle fibers with their central oval nuclei (black arrows). Still some pyknotic nuclei (dashed arrows) and fragmentation (F) of the muscle fiber were revealed H&E × 400.