Protective effects of an aged garlic extract on doxorubicin‐induced cardiotoxicity in the mouse

Protective effects of an aged garlic extract on the cardiotoxicity of doxorubicin (DOX) was evaluated using the mouse. DOX (1.5 mg/kg body wt i.p.) was administered three times per week for 40 days. An aged garlic extract, WG-1 (a preserved stock solution; Wakunaga Pharmaceutical) was administered intraperitoneally six times weekly. DOX caused changes in the electrocardiogram. In the control mice, the width of the QRS complex was 20 +/- 2.8 milliseconds, the R-R interval was 130 +/- 2.8 milliseconds, and the P-Q interval was 30 +/- 1.4 milliseconds. In mice treated with DOX for 40 days, the width of the QRS complex was 50 +/- 10 milliseconds (p < 0.05), the R-R interval was 240 +/- 30 milliseconds (p < 0.05), and the P-Q interval was 45 +/- 1.0 milliseconds (p < 0.01). These values were significantly smaller in mice treated with WG-1 + DOX than in mice treated with DOX. The width of the QRS complex was 29.3 +/- 5.8 milliseconds (p < 0.05), the R-R interval was 145.8 +/- 17.9 milliseconds (p < 0.01), and the P-Q interval was 37.8 +/- 3.5 milliseconds (p < 0.05). The lipid peroxidation in the heart homogenates prepared from DOX-treated mice, as measured by thiobarbituric acid-reactive substance (TBARS, nmol malondialdehyde/100 mg protein) was 332.5 +/- 67.0, which was significantly larger than that in the control mice (186.6 +/- 42.2) (p < 0.05). WG-1 decreased the level of TBARS in DOX-treated mice significantly. In the mice treated with WG-1 + DOX, TBARS was 221.3 +/- 31.6, which was significantly smaller than that of DOX-treated mice (p < 0.05). Histological study demonstrated that the heart treated with DOX had vacuolization in muscle cells, disrupted myofibrils, and swollen mitochondria. Mice that received WG-1 + DOX had no significant pathological lesions in the heart.