Lady's Bedstraw as a Powerful Antioxidant for Attenuation of Doxorubicin-Induced Cardiotoxicity

Abstract

This study aimed to examine the effects of a 14-day treatment with lady's bedstraw methanol extract on doxorubicin-induced cardiotoxicity through functional, biochemical and histological examinations. We used 24 male Wistar albino rats divided into the following groups: control (CTRL), doxorubicin (DOX), and DOX + GVE (Galium verum extract). GVE was administered orally at a dose of 50 mg/kg per day for 14 days, while a single dose of doxorubicin was injected into the DOX groups. After accomplishing treatment with GVE, cardiac function was assessed, which determined the redox state. During the autoregulation protocol on the Langendorff apparatus, ex vivo cardiodynamic parameters were measured. Our results demonstrated that the consumption of GVE effectively suppressed the disturbed response of the heart to changes in perfusion pressures caused by administration of DOX. Intake of GVE was associated with a reduction in most of the measured prooxidants in comparison to the DOX group. Moreover, this extract was capable of increasing the activity of the antioxidant defense system. Morphometric analyses showed that rat hearts treated with DOX showed more pronounced degenerative changes and necrosis compared to the CTRL group. However, GVE pretreatment seems to be able to prevent the pathological injuries caused by DOX injection via decrease in oxidative stress and apoptosis.

Keywords: cardiac function; doxorubicin-induced cardiotoxicity; lady’s bedstraw; oxidative stress; rat.

Figure 1

HPLC chromatogram of G. Verum methanol extract: compound 1—Chlorogenic acid; compound 2—Cynaroside; compound 3—Quercetin-3-O-glucoside; compound 4—Quercetin; compound 5—Luteolin.

Figure 2

Effects of consumption of G. verum extract on ex vivo cardiac function parameters: (A) Values of dp/dt max within each of the 3 groups during PCP 1 and PCP 2; (B) Values of dp/dt min within each of the three groups during PCP 1 and PCP 2; (C) Values of SLVP within each of the three groups during PCP 1 and PCP 2; (D) Values of DLVP within each of the three groups during PCP 1 and PCP 2; (E) values of HR within each of the three groups during PCP 1 and PCP 2; (F) Values of CF within each of the three groups during PCP 1 and PCP 2. Values are expressed as mean ± standard deviation (n = 8). DOX—doxorubicin; GVE—G. Verum extract; CPP—constant perfusion pressure.

Figure 3

Effects of consumption of G. verum extract on the systemic oxidative stress parameters: (A) H₂O₂; (B) O₂⁻; (C) NO₂⁻; (D) TBARS; (E) SOD; (F) CAT; (G) GSH. Values are expressed as median. The upper bar shows the value of the third quartile and lower bar shows the first quartile (n = 8). * p < 0.05 compared to CTRL group; # p < 0.05 compared to DOX group.

Figure 4

Effects of consumption of G. verum extract on the value of the antioxidant defense system in heart tissue: (A) TBARS; (B) CAT; (C) SOD; (D) GSH. Values are expressed as median. The upper bar shows the value of the third quartile and the lower bar shows the first quartile (n = 8). * p < 0.05 compared to CTRL group; # p < 0.05 compared to DOX group.

Figure 5

Representative heart tissue sections of hematoxylin/eosin-staining: (A) CTRL group; (B) DOX group; (C) DOX + GVE group. Red arrows indicate representative changes in the heart tissue. Original magnification 20×.

Figure 6

cTnT-immunostaining: (A) CTRL group; (B) DOX group; (C) DOX + GVE group. Original magnification 20×. Red arrow indicates the area with the least colored cTnT in the heart tissue.

Figure 7

Representative heart tissue sections of Bcl-2, Bax and Caspase-3 staining in CTRL, DOX and DOX + GVE groups. Original magnification 20×.

Figure 8

Representative heart tissue sections of immunohistochemical staining of Hsp 70. (A) CTRL group; (B) DOX group; (C) DOX + GVE group. Original magnification 20×.