Is the use of anthracyclines implicated in myocardial injury? Investigating the cardio modulatory effects of naringenin and apocynin in doxorubicin-induced cardiotoxicity in rats

Abstract

Naringenin, a major flavonoid in oranges, grapefruit, tomato skin and apocynin a polyphenolic compound isolated from plants, such as Apocynum cannabinum are known to possess anti-oxidant, anti-inflammatory, and anti-cancer properties. Doxorubicin (DOX) is an antibiotic, effective in the treatment of cancer, but notorious for its propensity to cause cardiotoxicity. This study investigated the combined effects of naringenin and apocynin in DOX-induced cardiac toxicity. Thirty rats were randomly divided into five groups (n = 6) as follows: Normal Control (NC), DOX only, DOX+ naringenin, DOX + apocynin and DOX +naringenin + apocynin. DOX (2.5 mg/kg) was administered intraperitoneally, three times per week for two weeks (cumulative dose of 15 mg/kg). Naringenin (50 mg/kg/day) and apocynin (25 mg/kg/day) were administered orally. ECG measurements were carried out and heart homogenates were used to estimate cardiac inflammatory (IL-6, CRP), cardiac toxicity (CTnT, LDH, CKMB) and hypertensive (NO, ACE) markers. Histopathological examination of the heart was performed. Doxorubicin significantly altered the ECG with large T-wave, ST-elevation and wide QRS-complex. Results also showed significant changes in cardiac inflammatory and hypertensive biomarkers. Naringenin and apocynin treatment significantly attenuated the impact of doxorubicin on rats ECG, decreased biomarkers levels of cardiac inflammatory and hypertensive biomarkers. The cytoarchitecture of heart significantly improved in naringenin and apocynin treated groups, when compared to DOX only group. This study indicates that administration of naringenin and apocynin have cardioprotective ability and also ameliorated cardiotoxicity-induced by doxorubicin probably due to its anti-inflammatory and free radical scavenging properties.

Keywords: Apocynin; Cardiac toxicity; Doxorubicin; Hypertension; Naringenin.

Graphical abstract

Fig. 1

(A-B). Body weight changes and final body weights in rats treated with doxorubicin, naringenin and apocynin. Fig. 1A. Daily body weight change. Fig. 1B. Final body weight change. *= p < 0.05 compared with control.

Fig. 2

Relative heart weight in control and experimental groups treated with naringenin and apocynin. No significant difference.

Fig. 3

(A-D). ECG waves of the different experimental groups. Fig. 3A. (P-R Interval), Fig. 3B. (QT interval), Fig. 3C. (ST segment), Fig. 3D (QRS interval). *= p < 0.05 compared with control; # = p < 0.05 compared with other doxorubicin-treated groups. E. Representative ECG tracing in control and groups treated with naringenin and apocynin following myocardial infarction. Red cycle shows the T-wave elevation.

Fig. 3

(A-D). ECG waves of the different experimental groups. Fig. 3A. (P-R Interval), Fig. 3B. (QT interval), Fig. 3C. (ST segment), Fig. 3D (QRS interval). *= p < 0.05 compared with control; # = p < 0.05 compared with other doxorubicin-treated groups. E. Representative ECG tracing in control and groups treated with naringenin and apocynin following myocardial infarction. Red cycle shows the T-wave elevation.

Fig. 4

(A-C). Treatment with naringenin and apocynin augmented the abnormal increase in cardiac injury makers. Fig. 4A. (Cardiac troponin I), Fig. 4B. (Lactate dehydrogenase), Fig. 4C. (Creatine kinase). *= p < 0.05 versus control group; # =p < 0.05 compared with DOX treated groups; a = p < 0.05 compared with DOX+ Apocynin group.

Fig. 5

(A-C). Naringenin and apocynin reduced abnormal increase in cardiac inflammatory response in Dox-induced cardiac toxicity. Fig. 5A. (Interleukin-6), Fig. 5B. (C-reactive protein), Fig. 5C (BCL-2). *= p < 0.05 versus control group; # =p < 0.05 compared with DOX treated groups; a = p < 0.05 compared with DOX+ Apocynin group.

Fig. 6

(A-B). Treatment with naringenin and apocynin reversed vasoconstrictive activity in Dox-induced cardiac toxicity. Fig. 6A (Angiotensin converting enzymes activity), Fig. 6B. (Nitric oxide). *= p < 0.05 compared with control; # = p < 0.05 compared with DOX-treated group with apocynin and naringenin.

Fig. 7

Photomicrographs of a cross section of the cardiac muscles in different experimental groups Magnification – (x 100), CM-Cardiac muscle, N-Nucleus. *= p < 0.05 compared with control; # = p < 0.05 compared with DOX-treated group with apocynin and naringenin.