Therapeutic Potentials of Selected Antihypertensive Agents and Their Fixed-Dose Combinations Against Trastuzumab-Mediated Cardiotoxicity

Abstract

Trastuzumab (TZM) is useful in the clinical management of HER2-positive metastatic breast, gastric, and colorectal carcinoma but has been limited by its off-target cardiotoxicity. This study investigates the therapeutic potentials of 0.25 mg/kg/day amlodipine, 0.035 mg/kg/day lisinopril, 5 mg/kg/day valsartan, and their fixed-dose combinations in TZM-intoxicated Wistar rats that were randomly allotted into 10 groups of 6 rats for each group. Group I rats were treated with 10 ml/kg/day sterile water orally and 1 ml/kg/day sterile water intraperitoneally; Groups II, III, and IV rats were orally gavaged with 5 mg/kg/day valsartan and 1 ml/kg/day sterile water intraperitoneally, 0.25 mg/kg/day amlodipine and 1 ml/kg/day sterile water via the intraperitoneal route, 0.035 mg/kg/day lisinopril and 1 ml/kg/day sterile water administered intraperitoneally, respectively. Group V rats were orally treated with 10 ml/kg/day of sterile water prior to intraperitoneal administration of 2.25 mg/kg/day of TZM. Groups VI-VIII rats were equally pretreated with 5 mg/kg/day valsartan, 0.25 mg/kg/day amlodipine, and 0.035 mg/kg/day lisinopril before intraperitoneal 2.25 mg/kg/day TZM treatment, respectively; Groups IX and X rats were orally pretreated with the fixed-dose combinations of 0.25 mg/kg/day amlodipine +0.035 mg/kg/day lisinopril and 5 mg/kg/day valsartan +0.035 mg/kg/day lisinopril, respectively, before TZM treatment. Cardiac injury and tissue oxidative stress markers, complete lipids profile, histopathological, and immunohistochemical assays were the evaluating endpoints. Results showed that repeated TZM treatments caused profound increases in the serum TG and VLDL-c levels, serum cTnI and LDH levels, and cardiac tissue caspase-3 and -9 levels but decreased BCL-2 expression. TZM also profoundly attenuated CAT, SOD, GST and GPx activities, and increased MDA levels in the treated tissues. In addition, TZM cardiotoxicity was characterized by marked vascular and cardiomyocyte congestion and coronary artery microthrombi formation. However, the altered biochemical, histopathological, and immunohistochemical changes were reversed with amlodipine, lisinopril, valsartan, and fixed-dose combinations, although fixed-dose valsartan/lisinopril combination was further associated with hyperlipidemia and increased AI and CRI values and coronary artery cartilaginous metaplasia. Thus, the promising therapeutic potentials of amlodipine, lisinopril, valsartan and their fixed-dose combinations in the management of TZM cardiotoxicity, majorly mediated via antiapoptotic and oxidative stress inhibition mechanisms were unveiled through this study.

Keywords: Wistar rats; cardiac injury biomarkers; fixed-dose antihypertensive combinations; oxidative stress markers; trastuzumab cardiotoxicity.

FIGURE 1

(A) A cross-sectional representative of the rat heart tissue pretreated with 10 ml/kg/day/p.o. sterile water and 1 ml/kg/day/i.p. route of sterile water showing normal cardiac histoarchitecture (×400 magnification, hematoxylin–eosin stain). (B) A cross-sectional representative of rat heart pretreated with 5 mg/kg/day/p.o. VAL dissolved in sterile water showing mild coronary artery congestion (indicated by the thin black arrow) and normal myocardiocytes (×400 magnification, hematoxylin–eosin stain). (C) A cross-sectional representative of the rat heart pretreated with 0.25 mg/kg/day/p.o. route ADP dissolved in sterile water showing mild congestion (indicated by the thin black arrow) and lymphocytic infiltration of cardiomyocytes (indicated by the thin red arrow) (×400 magnification, hematoxylin–eosin stain). (D) A cross-sectional representative of rat cardiac tissue pretreated with 0.035 mg/kg/day/p.o. route LSP dissolved in sterile water showing severe vascular congestion (indicated by the thick black arrow) and diffuse perivascular lymphocytic infiltration (indicated by the thin red arrow) (×400 magnification, hematoxylin–eosin stain). (E) A cross-sectional representative of untreated TZM-intoxicated rat cardiac tissue pretreated with 10 ml/kg/day/p.o. sterile water showing severe vascular and cardiomyocyte congestion (indicated by the thick black arrow) and intraparenchymal hemorrhage (indicated by the thick blue arrow) (×400 magnification, hematoxylin–eosin stain). (F) A cross-sectional representative of TZM-intoxicated rat cardiac tissue pretreated with 5 mg/kg/day/p.o. VAL showing coronary artery recanalization (indicated by the thick purple arrow) (×100 magnification, hematoxylin–eosin stain). (G) A cross-sectional representative of TZM-intoxicated rat cardiac tissue pretreated with 0.25 mg/kg/day/p.o. ADP dissolved in sterile water showing mild cardiac vascular congestion (indicated by the thin black arrow) with sparse lymphocytic infiltration of the cardiomyocytes (indicated by the thin red arrow) (×400 magnification, hematoxylin–eosin stain). (H) A cross-sectional representative of the TZM-intoxicated cardiac tissue pretreated with 0.035 mg/kg/day/p.o. LSP dissolved in sterile water showing moderate vascular congestion and cartilaginous metaplasia within the coronary blood vessel wall (indicated by the thick green arrow) (×400 magnification, hematoxylin–eosin stain). (I) A cross-sectional representative of TZM-intoxicated rat cardiac tissue pretreated with the fixed dose 0.25 mg/kg/day/p.o. route ADP +0.035 mg/kg/day/p.o. route LSP combination dissolved in sterile water showing moderate vascular congestion (indicated by the thin black arrow) with sparse lymphocytic infiltration (indicated by the thin red arrow) (×400 magnification, hematoxylin–eosin stain). (J) A cross-sectional representative of the TZM-intoxicated rat cardiac tissue pretreated with 5 mg/kg/day/p.o. route VAL +0.035 mg/kg/day/p.o. LSP showing mild-to-moderate vascular congestion (indicated by the thin black arrow) and coronary arterial wall cartilaginous metaplasia within the coronary blood vessel wall (indicated by the thick green arrow) (×400 magnification, hematoxylin–eosin stain).

FIGURE2

Effect of drug treatment on cardiac tissue caspase-3 levels in rats as measured by ELISA. Bar represents mean ± SEM (n = 4), significant difference denoted by #p < 0.05 vs. normal control (Group I) or *p < 0.05 vs. TZM by One-way ANOVA followed by Turkey’s post hoc test. Normal control, VAL-valsartan 5 mg/kg/day, ADP-amlodipine 0.25 mg/kg/day, LSP- lisinopril 0.035 mg/kg/day, and TZM-trastuzumab 2.25 mg/kg/day.

FIGURE 3

Effect of drug treatment on cardiac tissue caspase-9 levels in rats measured by ELISA. Bar represents mean ± SEM (n = 4), significant difference denoted by #p < 0.05 vs. normal control or *p < 0.05 vs. TZM-only by one-way ANOVA followed by Turkey’s post hoc test. Normal control, VAL-valsartan 5 mg/kg/day, ADP-amlodipine 0.25 mg/kg/day, LSP-lisinopril 0.035 mg/kg, and TZM-trastuzumab 2.25 mg/kg/day.

FIGURE 4

Representative photomicrographs of immunohistochemical expression of caspase-3 in cardiac tissue of rats (magnification ×400). (A) Normal control, (B) valsartan 10 mg/kg/day, (C) amlodipine 0.25 mg/kg/day, (D) lisinopril 0.035 mg/kg/day, (E) trastuzumab (TZM) 2.25 mg/kg/day, (F) TZM + valsartan 5 mg/kg/day, (G) TZM + amlodipine 0.25 mg/kg/day, (H) TZM + lisinopril 0.035 mg/kg, (I) TZM + amlodipine + lisinopril, (J) TZM + valsartan + lisinopril, and (K) intensity score of caspase-3 expression, mean ± SEM (n = 3), and significant difference denoted by #p < 0.05 vs. normal control or *p < 0.05 vs. TZM by one-way ANOVA followed by Turkey’s post hoc test.

FIGURE 5

Representative photomicrographs of immunohistochemical expression of BCL-2 in cardiac tissue of rats (magnification ×400). (A) Normal control, (B) valsartan (VAL) 5 mg/kg/day, (C) amlodipine (ADP) 0.5 mg/kg/day, (D) lisinopril (LSP) 0.035 mg/kg/day, (E) trastuzumab (TZM) 2.25 mg/kg/day, (F) TZM + valsartan 5 mg/kg/day, (G) TZM + amlodipine 0.25 mg/kg/day, (H) TZM + lisinopril 0.035 mg/kg/day, (I) TZM + amlodipine + lisinopril, (J) TZM + valsartan + lisinopril, and (K) intensity score of BCL-2 expression, mean ± SEM (n = 3), and significant difference denoted by ^# p < 0.05 vs. normal control or *p < 0.05 vs. TZM by one-way ANOVA followed by Turkey’s post hoc test.