Cardioprotective effects of Callicarpa tomentosa leaf extract in Wistar albino rats against isoproterenol-induced myocardial necrosis: Phytochemical analysis and in vitro antioxidant study

Abstract

Background: Globally, cardiovascular disease (CVD) remains the foremost cause of mortality. Conventional medications are associated with several complications, necessitating an alternative, safe and efficacious medicine. Therefore, the study was planned to assess the cardioprotective efficacy of Callicarpa tomentosa (CT) leaf extract against isoproterenol (ISO)-induced myocardial failure in experimental rats. Materials and methods: CT leaf extract was subjected to phytochemical analysis, total phenolic and flavonoid content measurement, and in vitro antioxidant evaluation. Additionally, the protection from myocardial injury was evaluated based on the estimation of biomarkers including CK-MB, CKNAC, and LDH in both the low-dose (200 mg/kg) and high-dose (400 mg/kg) groups of rats. We measured endogenous antioxidants in heart tissue to estimate the antioxidant potential. Histopathological analysis confirmed the biochemical results. Results: The findings of this study indicated that the CT leaf extract contained several phytoconstituents such as alkaloids, flavonoids, steroids and triterpenoids, cardiac glycosides, carbohydrates, phenols, saponins, and tannins. The CT's total phenol content was 33.3 ± 0.14 mg GAE (Gallic Acid Equivalent) per gram of extract, while its total flavonoid concentration was 76.5 ± 1.2 mg QUE (Quercetin Equivalent). In the DPPH assay, CT had a mean inhibitory effect of 60.06 ± 1.358 g/ml, whereas its IC50 in the H2O2 radical scavenging activity assay was 102.85 ± 0.194 g/ml. The electrocardiograms of the treated animals demonstrated considerable recovery from ISO-induced electrophysiological abnormalities as well and the amount of endogenous biomarkers was significantly reduced in animals that received CT treatment. Additionally, the use of CT reversed the effects of ISO administration on SOD activity, increased GSH levels, and lowered LPO levels. The damage to the heart tissues was significantly reduced, with the tissue architecture appearing closer to normal in groups that received high doses of CT. Conclusion: These results suggest that C. tomentosa leaf extract has potent antioxidant activity and provides protection against isoproterenol-induced cardiac necrosis in Wistar albino rats. The cardioprotective benefits are attributed to the presence of active components in the extract, which aid in the restoration of antioxidant equilibrium and the reduction of damage caused by oxidative stress.

Keywords

• Antioxidant
• Cardioprotective activity
• Callicarpa tomentosa
• Isoproterenol
• Myocardial infarction