Evaluation of the cardioprotective potential of hydroethanolic extract of Koenigia polystachya L. (Qiú xù liǎo) leaves against isoproterenol-induced myocardial infarction in rats

Myocardial infarction (MI) significantly contributes to mortality and morbidity among cardiovascular diseases (CVDs). Various plant species are employed as traditional remedies for CVD management, particularly MI. Koenigia polystachya , known as Qiú xù liǎo in Traditional Chinese Medicine (TCM), is valued for its therapeutic properties in regulating bodily functions and treating ailments such as diarrhea, indigestion, and superficial infections. This study assessed the cardioprotective efficacy of the hydro-ethanolic leaf extract of K. polystachya (HELeKP) in both in-vitro and in-vivo models against isoproterenol (ISO)-induced MI. A pre-treatment schedule with HELeKP was fixed for 28 days in the rats. The rats produced MI via isoproterenol administration (85 mg/kg b.w. s.c. ) on the 27th and 28th days. The experimental groups were: normal group, ISO-treated group, ISO + HELeKP low dose (66.6 mg/kg b.w./day p.o. ), ISO + HELeKP high dose (200 mg/kg b.w./day p.o. ), and ISO + Propranolol (10 mg/kg b.w./day p.o. ). Following the experimental period, the parameters of cardiac hypertrophy, electrocardiogram (ECG), blood/serum samples (for cardiac-related markers), and a histopathological investigation of the cardiac tissues were evaluated. The study confirmed that pre-treatment with the extract (HELeKP) significantly mitigated ISO-induced cardiotoxicity in rats, as evidenced by improved cell viability, normalized cardiac biomarkers, and restored ECG parameters. Additionally, the extract corrected ISO-induced dyslipidemia and preserved myocardial histoarchitecture, indicating its strong cardioprotective and hypolipidemic effects. In conclusion, the leaf extract of K. polystachya exhibits significant cardioprotective potential by effectively reducing oxidative stress, stabilizing myocardial function, and preserving cardiac tissue integrity. The extract shows promise as a potential cardioprotective agent, warranting further investigation into its therapeutic mechanisms and clinical applications.