Cardioprotective Effect of Mikania micrantha Kunth Leaf Extract in Isoproterenol-Induced Myocardial Injury in Experimental Animals

Background: Myocardial Infarction (MI), driven by oxidative stress-induced cardiomyocyte injury, is the most predisposing disease, causing prevalent mortality globally, among the various cardiovascular diseases. Present study evaluated the cardioprotective potential of the methanolic extract of Mikania micrantha leaves (MME) in experimental animal model. Materials and Methods: The extract was evaluated for its phytochemical analysis, antioxidant and anti-inflammatory activities. Cardioprotection was assessed with Isoproterenol (ISO)-induced myocardial injury in Wistar rats via Heart Weight Index (HWI), serum biomarkers including Creatine Kinase-MB (CK-MB) and Lactate Dehydrogenase (LDH), tissue antioxidants (lipid peroxidation, nitric oxide), 2,3,5-Triphenyltetrazolium Chloride (TTC) staining, and histopathology. Results: The presence of bioactive constituents revealed 112.86±0.061 mg GAE/g phenolic and 234.22±0.081 mg QE/g flavonoid content in the extract. LC-MS/MS profiling further confirmed the presence of several polyphenolic compounds. In vitro antioxidant assays (DPPH and reducing power) and anti-inflammatory protein denaturation assays demonstrated promising effect. Acute toxicity testing endorsed the safety of MME up to 2000 mg/kg. In vivo, pretreatment with MME (200 and 400 mg/kg) significantly attenuated ISO-induced elevations in HWI, biochemical parameters, lipid peroxidation, and nitric oxide levels, while TTC staining and histological analysis further substantiated myocardial tissue preservation in treated groups. M. micrantha at 400 mg/kg demonstrated effects similar to the standard Enalapril. Conclusion: The findings suggest that the cardioprotective effects of Mikania micrantha, by means of its anti-inflammatory and antioxidant properties, highlighting its potential as a natural therapeutic agent for myocardial injury and supporting further investigation into its active constituents.