The biological response that occurs when animals are exposed to stress affects their well-being. In this study, the methanolic extract of S. occidentalis was assessed for its ameliorative action against Adrenaline (Adr) toxicity in experimental myocardial stress induced by the administration of Adr in rats. Rats were treated with adrenaline, 2mg/kg of body weight intraperitoneally at an interval of 24 hours for 5days. Adr produced microscopic changes such as Cardiac Hypertrophy, Congestion, Fatty change, Focal Dystrophic Calcification in the stressed group. Other changes observed includes; Interstitial Fibrosis, Fatty infiltration, Focal vascular calcific stenosis, Focal interstitial lymphocytic infiltrate and Focal vascular calcific stenosis. Treatment with S. occidentalis and Propranolol reduced the complications in the heart. The result was thus concluded that the complications from the heart injury may have resulted in toxicity affecting normal histology of cardiac muscle.