Antimicrobial Activity, Antioxidant Property, and Acute Toxicity Profile of Methanol Extract of Alchornea cordifolia Leaf

Introduction: The increasing rate of antimicrobial resistance has necessitated the discovery of new therapeutic agents to fight this infectious disease and disorders associated with oxidative stress. Alchornea cordifolia is used traditionally to treat many microbial infections in Ghana. Hence, this study investigated phytochemical composition, antimicrobial activity, antioxidant property, and acute toxicity of the methanol extract of Alchornea cordifolia leaf. Methods: Phytochemical composition was determined in accordance with reference experimental protocols. The antimicrobial assays were done using eleven bacterial strains and a fungal strain. The assays were agar well diffusion, minimum inhibition concentrations (MIC), minimum bactericidal concentrations (MBC), and minimum fungicidal concentrations. Antioxidant property was evaluated using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The safety profile was obtained by an acute toxicity model using rats in five groups (n=6). Results and Discussion: Phytochemical screening of the extract revealed the presence of important secondary metabolites. The MIC and MBC values ranged from 3.125 mg/mL to 12.5 mg/mL and 50 mg/mL to 100 mg/mL respectively. The extract exhibited significant antioxidant activity with the scavenging activity comparable to ascorbic acid at higher concentrations and the highest value of 93.59±0.27 % recorded at a concentration of 500 µg/mL of the extract.  Acute toxicity studies confirmed the safety of the extract up to 5000 mg/kg. Conclusion: Alchornea cordifolia leaf extract can be used as both antimicrobial and antioxidant agents, the extract showed no toxicity in rats. Nevertheless, further investigation may be done to identify the exact compounds responsible for the observed biological activities.