Phytochemical composition, antioxidant and antibacterial activity of the Philippine copperleaf (Acalypha wilkesiana) ethanolic extract

Abstract

The Philippine copper leaf (<i>Acalypha wilkesiana</i>) is a relatively untapped plant with notable ethnopharmacological properties. This study investigated the phytochemical composition, antioxidant and antimicrobial activity of the leaf ethanolic extract of <i>A. wilkesiana</i> collected at Central Philippine University Gardens in Iloilo City, Philippines. Qualitative phytochemical analysis revealed the presence of bioactive compounds, including alkaloids, tannins, saponins, proteins, phenols, flavonoids, glycosides, carbohydrates, and terpenoids. Quantitatively, the total phenolics and flavonoid contents of the extract were 1,203.7±0.33 mg gallic acid equivalent (GAE)/g and 235.36±2.0 mg of quercetin equivalent (QE)/g, respectively. The antioxidant activity, assessed using the 1,1-diphenyl-1-picrylhydrazyl (DPPH) assay, demonstrated a concentration-dependent radical scavenging capacity. The ethanolic extract exhibited strong antibacterial effects against <i>Staphylococcus aureus</i>, methicillin-resistant <i>S. aureus</i> (MRSA), <i>Streptococcus agalactiae</i>, <i>Escherichia coli</i>, <i>Edwardsiella tarda</i>, <i>Pseudomonas aeruginosa</i>, and <i>Salmonella typhi</i>, with significant inhibition observed at 100 mg/mL. Resolute results from this first study on the phytochemicals, antioxidants, and antimicrobial activity of the Philippine copperleaf clearly demonstrate that it contains potent bioactive compounds with notable antibacterial and antioxidant properties. This underscores its potential for developing new therapeutic agents.