Abstract

Despite advances in modern healthcare delivery systems using Western medicines, medicinal plants still continue to play an essential and indispensable role in human and animal health. This study evaluated the phytochemical constituents, acute toxicity, antiradical, and antibacterial activities of the methanol extract of Justicia secunda leaves (JSL) using standard methods. Qualitative phytochemical screening of JSL revealed the presence of alkaloids, reducing sugars, saponins, phenolic compounds, terpenoids, and flavonoids. The total phenolic content was 12.83±0.97 mg of gallic acid equivalent/g of extract, while the total flavonoid content was 21.03±1.71 mg quercetin equivalent/g of extract. At the maximum dose of 5000 mg/kg, JSL extract was not toxic to adult albino Wistar rats. Histological examination of the kidneys of the rats in the control group and those administered JSL extract revealed no significant difference. However, there was dosedependent vasodilation and increased blood flow in the kidneys. Antibacterial analysis revealed that Pseudomonas aeruginosa and E. coli were sensitive to JSL extract at concentrations of 25, 50, 75 and 100 mg/mL, while P. vulgaris was resistant at all four concentrations. Staphylococcus aureus was sensitive to three concentrations (25, 50 and 75 mg/mL) of the extract. An in vitro antiradical study using 2,2-diphenyl-2-picryl hydrazyl (DPPH) gave IC50 values of 0.23 µg/mL for ascorbic acid and 11.40 µg/mL for the extract. These experimental outcomes underscore the pharmacological potential of JSL