Amorpha canescens, commonly known as lead plant, is a North American prairie shrub. It has several traditional medicinal uses. Native Americans have used the leaves mainly to make tea for throat infections and as smoking material.

Tea, water, and methanol extractions were made from the leaves of the lead plant and were tested for antioxidant activity and total phenolic content using spectrophotometric methods. The total phenolic contents of the water, tea and methanol extracts were 0.27-0.30 mg/g, 0.44-0.46 mg/g, and 0.47 mg/g, respectively. The antioxidant activities were 38-40%, 64-68% and 84%, compared to the standard, quercetin, which showed 92% activity. Data showed that total phenolic content and the antioxidant activity are highly correlated and that phenolic compounds are the main antioxidant agents in lead plant.

The extracts were tested on four strains of bacteria, Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. The water extract had no effect on any of the bacteria. The tea and methanol extracts had no effect on the Gram negative bacteria, E. coli and P. aeruginosa. The tea and methanol showed varying effects on the Gram positive bacteria. Tea had 30% inhibition on S. aureus and B. cereus compared to the inhibition of Gentamicin. Methanol had 40% inhibition on B. cereus and 50% inhibition on S. aureus.

Studying total phenolic, antioxidant and antibiotic activities of lead plant has provided new scientific evidence for Native American's uses of Amorpha canescens.