In one embodiment, synthesis of Nuxia oppositifolia nanoparticles includes providing a Nuxia oppositifolia powder; dissolving the powder in a first alcohol to provide a first alcohol extract; concentrating a filtrate from the first alcohol extract under reduced pressure to provide a dried alcohol extract; dissolving the dried alcohol extract in the first alcohol to provide a second alcohol extract; successively partitioning the second alcohol extract using n-hexane to provide an n-hexane extract; dissolving the n-hexane extract in a second alcohol and water to provide a first solution; and adding an acidic solution to the first solution to form a final solution including Nuxia oppositifolia nanoparticles.