Characterization and quantification of secondary metabolites and their bioactivity studies are essential to increase the knowledge on plants with traditional medicinal uses towards efficient and safe utilization. Three plant species of special relevance because of their widespread utilization in traditional medicine in Costa Rica as anti-inflammatories are Petiveria alliaceae, Phyllanthus niruri and Senna reticulata. Senna reticulata is a shrub belonging to the Fabaceae family, originally from Mesoamerica and South America (to Brazil), whose leaves and stems are used traditionally for rheumatism and skin conditions. Phyllanthus niruri is a shrub native to America and tropical areas of India and China, which belongs to the Phyllanthaceae family, and has diuretic and hepatoprotective properties. Finally, Petiveria alliacea, which belongs to the Phytholacaceae family, is distributed from the South of the United States to Brazil and its traditional uses include analgesic, anticoagulant and hypoglycemic properties.