Picao Preto has been the subject of recent clinical studies which has explained many of its uses in herbal medicine. It's antibacterial activity against Gram-positive bacteria was demonstrated in a 1997 study.⁽⁹⁾ New bioactive phytochemicals were discovered in 1996 which showed over growing actions against normal and transformed human cell lines.⁽¹⁰⁾ Also in 1996, a Picao Preto extract was shown to possess prostaglandin-synthesis inhibitory activity, a process linked to headaches and inflammatory diseases.⁽¹¹⁾ A research group in Taiwan documented its hepatoprotective (liver protecting) activity, stating that Bidens pilosus can "protect liver injuries from various hepatotoxins and have potential as broad spectrum antihepatic agents."⁽¹²⁾ This same research group clinically demonstrated Picao Preto's significant anti-inflammatory activities one year earlier in 1995.⁽¹³⁾ In 1991, Swiss scientists isolated several known phytochemical with antimicrobial and anti-inflammatory properties which led them to believe that the presence of these compounds "may rationalize the use of this plant in traditional medicine in the treatment of wounds, against inflammation and against bacterial infection of the gastrointestinal tract.⁽¹⁴⁾ During the same year, scientists in Egypt were studying and documenting Bidens pilosa's antimicrobial activity as well.⁽¹⁵⁾ Even as early as 1979 and 1980, scientists demonstrated that specific chemicals found in Picao Preto were phototoxic to bacteria and fungi.^{(16, 17)} The newest research documents Picao Preto's hypotensive properties suggesting: "Results suggest that the extract is a useful antihypertensive drug which has no effect on the heart frequency. The hypotensive effects of the extract may be induced by vasodilation."^{(18, 19)}