Several plants used in traditional folk medicine contain powerful natural antibiotics that fight bacterial and fungal infections, a study has found.Researchers in India tested extracts from the plants on microbes taken from the mouths of oral cancer patients. Eight had a significant impact on the growth of the organisms in the laboratory. Among the most effective were asparagus, desert date, false daisy, castor oil and fenugreek. Cancer patients were used in the study because they often have impaired immune systems, making them vulnerable to infections by bacteria and fungi.infections.