Resource: https://en.wikipedia.org/wiki/Tagetes_erecta
Since prehispanic times, this plant has been used for medicinal purposes.[citation needed] The Cherokee used it as a skin wash and for yellow dye.[22] The pigments of the erect tagetes are due to the presence of carotenoids, of which the main one is lutein, which is associated with the prevention of the development of age-related eye diseases such as cataracts and macular degeneration. The most intense orange tones of the flowers are related to a higher content of carotenoids, especially xanthophyll. Some studies indicate the effectiveness of the latter in the prevention of coronary artery disease, heart attacks, immune response, old age and cancer. In some regions of Mexico it is used in digestive ailments, such as stomach pain, as well as diarrhea, colic, liver problems, bile, vomiting, and indigestion. The plant also has a history of use against intestinal parasites and worms with one study indicating that it has a different mechanism than the anthelmintic drug levamisole.[23] Other uses include respiratory diseases such as colds, flu, bronchitis and nasal congestion as well as gynecological problems.[24]
Antioxidant activity has been discovered in the essential oil of this plant although less than that of α-Tocopherol, possibly attributable to the presence of camphor and methyl eugenol[25] It is most effective against the nematode species Pratylenchus penetrans.