Does Black-eyed Susan Boost Immune System Like Echinacea Does?
Answered by: Conrad Richter
Question from: Meegwitch
Posted on: August 17, 2004

Can I use black-eyed susan as a substitute for echinacea for boosting the immune system?

Black-eyed susan is known scientifically as Rudbeckia hirta. There is evidence that at least several species of Rudbeckia have immunostimulatory activity similar to echinacea. This is not surprising because the genus Rudbeckia is very close to the genus Echinacea taxonomically.

We know that the First Nations people of North America used black-eyed susan to treat colds. Of course, the prevention and treatment of colds and flus is what echinacea is most famously used for.

Rudbeckia possesses complex polysaccharides with significant immunological activity. Polysaccharides play a similar role in echinacea, so there appears to be a chemical connection between the two genera, in addition to the close taxonomic relationship.

In one study (, the immunostimulatory activity of Rudbeckia speciosa roots was compared to the activity of the roots of two species of Echinacea, E. angustifolia and E. gloriosa. It was found that Rudbeckia extract had a stronger effect than did the extracts from the two Echinacea species.

In another study, Rudbeckia subtomentosa was shown to contain two compounds called eudesmanolides that have significant antibacterial effects against Mycobacterium tuberculosis, the germ that causes tuberculosis.

Putting these pieces of information together it does seem likely that black-eyed susan has medicinal activity like echinacea, and it may even be more effective against colds and flus than echinacea. Certainly, more research is warranted.

Have sweet peas (flowers) any medicinal, culinary or cosmetic application?

According to the Plants For a Future database ( sweet pea (Lathyrus odoratus) seeds are rich in vitamin A, though they are not necessarily edible as a food. Sweet pea has no known medicinal uses, but the essential oil from it sweet scented flowers is used in perfumery.

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