Senecio serpens

I live in the island of Madeira in Portugal and here, many people still use medicinal plants. One of the plants we use a lot is a succulent called "Senecio serpens" or Blue chalk sticks. We use the sap in the eyes for eye infections and on the skin for wounds. I know the plant comes from South Africa but I can't find more information about it. Do you have more information about this plant?

Sorry, we have no information on this plant's medicinal uses. The plant is used as a ground cover in arid areas. But mostly it is grown as a potted plant subject. Its chalk-blue foliage is attractive.
The plant is in the Desert Tropicals database; here is the link: www.desert-tropicals.com/Plants/Asteraceae/Senecio_serpens.html
The plant was not listed in either the Plants for a Future database or Timothy Johnson's "CRC Ethnobotany Desk Reference" which suggests that its medicinal use is somewhat limited.
There are other species of Senecio that have uses similar to what you describe for Senecio serpens. Daniel Abbiw says in his "Useful Plants of Ghana" that the leaves of Senecio biafrae (syn. Crassocephalum biafrae) are used fresh on wounds, sores and cuts. The leaves of another species, Senecio abyssinicus, are used to treat the infectious tropical skin disease, yaws. These notes suggest that members of the Senecio genus have antibiotic properties which have not yet been studied thoroughly by science.