Vinca minor, V. major
Periwinkle
Many people would easily recognize the color periwinkle when included in a box of crayons, but fewer people realize that this color had a predecessor: a plant delicate in appearance yet persistent in nature.
The color denotes its blooms which can be found as charming ornamentals in groomed landscapes or as predominant and intrusive in the understory of forests in certain regions of the United States.
Vinca spp.
There are two principle types of periwinkle (Vinca spp.) plants used in herbalism: Vinca major and Vinca minor.
They are very similar in their botanical features, but as the species names suggest these features differ in size, with the latter having smaller leaves, flowers, and stems.
The genus name Vinca is derived from the Latin word vinco, meaning “to conquer” and is an observation on the plants ability to overcome or wrap themselves tightly around other plant species.
Vinca Alkaloids
Vinca alkaloids target microtubules, which are used to provide a skeletal system for living cells; they bind to tubulin, blocking and inhibiting its ability to polymerize into a microtubule. This subsequently causes an arrest to cells in metaphase and ultimately results in cell death.
This pharmacological action of vinca alkaloids is what makes them therapeutic and of interest in chemotherapy drugs, but at the same time it also contributes to their toxicity to the central and peripheral nervous systems.
While the mechanism behind this side effect is unknown, the neurotoxicity that occurs with chemotherapy is a frequent barrier that results in limiting the dose with these compounds.
When using plants that contain vinca alkaloids it is highly recommended to do so under the guidance of a skilled practitioner who is familiar and has experience with these herbs, as dosage is very important.