Periwinkle

Vincae minoris herba, small periwinkle.  

Periwinkle herb consists of the above-ground parts of Vinca minor L.  [Fam.  Apocynaceae], as well as preparations thereof.  

Periwinkle is used for circulatory disorders, cerebral circulatory impairment, support for the metabolism of the brain and its improved oxygen supply, prophylaxis of memory and concentration impairment, improvement of memory and thinking capacity, mental productivity, prevention of premature aging of brain cells, for geriatric support, as a sedative and as a blood pressure-lowering remedy, for catarrhs, feebleness, and for improvement of the immune function, for diarrhea, vaginal flux, throat ailments, tonsillitis and angina, sore throat, intestinal inflammation, toothache, dropsy, as a diuretic and blood-purifying remedy, for promotion of wound healing, as a hemostatic remedy, and a bitter principle.  

The effectiveness for the claimed applications has not been adequately documented.  

In animal experiments, administration of periwinkle caused destruction of blood components, manifested as leukocytopenia, lymphocytopenia, and lowering of the a, a₂-, and g-globulin level, all presumably due to a suppression of the immune system.  

The vincamine content in the herb is low and fluctuates greatly.  Vincamine, as a pure substance, is available for therapeutic administration.  

Since the effectiveness of periwinkle for most claimed applications is not sufficiently documented, adequate levels of vincamine in the plasma cannot be obtained with periwinkle herb and its preparations, and the suspicion of blood modifications in humans could not be removed, the therapeutic application of this herb and its preparations is not justifiable.