Current Use & What the Science Says?

            Horsetail is still used for various medicinal purposes, but unfortunately, not much scientific evidence exists to prove its efficacy. Therefore, the following list of current uses is for your information only.  

First, horsetail is known to be used to increase diuresis and to remove kidney stones. The herb seems to have an affinity for the urinary tract so it can be used to treat urinary tract inflammation, cystic ulceration, and other general infections. Second, it is also known to strengthen bones due to its silicon content, which is an important mineral for bone health and connective tissues. Therefore, horsetail was suggested as a treatment for osteoporosis and brittle nails. However, only one study was done in Italy to examine its effect on osteoporosis and it was poorly designed that no positive conclusion can be drawn. Third, horsetail can be applied topically to heal minor wounds and burns, as well as to treat conjunctivitis and gingivitis. Lastly, a recent study in Russia demonstrated that horsetail can remove lead accumulations; however, further studies with a larger pool of samples are needed.

Here are two recent studies of horsetail on the CNS activity and cancer cells that discusses about its therapeutic uses, disease treatment, and its overall efficacy:

Dos Santos and his researchers tested the sedative effect of hydroalcoholic extract of Equiseteum arvese (HAE) on rats by feeding 200 and 400 mg/kg of either saline or the extract. According to the result, the sleeping time of rats increased by 46% and 74% respectively to the doses, the number of falls from a rota rod increased, while the percentage of convulsion by 50% and 25% in the pentylenetetrazole-seizure. The seizure was induced by the intraperitoneal administration of 60mg/kg of pentylenetetrazole. The HAE sample was prepared by evaporating ethanol and storing the extract at -20.8 C to avoid confounding effect by the alcohol. The Chi-square test with p = 0.01 showed the significance in the effect of HAE. Although the protocol seems sound and reasonable, the sample size of 8 is small and the measurement of seizure is too subjective.

·        Dos Santos JG Jr, Blanco MM, Do Monte FH, et al. (2005). Sedative and anticonvulsant effects of hydroalcoholic extract of Equisetum arvense. Fitoterapia. 76:508-13

Another study by Cetojevic-Simin investigated antioxidative effect of horsetail by measuring with the electron spin resonance spectroscopy, while examining antiproliferative activity by using the sulforhodamine B colorimetric assay on the human cancer cell lines HeLa, HT-29, and MCF7. The extract was prepared using n-butalnol, methanol, ethyl acetate, and water. The test demonstrated the strong antioxidative effects in vitro, especially with ethyl acetate extract, as the extract prevented the formation of liqid peroxyl radicals. Similarly, the extract inhibited cell growth. This test was conducted extensively and the evidence was supported with statistical analysis and images of cell lines. Further studies in vivo supporting the use of horsetail as an antioxidant is needed, however.      

·         Cetojević-Simin DD, Canadanović-Brunet JM, Bogdanović GM, Djilas SM, Cetković GS, Tumbas VT, Stojiljković BT. (2010). Antioxidative and antiproliferative activities of different horsetail (Equisetum arvense L.) extracts. J Med Food. 13(2):452-9.