Uncaria
FAMILY: Rubiaceae.
HABITAT: the South American continent, particularly in the forests of Peru, Colombia and Brazil.
USED PART: the bark and root.
PHARMACEUTICAL PREPARATIONS: nebulised dry extract titrated in total oxindole alkaloids (min. 3%). Its daily dosage ranges from 2 to 4 mg/kg, divided into two doses, preferably between meals.
CHEMICAL COMPOSITION: it is a plant rich in alkaloids of the oxindole tetra and pentacyclic group, particularly rhynchophylline, isorhynchophylline. We also find pteropodine and isopteropodine in the roots. Quinovic acid glycosides have recently been identified. We also find epicatechin, four dimer procyanidins and polyoxygenated triterpenes.
THERAPEUTIC PROPERTIES: This plant is recognised for its immunomodulatory , anti-inflammatory and antialgic properties. Uncaria enhances the activity of NK cells and cytotoxic T lymphocytes, although this effect takes 2 to 3 days for NK cells and about 3 weeks for cytotoxic T lymphocytes to fully manifest itself. Since NK cells and cytotoxic T lymphocytes are largely responsible for the recognition and destruction of cells infected by viruses or degenerated by tumour processes, Uncaria tomentosa-induced stimulation of these cells could have important applications in antiviral and anti-cancer therapies. The increases in all these parameters are statistically significant compared to placebo.
A clinical study was done in a group of healthy volunteers, who received an oral dose of uncaria titrated dry extract of 45 mg for 8 weeks. In patients treated with the extract compared to those receiving placebo, there was a statistically significant increase in white blood cell activity, in their ability to attack viruses and bacteria, and in natural killer (NK) cell activity. The pentacyclic alkaloids appear to be the most important ingredients of the phytocomplex for the occurrence of the immunomodulatory action.
- A controlled clinical study evaluated the antialgic and anti-inflammatory effects of a hydroalcoholic extract of uncaria in patients suffering from rheumatoid arthritis. Forty patients treated with sulfasalazine or hydroxychloroquine (two drugs used in the treatment of this disease), to which uncaria extract was or was not added, were enrolled. The duration of the study was 1 year. At the end of the study, pain reduction was significantly better in patients who also took uncaria extract along with the drugs. Side effects were very minor and limited to moderate gastrointestinal complaints, in two cases accompanied by diarrhoea. The study demonstrated the usefulness of hydroalcoholic uncaria extract in patients with rheumatoid arthritis undergoing drug therapy.
SIDE EFFECTS: An overdose may give diarrhoea, which regresses with discontinuation of therapy.
CONTRAINDICATIONS: Administration in patients in whom iatrogenic immunodepression is caused for therapeutic purposes is contraindicated.
It is not recommended during pregnancy and lactation because of its probable action on the uterine musculature and because there are currently no data on its action on the foetus. Do not administer to children under 9-10 years of age.
DRUG INTERACTIONS: not known.