- Clinical data 90%
- Efficacy 80%
- Security 70%
- Toxicity 30%
Turnera diffusa Willd. ex Schult.
Major chemical constituents
Essential oil (0.5-1%): 1,8-cineole, α and β-pinene (2%), p-cymene (2%), thymol, sesquiterpenes (α-copaene, δ-cadinin, elemenum, calamenene ).
Other: tannins (3.5-4 %%); hydroquinone glycosides: arbutoside (0.2-0.7%); cyanogenic heterosides (tetrafilin B or barterin); alkaloids (7%); alkanes (triacantane; hexosanol-1); flavonoids (gonzalitosin 1 [5-HO-7,3 ‘, 4’ trimethoxyflavone], luteolin derivatives, apigenin 7-glucoside, siringetine); β-sitosterol; methylxanthine (caffeine); damianina (bitter principle); resin (6-14%), gum (13.5%), proteins (15%).
It is traditionally considered a general tonic, an antidepressant and an aphrodisiac. This last activity would depend in part on the general tonic effects, although aphrodisiac effects are not ruled out, as some studies have shown in male rats (greater number of copulas, smaller interval between each ejaculation), in which flavonoids would play a very important role. important. Diuretic and mildly antiseptic urinary activity is also reported (due to the activity of the essential oil and the arbutoside).
The essential oil experimentally demonstrated an expectorant effect, while the resin behaves as a laxative and damianina as an aperitif. Extracts of the leaves of this plant showed hypoglycaemic effects in diabetic rats, both orally and intraperitoneally. Antioxidant activity of the aerial parts and sedative activity of apigenin were also experimentally demonstrated.
In experimental animals, the gastric antiulcer activity of arbutoside was confirmed.
Indications / recommendations
Turnera diffusa has traditionally been used to increase the overall volume and reduce the feeling of fatigue, as well as to facilitate digestion. It would be necessary to carry out more clinical studies to confirm the aphrodisiac activity for which it enjoys wide popular reputation. No substances or active principles of a hormonal type have been found, instead it is estimated that the stimulating effect on the central nervous system and the slightly irritating action of the essential oil on the urinary tract (giving greater sensitivity to ejaculation), could be involved in its use as an aphrodisiac.
A coadjuvant product in the treatment of overweight, made from dried extracts of damiana, yerba mate (Ilex paraguariensis) and guarana (Paulinia cupana), demonstrated through a randomized and placebo controlled clinical trial, weight-reducing effects. This effect increases when soluble fiber (inulin) is added to the treatment.
Pregnancy and lactation, due to the lack of safety demonstration in these circumstances. Anxiety, insomnia, tachycardia, irritable bowel syndrome (for its stimulating effect on the central nervous system).
It is recommended not to associate with other psycho-stimulant drugs (coffee, tea, guarana, cola, ginseng, yerba mate, etc).
Very high doses of damiana can cause purging effects, tachycardia, insomnia, headache and irritability of the mucous urinary tract. A case of toxicity in humans has been mentioned after the oral administration of 200 g of damiana extract, observing tetaniform-type convulsions and paroxysms similar to intoxications with strychnine.
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