A new herbal combination, Etana, for enhancing erectile function: an efficacy and safety study in animals.

We present herein a new herbal combination called Etana that is composed of five herbal extracts including Panax quinquelotius (Ginseng), Eurycoma longifolia (Tongkat Ali), Epimedium grandiflorum (Horny goat weed), Centella asiatica (Gotu Kola) and flower pollen extracts. Most of the above-mentioned extracts have a long historical and traditional use for erectile dysfunction (ED). On the basis of the mechanism of action of each of the above, a combination is introduced to overcome several physiological or induced factors of ED. This study was conducted to show an enhancement of erectile function in male rats. The animals were observed for 3 h after each administration for penile erection, genital grooming and copulation mounting, and the penile erection index (PEI) was calculated. The maximum response was observed at the concentration of 7.5 mg kg(-1) of Etana. At a 7.5 mg kg(-1) single dose, the percentage of responding rats was 53+/-7 with a PEI of 337+/-72 compared with 17+/-6 with a PEI of 30+/-10 for control animals. This PEI was significantly (P<0.001) higher than each single component and than the sum of any two herbal components of Etana. When compared with sildenafil citrate, Etana induced more pronounced PEI than 0.36 mg kg(-1), but similar to 0.71 mg kg(-1) of sildenafil. Furthermore, full acute and sub-acute toxicity studies showed no toxic effects of Etana. In conclusion, this study describes a new and safe combination of herbal components that enhance erectile function in male rats. Clinical studies are warranted for evaluating Etana's significance in ED.