The plant Tribulus terrestris L., has long been known in folk medicine of both Eastern countries and Bulgaria and has been used in the treatment of sexual deficiency. The original phytochemical preparation Tribestan, with stimulating effect on the sexual functions was formulated and approved for production and administration in medical practice at the Chemical Pharmaceutical Research Institute of Pharmachim on the basis of accumulated data in 1981. Tribulus terrestris L. A pronounced stimulating effect on the spermatogenesis is observed after the preparation is administered orally to sexually mature rats. Increased number of spermatogonia, spermatocytes, spermatids and mature spermatozoa in the testes has been observed without widening of the diameter of the seminiferous tubules. In parallel, increased number of Sertoli cells is observed in a volume unit from rat testes.
Oral administration stimulates the mitotic activity of spermatogonia in mature rats.
Oral administration of the preparation leads to intensification of spermatogenesis and enhancement of the quality of spermatozoa in sexually mature rats. The percentage of motile spermatozoa increases, the characteristics of their motility improve, prolonging the period of their viability at the same time. Given orally to swine, Tribestan stimulates their sexual behavior. The clinical trials of the preparation have also confirmed the experimental data. The preparation has marked effect on the motility of spermatozoa in case of oligoasthenozoospermia, as revealed by the study of its therapeutic properties in men.