The problem of stimulation of sexual function of the sexual function, and of spermatogenesis and ovogenesis in particular, is both of biological and medical significance, as it is associated with the problem of preservation of the sexual potential of male and female individuals. According to statistical data, 10 - 20% of all marriages are childless. In about 30 - 50% of the cases, male sterility is the cause. The diagnostics and treatment of male sterility is still a very difficult task.

At present, drugs on hormonal basis are predominantly used in the treatment of hypogonadism and genital anomalies. In fact, the substitutive hormonal therapy is sometimes ineffective and quite often it induces a lasting hypofunction of the hypothalamic-pituitary-gonadal axis. Therefore, regardless of the great number of new, highly effective and possibly less harmful drugs, studies in this field are very topical. The formulation of a non-hormonal preparation with sufficient activity and without harmful side effects, could contribute to overcoming of the therapeutic problems in the sphere of sexual functional disorders.

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.

The present booklet is intended to acquaint the reader with the pharmacological, toxicological and clinical-therapeutic characteristics of the phytochemical preparation

Tribestan® is an original non-hormonal preparation. Its active components are non-steroid saponins of the furostanol type isolated from the plant 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.

Tribestan®, administered to male subjects with disorders in the spermogram, due to varicocele, increases the volume of ejaculated sperm by 1-2 ml, increases spermatozoal concentration by 30million/ml; increases the percentage of motile spermatozoa by 30%. 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. The mean number of motile spermatozoa in the group studied was 29% prior to the study, and later it reached up to 36.6%. The motility rate of the spermatozoa prior to the treatment was 1.95 mm/sec and 3.76 mm/sec post treatment.

Of definite interest is the treatment of patients with unilateral and bilateral hypotrophy of the testes, combined with disorders of the spermogram. The libido was enhanced after 60-day Tribestan® treatment and the characteristics of the spermogram were improved. Recovery and enhanced libido were observed in patients with primary and secondary hypogonadism after administration, as well as prolonged erection.

Both experimental and clinical studies reveal that Tribestan® is not toxic and induces no adverse effects.