Zoapatle. XII. In vitro effect of kaurenoic acid isolated from Montanoa frutescens and two derivatives upon human spermatozoa.

Zoapatle aqueous crude extract (ZACE) from Montanoa tomentosa has been used as an oral contraceptive in traditional Mexican medicine for centuries. Kaurenoic acid, as isolated from Montanoa frutescens, and the methyl esters of 15-hydroxy-dihydro-kaurenoic acid and 15-keto-dihydro-kaurenoic acid were tested in vitro on human sperm motility and viability. The estimated ED50 concentrations immobilization were 374, 126 and 58 micrograms/ml, respectively using 15 X 10(6) sperms/500 microliter. Kaurenoic acid and both of its derivatives displayed only weak to negligible capacity for killing human sperms.

PIP: The effects on human sperm motility and viability of 3 compounds isolated from an aqueous extract of Montanoa frutescens Cerv (Compositae, Heliantheae) were tested. The plant is related to the zoapatle, traditionally used as a contraceptive, and known to have uterotonic and luteolytic activity. Kaurenoic acid, its 15 hydroxy- and its methyl ester were prepared from the polar fraction, and dissolved in 95% ethanol at a concentration of 10 mg/ml. Human sperm, suspended in Bigger's Whitten and Wittingham medium at a final concentration of 15 million sperm per 500 mcl were incubated at 37 degrees C. for 60 seconds. Judging sperm motility under phase contrast microscopy, kaurenoic acid was 0.89 times less effective, and the hydroxy kaurenoic acid 2.6 times more effective than verapamil, while the keto derivative was 5.7 times more potent than verapamil at the same concentration. Sperm viability assessed by vital staining was hampered only about 10% by the keto-kaurenoic acid, 21% by kaurenoic acid, and 33% by hydroxy-kaurenoic acid. Doses required for immobilization of 50% of human sperms ranged from 58 to 374 mcg/ml. This is 225 times lower than that reported for gossypol in vitro, and much lower than the millimolar range needed to inactivate sperm with nonoxynol. Thus these drugs may prompt a search for analogs useful in vaginal contraceptives.

The zoapatle. IX. In vitro effect of Montanoa tomentosa and Montanoa frutescens upon human sperm and red cells.

The effect of zoapatle aqueous crude extract (ZACE) was further studied and partially characterized upon human and rabbit spermatozoa. ZACE prepared from Montanoa tomentosa s.s.p tomentosa did not influence sperm motility or viability in a wide range of ZACE concentrations tested; on the other hand, ZACE prepared from Montanoa frutescens had immediate and constant inhibitory effect upon motility and decreased cell viability. Red cell lysis was readily observed with ZACE-frutescens, but not with ZACE-tomentosa. The effect of time on ZACE-frutescens potency for inducing red cell lysis was observed.

Exchange of lipids between spermatozoa and seminal plasma in normal and pathological human semen.

Normal and pathological semen were studied with regard to cholesterol and phospholipid content of sperm cells and seminal plasma. Spermatozoa from pathologic semen have similar concentrations of phospholipid-phosphorous and significantly higher cholesterol concentration than spermatozoa from normal semen. However, only oligoasthenospermic spermatozoa showed a significantly higher cholesterol/phospholipid ratio. Azoospermic seminal plasma showed the lowest values of both cholesterol and phospholipids, but the ratio of cholesterol to phospholipids was equal to that in normal spermatozoa. No significant difference was found in the cholesterol concentration of seminal plasma from oligoasthenospermic, asthenospermic, and normospermic subjects and only asthenospermic plasma showed a significantly lower concentration of this compound. Cholesterol and phospholipid exchange between sperm cells and seminal plasma was shown by the striking correlation between the lipid composition of seminal plasma with that of sperm cells.