Héctor Ponce-Monter

The zoapatle III — Biological and uterotonic properties of aqueous plant extract

Differences in uterotonic activity were observed between zoapatle Montanoa (Cerv.), plants growing in their natural habitat and plants growing in an experimental agricultural plot. Details of an in vitro analogic model for assaying uterotonic potency in guinea pig strips is described. Important species differences on the uterine response to zoapatle aqueous crude extract were noticed in rats, hamsters, guinea pigs, cats and Rhesus monkeys. The need for proper biological evaluation of chemical substances already isolated from zoapatle specimens, is mentioned, and the advantages of working with zoapatle specimens grown under controlled ecological conditions are pointed out.

The zoapatle V — The effect of kauradienoic acid upon uterine contractility

Kauradienoic acid was obtained from the hexanic extract of M. tomentosa (Cerv) leaves by chromatographic separation. This substance influenced the in vitro contractility of the rat, dog and guinea pig uterine strips. It also induced strong contractions of the guinea pig uterus in vivo when administered intravenously, without changes on arterial blood pressure. The effects produced by the plant infusion, the hexanic extract and pure species were compared. The hexanic of other utero-active compounds in M. tomentosa in addition to those already described is discussed.

Effect of kauranes from Montanoa spp. on rat uterus

The effect of kaurenoic acid (from Montanoa frutescens), grandifloric and kauradienoic acid (from M. tomentosa) and 16α‐hydroxy‐ent‐kauran‐19‐oic acid and its methyl ester (from M. hibiscifolia) were assayed on the contractions of rat uterus induced by acetylcholine, oxytocin and serotonin. The four kauranes assayed inhibited the contractile activity induced by the three agonists through a mechanism independent of either β2‐adrenergic or H2‐histaminergic receptors present in uterine smooth muscle. Oestrogenized uteri treated with kauradienoic acid underwent histological changes including epithelial flattening and desquamation.© 1997 John Wiley & Sons, Ltd.

Simplified method to quantify furosemide in urine by high-performance liquid chromatography and ultraviolet detection

Simplified reversed-phase high-performance liquid chromatographic method with ultraviolet detection at 280 nm without extraction procedure is described to quantify furosemide in rabbit and human urine. An internal standard was not used. The lower limit of quantitation was 0.750 microg/ml using 50 microl urine samples (100 microl of total injection volume), and linear response was tested from 0.750 to 250 microg/ml in both humans and rabbits. Within and between-day accuracy and precision were always below 10% at all analyzed concentrations. Validation data showed that this method is linear, sensitive, selective, specific, accurate and reproducible.

Anatomical differences in uterine sensitivity to prostaglandin F2α and serotonin in non-pregnant rats

The ovarian steroids regulate the sensitivity of a population of uterine receptors to prostaglandin F(2alpha), serotonin and oxytocin. However, the uterine sensitivity to prostaglandin F(2alpha) and oxytocin does not coincide with the estrogen-induced increase in the number of receptors. Anatomical differences affect the uterine sensitivity to agonists. We investigated whether anatomical differences between ovarian and cervical uterine regions modulate the hormone-regulated sensitivity to prostaglandin F(2alpha), serotonin and oxytocin. Non-cumulative concentration-response curves for these agonists were recorded for ovarian and cervical uterine segments from adult ovariectomized rats treated with 17beta-estradiol, 17beta-estradiol+progesterone, or vehicle. The ovarian segments displayed a higher maximal response (E(max)) to prostaglandin F(2alpha) and a lower E(max) to serotonin than the cervical segments. Both uterine segments displayed a similar sensitivity to oxytocin. The ovariectomized controls displayed the highest E(max) and the lowest effective concentration 50 (EC(50)) for oxytocin and prostaglandin F(2alpha). Anatomical differences between ovarian and cervical uterine regions modulate the hormonal regulation of uterine sensitivity to serotonin and prostaglandin F(2alpha) in the non-pregnant rat uterus.

Effect of xanthorrhizol, xanthorrhizol glycoside and trachylobanoic acid isolated from cachani complex plants upon the contractile activity of uterine smooth muscle

Xanthorrhizol, xanthorrhizol glycoside, and trachylobanoic acid, compounds isolated from medicinal plants that are grouped in the complex known as Cachani have been shown to inhibit the tonic contraction of rat uterus induced by: (a) depolarizing K+ solution (60 mM), (b) CaCl2 (1 mM), and (c) BAY K 8644 (0.3 µM) in a concentration‐dependent manner (1–30 µg/mL). The inhibitory potency was displayed as follows: xanthorrhizol > xanthorrhizol glycoside > trachylobanoic acid. These results suggest that the assayed compounds might block voltage operated calcium influx in myometrial cells as they displayed a calcium‐antagonistic activity. This effect is not due to peripheral receptor activation (β2‐adrenergic, H2‐histaminergic) as neither propranolol nor cimetidine modified the inhibitory effect of the compounds assayed. This is the first report showing that plants belonging to the Cachani complex may contain uterine smooth muscle bioactive substances. Copyright

The zoapatle II--botanical and ecological determinants.

A collection of Montanoa (Cerv) specimens was conducted throughout Mexico. Twenty-one specimens were classified, some of them grown in the greenhouse and transplanted in an agricultural experimental field station in the Valley of Mexico. In vitro uterotonic potency was assayed and the results expressed as equivalents of oxytocine, by using estrogenized guinea pig uterine strips. A great variation of uterotonic potency was observed among the wild plants. A clear decrease and uniformity of uterotonic potency was found in plants grown in the experimental field. The study points out the importance of ecological variations in expression of the plants biological activity.

The zoapatle. XI: Effects elicited by Montanoa tomentosa and Montanoa frutescens on rat uterine strips

Zoapatle aqueous crude extract (ZACE) obtained from Montanoa tomentosa (M.t.) inhibits the in vitro spontaneous contractility pattern of rat uterine tissue. The opposite effect was observed with ZACE from Montanoa frutescens (M.f.) in the same preparation. Both plant extracts, M.t. and M.f., increased the in vitro spontaneous contractility pattern in the uterine guinea pig assay. In depolarized uterine tissue, propranolol (beta-blocker) inhibited the relaxing effect induced by M.t.. Atropine (cholinergic antagonist) abolished the increase in uterus contractility produced by the presence of M.f.

The zoapatle VII. Antiimplantation effect in the rat of zoapatle aqueous crude extract (ZACE) from Montanoa tomentosa and Montanoa frutescens

Intrauterine administration of zoapatle aqueous crude extract (ZACE) from Montanoa frutescens on the fourth day of rat pregnancy, at concentrations equivalent to 50 mg and 5 mg of dry leaves, was associated with total inhibition of implantation sites. On the other hand, ZACE from Montanoa tomentosa equivalent to 50 and/or 100 mg of dry leaves, prepared and administered in the same fashion, did not inhibit the number of implants by day 11 of pregnancy. However, most implants were found abnormal, of blue color, poor orientation or spacing; these morphological changes could be considered as reabsorption sites.

The zoapatle IV — Toxicological and clinical studies

The zoapatle aqueous crude extract has been used in Mexico for the last 5 centuries for the induction of labor, treatment of post-partum bleeding problems, and as a menses inducer. Today, it is sold in street markets, and its long documented history of use by humans could be taken as indirect evidence of a lack of toxicity. Rigorous pharmacological and clinical studies described here, fully confirm the empirical observations.