Effect of kauranes from Montanoa spp. on rat uterus

The semi-synthetic kaurane ent-16α-methoxykauran-19-oic acid induces vascular relaxation and hypotension in rats

“…The present findings corroborate previous studies showing that alterations in the chemical structure of kauranes modify their biological actions (Ambrosio et al, 2004;Muller et al, 2003;Zamilpa et al, 2002). The carboxyl group at C-19 is an important structural element (Enriquez et al, 1984;Campos-Bedolla et al, 1997) but is not the only component responsible for the antispasmodic and relaxant effects of diterpenes (Muller et al, 2003;Ambrosio et al, 2004). In fact, Zamilpa et al (2002) showed that ent-beyer-15-en-19-oic acid, a diterpene that differs slightly from kaurenoic acid in ring D, was more effective than kaurenoic acid at inhibiting electrically induced contractions in guinea-pig ileum.…”

Terpenoid Compounds From Montanoa tomentosa Cerv. With Anti‐inflammatory Potential

“…On the other hand, several studies have shown that taraxasterol (5) has antiinflammatory properties [28,29]. It should be noted that M. tomentosa has traditionally been used for therapeutic purposes as a uterotonic, uterorelaxant and antibiotic agent, which has been attributed to the presence of compounds 3 and 4 [3,4,26,30,31], which, according to the results of this study, could also be associated with the anti-inflammatory effect observed in this species. In accordance with these results, this study provides preliminary information on the use of M. tomentosa leaves as a potential anti-inflammatory agent.…”

Antispasmodic effects of a new kaurene diterpene isolated from Croton argyrophylloides on rat airway smooth muscle

“…Adrenergic involvement was similarly discarded as an explanation for the relaxant effects of other kaurane diterpenes in uterine smooth muscle. [25] TCCA significantly reduced contractions induced by EFS in a concentration-dependent manner (Figure 2b). It is well known that trains of EFS pulses (0.5 ms duration) applied directly to smooth muscle tissues stimulate only intramural nerve terminals promoting neurotransmitter release, [26] which may produce both excitatory or inhibitory influences depending on the nature of neurotransmitter.…”