Terpinen-4-ol inhibits the growth of Sporothrix schenckii complex and exhibits synergism with antifungal agents.

Aim: This study investigated the effect of terpinen-4-ol against Sporothrix schenckii complex and its interactions with antifungals. Materials & methods: The antifungal activity of terpinen-4-ol was evaluated by broth microdilution. The potential effect on cellular ergosterol concentration was evaluated by spectrophotometry. The antibiofilm activity was evaluated by violet crystal staining and XTT reduction assay. The potential pharmacological interactions with antifungals were evaluated by the checkerboard assay. Results: terpinen-4-ol (T-OH) showed minimal inhibitory concentrations ranging from 4 to 32 mg/l decreasing cellular ergosterol content and presented a SMIC ranging from 64 to 1024 mg/l for Sporothrix spp. The combinations of T-OH with itraconazole or terbinafine were synergistic. Conclusion: T-OH has antifungal activity against Sporothrix spp. and acts synergistically with standard antifungals.

Relaxant effect and possible mechanism of 17-nor-subincanadine E in rabbit corpora cavernosa.

Compounds with dual action on cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) may be a treatment option for erectile dysfunction, as they not only promote penile erection but also prevent the upregulation of phosphodiesterase-5. In this study, we examined the possible relaxant effect and mechanism of 17-nor-subincanadine E (SEC, 0.2-200 µmol l⁻¹), a plant-derived alkaloid, in rabbit corpus cavernosum (RbCC) strips that had been precontracted by exposure to phenylephrine (10 µmol l⁻¹) or a high concentration of K(+) (60 mmol l⁻¹) in vitro. In addition to SEC's effect on cAMP and cGMP levels, electrical field stimulation (EFS) in phenylephrine-precontracted RbCC and calcium chloride (1-100 mmol l⁻¹) evoked responses in depolarized RbCC were analysed. SEC relaxed the phenylephrine-precontracted RbCCs in a concentration-dependent manner. Atropine, guanethidine and N-ω-nitro-l-arginine methyl ester (L-NAME) did not have any effect on the relaxation of RBCCs. When 1H-(1, 2, 4)oxadiazole[4,3-a] quinoxalin-1-one (ODQ) was added, it effectively blocked the relaxant response of SEC. Although SEC enhanced the maximal relaxation produced by sodium nitroprusside (SNP) and forskolin in phenylephrine-precontracted cavernosal smooth muscle, it caused a decrease in the maximal contractile response induced by calcium chloride in depolarized RbCCs. The relaxant effect of SEC was paralleled by an increase in the tissue levels of the cyclic nucleotides cAMP and cGMP. We conclude that SEC promotes the relaxation of RbCC, possibly favouring cAMP and cGMP accumulation and calcium blockade. This novel mechanism could be useful for patients who do not benefit from phosphodiesterase inhibitors and for those with endothelial and nitrergic dysfunction, such as patients with diabetes, hypertension and dyslipidaemias.