Screening of alkaloids and withanolides isolated from Solanaceae plants for antifungal properties against non-wild type Sporothrix brasiliensis.

Antifungal resistance has often been found in animal sporotrichosis in Southern Brazil. The biological potential of compounds from plants of the Solanaceae family against infectious diseases is known, however, it is still unknown against Sporothrix brasiliensis. This study evaluated the anti-Sporothrix brasiliensis activity, synergism, cytotoxicity, and action mechanism of steroidal lactones (withanolides) and alkaloids isolated from these plants. Pure compounds of withanolide D (WNOD), physalin F (PHYF), withanicandin (WNIC), nicandin B (NICB), solasonine (SSON), and solamargine (SMAR) were tested against 12 Sporothrix brasiliensis isolated from cats (n = 11) and dogs (n = 2) through M38-A2 CLSI. For the compounds with the best activity, a checkerboard assay for synergism, sorbitol protection, and ergosterol effect for action mechanism; and MTT test for cytotoxicity were performed. The withanolides WNOD, PHYF, WNIC, and NICB were not antifungal, but SSON (MIC 0.125-1 mg/mL) and SMAR (MIC 0.5-1 mg/mL) were both fungistatic and fungicidal (MFC 0.5-1 mg/mL for both) against wild-type (WT) and non-WT isolates. The activity of SSON and SMAR was indifferent when combined with itraconazole. In the mechanism of action, cell wall and plasma membrane by complexation with ergosterol seemed to be two target structures of SSON and SMAR. SSON was selected for cytotoxicity, whose cell viability in MDBK cells ranged from 28.85 % to 101.75 %, and was higher than 87.49 % at concentrations ≤0.0015 mg/ml. Only the steroidal alkaloids SSON and SMAR were active against non-WT isolates, being promising antifungal candidates for the treatment of feline and canine sporotrichosis with low susceptibility to itraconazole.

Anti-asthmatic effect of nitric oxide metallo-donor FOR811A [cis-[Ru(bpy)2(2-MIM)(NO)](PF6)3] in the respiratory mechanics of Swiss mice.

We aimed at evaluating the anti-asthmatic effect of cis-[Ru(bpy)2(2-MIM)(NO)](PF6)3 (FOR811A), a nitrosyl-ruthenium compound, in a murine model of allergic asthma. The anti-asthmatic effects were analyzed by measuring the mechanical lung and morphometrical parameters in female Swiss mice allocated in the following groups: untreated control (Ctl+Sal) and control treated with FOR811A (Ctl+FOR), along asthmatic groups untreated (Ast+Sal) and treated with FOR811A (Ast+FOR). The drug-protein interaction was evaluated by in-silico assay using molecular docking. The results showed that the use of FOR811A in experimental asthma (Ast+FOR) decreased the pressure-volume curve, hysteresis, tissue elastance, tissue resistance, and airway resistance, similar to the control groups (Ctl+Sal; Ctl+FOR). However, it differed from the untreated asthmatic group (Ast+Sal, p<0.05), indicating that FOR811A corrected the lung parenchyma and relaxed the smooth muscles of the bronchi. Similar to control groups (Ctl+Sal; Ctl+FOR), FOR811A increased the inspiratory capacity and static compliance in asthmatic animals (Ast+Sal, p<0.05), showing that this metallodrug improved the capacity of inspiration during asthma. The morphometric parameters showed that FOR811A decreased the alveolar collapse and kept the bronchoconstriction during asthma. Beyond that, the molecular docking using FOR811A showed a strong interaction in the distal portion of the heme group of the soluble guanylate cyclase, particularly with cysteine residue (Cys141). In summary, FOR811A relaxed bronchial smooth muscles and improved respiratory mechanics during asthma, providing a protective effect and promising use for the development of an anti-asthmatic drug.

Disseminated histoplasmosis in a cat rescued in Fortaleza, Brazil, and successfully treated with itraconazole - First case report identified molecularly.

An unneutered female cat of unknown age presented bloody lesions on the edematous face, and respiratory signs. Cytology and culture from the skin sample collected with fine-needle aspiration showed yeasts inside activated macrophages, and fungal growth characteristic of Histoplasma spp., which was molecularly confirmed that was Histoplasma capsulatum var. capsulatum. The cat was successfully treated with oral itraconazole (10 mg/kg/daily) for 120 days. This is the first case report of feline histoplasmosis confirmed molecularly in Brazil.

Antihypertensive potential of cis-[Ru(bpy)2(ImN)(NO)]3+, a ruthenium-based nitric oxide donor.

The aim of this study was to investigate the antihypertensive properties of cis-[Ru(bpy)2ImN(NO)]3+ (FOR0811) in normotensive and in Nω-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats. Vasorelaxant effects were analyzed by performing concentration response curve to FOR0811 in rat aortic rings in the absence or presence of 1H-[1,2,4]-oxadiazolo-[4,3,-a]quinoxalin-1-one (ODQ), L-cysteine or hydroxocobalamin. Normotensive and L-NAME-hypertensive rats were treated with FOR0811 and the effects in blood pressure and heart rate variability in the frequency domain (HRV) were followed. FOR0811 induced relaxation in rat aortic rings. Neither endothelium removal nor L-cysteine altered the FOR0811 effects. However, the incubation with ODQ and hydroxocobalamin completely blunted FOR0811 effects. FOR0811 administered intravenously by bolus infusion (0.01-1 mg/bolus) or chronically by using subcutaneous implanted osmotic pumps significantly reduced the mean arterial blood pressure. The effect was long lasting and did not induce reflex tachycardia. FOR0811 prevented both LF and VLF increases in L-NAME hypertensive rats and has antihypertensive properties. This new ruthenium complex compound might be a promising nitric oxide donor to treat cardiovascular diseases.

The extract of the jellyfish Phyllorhiza punctata promotes neurotoxic effects.

Phyllorhiza punctata (P. punctata) is a jellyfish native to the southwestern Pacific. Herewith we present the biochemical and pharmacological characterization of an extract of the tentacles of P. punctata. The tentacles were subjected to three freeze-thaw cycles, homogenized, ultrafiltered, precipitated, centrifuged and lyophilized to obtain a crude extract (PHY-N). Paralytic shellfish poisoning compounds such as saxitoxin, gonyautoxin-4, tetrodotoxin and brevetoxin-2, as well as several secretory phospholipase A(2) were identified. PHY-N was tested on autonomic and somatic neuromuscular preparations. In mouse vas deferens, PHY-N induced phasic contractions that reached a peak of 234 ± 34.7% of control twitch height, which were blocked with either 100 µ m of phentolamine or 1 m m of lidocaine. In mouse corpora cavernosa, PHY-N evoked a relaxation response, which was blocked with either L-N(G) -Nitroarginine methyl ester (0.5 m m) or 1 m m of lidocaine. PHY-N (1, 3 and 10 µg ml(-1) ) induced an increase in tonus of the biventer-cervicis neuromuscular preparation that was blocked with pre-treatment of galamine (10 µ m). Administration of 6 mg kg(-1) PHY-N intramuscularly produced death in broilers by spastic paralysis. In conclusion, PHY-N induces nerve depolarization and nonspecifically increases neurotransmitter release.