Bio-guided fractionation to identify Senegalia gaumeri leaf extract compounds with anthelmintic activity against Haemonchus contortus eggs and larvae

Small ruminants browsing in tropical forests readily consume the foliage of Senegalia gaumeri. A S. gaumeri methanol:water extract was recently shown to have ovicidal activity against Haemonchus contortus eggs in vitro. In the present study, the fraction of a S. gaumeri methanol:water extract with ovicidal activity against H. contortus eggs and the metabolites potentially involved in this activity were identified. Bio-guided fractionation of the S. gaumeri methanol:water extract identified high ovicidal activity (80.29%, EC50 = 58.9 μg/mL) in the non-polar sub-fraction P1. Gas chromatography-mass spectrometry (GC–MS) identified several fatty acids: pentacosane (18.05%), heneicosane (18.05%), triacontane (30.94%), octacosane (18.05%), and hexanedioic acid bis-(2-ethylhexyl) ester (32.72%). Purification of the polar components of sub-fraction P1 led to the identification of p-coumaric acid as a major constituent. In egg hatch tests, 400 μg/mL p-coumaric acid resulted in an ovicidal effect of 8.7%, a larvae failing eclosion effect of 2.9%, and of the emerged larvae (88.4%), many were damaged. In conclusion, the low AH activity of p-coumaric acid against H. contortus eggs indicates that it is not solely responsible for the ovicidal activity of sub-fraction P1 but might act in synergy with other compounds in this fraction. However, p-coumaric acid showed potential anthelmintic effects against the larval stage of H. contortus

Quinones as Promising Compounds against Respiratory Viruses: A Review

Respiratory viruses represent a world public health problem, giving rise to annual seasonal epidemics and several pandemics caused by some of these viruses, including the COVID-19 pandemic caused by the novel SARS-CoV-2, which continues to date. Some antiviral drugs have been licensed for the treatment of influenza, but they cause side effects and lead to resistant viral strains. Likewise, aerosolized ribavirin is the only drug approved for the therapy of infections by the respiratory syncytial virus, but it possesses various limitations. On the other hand, no specific drugs are licensed to treat other viral respiratory diseases. In this sense, natural products and their derivatives have appeared as promising alternatives in searching for new compounds with antiviral activity. Besides their chemical properties, quinones have demonstrated interesting biological activities, including activity against respiratory viruses. This review summarizes the activity against respiratory viruses and their molecular targets by the different types of quinones (both natural and synthetic). Thus, the present work offers a general overview of the importance of quinones as an option for the future pharmacological treatment of viral respiratory infections, subject to additional studies that support their effectiveness and safety

Nanostructured chitosan-palygorskite hybrid microspheres for controlled delivery of thymol

Hybrid microspheres from palygorskite (PAL) nanoclay and crosslinked chitosan (QS) were prepared with the emulsion method to trap and control the release of thymol (TIM). The morphology of the microspheres was characterized by scanning electron microscopy and x-ray diffraction. The size of the microspheres, the swelling rate, the encapsulation efficiency and thymol release rate were characterized. Compared to pristine chitosan microspheres, hybrid microspheres showed the highest encapsulation efficiency. The average particle sizes of the QS and QS-PAL microspheres are in a range of 20 to 50 μ m, with a size distribution of the hybrid microspheres showing less size polydispersity. The QS-PAL microspheres have a higher swelling rate than the QS microspheres. The lowest swelling degree, 88%, was from the microspheres without PAL cross-linked with 950 μ l of glutaraldehyde (GL), and the highest swelling degree, 146%, was from the microspheres with 10% PAL crosslinked with 630 μ l of GL. The thymol release kinetics was modified by the palygorskite content of the chitosan hybrid microspheres

Additional flavonoids from Lonchocarpus yucatanensis and L. xuul

Two new natural flavanones, 5-hydroxy-6,7-(2",2"-dimethylchromene)flavanone (1) and 5-methoxy-3-hydroxy-6,7-(2",2"-dimethylchromene)flavanone (2), were isolated from the root extracts of L. yucatanensis and L. xuul, respectively. Additionally, four known metabolites, the glycosidic flavonoids quercetin-3-rhamnoglucoside and kaempferol-3-rhamnoglucoside, together with 4-hydroxy-N-methyl-proline, and p-coumaric acid methyl ester, were isolated for the first time from the leaves of L. xuul. The various metabolites were identified on the basis of their spectroscopic data and by comparison with those reported in the literature

Bioassay-Guided Fractionation of Erythrostemon yucatanensis (Greenm.) Gagnon & GP Lewis Components with Anti-hemagglutinin Binding Activity against Influenza A/H1N1 Virus

Erythrostemon yucatanensis (Greenm.) Gagnon & GP Lewis is a legume tree native to and widely distributed in southeast Mexico, where its branches are used in traditional medicine. An in vitro evaluation of the antiviral activity of extracts and fractions from the leaves, stem bark and roots against two strains of the AH1N1 influenza virus was performed, leading to the identification of bioactive compounds in this medicinal plant. In a cytopathic effect reduction assay, the fractions from the leaves and stem bark were the active elements at the co-treatment level. These were further fractionated based on their hemagglutination inhibition activity. The analysis of spectroscopy data identified a combination of phytosterols (β-sitosterol, stigmasterol and campesterol) in the stem bark active fraction as the main anti-hemagglutinin binding components, while 5-hydroxy-2(2-hydroxy-3,4,5-trimethoxyphenyl)-7-metoxi-4H(chromen-4-ona), which was isolated from the leaf extracts, showed a weak inhibition of viral hemagglutinin. Time of addition experiments demonstrated that the mixture of sterols had a direct effect on viral particle infectivity at the co-treatment level (IC50 = 3.125 µg/mL). This effect was also observed in the virus plaque formation inhibition assay, where the mixture showed 90% inhibition in the first 20 min of co-treatment at the same concentration. Additionally, it was found using qRT-PCR that the NP copy number was reduced by 92.85% after 60 min of co-treatment. These results are the first report of components with anti-hemagglutinin binding activity in the genus Erythrostemon sp

Anti-inflammatory activity of critonia aromatisans and montanoa grandiflora leaves extracts, plants used in mayan traditional medicine to treat inflammation

The aim of the study is to investigate anti-inflammatory properties of polar and non-polar extracts prepared from Critoniaaromatisansand Montanoa grandiflora, two common native species used in Mayan traditional ointments to treat inflammation, joint pain and rheumatism. The antiinflammatory properties of methanol/acetonitrile and n- hexane leaf extracts were tested in vivo and in vitro. The extracts of C. aromatisansand M. grandiflora decreased in a concentration-dependent manner lipopolysaccharide (LPS)-induced nitric oxide (NO) production without affecting the cell viability. The extracts of C. aromatisansat dose of 200 mg/kg exhibited substantial anti-inflammatory activity in the carrageenaninduced paw oedema test and 12-O-Tetradecanoylphorbol-13-acetate (TPA)-induced ear oedema inhibition assay with a reduction in inflammation of up to 90 and 80%, respectively. These results validate the traditional uses by Mayan communities that endorse the use of this species to treat inflammation.El objetivo del estudioesinvestigar las propiedadesantiinflamatorias de extractos de Critoniaaromatisansy Montanoa grandiflora, dos especiesnativascomunesutilizadasenungüentostradicionalesmayas para tratar la inflamación, dolor en las articulaciones y el reumatismo. Las propiedadesantiinflamatorias de extractosmetanol/acetonitrilo y n-hexánicos de hojasfueronevaluadosin vitro e in vivo. Los extractos de C. aromatisans y M. grandiflora disminuyeron la producción de óxidonítrico (NO) inducidaporlipopolisacárido (LPS) de maneradependiente de la concentración sin afectar la viabilidadcelular. Los extractos de C. aromatisans, a dosis de 200 mg/kg exhibenactividadantiinflamatoriasustancialen el ensayo de edema plantar inducidoporcarragenina y en el ensayo de inhibición de edema de la orejainducidopor TPA con unareducciónen la inflamación de 90 y 80%, respectivamente. Estosresultadosvalidanlosusostradicionales de las comunidadesmayas que avalan el uso de estaespecie para el tratamiento de la inflamación

Cytotoxic studies and in vitro effects of trans-3,4,4',5-tetramethoxystilbene, a bioactive compound isolated from Lonchocarpus punctatus Kunth

The bioassay-guided fractionation of Lonchocarpus punctatus inflorescence extracts led to the purification of the trans (1) and cis (2) isomers of 3,5-dimethoxystilbene, trans-3,4,4’,5-tetramethoxystilbene (3), 4,4’,6’-trimethoxychalcone (4) and 5- hydroxy-7,4’-dimethoxyflavone (5) as their main constituents. the structures of the compounds were established by comparing their nuclear magnetic resonance and mass spectrometry data with that from the literature. among these metabolites, trans-3,4,4’,5-tetramethoxystilbene (3) exhibited potent cytotoxic activity against luminal a (CC50= 2.2 μM), HER2 (CC50= 1.1 μM) and basal triple negative (CC50= 1.8 μM) breast cancer cell lines, but no cytotoxic effects were observed against immortalized hepatocyte cell lines (CC50> 50 μM), and medium (CYP3A4, CYP2C9) and low (CYP2D6) inhibitory properties were observed for P450 isoforms.El fraccionamiento biodirigido de extractos obtenidos de las inflorescencias de Lonchocarpus punctatus Kunth permitieron la purificación de los isómeros trans (1) y cis (2) de 3,5 dimetoxiestilbeno, trans-3,4,4’,5- tetrametoxiestilbeno (3) 4,4’,6’-trimetoxichalcona (4) y 5-hidroxi-7,4’-dimetoxiflavona (5) como sus principales constituyentes. Las estructuras de los compuestos fueron establecidas por comparación de sus datos de resonancia magnética nuclear y espectrometría de masas con los reportados en la literatura. De todos los metabolitos aislados, trans-3,4.4’,5-tetrametoxiestilbeno (3) exhibió potente actividad citotóxica contra las líneas celulares de cáncer luminal a (CC50= 2.2 μM), HEr2 (CC50 = 1.1 μM) y triple negativo basal (CC50= 1.8 μM) pero ningún efecto citotóxico fue observado contra la línea celular inmortalizada de hepatocitos (CC50 > 50 μM), así como propiedades inhibitorias moderadas (CYP3A4, CYP2C9) y bajas (CYP2D6) en las isoformas del citocromo P450