Marcos Soto-Hernández

HPLC/MS analysis and anxiolytic-like effect of quercetin and kaempferol flavonoids from Tilia americana var. mexicana

AIM OF THE STUDY Around the world, Tilia species have been used in traditional medicine for their properties as tranquilizer. Furthermore, Mexican species of Tilia have been grouped as Tilia americana var. mexicana, but their specific content in flavonoids is poorly described. In this study, inflorescences of Mexican Tilia were collected in three different regions of Mexico to compare their flavonoid content and anxiolytic-like response. MATERIALS AND METHODS Flavonoid content was analyzed by using an HPLC-MS technique. For anxiolytic-like response, Tilia inflorescences extracts (from 10 to 300 mg/kg, i.p.) were tested in experimental models (open-field, hole-board and plus-maze tests, as well as sodium pentobarbital-induced hypnosis) in mice. RESULTS HPLC-MS analysis revealed specific peaks of flavonoid composition demonstrating some differences in these compounds in flowers and bracts depending on the region of collection. No differences in the neuropharmacological activity among these samples of Tilia were found. Moreover, their effects were associated with quercetin and kaempferol glycosides. CONCLUSIONS Dissimilarities in the flavonoid composition of Mexican Tilias might imply that these species must be re-classified in more than one species, not as a unique Tilia americana var. mexicana. Since quercetin and kaempferol aglycons demonstrated anxiolytic-like response and that no difference in the pharmacological evaluation was observed between these three Mexican Tilias, we suggest that this pharmacological effect of Tilia inflorescences involves these flavonoids occurrence independently of the kind of glycosides present in the samples reinforcing their use in traditional medicine in several regions of Mexico.

Erythrina americana Miller (Colorin; Fabaceae), a versatile resource from Mexico: A review

We present a review of published and unpublished information on the multipurpose tropical legume tree, Erythrina americana. The genusErythrina (Fabaceae) consists of 115 species distributed throughout the tropical regions of the world; 25 species are known from Mexico. E. americana is used as an ornamental tree, also as shade for cocoa and coffee and as a support tree, as a live fence, and for green manure and animal feed. The flowers are frequently eaten, used to make tea and as a sedative. The seeds are toxic because of alkaloids; they are applied in folk medicine as laxative, diuretic, expectorant, anti-asthmatic and antimalarial. The first compounds isolated were isoquinoline alkaloids; of these, β-erythroidine and its more potent derivate dihydro-β-erythroidine were shown to possess curariform activity. Of both compounds, the LD50 has been evaluated, and their effects on the central nervous system have been studied. These studies confirmed some applications in popular medicine.AbstractPresentamos un panorama de informatión publicada e inédita sobre la leguminosa arborescente tropical de uso múltiple, Erythrina americana. El género Erythrina (Fabaceae) comprende 115 especies distribuidas a través de las regiones tropicales del mundo; 25 de ellas se encuentran en México.E. americana se usa como árbol ornamental, como árbol de sombra en cultivos de café y cacao, como soporte en otros cultivos y en cercos vivos en linderos, también como abono y alimento para animates. Las flores son comestibles y a partir de ellas se preparan infusiones, a los cuales se atribuyen propiedades sedativas. Las semillas son tóxicas por la presencia de alcaloides. En la medicina traditional se emplea como laxante, diuretico, expectorante, antiasmático y antimalárico. Los primeros compuestos aislados fueron los alcaloides isoquinolínicos; de ellos, la β-erythroidina y su más potente derivado, la dihidro-β-erythroidina, presentan actividad curariforme. Se conoce la LD50, y se han estudiado sus efectos en el sistema nervioso central. Los estudios fitoquímicos y farmacológicos convalidan algunas de las propiedades medicinales atribuidas a esta especie en la medicina popular.

Alkaloids from six Erythrina species endemic to Mexico

Abstract The alkaloids present in the seeds or foliage of six Erythrina species, E. americana Miller, E. coralloides A. DC., E. lepthoriza A. DC., E. mexicana Krukoff, E. oaxacana Krukoff and E. sousae Krukoff have been screened by gas chromatography-mass spectrometry (GC/MS). The concentration of alkaloids was variable among species and organs, but highest in flowers and seeds. The composition of alkaloids in seeds, flowers, leaves and bark was different among species. The alkaloids of the dienoid type were most abundant than alkenoid series. Erysotrine, erythraline and erythratidine were detected in E. lepthoriza, E. mexicana, E. oaxacana and E. sousae. 11-hydroxylated, 11-methoxylated and y 8-oxo-alkaloids (crystamidine and erysotramidine) and erybidine, not described previously in these species were also detected. Erysotrine-N-oxide has been isolated from E. leptorhiza for the first time. The erythroidines were the main alkaloids detected in E. americana and E. coralloides together with minor alkaloids which support their taxonomic differences.

Anti-ulcer activity of Cyrtocarpa procera analogous to that of Amphipterygium adstringens, both assayed on the experimental gastric injury in rats.

ETHNOPHARMACOLOGICAL RELEVANCE The bark of Amphipterygium adstringens (Aa) is commonly mixed or adulterated with the bark of Cyrtocarpa procera (Cp) and sold in Mexican markets. Aa is a well known species in Mexico used as decoction to relieve ulcers. Scientific reports reinforcing the anti-ulcer activity of Aa have been previously described, but those describing the anti-ulcer properties of Cp as a substitute for Aa in folk medicine are scarce. AIM OF THE STUDY To investigate anatomical and phytochemical differences between these species, as well as to assess the anti-ulcer effect of Cp extracts in comparison to the Aa extracts. MATERIAL AND METHODS Anatomical micro-technique and physical and spectroscopic data were used to analyze differences between Cp and Aa. Regard to the pharmacological activity, it was assessed by using the ethanol-induced gastric damage model in rats. RESULTS Whereas the bark anatomy of Aa was characterized by vertical canals in the periderm and the rare occurrence of fibers in its phloem, a periderm without vertical canals and abundant fibers in the phloem were distinctive features of Cp. Phytochemical analysis allowed the identification of tirucallane, masticadienonic and 3α-hydroxymasticadienonic acids as major components in Aa, while β-amyrin and β-sitosterol were obtained from Cp. Gastric lesions observed in the control group decreased in the presence of 100mg/kg of hexane, ethyl acetate and methanol extracts from the normal or regenerated bark of Cp, thus resembling the anti-ulcer effect of Aa. Nevertheless, major anti-ulcer potency was observed with the most active methanol extract from Cp obtained from normal [the effective dose fifty ED(50)=45.54 mg/kg] or regenerated (ED(50)=36.68 mg/kg) bark in comparison to Aa (ED(50)=115.64 mg/kg). CONCLUSION Chemical and anatomical differences were found between these species, but since the anti-ulcer activity of Cp is similar to that shown by Aa our results reinforce the use of both species for the relief of gastric ulcer in folk medicine.

Flavonoids and antioxidant activity of flowers of Mexican Crataegus spp.

Flavonoids and antioxidant activity of extracts of flowers from some Mexican accessions of Crataegus were studied using six accessions with the purpose of contributing to the knowledge of the nutraceutical properties of the accessions of the Germplasm Bank of the Universidad Autonoma Chapingo. Flavonoids were identified by HPLC–MS. Among the flavonoids, the quercetin 3-O-glucoside (3), quercetin 3-O-rhamnoside (4), quercetin 3-O-rhamnosyl-(1 → 6)-glucoside (2) and quercetin 3-O-rhamnosyl-(1 → 2)-[rhamnosyl-(1 → 6)]-glucoside (1) were assigned. Flavonoid content and radical scavenging activity explain some of the medicinal properties attributed to flowers of Mexican hawthorns.

Alkaloid production in elicited cell suspension cultures of Erythrina americana Miller

A number of species of the genus Erythrina are rich in secondary metabolites, particularly phenolics and alkaloids that exhibit interesting anti-inflammatory, anti-plasmodial, bactericidal, curariform and fungicidal activities. Unfortunately, the isolation of these compounds through the extraction of organs and seeds of whole plants is becoming more difficult since the natural growing areas of many of the species, and particularly of Erythrina americana, are being urbanised. Plant tissue culture not only constitutes a viable method through which to preserve the species, but may also represent a constant and stable source of target alkaloids. Currently, however, in vitro systems, and especially cell suspension cultures, only accumulate low levels of the desired products. A number of strategies for increasing production have been proposed, the most successful of which involves elicitation of suspension cells with plant growth regulators. In this context, excellent results have been reported following elicitation of cell cultures derived from different species and genera with jasmonic acid and methyl jasmonate. The present paper provides a brief review of the novel approaches to the use of Erythrina alkaloids that have recently been described, and of the advances that have been made in the formation of tissue cultures of E. americana and their subsequent elicitation in attempts to augment alkaloid accumulation.

Wood chemical composition in species of Cactaceae: the relationship between lignification and stem morphology.

In Cactaceae, wood anatomy is related to stem morphology in terms of the conferred support. In species of cacti with dimorphic wood, a unique process occurs in which the cambium stops producing wide-band tracheids (WBTs) and produces fibers; this is associated with the aging of individuals and increases in size. Stem support and lignification have only been studied in fibrous tree-like species, and studies in species with WBTs or dimorphic wood are lacking. In this study, we approach this process with a chemical focus, emphasizing the role of wood lignification. We hypothesized that the degree of wood lignification in Cactaceae increases with height of the species and that its chemical composition varies with wood anatomy. To test this, we studied the chemical composition (cellulose, hemicellulose, and lignin content) in 13 species (2 WBTs wood, 3 dimorphic, and 8 fibrous) with contrasting growth forms. We also analyzed lignification in dimorphic and fibrous species to determine the chemical features of WBTs and fibers and their relationship with stem support. The lignin contents were characterized by Fourier transform infrared spectroscopy and high performance liquid chromatography. We found that 11 species have a higher percentage (>35%) of lignin in their wood than other angiosperms or gymnosperms. The lignin chemical composition in fibrous species is similar to that of other dicots, but it is markedly heterogeneous in non-fibrous species where WBTs are abundant. The lignification in WBTs is associated with the resistance to high water pressure within cells rather than the contribution to mechanical support. Dimorphic wood species are usually richer in syringyl lignin, and tree-like species with lignified rays have more guaiacyl lignin. The results suggest that wood anatomy and lignin distribution play an important role in the chemical composition of wood, and further research is needed at the cellular level.

Isolation of alkaloids of Erythrina from tissue culture

Seeds of two species of Erythrina (Leguminosae) were examined for the presence of biologically active alkaloids. Undifferentiated callus of Erythrina coralloides and E. americana produced the tetracyclic alkaloids typical for each species, but an unexpected profile of oxygenated alkaloids was observed. The tissue was analysed after isolation and purification, and identification of the alkaloids was by gas chromatography-mass spectrometry (GC-MS). A higher amount of alkaloid was observed in seeds compared with callus of E. americana. A considerable difference is observed when the alkaloid content from callus is compared with that of the intact plant. Copyright

Bactericidal and Fungicidal Activities of Calia secundiflora (Ort.) Yakovlev

Calia secundiflora (Ortega) Yakovlev (Fabaceae) is considered a medicinal plant in Mexico but has scarcely been used because of the toxicity of its quinolizidine alkaloids. Several quinolizidine alkaloids have shown bactericidal, nematicidal, and fungicidal activities. The purpose of this study was to identify the alkaloids in the seeds and evaluate the activity of the organic extract on several phytopathogenic fungi and bacteria. An in vitro bioassay was conducted with species of the following phytopathogenic fungi: Alternaria solani, Fusarium oxysporum and Monilia fructicola; and of the following bacteria Pseudomonas sp., Xanthomonas campestris and Erwinia carotovora. Cytisine, lupinine, anagyrine, sparteine, N-methylcytisine, 5,6-dehydrolupanine, and lupanine were identified by liquid chromatography-mass spectrometry in the extract of seeds; the most abundant compound of the extract was cytisine. It was observed that the crude extract of Calia secundiflora was moderately active on bacteria and more potent on phytopathogenic fungi. In contrast cytisine showed the opposite effects.

Phytochemical Differences between Calia secundiflora (Leguminosae) Growing at Two Sites in Mexico

Abstract The ecology and quinolizidine alkaloid chemistry of Calia secundiflora (Ortega) Yakovlev growing at two sites in Mexico were compared. At one site (Hidalgo) the vegetation was dominated by Flourensia resinosa and C. secundiflora, at the other site (Queretaro) C. secundiflora and Dodanaea viscosa were dominant. The Hidalgo site had shallower soils with less organic matter, N, P, and CaCO3. Seeds of C. secundiflora from each site accumulated a similar range of quinolizidine alkaloids, but the profile of alkaloids in the leaves and roots were different. The leaves and roots of plants at Hidalgo accumulated a similar range of alkaloids to the seeds with cytisine and/or N-methylcytisine being most abundant, whereas at Queretaro the leaves and roots accumulated lupinine, with other alkaloids being relatively minor constituents. The latter profile has not been reported previously for C. secundiflora