DIVERSIDAD GENÉTICA Y MEJORAMIENTO DE PLANTAS MEDICINALES= Medicinal plants and improvement of medicinal herbs

The authors have isolated and characterized a cDNA clone encoding the cytosolic form of carbonic anhydrase in the leaves in Flaveria bidentis, a C4 dicotyledonous plant. The deduced amino acid sequence is similar to the carbonic anhydrase found in the chloroplasts of C3 dicotyledonous plants. Western blot anal. of crude leaf exts. of F. bidentis indicates that the leader sequence (equiv. to the transit peptide of the chloroplastic form of CA found in C3 plants) is not removed following translation of mRNA.

ÚLTIMOS AVANCES EN LA QUÍMICA Y ACTIVIDADES BACTERIOLÓGICAS EN LAS PLANTAS MEDICINALES= Medicinal plants, last advances on chemistry and bacteria activities on the medicinal herbs

1) A well-resolved phylogeny of Flaveria is used to infer evolutionary relationships among species, biogeog. distributions, and C4 photosynthetic evolution.  Data on morphol., life history, and DNA sequences (chloroplastic trnL-F, nuclear ITS and ETS) for 21 of 23 known species were collected.  Each data set was analyzed sep. and in combination using max. parsimony and Bayesian analyses.  The phylogeny of Flaveria is based on the combined anal. of all data.  Our phylogenetic evidence indicates that C3 Flaveria are all basal to intermediate (C3-C4 and C4-like) and fully expressed C4 Flaveria species.  Two strongly supported clades (A and B) are present.  Using this phylogeny, we evaluate the current systematics of the genus and suggest the removal and reevaluation of certain taxa.  We also infer the center of origin and dispersal of Flaveria species.  Multiple origins of photosynthetic pathway intermediacy in Flaveria are recognized.  C3-C4 intermediacy has evolved twice in the genus and is found to be evolutionarily intermediate in clade A, but not necessarily in clade B.  C4-like photosynthesis is also derived once in each clade.  In addn., fully expressed C4 photosynthesis may have evolved up to three times within clade A.

2) Biomols. can be oxidized by free radicals.  This oxidative damage has an important etiol. role in aging and the development of diseases like cancer, atherosclerosis, and other inflammatory disorders.  Synthetic antioxidants, like butylated hydroxyanisole, are good free radical scavengers, however, the synthetic antioxidants can be carcinogenic.  Therefore, there is an increasing interest in searching for antioxidants of natural origin.  We report here the results of a screening for antioxidant activity of 53 ethanolic exts. from 40 Peruvian plants used in traditional medicine for the treatment of several infectious and inflammatory diseases.  The antioxidant activity in vitro was measured by means of the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay.  Rutin, a natural antioxidant, was used as a control.  Twenty one (39.6%) of the plant exts. showed an EC50 lower than 50 mg/mL.  The plants with the highest activity were Gentianella nitida, Iryanthera lancifolia, Lepechinia meyenii, Oenothera multicaulis, Philodendron solimoesense and Tetracera volubilis, which showed an EC50 of 13.70, 14.08, 16.65, 16.89, 8.80, and 5.29 mg/mL, resp.  The crude ethanolic ext. of Tetracera volubilis has better antioxidant activity in vitro than the pure natural antioxidant rutin (EC50 = 7.16 mg/mL).

3) Quercetin 3-acetyl-7,3',4'-trisulfate (ATS) and quercetin 3,7,3',4'-tetrasulfate (QTS) obtained from Flaveria bidentis (Asteraceae) were investigated in vitro for anticoagulant activity.  Three different concns. of each flavonoid were assayed at different incubation times, showing at 1 mM significant prolongation on the activated partial thromboplastin time (APTT), less on the prothrombin time (PT), and no effect on the thrombin time (TT).  In order to define the action mechanism of the anticoagulant activity, all coagulation factors were evaluated and no important activity decrease was obsd., indicating that another mechanism is involved.  Thus, thrombin inhibition mediated by antithrombin III (ATIII) and heparin cofactor II (HCII) activation was investigated in comparison to the physiol. activators, heparin and dermatan sulfate (DS), resp.  As a conclusion, no activation on ATIII for neither flavonoids was obsd.  On the contrary, QTS much more than ATS produced an activation on HCII comparable to the one of DS, indicating that these flavonoids act as agonists of this inhibitor.  A plausible explanation of the effects of both flavonoids could be due to the different degree of sulfation of these mols.  According to the results obtained, and taking in account the high soly. of these natural products in aq. media and the nontoxic nature of this family of compds., further investigation on the antithrombotic effects of these flavonoids are merited.

Summary
Flaveria bidentis (Compositae) is a widely distributed medicinal herb throughout the American continent. Commonly used as an anti-parasitizing, expectorant and digestive agent, preliminary studies have partially validated the former activity for the aqueous extract, more specifically in an in vivo model against certain pathogenic parasites to man. Recent investigations have also shown that quercetin sulfate derivatives present in the plant possess high therapeutic potential, especially regarding anti-clotting properties and as a co adjuvant in the treatment of cataracts in diabetic patients.

PARTE UTILIZADA= Used part: Hojas. 

ACCIÓN FARMACOLÓGICA= Pharmacological action: Alexifármaco (antídoto), digestivo, emenagogo, excitante, vermífugo, tónico.

COMPOSICIÓN QUÍMICA= Chemical composition: Ethnobotanical reports indicate that Flaveria bidentis "matagusano" is a plant used to combat antiparasitic and bronchial diseases, mainly in the children of the countryside from Supe Pueblo (Barranca-Lima), where the plant material was collected for the present study. The phytochem. screening of the capitulum, stems, leaves and roots of Flaveria bidentis permitted detection of tannins, flavonoids, leucoanthocyanidins, steroids and triterpenoids. Making use of techniques such as column chromatog. and thin-layer chromatog., two compds. were isolated: 1-methyl-3-(methylthio)benzene (capitulum) and 3-methylbenzyl mercaptan (leaves). Biol. assays showed that both compds. had nematocidal activity after 72 h against larvae (J2) of Meloidogyne incognita.

ZONA GEOGRÁFICA= Geografical zone: América calida y templada. 

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Parte utilizada
Se cita el uso de las partes aéreas. En Perú se emplea la planta entera, sin la raíz (Palacios Vaccaro, 1997).

Farmacodinamia - Acciones farmacológicas
Área infectológica, Actividad anticoagulante, Área oftálmica

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Partes usadas:
hojas-ramas

Usos tradicionales:
a) uso interno: parásitos intestinales; fiebre; menstruaciones escasas y dolorosas; estitiquez.
La infusión se prepara con 1 cucharada del vegetal para 1litro de agua recién hervida: beber 1 taza 3 veces en el día.
b) uso externo: heridas y úlceras; contra veneno de animales e insectos.
La misma preparación sirve para lavar heridas.

Efectos: vermífugo, emenagogo, sudorífico, laxante

Precauciones: no administrar en caso de estar tomando anticoagulantes pues se podría potenciar el efecto anticoagulante del medicamento.

1) TOURSARKISSIAN, Martín. Plantas medicinales de Argentina : sus nombres botánicos, vulgares, usos y distribución geográfica. Buenos Aires : Hemisferio Sur, 1980, p.31.

2) PASTOR DE ABRAM, Ana; ZELADA MARILUZ, Bertha Ruth. Phytochemical study of Flaveria bidentis (L.) Kuntze (Asteraceae).Revista de la Sociedad Quimica del Peru. 2006, vol.72, nº1, p.3-11.
 
3) CAVALLARO, Antonino; LUDWIG, Martha; BURNELL, James. The nucleotide sequence of a complementary DNA encoding Flaveria bidentis carbonic anhydrase. FEBS Letters. 1994, vol.350, nº2-3, p.216-218.
 
4) MCKOWN, Athena D.; MONCALVO, Jean-Marc; DENGLER, Nancy G. Phylogeny of Flaveria (Asteraceae) and inference of C4 photosynthesis evolution. American Journal of Botany. 2005, vol.92, nº11, p.1911-1928.
 
5) LOCK, O., et al Antioxidant activity in vitro of selected Peruvian medicinal plants.  Acta Horticulturae. 2005, Vol.675 (Proceedings of WOCMAP III: The IIIrd World Congress on Medicinal and Aromatic Plants). 2003, p.103-106.
 
6) GUGLIELMONE, Hugo A., et al. Anticoagulant effect and action mechanism of sulphated flavonoids from Flaveria bidentis. Thrombosis Research. 2002, vol.105, nº2, p.183-188.

7) ALONSO, Jorge ; DESMARCHELIER, Cristian. Plantas medicinales autóctonas de la Argentina : bases científicas para su aplicación en atención primaria de la salud.  Buenos Aires: L.O.L.A, 2005, p. 74.

8) Plantas medicinales autóctonas de la Argentina. Bases científicas para su aplicación en atención primaria de la salud / Jorge Alonso y Cristian Jorge Desmarchelier. - 1a ed. - Ciudad Autónoma de Buenos Aires: Corpus Libros Médicos y Científicos, 2015.

7) Hierbas medicinales/ Chile. Ministerio de Agricultura.  p.64