Ramiro Quintanilla-Licea

Anti-Trypanosoma cruzi activity of 10 medicinal plants used in northeast Mexico.

The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis.

Bioassay-Guided Isolation and Identification of Cytotoxic Compounds from Gymnosperma glutinosum Leaves

Bioassay-guided fractionation of hexane extracts of Gymnosperma glutinosum (Asteraceae) leaves, collected in North Mexico, afforded the known compounds hentriacontane (1) and (+)-13S,14R,15-trihydroxy-ent-labd-7-ene (2), as well as the new ent-labdane diterpene (−)-13S,14R,15-trihydroxy-7-oxo-ent-labd-8(9)-ene (3). In addition, D-glycero-D-galactoheptitol (4) was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the in vitro L5178Y-R lymphoma murine model. Hentriacontane (1) and the new ent-labdane 3 showed weak cytotoxicity, whereas the ent-labdane 2 showed significant (p < 0.05) and concentration dependent cytotoxicity (up to 78%) against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

Differential effects of synthetic indoloquinolizines on in vitro rat lymphocyte and macrophage functions

Indoloquinolizines are natural alkaloid indole products grouped as beta-carbolines. These compounds are commonly associated with neurological activities, but little is known about their role as immunomodulating agents. The present study was undertaken to evaluate the effects of synthetic indoloquinolizines on in vitro parameters of rat lymphocyte and macrophage functions. It was observed that proliferation of thymic lymphocytes was significantly (p<0.05) increased (20-30% increase) by dihydro-indoloquinolizinium chloride (2). dihydro-indoloquinolizinyl-ethanone (3). and dimeric dihydro-indoloquinolizinium dichloride (6). whereas dimeric indoloquinolizine (7). caused up to 40% increase in lymphoproliferation at concentrations ranging from 10(-11) to 10(-5) M, compared with untreated control. In contrast, indoloquinolizinium chloride (4) and indoloquinolizine (5). were toxic for lymphocytes at concentrations from 10(-9) to 10(-5) M, and compounds 6 and 7 were toxic at 10(-5) M. In addition, nitric oxide production by LPS-treated peritoneal macrophages was significantly (p<0.05) increased (up to 30% increase) by compounds 4 and 5 at concentrations of 10(-11) to 10(-5) M, and 10(-5) M, respectively; however, compounds 6 and 7 were toxic for macrophages at all concentrations tested. Furthermore, TNF-alpha production was also significantly increased (p<0.01) by compounds 4 and 5 (up to 30-fold increase) compared with untreated control. These novel synthetic indoloquinolizines could serve as immunotherapeutic agents by selectively increasing the pool of activated T lymphocytes or stimulating macrophage functions, with potential use in the treatment of infectious diseases including AIDS and cancer.

Antitumor Properties of Gymnosperma Glutinosum Leaf Extracts

The present study was undertaken to validate the antitumor potential of Gymnosperma glutinosum from regional peoples account, using the in vitro and in vivo L5178Y-R lymphoma murine model. Non-polar G. glutinosum crude extracts were tested on L5178Y-R cells. We found significant (p < 0.05) cytotoxic activity (up to 40%) of the hexane extract, which was further fractioned; fraction 1 (F1) was then observed to produce up to 51% apoptosis-mediated L5178Y-R cytotoxicity in vitro at concentrations lower than 0.98 μ g/ml, and possess significant in vivo antitumor activity. This study may support further evaluation of active F1 in clinical trials.

Antiprotozoal Activity against Entamoeba histolytica of Plants Used in Northeast Mexican Traditional Medicine. Bioactive Compounds from Lippia graveolens and Ruta chalepensis

Amoebiasis caused by Entamoeba histolytica is associated with high morbidity and mortality is becoming a major public health problem worldwide, especially in developing countries. Because of the side-effects and the resistance that pathogenic protozoa build against the standard antiparasitic drugs, e.g., metronidazole, much recent attention has been paid to plants used in traditional medicine around the world in order to find new antiprotozoal agents. We collected 32 plants used in Northeast Mexican traditional medicine and the methanolic extracts of these species were screened for antiprotozoal activity against E. histolytica trophozoites using in vitro tests. Only 18 extracts showed a significant inhibiting activity and among them six plant extracts showed more than 80% growth inhibition against E. histolytica at a concentration of 150 µg/mL and the IC50 values of these extracts were determined. Lippia graveolens Kunth and Ruta chalepensis Pers. showed the more significant antiprotozoal activity (91.54% and 90.50% growth inhibition at a concentration of 150 µg/mL with IC50 values of 59.14 and 60.07 µg/mL, respectively). Bioassay-guided fractionation of the methanolic extracts from these two plants afforded carvacrol (1) and chalepensin (2), respectively, as bioactive compounds with antiprotozoal activity.

Long-chain alkanes and ent-labdane-type diterpenes from Gymnosperma glutinosum with cytotoxic activity against the murine lymphoma L5178Y-R.

The antitumor potential of Gymnosperma glutinosum was previously reported using the in vitro and in vivo L5178Y‐R lymphoma murine model. The present study was carried out to isolate and identify the cytotoxic compounds present in the Gymnosperma glutinosum leaf hexane extract. Gymnosperma glutinosum was collected in the semi‐arid region of Escobedo, State of Nuevo León, México, but it is commonly found in northeastern Mexico; it is traditionally used as a treatment for diarrhea, ulcers and rheumatism. G. glutinosum leaves were extracted with hexane and further fractioned and subfractioned over silica gel by gradient elution with hexane, chloroform, ethyl acetate and methanol. The cytotoxicity of fractions and subfractions was assessed in vitro against L5178Y‐R lymphoma cells. Structure elucidation of the active compounds was determined by spectroscopic methods. Fractions and subfractions showed significant (p < 0.05) and concentration‐dependent 20% to 56% cytotoxicity against L5178Y‐R cells at concentrations ranging from 7.8 µg/mL to 500 µg/mL. The bioassay‐guided fractionation of the hexane extract resulted in the isolation and identification of the alkane hentriacontane and the diterpene ent‐labd‐7‐en‐13S,14R,15‐triol as the metabolites responsible for the activity. Copyright

ANTIMICROBIAL ACTIVITY OF GYMNOSPERMA GLUTINOSUM (SPRENG.) LESS. (ASTERACEAE) METHANOL EXTRACTS AGAINST HELICOBACTER PYLORI

Background: Prolonged use of antibiotics may lead to the selection of drug-resistant bacteria; as a result, efforts are being made to identify new and effective antimicrobial agents, particularly, from medicinal plants, against bacterial infections. Antimicrobial activity of Gymnosperma glutinosum against Helicobacter pylori has not yet been reported. Materials and methods: The antibacterial in vitro effect of Gymnosperma glutinosum methanol leaf extracts against Helicobacter pylori (ATCC 43504) was evaluated in liquid medium by the colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) reduction assay and in solid medium by the colony forming units (CFU) method. Results: Methanol extracts significantly (p<0.05) inhibited in vitro H. pylori growth in liquid medium from 24% to 82% at concentrations ranging from 31.25 mg/ml to 500 mg/ml, respectively, and in solid medium the extracts caused significant (p<0.05) 52% and 100% bacterial growth inhibition at concentrations of 250 μg/mL and 500 μg/mL, respectively, as compared with untreated control. Methanol vehicle did not affect H. pylori growth. Conclusion: The observed antibacterial effect of G. glutinosum extracts may be of benefit as an adjuvant treatment of diseases caused by H. pylori.

Antibacterial Activity of Oenothera rosea (L 'Hér) Leaf Extracts.

Aims: To determine the antibacterial effect of Oenothera rosea against Escherichia coli, Salmonella enteritidis and Vibrio cholerae. Study Design: In vitro antibacterial study. Place and Duration of Study: Universidad Autonoma de Nuevo Leon, Facultad de Ciencias Biologicas, Departamento de Microbiologia e Inmunologia and Departamento de Quimica, San Nicolas de los Garza, NL. Mexico, from June 2010 to June 2011. Methodology: The antibacterial in vitro effect of methanol and aqueous extracts of the Mexican plant O. rosea against strains of E. coli, S. enteritidis and V. cholerae was evaluated in liquid medium by the colorimetric 3-[4,5-dimethylthiazol-2-yl]-2,5diphenyltetrazolium bromide (MTT) reduction assay. Results: Methanol and aqueous extracts significantly inhibited growth of all bacterium strains tested. The methanol extract caused up to 55%, 66% and 87% growth against E. coli, S. enteritidis and V. cholerae, respectively, whereas the aqueous extract induced up to 54%, 69% and 88% bacterial growth inhibition, respectively. Methanol and aqueous Research Article British Journal of Medicine & Medical Research, 2(3): 396-404, 2012 397 vehicle controls did not alter bacterial growth. Conclusion: The observed antibacterial effect of O. rosea extracts may be of benefit as an adjuvant treatment of diseases caused by the studied enterobacteria.

5,5’-Biindole

Abstract: Synthesis of 5,5’-biindole was carried out by the Madelung indole reaction. Understrong basic conditions and high temperatures (350 oC),

Antitumor activity of Chlorella sorokiniana and Scenedesmus sp. microalgae native of Nuevo León State, México

,’ - bis -formyl- o -tolidineunderwent cyclization to produce high amounts of the dimeric indole. Full and unambiguousassignments of all 1 H- and 13 C-NMR resonances of indole and 5,5’-biindole in DMSO- d 6 arealso reported. Keywords: Indoloquinolizine, Antitumor activity, Teuber’s reaction, Indole synthesis, 1 H-NMR, 13 C-NMR. Introduction Indoles are one of the most widely distributed heterocyclic compounds in nature [1-3]. The indole ringappears in tryptophan [4], an essential aminoacid, and metabolites of tryptophan are important in thebiological chemistry of both plants and animals. In plants, indole alkaloids, including indole-3-acetic acidand its secondary metabolites, are known as plant growth hormones [5]; in animals, serotonin(5-hydroxytryptamine) is a crucial neurotransmitter in the central nervous system [6]. The potentphysiological properties of these indole derivatives led to vast research of their use as medicines in thefield of pharmaceutical chemistry. Furthermore, indomethacin [7], a non-steroidal anti-inflammatoryagent, and pindolol [8], a b-adrenergic blocker, are clinically proven indole compounds. Several naturally-occurring indoles are also of clinical relevance; vincristine, a dimeric indole alkaloid, and relatedcompounds, were the first of the antimitotic class of chemotherapeutic agents for cancer [9]. Themitomycins [10] and derivatives of ellipticine [11] are other examples of compounds having antitumoractivity. Extensive research on reactivity and synthesis of indoles has been done and there is increased