Víctor Arana-Argáez

Antitumor and immunomodulatory effects of Justicia spicigera Schltdl (Acanthaceae).

ETHNOPHARMACOLOGICAL RELEVANCE Medicinal plants are an important source of antitumor compounds. This study evaluated the acute toxicity in vitro and in vivo, as well as the cytotoxic, antitumor and immunomodulatory effects of ethanolic extracts of Justicia spicigera leaves (JSE). MATERIALS AND METHODS The in vitro and in vivo toxicity of JSE was evaluated with comet assay in peripheral blood mononuclear cells (PBMC) and acute toxicity in mice, according to the Lorke procedure, respectively. The apoptotic effect of JSE on human cancer cells and human noncancerous cells was evaluated using flow cytometry with annexin-Alexa 488/propidium iodide. Also, different doses of JSE were injected intraperitoneally daily into athymic mice bearing tumors of HeLa cells during 18 days. The growth and weight of tumors were measured. The in vitro immunomodulatory effects of JSE were evaluated estimating the effects of JSE on the phagocytosis of the yeast Saccharomyces cerevisiae, NO production and H(2)O(2) release in macrophages, as well as the proliferation of splenocytes and NK activity. RESULTS The comet assay showed that only JSE tested at 200 and 1000 μg/ml induced a significantly DNA damage in PBMC, compared to untreated cells, whereas the LD(50) was >5000 mg/kg by intraperitoneal route (i.p.) and by oral route. JSE showed pro-apoptotic (Annexin/PI) effects by 35% against HeLa cells, but lack toxic effects against human normal cells. JSE administrated at 10, 50 and 100 mg/kg i.p. inhibited the tumor growth by 28%, 41% and 53%, respectively, in mice bearing HeLa tumor. JSE stimulated, in a concentration dependent manner, the phagocytosis of Saccharomyces cerevisiae yeasts, the NO production and H(2)O(2) release by human differentiated macrophages. In addition, JSE stimulated the proliferation of murine splenocytes and induced the NK cell activity. CONCLUSION Justicia spicigera shows low toxic effects in vitro and in vivo, exerts apoptotic effects on HeLa cells, has antitumor effects in mice bearing HeLa tumor and induces immunomodulatory activities in vitro.

Antidiabetic effects of Justicia spicigera Schltdl (Acanthaceae)

ETHNOPHARMACOLOGICAL IMPORTANCE Justicia spicigera is a plant species used for the Teenak (Huesteca Potosina) and Mayan (Yucatan peninsula) indigenous for the empirical treatment of diabetes, infections and as stimulant. AIM OF THE STUDY To evaluate the cytotoxicity, antioxidant and antidiabetic properties of J. spicigera. MATERIALS AND METHODS The effects of ethanolic extracts of J. spicigera (JSE) on the glucose uptake in insulin-sensitive and insulin-resistant murine 3T3-F442A and human subcutaneous adipocytes was evaluated. The antioxidant activities of the extract of JSE was determined by ABTS and DPPH methods. Additionally, it was evaluated the antidiabetic properties of JSE on T2DM model. RESULTS JSE stimulated 2-NBDG uptake by insulin-sensitive and insulin-resistant human and murine adipocytes in a concentration-dependent manner with higher potency than rosiglitazone 1mM. JSE showed antioxidant effects in vitro and induced glucose lowering effects in normoglycemic and STZ-induced diabetic rats. CONCLUSION The antidiabetic effects of administration of J. spicigera are related to the stimulation of glucose uptake in both insulin-sensitive and insulin-resistant murine and human adipocytes and this evidence justify its empirical use in Traditional Medicine. In addition, J. spicigera exerts glucose lowering effects in normoglycemic and STZ-induced diabetic rats.

Genome-wide identification, in silico characterization and expression analysis of ZIP-like genes from Trichomonas vaginalis in response to Zinc and Iron

Trace elements such as Zinc and Iron are essential components of metalloproteins and serve as cofactors or structural elements for enzymes involved in several important biological processes in almost all organisms. Because either excess or insufficient levels of Zn and Fe can be harmful for the cells, the homeostatic levels of these trace minerals must be tightly regulated. The Zinc regulated transporter, Iron regulated transporter-like Proteins (ZIP) comprise a diverse family, with several paralogues in diverse organisms and are considered essential for the Zn and Fe uptake and homeostasis. Zn and Fe has been shown to regulate expression of proteins involved in metabolism and pathogenicity mechanisms in the protozoan pathogen Trichomonas vaginalis, in contrast high concentrations of these elements were also found to be toxic for T. vaginalis trophozoites. Nevertheless, Zn and Fe uptake and homeostasis mechanisms is not yet clear in this parasite. We performed a genome-wide analysis and localized the 8 members of the ZIP gene family in T. vaginalis (TvZIP1-8). The bioinformatic programs predicted that the TvZIP proteins are highly conserved and show similar properties to the reported in other ZIP orthologues. The expression patterns of TvZIP1, 3, 5 and 7 were diminished in presence of Zinc, while the rest of the TvZIP genes showed an unchanged profile in this condition. In addition, TvZIP2 and TvZIP4 showed a differential expression pattern in trophozoites growth under different Iron conditions. These results suggest that TvZIP genes encode membrane transporters that may be responsible for the Zn and Fe acquisition in T. vaginalis.

Immunomodulatory effects of the methanolic extract from Pouteria campechiana leaves in macrophage functions

ABSTRACT The present study aimed to examine the immunomodulatory properties of the methanolic (MeOH) extract from Pouteria. campechiana leaves in peritoneal macrophages of Balb/c mice. Peritoneal macrophages isolated from mice and Vero cells were treated with the MeOH extract from leaves. Cell viability of the macrophages and Vero cells were evaluated by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide method. The phagocytic activity, as nitric oxide (NO), hydrogen peroxide (H2O2), interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α) production were evaluated on peritoneal macrophages. Results showed that the MeOH extract from leaves was able to stimulate the phagocytic activity and increase NO, H2O2 and cytokines production. The viability assays do not show cytotoxic effect on cell viability and cause a significative proliferative effect in the macrophages of a concentration-dependent manner. These results conclude that the MeOH extract from P. campechiana leaves possessed a stronger immunostimulatory effect in a concentration-dependent manner without affect the cell viability.

Pharmacological evaluation of 2-angeloyl ent-dihydrotucumanoic acid

Abstract Context: Gymnosperma glutinosum (Spreng.) Less. (Asteraceae) is a bush used for the empirical treatment of pain, fever, and cancer. An ent-neo-clerodane diterpene (2-angeloyl ent-dihydrotumanoic acid; ADTA) was isolated from G. glutinosum. Objective: This study evaluates the cytotoxic, anti-inflammatory, and antinociceptive effects of ADTA. Materials and methods: The cytotoxic effects of ADTA (1–350 μM) were evaluated using the MTT assay with human tumorigenic (SW-620, MDA-MB231, SKLU1, SiHa, and PC-3), and non-tumorigenic (HaCaT) cells for 48 h. The in vitro anti-inflammatory effects of ADTA (0.23–460 μM) were assessed using murine peritoneal macrophages stimulated with LPS and estimating the levels of pro-inflammatory mediators for 48 h. The antinociceptive effects of ADTA (25–100 mg/kg p.o.) were evaluated using two in vivo models of chemical-induced nociception during 1 h. Results: ADTA lacked cytotoxic activity (IC50> 100 μM) on tumorigenic cells. In non-tumorigenic cells (HaCaT), ADTA exerted low cytotoxic effects (IC50 = 273 μM). ADTA, at concentrations of 115 μM or higher, decreased the release of pro-inflammatory mediators. The maximum antinociceptive effects of ADTA in the acetic acid-induced abdominal constrictions by ADTA was found at 100 mg/kg (63%), whereas in the formalin test at phase 1 and phase 2, ADTA (100 mg/kg) decreased the licking time by 47 and 71%, respectively. Conclusion: The results indicate that ADTA, obtained from G. glutinosum, exerts moderate in vitro anti-inflammatory and in vivo antinociceptive effects, but lacks cytotoxic effects on human cancer cells.

IMMUNOSUPPRESIVE EFFECTS OF THE METHANOLIC EXTRACT OF CHRYSOPHYLLUM CAINITO LEAVES ON MACROPHAGE FUNCTIONS

Background: The aim of this work was to evaluate the immunomodulatory effect of the methanol extract (MeOH) from Chrysophyllum cainito leaves on the MΦs functions. Material and Methods: Peritoneal murine MΦs isolated from Balb/c mice were treated with the MeOH extract and stimulated with LPS. The effect on the phagocytosis was evaluated by flow cytometry assay. The nitric oxide (NO) and hydrogen peroxide (H2O2) production was measured by the Griess reagent and phenol red reaction, respectively. Levels of IL-6 and TNF-α was measured using an ELISA kit. Viability of MΦs and Vero cells was determined by the MTT method. Results: The MeOH extract of C. cainito leaves inhibited significantly the phagocytosis, and decreased IL-6 and TNF-α production as well as NO and H2O2 released by the MΦs, in a concentration-dependent manner. In addition, MeOH extract of C. cainito showed low cytotoxicity effect against the cells. Conclusion: These results suggest that MeOH extract of C. cainito leaves has an immunosuppressive effect on murine MΦs, without effects on cell viability. GC-MS chromatogram analysis of MeOH extract showed that lupeol acetate and alpha-amyrin acetate are the principal compounds.

Zinc Efflux in Trichomonas vaginalis: In Silico Identification and Expression Analysis of CDF-Like Genes

Zinc (Zn) is a common essential component for all organisms because this metal serves as a cofactor or structural element for enzymes and metalloproteins involved in several important biological processes. However, excess levels of Zn can be toxic, as a consequence, the cells have evolved homeostatic mechanisms to regulate intracellular levels of this trace mineral. Zinc efflux and sequestration into internal cellular compartments from cells are mediated, in large part, by the ZNT/SLC30 proteins, which belong to the CDF family of ion transporters. The CDF family has evolved in prokaryotes and has been reported in several organisms, such as fungi, plants, and animals. Zn has been shown to regulate expression of proteins involved in metabolism and pathogenicity mechanisms in the protozoan pathogen Trichomonas vaginalis, in contrast high concentrations of this element were also found to be toxic for T. vaginalis trophozoites. Until now, Zn homeostasis mechanisms are not yet clear in this parasite. We performed a genome-wide analysis and localized eight members of the CDF gene family in T. vaginalis (TvCDF1-8). With the use of in silico analyses, the TvCDF protein sequences revealed high conservation and show similar properties to the reported in other CDF orthologs. We analyzed the expression patterns of TvCDF1-8 transcripts in trophozoites growth under high zinc concentrations, which showed down-regulation in expression. These results indicate that TvCDF genes encode membrane transporters and strongly supported their identity as members of CDF-like gene family, and further suggest the function in Zn efflux and sequestration in T. vaginalis.

The Role of Iron Status in the Early Progression of Metronidazole Resistance in Trichomonas vaginalis Under Microaerophilic Conditions

Trichomonas vaginalis is the etiological agent of human trichomoniasis. Metronidazole has high treatment success rate among trichomoniasis patients. However, metronidazole‐resistant T. vaginalis has been reported, contributing in an increasing number of refractory cases. The mechanism of metronidazole resistance in this parasite is still unclear. In the vaginal environment, where the microaerophilic conditions prevail but the iron concentration is constantly fluctuating, the metronidazole resistance profile of T. vaginalis could be altered. In this study, we developed metronidazole‐resistant strains of T. vaginalis and evaluate if iron availability is important to the action of the drug. The modulation of iron levels and iron chelation affected the actions of metronidazole both in susceptible and resistant strains. Interestingly, the early resistant strains exhibited minor iron content. The results of transcription analysis in the early resistant strains showed dysregulation in the expression of genes that codified proteins involved in iron transporter, iron–sulfur cluster assemblage, and oxidative stress response, which could not be observed in the late resistant and susceptible strains. Our results indicate that iron content plays an important role in the metronidazole action in T. vaginalis and likely to be related to iron–sulfur proteins involved in metronidazole activation and oxidative stress via Fenton reaction.

Pharmacological and toxicological study of a chemical-standardized ethanol extract of the branches and leaves from Eysenhardtia polystachya (Ortega) Sarg. (Fabaceae)

Eysenhardtia polystachya is used for the empirical treatment of cancer, infections, diarrhea, inflammation, and pain. This study identified, using GC-MS, the main chemical components in an ethanol extract of E. polystachya branches and leaves (EPE) and tested its cytotoxic, antimicrobial, anti-diarrheal, anti-inflammatory, and antinociceptive effects. The in vitro and in vivo toxicity of EPE was evaluated using the comet assay in human peripheral blood mononuclear cells (PBMC) and the acute toxicity test in mice, respectively. The cytotoxic and the antimicrobial effects were performed using the MTT assay and the minimum inhibitory concentration (MIC) test, respectively. The levels of pro-inflammatory mediators in LPS-stimulated macrophages were measured to evaluate the in vitro anti-inflammatory effects of EPE. The antidiarrheal (castor oil test, small intestine transit, and castor oil-induced enteropooling), and anti-inflammatory activities (TPA and carrageenan) of EPE were also performed. The antinociceptive actions of EPE were carried out with the following tests: acetic acid, formalin, and hot plate. The hypnotic and locomotor effects were analyzed using pentobarbital and a rotarod system, respectively. The main component in EPE was D-pinitol (26.93%). The antidiarrheal and antinociceptive effects of D-pinitol were also evaluated. EPE showed low in vitro toxicity (DNA damage in PBMC at concentrations higher than 200 µg/ml), and low in vivo toxicity (LD50 > 2000 mg/kg i.p. and p.o.). Furthermore, EPE lacked cytotoxic activity (IC50 > 300 µg/ml) on human cancer cells, but showed good antimicrobial effects in E. coli (MIC=1.56 µg/ml) and S. aureus (MIC = 0.78 µg/ml). In multi-drug resistant microorganisms, EPE showed MIC> 100 µg/ml. EPE exerted in vitro anti-inflammatory effects, mainly, by the decrease in the production of H2O2 (IC50 = 43.9 ± 3.8 µg/ml), and IL-6 (73.3 ± 6.9 µg/ml). EPE (ED50 =7.5 ± 0.9 mg/kg) and D-pinitol (ED50 = 0.1 ± 0.03 mg/kg) showed antidiarrheal activity, and antinociceptive effects in the acetic acid test with ED50 = 117 ± 14.5 mg/kg for EPE and 33 ± 3.2 mg/kg for D-pinitol. EPE showed also antinociceptive activity in the phase 2 of the formalin test (ED50 = 48.9 ± 3.9 mg/kg), without inducing hypnotic effects or altering the locomotor activity in mice. The results here presented corroborate the folk medicinal use of Eysenhardtia polystachya in the treatment of infections, diarrhea, inflammation, and pain. D-pinitol, the main metabolite of EPE, showed antinociceptive and antidiarrheal effects with similar potency compared to standard drugs.

Anti-inflammatory and antinociceptive effects of tilifodiolide, isolated from Salvia tiliifolia Vahl (Lamiaceae)

Salvia tiliifolia Vahl (Lamiaceae) is used for the empirical treatment of pain and inflammation. The diterpenoid tilifodiolide (TFD) was isolated from Salvia tiliifolia. The in vitro anti‐inflammatory effects of TFD (0.1–200 µM) were assessed using murine macrophages stimulated with LPS and estimating the levels of pro‐inflammatory mediators for 48 h. The in vivo anti‐inflammatory activity of TFD was assessed using the carrageenan‐induced paw edema test for 6 h. The antinociceptive effects of TFD were evaluated using the formalin test and the acetic acid induced‐writhing test. The effects of TFD on locomotor activity were assessed using the open field test and the rotarod test. TFD inhibited the production of TNF‐α (IC50 = 5.66 µM) and IL‐6 (IC50 = 1.21 µM) in macrophages. TFD (200 mg/kg) showed anti‐inflammatory effects with similar activity compared to 10 mg/kg indomethacin. The administration of TFD induced antinociception in the phase 1 (ED50 = 48.2 mg/kg) and the phase 2 (ED50 = 28.9 mg/kg) of the formalin test. In the acetic acid assay, TFD showed antinociceptive effects (ED50 = 32.3 mg/kg) with similar potency compared to naproxen (ED50 = 36.2 mg/kg). In the presence of different inhibitors in the acetic acid assay, only the co‐administration of TFD and naloxone reverted the antinociceptive activity shown by TFD alone. TFD did not affect locomotor activity in mice. TFD exerts in vitro and in vivo anti‐inflammatory activity and in vivo antinociceptive effects.