This study investigates the relationship between genetic ancestry, breast cancer subtypes, and survival outcomes among 951 locally advanced breast cancer cases from Argentina, Brazil, Chile, Mexico, and Uruguay, participating in the Molecular Profile of Breast Cancer Study. Array-based genotyping and ADMIXTURE analysis were used for genetic ancestry evaluation. Breast cancer subtypes were defined by IHC and the gene expression-based PAM50 algorithm. The distribution of genetic ancestry, including European, Indigenous American (IA), African (AFR), and East Asian components, revealed a heterogeneous genetic admixture across countries, with the highest IA ancestry observed in Chile (30.9%) and Mexico (30.8%). Testing the relationship between genetic ancestry and breast cancer subtypes demonstrated that a 10% increase in European ancestry was significantly associated with a 14% decrease in the odds of developing HER2-enriched breast cancer, after adjustment by age, nodal status, and the AFR component (adj. P = 0.021, luminal A as reference). Accordingly, a 10% increase in IA ancestry was associated with a 21% increase in the probability of having HER2-enriched breast cancer (adj. P = 0.022). IA ancestry also significantly increased overall survival after adjustment by age, nodal status, and AFR ancestry, although this result is controversial and may be affected by the size and heterogeneity of the Molecular Profile Breast Cancer Study cohort. Our research confirms previous findings of a high prevalence of HER2-dependent breast tumors among Hispanic/Latina women and strengthens the hypotheses of the existence of either population-specific genetic variant(s) or of other ancestry-correlated factors that impact HER2 expression in breast cancer consistently across different Latin American regions. SIGNIFICANCE:The evidence in this work supports the idea that factors linked to genetic ancestry influence the prevalence of breast cancer subtypes in Latin America, potentially affecting treatment needs in the region.

PURPOSEBreast cancer mortality rates in Latin America (LA) are higher than those in the United States, possibly because of advanced disease presentation, health care disparities, or unfavorable molecular subtypes. The Latin American Cancer Research Network was established to address these challenges and to promote collaborative clinical research. The Molecular Profiling of Breast Cancer Study (MPBCS) aimed to evaluate the clinical characteristics and treatment outcomes of LA participants with locally advanced breast cancer (LABC).PATIENTS AND METHODSThe MPBCS enrolled 1,449 participants from Argentina, Brazil, Chile, Mexico, and Uruguay. Through harmonized procedures and quality assurance measures, this study evaluated clinicopathologic characteristics, neoadjuvant chemotherapy response, and survival outcomes according to residual cancer burden (RCB) and the type of surgery.RESULTSOverall, 711 and 480 participants in the primary surgery and neoadjuvant arms, respectively, completed the 5-year follow-up period. Overall survival was independently associated with RCB (worse survival for RCBIII-adjusted hazard ratio, 8.19, P < .001, and RCBII [adjusted hazard ratio, 3.69, P < .008] compared with RCB0 [pathologic complete response or pCR]) and type of surgery (worse survival in mastectomy than in breast-conserving surgery [BCS], adjusted hazard ratio, 2.97, P = .001). The hormone receptor–negative-human epidermal growth factor receptor 2–positive group had the highest proportion of pCR (48.9%). The analysis of the ASCO Quality Oncology Practice Initiative breast module revealed high compliance with pathologic standards but lower adherence to treatment administration standards. Notably, compliance with trastuzumab administration varied widely among countries (33.3%-88.7%).CONCLUSIONIn LABC, we demonstrated the survival benefit of BCS and the prognostic effect of the response to available neoadjuvant treatments despite an important variability in access to key treatments. The MPBCS represents a significant step forward in understanding the real-world implementation of oncologic procedures in LA.

Sweet potato (SP; Ipomoea batatas (L.) Lam; a.k.a. “boniato,” “moniato,” “caiapo,” “kumara,” or “kumera”) is a tuberous staple food native to America with >1600 species (wild + domesticated). SP is the sixth most important food crop worldwide, and China leads its global market, valued at 45 trillion USD. SP domesticated varieties differ in specific phenotypic/genotypic traits, yet all of them are rich in sugars, slowly digestible/resistant starch, and a wide range of nutrients (e.g., vitamins and minerals)/xenobiotics (carotenoids, polyphenols, ascorbic acid, alkaloids, and saponins) with antioxidant, anti-nyctalopia, anti-xerophthalmia, hepatoprotective, anticoagulant/anti-HIV, antibacterial, and antidiabetic potential; the evidence on such bioactivities come from in vitro, in vivo, ex vivo assays and human clinical trials in an illness-dependent manner. However, such health benefits seem to be varietal-specific (phenogenotype) and plant location-specific (leaves, steams, storage root). These and other topics, including gross global production, market diversification of raw SP and its products, the effect of food processing, and potential pharmacological (mechanisms) effects, are briefly discussed in this chapter.

Background In Mexico, there is an ancestral custom about the knowledge of the medicinal use of plants. Bixa orellana L. is a plant species that represents one of the main crops used in traditional medicine in southeastern Mexico. Background studies on its biological properties have been conducted on accessions harvested in Conkal, Yucatan, Mexico. Objectives In this work, the idea was to perform a phytochemical analysis of methanolic extracts of B. orellana . Materials and Methods Phytochemical screening was performed on methanolic extracts of leaves and seeds from two accessions of B. orellana , as well as on their antioxidant and antiproliferative activities. Results The phytochemical screening of the methanolic extracts of the leaves revealed the presence of tannins, terpenes, and saponins. A higher total content of phenols and flavonoids in leaves was also found compared to seeds, which coincides with a higher antioxidant activity in leaves compared to seeds. Regarding antiproliferative activity, the seeds and leaves of accession 3 showed the best results. Conclusion Accession 3 has better bioactive properties and can be a candidate in the search for antiproliferative and antioxidant compounds; this is the first study that associates this plant with this activity and demonstrates the chemical differences that exist between the accessions of B. orellana . Keywords Antioxidant activity , accessions , L. , antiproliferative activity

Background In Mexico, there is an ancestral custom about the knowledge of the medicinal use of plants. Bixa orellana L. is a plant species that represents one of the main crops used in traditional medicine in southeastern Mexico. Background studies on its biological properties have been conducted on accessions harvested in Conkal, Yucatan, Mexico. Objectives In this work, the idea was to perform a phytochemical analysis of methanolic extracts of B. orellana. Materials and Methods Phytochemical screening was performed on methanolic extracts of leaves and seeds from two accessions of B. orellana, as well as on their antioxidant and antiproliferative activities. Results The phytochemical screening of the methanolic extracts of the leaves revealed the presence of tannins, terpenes, and saponins. A higher total content of phenols and flavonoids in leaves was also found compared to seeds, which coincides with a higher antioxidant activity in leaves compared to seeds. Regarding antiproliferative activity, the seeds and leaves of accession 3 showed the best results. Conclusion Accession 3 has better bioactive properties and can be a candidate in the search for antiproliferative and antioxidant compounds; this is the first study that associates this plant with this activity and demonstrates the chemical differences that exist between the accessions of B. orellana.

Purposes:Most molecular-based published studies on breast cancer do not adequately represent the unique and diverse genetic admixture of the Latin American population. Searching for similarities and differences in molecular pathways associated with these tumors and evaluating its impact on prognosis may help to select better therapeutic approaches.Patients and Methods:We collected clinical, pathological, and transcriptomic data of a multi-country Latin American cohort of 1,071 stage II-III breast cancer patients of the Molecular Profile of Breast Cancer Study (MPBCS) cohort. The 5-year prognostic ability of intrinsic (transcriptomic-based) PAM50 and immunohistochemical classifications, both at the cancer-specific (OSC) and disease-free survival (DFS) stages, was compared. Pathway analyses (GSEA, GSVA and MetaCore) were performed to explore differences among intrinsic subtypes.Results:PAM50 classification of the MPBCS cohort defined 42·6% of tumors as LumA, 21·3% as LumB, 13·3% as HER2E and 16·6% as Basal. Both OSC and DFS for LumA tumors were significantly better than for other subtypes, while Basal tumors had the worst prognosis. While the prognostic power of traditional subtypes calculated with hormone receptors (HR), HER2 and Ki67 determinations showed an acceptable performance, PAM50-derived risk of recurrence best discriminated low, intermediate and high-risk groups. Transcriptomic pathway analysis showed high proliferation (i.e. cell cycle control and DNA damage repair) associated with LumB, HER2E and Basal tumors, and a strong dependency on the estrogen pathway for LumA. Terms related to both innate and adaptive immune responses were seen predominantly upregulated in Basal tumors, and, to a lesser extent, in HER2E, with respect to LumA and B tumors.Conclusions:This is the first study that assesses molecular features at the transcriptomic level in a multicountry Latin American breast cancer patient cohort. Hormone-related and proliferation pathways that predominate in PAM50 and other breast cancer molecular classifications are also the main tumor-driving mechanisms in this cohort and have prognostic power. The immune-related features seen in the most aggressive subtypes may pave the way for therapeutic approaches not yet disseminated in Latin America.Clinical Trial Registration:ClinicalTrials.gov (Identifier: NCT02326857).

Aims Giardia lambliais a protozoan parasite that causes giardiasis, one of the most common worldwide gastrointestinal diseases. For rational development of aGiardiavaccine, increasing our understanding of the host-Giardiainteraction is crucial. In this study, we analysed the immunogenicity and antigenicity of twoG lambliastrain variants [GS and GS-5G8 (+)], which express different levels of the variant-specific surface protein (VSP) 5G8 and also analysed the intestinal histological changes associated withGiardiainfection. Methods and results We evaluated the antibody responses induced byG lambliastrains in infected, reinfected and immunized C3H/HeJ mice using ELISA, flow cytometry, Western blotting and histological analysis. Our results showed thatG lambliaGS-5G8 (+) was more immunogenic and antigenic than the GS strain. The antibody response against the GS-5G8 (+) strain primarily recognized 5G8 protein. Serum antibody from infected and reinfected mice exhibited specific agglutination of trophozoites in vitro. GS-5G8 (+)-infected mice showed higher CD19(+)infiltrating cell levels compared to GS-infected animals. Conclusion G lambliastrains with different expression levels of an immunogenic antigen (VSP 5G8) induce differential antibody responses. A better understanding of the immunogenic proteins ofG lambliawill contribute to the rational development of an effective vaccine against this parasitic disease.

Small berries are rich in polyphenols whose first-pass metabolism may alter their ultimate physiological effects. The antioxidant capacity and polyphenol profile of three freeze-dried berries (blackberry, raspberry, Red Globe grape) were measured and their apparent permeability (Papp) and first-pass biotransformation were tracked with an ex vivo bioanalytical system [everted gut sac (rat) + three detection methods: spectrophotometry, HPLC-ESI-QTOF-MS, differential pulse voltammetry (DPV)]. Total polyphenol (ratio 0.07-0.14-1.0) and molecular diversity (anthocyanins>flavan-3-ols), antioxidant capacity (DPPH, FRAP), anodic current maxima and Papp (efflux> uptake) were in the following order: blackberry > raspberry > Red Globe grape. Epicatechin, pelargonidin & cyanin (all), callistephin (raspberry/blackberry), catechin (grape), cyanidin glycosides (blackberry) and their derived metabolites [quinic acid, epicatechin, cyanidin/malvidin glucosides, and chlorogenic/caffeic acids] were fruit-specific and concentration-dependent. Time-trend DPV kinetic data revealed concurrent epithelial permeability & biotransformation processes. Regular permeability and high-biotransformation of berry polyphenols suggest fruit-specific health effects apparently at the intestinal level.

Giardiasis is one of the most common gastrointestinal diseases worldwide, caused by the protozoan parasite Giardia lamblia. Although several immunogenic proteins of the parasite have been identified, the capacity of inducing a protective humoral response has been scarcely evaluated. Our research group have identified and characterized the immunogenic 5G8 protein, a 70 kDa Variant‐specific surface protein (VSP). The administration of 5G8‐specific monoclonal antibodies (AcMo 5G8.B5) to infected animal decreased the parasite intestinal load. The aim of the present study was to evaluate the in vitro effect of 5G8 specific antibodies on G. lamblia trophozoites. We isolated 5G8 protein by passive elution from SDS‐PAGE (membrane protein enriched fraction of trophozoites lysates). C3H/HeJ mice were intraperitoneally immunized with isolated 5G8 protein to generate polyclonal antibodies. GS/M‐83‐H7 5G8 (+) trophozoites were incubated with monoclonal and polyclonal antibodies specific to the 5G8 protein, and their agglutination capacity was evaluated. After 24, 48 and 72 hours incubation, cell proliferation was determinated and the expression of 5G8 protein on trophozoites was evaluated by Flow Cytometry. Polyclonal antibodies recognized 97 % of GS/M‐83‐H7 5G8 (+) trophozoite population, and a single band of 70 kDa (SDS‐PAGE). The AcMo 5G8.B5 and polyclonal antibodies had the ability to agglutinate G. lamblia trophozoites in vitro after 60 min of antibody exposure. Antibody treatments inhibited the in vitro G. lamblia growth. Isotype control antibody and preimmunized serum showed no inhibition of trophozoites proliferation. Surface 5G8 protein expression did not change during antibody treatments. Altogether, our data suggest a possible in vitro cytostatic effect of 5G8 specific antibodies on G. lamblia trophozoites. These findings put forward the capacity of the 5G8 protein to induce a protective humoral response against the infection.Support or Funding InformationCONACYT: CB‐2010‐01/155224This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Los extractos del espárrago han sido anteriormente utilizados por sus propiedades medicinales. El objetivo de este trabajo fue evaluar la actividad biológica del Asparagus officinalis cultivado en la región de Caborca, Sonora, en base a su actividad antioxidante y antiproliferativa. El vegetal fue separado en parte comestible (EPC) y no comestible (EPNC). La actividad antioxidante se evalúo en la EPC, antes y después de un tratamiento térmico; mientras que la antiproliferativa se determinó en la EPC y EPNC. La actividad antioxidante (DPPH) mostró que a una misma concentración (800 μg/mL) no existen diferencias significativas entre el espárrago fresco y el cocido (65.26 ± 0.16 y 66.92 ± 3.29 %, respectivamente). El agua de cocción mostró actividad antioxidante; sin embargo, fue menor que en el espárrago cocido (54.95 ± 2.05 %). La actividad antiproliferativa sobre las líneas celulares HeLa y A-549 se evaluó por el método MTT. El extracto EPC mostró mayor actividad antiproliferativa que el EPNC (IC50 de 2563.4 ± 4.5 y 2853.6 ± 22.8 μg/mL, respectivamente). Los resultados muestran que la actividad antioxidante no se ve afectada por el tratamiento térmico. Sin embargo, no se encontró alta actividad antiproliferativa en el espárrago cultivado en esta región.

The antioxidant properties of several polyphenolics of propolis have been reported, however their protective effect against oxidative stress considering cell integrity is scarce. In this study, we evaluated the cellular antioxidant activity (CAA) of caffeic acid phenetyl ester (CAPE), rutin and galangin (Sonoran propolis constituents) using two murine cell lines derived from different immunological lineages (B-cell lymphoma and macrophages), based on the fluorescence of intracellularly oxidised 2′-7′-dichlorofluorescein (DCF) probe, together with cell morphology analysis and membrane integrity assessment by flow cytometry. CAPE (5 μM) showed the highest CAA (97.9%) on B-cell lymphoma cells against 1 mM H2O2, followed by rutin (25 μM; 30.9%), meanwhile galangin (25 μM) did not show CAA. CAPE exhibited a higher CAA than the antioxidant controls [quercetin (12.5 μM), ascorbic acid (50 μM) and trolox (10 μM)], and additionally it helped to preserve cellular morphology. Similar effects were observed on macrophage cells, indicating that CAPE has a cellular protective effect against ROS. Further studies are needed to investigate the potential health benefits of CAPE.

Giardia lamblia is a protozoan parasite that causes one of the most common gastrointestinal diseases worldwide. To eliminate the parasite from the host intestine, it is necessary the activation of B-cell and T-cell dependent mechanisms. The knowledge about Giardia antigens that can stimulate the host immune response is limited. Recently, it has been described the Binding Immunoglobulin Protein (BIP) of G. lamblia (71kDa) as a potential immunogen. Additionally, our group has identified a highly immunogenic antigen (5G8 protein) of G. lamblia with a relative molecular mass of approximately 70kDa. There is some evidence suggesting that the 5G8 protein may activate both humoral and cellular immune responses. Based on these observations and preliminary mass spectrometry analyses, we hypothesized that the antigen 5G8 could be the BIP protein. In the present study, we characterize immunochemically the BIP protein of Giardia. Flow cytometric assays and western blotting were used to determine the expression profile of BIP and 5G8 antigens in Giardia trophozoites. The differences in expression profile indicated that BIP and 5G8 are not the same molecule. ELISA and Western blotting assays revealed that BIP protein was recognized by antibodies produced during G. lamblia infection in C3H/HeN mice. MTT assays did not reveal the activation of cellular immune response induced by BIP protein in vitro. In addition, we identified the potential B-cell and T-cell epitopes of G. lamblia BIP protein. This molecule is a conserved protein among Giardia strains and other pathogens. The complete immunological characterization of this antigen will contribute to a better understanding of the host–parasite interactions in Giardia infection.

Humoral and cellular immune responses play an important role during Giardia lamblia infection. Several Giardia proteins have been identified as immunogenic antigens based on their elicited humoral immune response. Poorly is known about Giardia antigens that stimulate a cellular immune response. The main purpose of this study was to isolate and partial characterize an immunogenic antigen (5G8) of G. lamblia. The 5G8 protein was isolated from G. lamblia trophozoite lysates by affinity chromatography using moAb 5G8-coupled CNBr-Sepharose. The isolated protein was analysed by electrospray tandem mass spectrometry (ESI-MS/MS), and by diverse bioinformatics tools (GiardiaDB, BLASTn, BLASTp and ExPASy). Additionally, several biochemical and immunological characteristics of the isolated protein were analysed. By ESI-MS/MS the amino acidic 5G8 sequence was deduced. The 5G8 antigen belongs to the VSP family proteins of G. lamblia. This protein is composed by one polypeptide chain (±71kDa). Using the algorithm SYFPHEITI, we identified candidate CD4+ T-cell epitopes from the 5G8 antigen, which can elicit cell-mediated immune responses. In this study, we have identified a G. lamblia protein that induces a strong immune response in infected mice. The biochemical and immunological characterization of the immunogenic 5G8 antigen may contribute to the rational design of a Giardia vaccine.

Giardia spp. is a protozoan parasite that inhabits the upper small intestine of mammals and other species and is the aetiological agent of giardiasis. It has been demonstrated that nitric oxide, mast cells and dendritic cells are the first line of defence against Giardia. IL-6 and IL-17 play an important role during infection. Several cytokines possess overlapping functions in regulating innate and adaptive immune responses. IgA and CD4(+) T cells are fundamental to the process of Giardia clearance. It has been suggested that CD4(+) T cells play a double role during the anti-Giardia immune response. First, they activate and stimulate the differentiation of B cells to generate Giardia-specific antibodies. Second, they act through a B-cell-independent mechanism that is probably mediated by Th17 cells. Several Giardia proteins that stimulate humoral and cellular immune responses have been described. Variant surface proteins, α-1 giardin, and cyst wall protein 2 can induce host protective responses to future Giardia challenges. The characterization and evaluation of the protective potential of the immunogenic proteins that are associated with Giardia will offer new insights into host-parasite interactions and may aid in the development of an effective vaccine against the parasite.

Abstract The protozoan parasite G. lamblia is an intestinal parasite of humans, which the World Health Organization estimates to have infected 250 million people worldwide. Clinical manifestations of G. lamblia infections vary from the asymptomatic carrier state to severe diarrhea, abdominal pain, nausea, malabsorption and weight loss. Our knowledge about the immunogenic antigens of G. lamblia is limited. The purpose of this study was immunologically and biochemically characterize an immunogenic antigen (protein 5G8) of G. lamblia. We generated monoclonal antibodies (moAbs) spe­cific to the protein 5g8 of the parasite by using splenocytes derived from in­fected mice. All of these moAbs recognized a protein of 71 kDa by Western blotting. This protein was isolated from a G. lamblia trophozoite lysate by affinity chromatography. The purified 71 kDa protein was analyzed by mass spectrometry. This immunogenic antigen was expressed inside of the G.lamblia trofozoites (>90% of total cell population) and only a small percentage (≈ 2-5%) of those trophozoites expressed high levels of the 5G8 protein on the cell surface. Trophozoite population expressing the 5G8 protein on the cell surface induced stronger antibody response that trophozoite population that does not express this protein on cell surface. The characterization of this antigen will provide a better understanding of the G. lamblia-host interaction, and will be important for developing effective control strategies against giardiasis.

Abstract Propolis is a cereus resin with a complex chemical composition that possesses a wide range of biological activities. The aim of this study was to evaluate the in vitro anti-Giardia lamblia activity of Sonoran propolis collected from three different areas of Sonoran Desert in northwestern Mexico (Caborca, Pueblo de Alamos, and Ures) and some of its chemical constituents. Additionally, we also analyzed the seasonal effect on the anti-G. lamblia activity of propolis. G. lamblia trophozoite cultures were treated with different concentrations of Sonoran propolis or chemical compounds during 48 h cell proliferation and cell viability were determined. Ures propolis showed the highest inhibitory activity against G. lamblia (IC50 63.8 ± 7.1 µg/mL) in a dose-dependent manner (Ures > Pueblo de Alamos > Caborca). Season had a significant effect on the in vitro anti-G. lamblia activity of Ures propolis. Summer propolis showed the highest inhibitory effect on the G. lamblia trophozoite growth (IC50 23.8 ± 2.3 µg/mL), followed by propolis collected during winter (IC50 59.2 ± 34.7 µg/mL), spring (IC50 102.5 ± 15.3 µg/mL), and autumn (IC50 125.0 ± 3.1 µg/mL). Caffeic acid phenethyl ester, an Ures propolis exclusive constituent, had the highest growth-inhibitory activity towards G. lamblia [IC50 63.1 ± 0.9 µg/mL (222.1 ± 3.2 µM)]. To our knowledge, this is the first study showing that caffeic acid phenethyl ester possesses antiparasitic activity against G. lamblia. Naringenin [IC50 125.7 ± 20.7 µg/mL (461.8 ± 76.3 µM)], hesperetin [IC50 149.6 ± 24.8 µg/mL (494.9 ± 82.2 µM)], and pinocembrin [IC50 174.4 ± 26.0 µg/mL (680.6 ± 101.7 µM)] showed weak anti-G. lamblia activity. On the other hand, chrysin and rutin did not show significant antiparasitic activity. In conclusion, our results suggest that Sonoran propolis and some of its chemical constituents had inhibitory effects on the in vitro growth of G. lamblia trophozoites.

The humoral immune response plays an important role in the clearance of Giardia lamblia. However, our knowledge about the specific antigens of G. lamblia that induce a protective immune response is limited. The purpose of this study was to identify and characterise the immunogenic proteins of G. lamblia in a mouse model. We generated monoclonal antibodies (moAbs) specific to G. lamblia (1B10, 2C9.D11, 3C10.E5, 3D10, 5G8.B5, 5F4, 4C7, 3C5 and 3C6) by fusing splenocytes derived from infected mice. Most of these moAbs recognised a band of ± 71 kDa (5G8 protein) and this protein was also recognised by serum from the infected mice. We found that the moAbs recognised conformational epitopes of the 5G8 protein and that this antigen is expressed on the cell surface and inside trophozoites. Additionally, antibodies specific to the 5G8 protein induced strong agglutination (> 70-90%) of trophozoites. We have thus identified a highly immunogenic antigen of G. lamblia that is recognised by the immune system of infected mice. In summary, this study describes the identification and partial characterisation of an immunogenic protein of G. lamblia. Additionally, we generated a panel of moAbs specific for this protein that will be useful for the biochemical and immunological characterisation of this immunologically interesting Giardia molecule.

T-cell immune response plays an important role in controlling Giardia lamblia infections. Little is known about the G. lamblia-specific antigens that stimulate a cell-mediated immune response. The aim of the present study was to identify T-cell stimulating G. lamblia antigens. For this purpose, we generated a group of Giardia-specific T-cell hybridomas (2F9, 4D5, 6D10, 8B9, 9B10, 10F7 and 10G5). Hybridomas were screened for reactivity with G. lamblia protein extract by the CTLL bioassay. These T-cell hybridomas did not exhibit any significant activation either in the absence of G. lamblia protein extract or in the presence of irrelevant antigen (hen white egg lysozyme). To further characterize the T-cell hybridomas generated, we selected three hybridomas (10G5, 4D5 and 9B10). Giardia lamblia proteins of 90-110, 65-77 and 40-64 kDa showed T-cell stimulating activity for the hybridomas 10G5, 4D5 and 9B10, respectively, in a concentration-dependent manner. Protein extract obtained from different G. lamblia strains (GS/M-83-H7, WB C6 and a clinical isolate (YJJ)) stimulated all T-cell hybridomas, indicating that T-cell-stimulating antigens are expressed among different G. lamblia strains. In conclusion, we identified T-cell stimulating G. lamblia antigens by using Giardia-specific T-cell hybridomas. To our knowledge, these hybridomas are the first-described T-cell hybridomas specific for G. lamblia.

In this study, we have analyzed the chemical composition and antiproliferative activity of propolis from three different arid and semiarid regions of Sonora, Mexico. We identified and quantitated the main chemical constituents of propolis by HPLC-MS. The most abundant constituents of propolis were pinocembrin, pinobanksin 3-acetate, and chrysin. Sonoran propolis had a strong antiproliferative activity on both murine and human cancer cell lines in a concentration-dependent manner. The propolis constituents CAPE, galangin, xanthomicrol and chrysin showed significant antiproliferative activity on most of the cancer cells tested. DNA harvested from cancer cell cultures treated with Sonoran propolis exhibited a ladder of internucleosomal DNA cleavage characteristic of apoptosis. In summary, we have identified and quantitated the main constituents of Sonoran propolis. These propolis samples possess a strong antiproliferative activity on cancer cell lines.