Ursolic and oleanolic acids as antimicrobial and immunomodulatory compounds for tuberculosis treatment

BACKGROUND: New alternatives for the treatment of Tuberculosis (TB) are urgently needed and medicinal plants represent a potential option. Chamaedora tepejilote and Lantana hispida are medicinal plants from Mexico and their hexanic extracts have shown antimycobacterial activity. Bioguided investigation of these extracts showed that the active compounds were ursolic acid (UA) and oleanolic acid (OA). METHODS: The activity of UA and OA against Mycobacterium tuberculosis H37Rv, four monoresistant strains, and two drug-resistant clinical isolates were determined by MABA test. The intracellular activity of UA and OA against M. tuberculosis H37Rv and a MDR clinical isolate were evaluated in a macrophage cell line. Finally, the antitubercular activity of UA and OA was tested in BALB/c mice infected with M. tuberculosis H37Rv or a MDR strain, by determining pulmonary bacilli loads, tissue damage by automated histomorphometry, and expression of IFN-γ, TNF-α, and iNOS by quantitative RT-PCR. RESULTS: The in vitro assay showed that the UA/OA mixture has synergistic activity. The intracellular activity of these compounds against M. tuberculosis H37Rv and a MDR clinical isolate in a macrophage cell line showed that both compounds, alone and in combination, were active against intracellular mycobacteria even at low doses. Moreover, when both compounds were used to treat BALB/c mice with TB induced by H37Rv or MDR bacilli, a significant reduction of bacterial loads and pneumonia were observed compared to the control. Interestingly, animals treated with UA and OA showed a higher expression of IFN-γ and TNF-α in their lungs, than control animals. CONCLUSION: UA and OA showed antimicrobial activity plus an immune-stimulatory effect that permitted the control of experimental pulmonary TB

16α‐Bromoepiandrosterone as a new candidate for experimental diabetes‐tuberculosis comorbidity treatment

Tuberculosis (TB) is the leading cause of death from a single bacterial infectious agent and is one of the most relevant issues of public health. Another pandemic disease is type II diabetes mellitus (T2D) that is estimated to affect half a billion people in the world. T2D is directly associated with obesity and a sedentary lifestyle and is frequently associated with immunosuppression. Immune dysfunction induced by hyperglycemia increases infection frequency and severity. Thus, in developing countries the T2D/TB co-morbidity is frequent and represents one of the most significant challenges for the health-care systems. Several immunoendocrine abnormalities are occurring during the chronic phase of both diseases, such as high extra-adrenal production of active glucocorticoids (GCs) by the activity of 11-β-hydroxysteroid dehydrogenase type 1 (11-βHSD1). 11-βHSD1 catalyzes the conversion of inactive cortisone to active cortisol or corticosterone in lungs and liver, while 11-β-hydroxysteroid dehydrogenase type 2 (11-βHSD2) has the opposite effect. Active GCs have been related to insulin resistance and suppression of Th1 responses, which are deleterious factors in both T2D and TB. The anabolic adrenal hormone dehydroepiandrosterone (DHEA) exerts antagonistic effects on GC signaling in immune cells and metabolic tissues; however, its anabolic effects prohibit its use to treat immunoendocrine diseases. 16α-bromoepiandrosterone (BEA) is a water miscible synthetic sterol related to DHEA that lacks an anabolic effect while amplifying the immune and metabolic properties with important potential therapeutic uses. In this work, we compared the expression of 11-βHSD1 and the therapeutic efficacy of BEA in diabetic mice infected with tuberculosis (TB) (T2D/TB) with respect to non-diabetic TB-infected mice (TB). T2D was induced by feeding mice with a high-fat diet and administering a single low-dose of streptozotocin. After 4 weeks of T2D establishment, mice were infected intratracheally with a high-dose of Mycobacterium tuberculosis strain H37Rv. Then, mice were treated with BEA three times a week by subcutaneous and intratracheal routes. Infection with TB increased the expression of 11-βHSD1 and corticosterone in the lungs and liver of both T2D/TB and TB mice; however, T2D/TB mice developed a more severe lung disease than TB mice. In comparison with untreated animals, BEA decreased GC and 11-βHSD1 expression while increasing 11-βHSD2 expression. These molecular effects of BEA were associated with a reduction in hyperglycemia and liver steatosis, lower lung bacillary loads and pneumonia. These results uphold BEA as a promising effective therapy for the T2D/TB co-morbidity.Fil: López Torres, Manuel Othoniel. Instituto Nacional de la Nutrición Salvador Zubiran; MéxicoFil: Marquina Castillo, Brenda. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Ramos Espinosa, Octavio. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Mata Espinosa, Dulce. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Barrios Payan, Jorge A.. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Baay Guzman, Guillermina. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Huerta Yepez, Sara. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Bini, Estela Isabel. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Torre Villalvazo, Ivan. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Torres, Nimbe. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Tovar, Armando. Instittuto de Ciencias Médicas y Nutrición; MéxicoFil: Chamberlin, William. No especifíca;Fil: Ge, Yu. No especifíca;Fil: Carranza, Maria Andrea. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Houssay. Instituto Alberto C. Taquini de Investigaciones En Medicina Traslacional. - Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Cardiologicas "prof. Dr. Alberto C. Taquini". Instituto Alberto C. Taquini de Investigaciones En Medicina Traslacional.; ArgentinaFil: Hernández Pando, Rogelio. Instituto Nacional de Ciencias Medicas y Nutricion; Méxic

Beneficial or detrimental activity of regulatory T cells, indoleamine 2,3-dioxygenase, and heme oxygenase-1 in the lungs is influenced by the level of virulence of Mycobacterium tuberculosis strain infection

Tuberculosis (TB) caused by the complex Mycobacterium tuberculosis (Mtb) is the main cause of death by a single bacterial agent. Last year, TB was the second leading infectious killer after SARS-CoV-2. Nevertheless, many biological and immunological aspects of TB are not completely elucidated, such as the complex process of immunoregulation mediated by regulatory T cells (Treg cells) and the enzymes indoleamine 2,3-dioxygenase (IDO) and heme oxygenase 1 (HO-1). In this study, the contribution of these immunoregulatory factors was compared in mice infected with Mtb strains with different levels of virulence. First Balb/c mice were infected by intratracheal route, with a high dose of mild virulence reference strain H37Rv or with a highly virulent clinical isolate (strain 5186). In the lungs of infected mice, the kinetics of Treg cells during the infection were determined by cytofluorometry and the expression of IDO and HO-1 by RT-PCR and immunohistochemistry. Then, the contribution of immune-regulation mediated by Treg cells, IDO and HO-1, was evaluated by treating infected animals with specific cytotoxic monoclonal antibodies for Treg cells depletion anti-CD25 (PC61 clone) or by blocking IDO and HO-1 activity using specific inhibitors (1-methyl-D,L-tryptophan or zinc protoporphyrin-IX, respectively). Mice infected with the mild virulent strain showed a progressive increment of Treg cells, showing this highest number at the beginning of the late phase of the infection (28 days), the same trend was observed in the expression of both enzymes being macrophages the cells that showed the highest immunostaining. Animals infected with the highly virulent strain showed lower survival (34 days) and higher amounts of Treg cells, as well as higher expression of IDO and HO-1 one week before. In comparison with non-treated animals, mice infected with strain H37Rv with depletion of Treg cells or treated with the enzymes blockers during late infection showed a significant decrease of bacilli loads, higher expression of IFN-g and lower IL-4 but with a similar extension of inflammatory lung consolidation determined by automated morphometry. In contrast, the depletion of Treg cells in infected mice with the highly virulent strain 5186 produced diffuse alveolar damage that was similar to severe acute viral pneumonia, lesser survival and increase of bacillary loads, while blocking of both IDO and HO-1 produced high bacillary loads and extensive pneumonia with necrosis. Thus, it seems that Treg cells, IDO and HO-1 activities are detrimental during late pulmonary TB induced by mild virulence Mtb, probably because these factors decrease immune protection mediated by the Th1 response. In contrast, Treg cells, IDO and HO-1 are beneficial when the infection is produced by a highly virulent strain, by regulation of excessive inflammation that produced alveolar damage, pulmonary necrosis, acute respiratory insufficiency, and rapid death

The Role of High Mobility Group Box 1 Protein (HMGB1) in the Immunopathology of Experimental Pulmonary Tuberculosis

Background The high mobility group box 1 (HMGB1) is the prototype of alarmin protein released by stressed or dying cells. The redox state of this protein confers different functions in the regulation of inflammation and immune response. Aim Determine the kinetics, cellular sources and function of HMGB1 in experimental tuberculosis. Methods BALB/c mice were infected with Mycobacterium tuberculosis strain H37Rv. At different time points, HMGB1 was quantified in bronchial lavage fluid (BALF) and in lungs was determined its cellular sources by immunohistochemistry. HMGB1 was blocked with specific antibodies or recombinant HMGB1 was administered during early or late infection. Bacilli burdens, inflammation and cytokines expression were determined. Results The maximal concentration of HMGB1 in BALF was at day one of infection. Bronchial epithelium and macrophages were the most important sources. At day 7 to 21 the oxidized HMGB1 was predominant, while during late infection only the reduced form was seen. Blocking HMGB1 during early infection produced significant decrease of bacilli burdens and high production of pro-inflammatory cytokines, while the opposite was seen when HMGB1 was administered. Blocking HMGB1 activity or administrated it in high amounts during late infection worsening the disease. Conclusions HMGB1 is liberated during experimental tuberculosis and promotes or suppress the immune response and inflammation depending on the redox state.Fil: Bottasso, Oscar. Institute of Experimental and Clinic Immunology, Rosario, IDICER, CONICET, School of Medical Sciences. UNR. Rosario; ArgentinaFil: Bini, Estela Isabel. Institute of Experimental and Clinic Immunology, Rosario, IDICER, CONICET, School of Medical Sciences. UNR. Rosario; Argentin

The Therapeutic Effect of Intranasal Administration of Dexamethasone in Neuroinflammation Induced by Experimental Pulmonary Tuberculosis

Tuberculosis (TB) is an important infectious disease and a public health problem. The organs most frequently affected by TB are the lungs; despite this, it has been reported that TB patients suffer from depression and anxiety, which have been attributed to social factors. In previous experimental work, we observed that the extensive pulmonary inflammation characteristic of TB with high cytokine production induces neuroinflammation, neuronal death and behavioral abnormalities in the absence of brain infection. The objective of the present work was to reduce this neuroinflammation and avoid the psycho-affective disorders showed during pulmonary TB. Glucocorticoids (GCs) are the first-line treatment for neuroinflammation; however, their systemic administration generates various side effects, mostly aggravating pulmonary TB due to immunosuppression of cellular immunity. Intranasal administration is a route that allows drugs to be released directly in the brain through the olfactory nerve, reducing their doses and side effects. In the present work, dexamethasone’s (DEX) intranasal administration was evaluated in TB BALB /c mice comparing three different doses (0.05, 0.25 and 2.5 mg/kg BW) on lung disease evolution, neuroinflammation and behavioral alterations. Low doses of dexamethasone significantly decreased neuroinflammation, improving behavioral status without aggravating lung disease

In Vitro, In Vivo and In Silico Assessment of the Antimicrobial and Immunomodulatory Effects of a Water Buffalo Cathelicidin (WBCATH) in Experimental Pulmonary Tuberculosis

Tuberculosis (TB) is considered the oldest pandemic in human history. The emergence of multidrug-resistant (MDR) strains is currently considered a serious global health problem. As components of the innate immune response, antimicrobial peptides (AMPs) such as cathelicidins have been proposed to have efficacious antimicrobial activity against Mycobacterium tuberculosis (Mtb). In this work, we assessed a cathelicidin from water buffalo, Bubalus bubalis, (WBCATH), determining in vitro its antitubercular activity (MIC), cytotoxicity and the peptide effect on bacillary loads and cytokines production in infected alveolar macrophages. Our results showed that WBCATH has microbicidal activity against drug-sensitive and MDR Mtb, induces structural mycobacterial damage demonstrated by electron microscopy, improves Mtb killing and induces the production of protective cytokines by murine macrophages. Furthermore, in vivo WBCATH showed decreased bacterial loads in a model of progressive pulmonary TB in BALB/c mice infected with drug-sensitive or MDR mycobacteria. In addition, a synergistic therapeutic effect was observed when first-line antibiotics were administered with WBCATH. These results were supported by computational modeling of the potential effects of WBCATH on the cellular membrane of Mtb. Thus, this water buffalo-derived cathelicidin could be a promising adjuvant therapy for current anti-TB drugs by enhancing a protective immune response and potentially reducing antibiotic treatment duration

Identificación y selección de árboles plus de Primavera (Roseodendron donell-smithii Miranda syn Tabebuia donell-smithii Rose) y Roble (Tabebeuia rosea Bertol) en el Soconusco, Chiapas, México.

Objective: Identify and select primavera plus trees (Roseodendron donell-smithiiMiranda syn Tabebuia donell-smithii Rose) and roble (Tabebeuia rosea Bertol) inSoconusco, Chiapas, Mexico.Design/methodology/approach: Methods were applied to qualify morphometricmarkers such as height, normal diameter, total height and free stem height as mainindicators. With selection intensities to identify future genetic gains, 155 candidate treesand 18 plus trees from Tabebuia donnell-smithii and 140 candidate trees and 16 plustrees from T. rosea were identified.Results: The 34 plus trees showed superior characteristics in quality and volume, sothey were grouped in List A, which is the population that is recommended for immediateuse as Forest Germplasm Producing Units of known origin and provenance. Thesetrees are part of the base population for the improvement program in the Soconusco region (Chiapas, Mexico). The 295 candidate trees maintain at least one superiorcharacter (volume or quality) can be considered in the improvement population, beinglocated in List B.Limitations on study/implications: This work allows defining the commercialpopulation for immediate use and the base population for improvement. Candidateindividuals with potential to be incorporated into future controlled crossing programswere also identified. The procedure allows generating records of the population massand accreditation of the plus tree phenotype.Findings/conclusions: This work allows defining the commercial population forimmediate use and the base population for improvement. Candidate individuals withpotential to be incorporated into future controlled crossing programs were alsoidentified. The procedure allows generating records of the population mass andaccreditation of the plus tree phenotype.Objetivo: Identificar y seleccionar árboles plus de Primavera (Roseodendron donell-smithii Miranda syn Tabebuia donell-smithii Rose) y Roble (Tabebeuia rosea Bertol) en el Soconusco, Chiapas, México.Diseño/metodología/aproximación: Se aplicaron métodos para calificar marcadores morfométricos como altura, diámetro normal, altura total y altura de fuste libre como indicadores principales. Con intensidades de selección para identificar ganancias genéticas futuras, se lograron identificar 155 árboles candidatos y 18 árboles plus de Tabebuia donnell-smithii y 140 árboles candidatos y 16 árboles plus de T. rosea.Resultados: Los 34 árboles plus mostraron características superiores en calidad y volumen, por lo que fueron agrupados en una Lista A que es la población que se recomienda para uso inmediato como Unidades Productoras de Germoplasma Forestal con origen y procedencia conocidos. Estos árboles forman parte de la población base para el programa de mejoramiento en la región Soconusco (Chiapas, México). Los 295 árboles candidatos mantienen al menos un caracter superior (volumen o calidad)pueden ser considerados en la población de mejora ubicándose en una Lista B.Hallazgos/conclusiones: Este trabajo permite definir la población comercial de uso inmediato y la población base de mejoramiento. También se identificaron individuos candidatos con potencial para ser incorporados a los programas de cruzas controladas en un futuro. El procedimiento permite generar registros de la masa poblacional y acreditación del fenotipo del árbol plus