Incidence of the nordihydroguaiaretic acid content on the in vitro antiviral activity of extracts obtained from larrea divaricata cav. (Zygophyllaceae)

The South American species Larrea divaricata Cav. (Zygophyllaceae) has been widely used in folk medicine against infectious diseases. In previous studies, we reported that several extracts obtained from the aerial parts of this species and the nordihydroguaiaretic acid (NDGA), its main lignan, inhibited Junin Virus (JUNV) in vitro. In this work, the objective was to assess whether NDGA is truly responsible for the antiviral activity produced by the extracts. Therefore, the presence and amount of NDGA in extracts were determined by HPLC. We established that NDGA in the extracts analyzed is required to inhibit JUNV and observed that some components of the bioactive extracts would increase the antiviral effect of NDGA. On the other hand, we estimated the selectivity index for NDGA against JUNV. Thus, NDGA and extracts containing this lignan exhibited potential therapeutic effects against the etiologic agent of the Argentine Hemorrhagic Fever, an endemo-epidemic illness in this country.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Determination of non-toxic and subtoxic concentrations of potential antiviral natural anthraquinones

Anthraquinones-rich extracts of Heterophyllaea pustulata Hook f. (Rubiaceae) exhibited in vitro antiviral activity against Herpes Simplex Virus Type I, from which several anthraquinones (AQs) were isolated and identified. The Maximum Non-Cytotoxic Concentration (MNCC), the subtoxic concentration (SubTC), and the CC50 of each AQ were determined on a mammalian eukaryotic cell line (Vero cells) by means of Neutral Red uptake assay; the cytopathic effect was simultaneously evaluated by optical microscopy. The range of concentrations where each AQ did not exhibit cytotoxicity was established, which is limited by the MNCC: rubiadin 1-methyl ether, damnacanthol and pustuline were found to be markedly less cytotoxic. To the remaining AQs, we could estimate a SubTC (about 10 μg/mL) that assures 80 % cellular viability. Therefore, we determined a concentration range which could be used to evaluate the antiviral effect of each AQ since it ensures the viability of the host cell.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Spontaneous photosensitization by Heterophyllaea pustulata Hook. f. (Rubiaceae), in sheep from Northwestern Argentina

Heterophyllaea pustulata Hook. f. (Rubiaceae) is a phototoxic plant. It grows in the Andean area of northwest of Argentina, and it causes significant economic losses in the livestock. This plant induces dermal lesions by photosensitization probably due to its content of photosensitizing anthraquinones. This paper describes an outbreak of poisoning in Corriedale sheepfold, which had an incidence of 49%. Ear skin biopsies and blood samples were collected of six affected animals. Liver enzymes remained within the reference limits. Histopathologically, a deep necrotizing dermatitis was identified in all samples. H. pustulata was identified in the areas of grazing. Anthraquinone concentration in leaves was 0.84% p/p, expressed as rubiadin. All findings allow us to conclude that the diagnosis is a primary photosensitization. Huge regional economic losses could be attributed to H. pustulata poisoning, although its toxicity has been little studied.Facultad de Ciencias Veterinaria

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Partition coefficient (log P) determination of anthraquinone derivatives isolated from Heterophyllaea pustulata Hook. f. (Rubiaceae)

Las antraquinonas (AQs) aisladas de la especie fototóxica Heterophyllaea pustulata Hook. f. (Rubiáceas), soranjidiol, 1-metil éter de soranjidiol, rubiadina, 1-metil éter de rubiadina, damnacantal y damnacantol, son agentes fotosensibilizantes Tipo I y/o Tipo II. A su vez, presentan una potencial aplicación terapéutica debido a que extractos enriquecidos en las mismas y obtenidos a partir de hojas y tallos de H. pustulata, demostraron una importante actividad antibacteriana y antifúngica in vitro con baja toxicidad aguda in vivo. Con el fin de estimar la capacidad de estas AQs para ingresar y distribuirse en el organismo, atravesando membranas biológicas y así, poder desencadenar los efectos biológicos descriptos, se determinó el log P (expresión logarítmica de la lipofilicidad) de las mismas mediante el método de la ampolla. Con excepción de damnacantol, las AQs ensayadas presentaron un valor superior de log P en comparación a metoprolol. Además el valor promedio de log P para cada AQ fue comparable al valor obtenido mediante cálculos teóricos (CLogP).The anthraquinones isolated from the phototoxic species Hetero-phyllaea pustulata Hook. f. (Rubiáceas), soranjidiol, soranjidiol 1-methyl ether, rubiadin, rubiadin 1-methyl ether, damnacanthal and damnacanthol, are Type I and/or Type II photosensitizers. In addition, they show a potential therapeutic use according to results where extracts enriched in these metabolites and obtained from leaves and stems of H. pustulata demonstrated an important antibacterial and antifungal activity in vitro with a low acute toxicity in vivo. In order to estimate the capacity of these AQs to penetrate into the cells and their body distribution by going through biological membranes with the aim to unleash the described biological effects, we determinated the log P of each one by using the shake flash technique. Except for damnacanthol, all of the AQs tested showed a higher value of log P compared to metoprolol. In addition, the average value of log P for each AQ was similar to the theoretical value (CLogP).Colegio de Farmacéuticos de la Provincia de Buenos Aire

Partition coefficient (log P) determination of anthraquinone derivatives isolated from Heterophyllaea pustulata Hook. f. (Rubiaceae)

Las antraquinonas (AQs) aisladas de la especie fototóxica Heterophyllaea pustulata Hook. f. (Rubiáceas), soranjidiol, 1-metil éter de soranjidiol, rubiadina, 1-metil éter de rubiadina, damnacantal y damnacantol, son agentes fotosensibilizantes Tipo I y/o Tipo II. A su vez, presentan una potencial aplicación terapéutica debido a que extractos enriquecidos en las mismas y obtenidos a partir de hojas y tallos de H. pustulata, demostraron una importante actividad antibacteriana y antifúngica in vitro con baja toxicidad aguda in vivo. Con el fin de estimar la capacidad de estas AQs para ingresar y distribuirse en el organismo, atravesando membranas biológicas y así, poder desencadenar los efectos biológicos descriptos, se determinó el log P (expresión logarítmica de la lipofilicidad) de las mismas mediante el método de la ampolla. Con excepción de damnacantol, las AQs ensayadas presentaron un valor superior de log P en comparación a metoprolol. Además el valor promedio de log P para cada AQ fue comparable al valor obtenido mediante cálculos teóricos (CLogP).The anthraquinones isolated from the phototoxic species Hetero-phyllaea pustulata Hook. f. (Rubiáceas), soranjidiol, soranjidiol 1-methyl ether, rubiadin, rubiadin 1-methyl ether, damnacanthal and damnacanthol, are Type I and/or Type II photosensitizers. In addition, they show a potential therapeutic use according to results where extracts enriched in these metabolites and obtained from leaves and stems of H. pustulata demonstrated an important antibacterial and antifungal activity in vitro with a low acute toxicity in vivo. In order to estimate the capacity of these AQs to penetrate into the cells and their body distribution by going through biological membranes with the aim to unleash the described biological effects, we determinated the log P of each one by using the shake flash technique. Except for damnacanthol, all of the AQs tested showed a higher value of log P compared to metoprolol. In addition, the average value of log P for each AQ was similar to the theoretical value (CLogP).Colegio de Farmacéuticos de la Provincia de Buenos Aire

Enhanced photodynamic effect of a natural anthraquinone on Candida tropicalis biofilms using a stepwise irradiation strategy

Background: Antimicrobial Photodynamic Therapy (aPDT) has demonstrated effectiveness against various Candida biofilms, typical resistant to conventional treatments. Some strategies have shown to enhance the photoactivity of some photosensitizers (PS), such as the use of a multiple irradiation scheme or the combination with drugs that improve the penetration of the PS through the microbial membrane. Purpose: Having demonstrated the photodynamic antibiofilm activity of some natural anthraquinones (AQs), we selected rubiadin 1-methyl ether (R-1ME) that showed a low photo-reduction percentage (%R) on the biofilm mass, with the aim to improve its effect. Study Design: Experimental in vitro photo-stimulation protocols have been developed, which include successive light exposures and the combination of this AQ with a commonly used antifungal such as Amphotericin B (AmB). Methods: The biofilms reduction was quantified by Crystal Violet staining. Reactive oxygen and nitrosative species were observed as action mechanism, alongside an assessment of antioxidant response through superoxide dismutase enzyme activation and total antioxidant system capacity. Results: Applying R-1ME to C. tropicalis biofilms with sequential 15-min irradiation sessions at varied incubation intervals (0, 3, 6, 24, 27, and 30 h) yielded a substantial photo-reduction (62.9%R) on biofilm mass, even halving the bioactive concentration of R-1ME. Moreover, combining R-1ME with AmB under this irradiation pattern produced an even greater impact (82%R) at concentrations below the Minimal Inhibitory Concentration. Evident redox imbalances in the biofilm were linked to this photosensitized activity. Conclusions: A new strategy was found to improve the activity of a natural PS on fungal biofilms, by combining it with antifungal drugs, under a staged irradiation scheme, which, in turn, required low doses of the PS and the antifungal to achieve this improved photo-reduction

Photosensitization Induced by Heterophyllaea pustulata in Goats: Sequential Development of Skin Lesions

Five adult Saanen goats received a single oral dose of Heterophyllaea pustulata containing 42.25 μg/kg rubiadin (anthraquinone) and 3 adult goats were untreated controls. All goats were exposed to sunlight and sequential ear skin biopsies were collected before treatment and at 32 hours, 3 days, 8 days, and 15 days after treatment. Changes at 32 hours after dosing included epidermal spongiosis, single cell death and acantholysis, an increased BAX/BCL-2 protein ratio, and dermal edema. Lesions at day 3 included epidermal and adnexal necrosis, crust formation, and acanthosis. Acanthosis, hyperkeratosis, and dermal fibrosis and neovascularization were present at day 15. The pro-apoptotic (BAX)/anti-apoptotic (BCL-2) protein ratio increased at 32 hours, whereas epidermal and dermal PCNA immunolabeling increased between days 8 and 15 after treatment. The cutaneous lesions were consistent with sunlight-induced damage, and the occurrence in treated but not control goats indicates photosensitization.Estación Experimental Agropecuaria SaltaFil: Micheloud, Juan Francisco. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina. Universidad Católica de Salta, Argentina.Fil: Luján, Lluís. Universidad de Zaragoza; EspañaFil: Colque-Caro, Luis A. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Salta; Argentina. Universidad Católica de Salta, Argentina.Fil: Múñez-Montoya, Susana C. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Córdoba; Argentina.Fil: Barbeito, Claudio G. Universidad Nacional de La Plata; Argentina.Fil: Portiansky, Enrique L. Universidad Nacional de La Plata; Argentina.Fil: Gimeno, Eduardo J. Universidad Nacional de La Plata;Argentina