Tumour growth inhibitory effect of Ibervillea sonorae phytopreparations in cervical cancer xenografts.

Cucurbitacin IIb, a triterpene obtained from the Ibervillea sonorae plant, reduces tumour development in a preclinical model of cervical cancer. Acetison and Etanison, phytopreparations made from I. sonorae, present biological activity analogous to CIIb in HeLa. This research evaluated the tumour growth inhibitory effect of these phytopreparations in a HeLa xenograft tumour model in BALB/c nude mice. Tumours in mice were treated every 3 days for 12 days with cisplatin (2 mg/kg), CIIb (5 mg/kg), Acetison (20 mg/kg), Etanison (30 mg/kg), and DMSO at 2%. For histological observations, tumours were stained with H&E. Fingerprinting of both phytopreparations was performed using HPLC-UV and UHPLC-APCI-IT-MS. Both phytopreparations and CIIb inhibit tumour development as well as Cisplatin (75.5%); Etanison (77.7%), Acetison (73.6%), and CIIb (73.0%). Furthermore, only tumours treated with cisplatin showed invasion of bone tissue. The results show the potential use of I. sonorae phytopreparations in the treatment of cervical cancer.

Binding of green tea epigallocatechin gallate to the arginine kinase active site from the brown recluse spider (Loxosceles laeta): A potential synergist to chemical pesticides.

Loxosceles spp. spiders can cause serious public health issues. Chemical control is commonly used, leading to health and environmental problems. Identifying molecular targets and using them with natural compounds can help develop safer and eco-friendlier biopesticides. We studied the kinetics and predicted structural characteristics of arginine kinase (EC 2.7.3.3) from Loxosceles laeta (LlAK), a key enzyme in the energy metabolism of these organisms. Additionally, we explored (-)-epigallocatechin gallate (EGCG), a green tea flavonoid, as a potential lead compound for the LlAK active site through fluorescence and in silico analysis, such as molecular docking and molecular dynamics (MD) simulation and MM/PBSA analyses. The results indicate that LlAK is a highly efficient enzyme (K m Arg 0.14 mM, K m ATP 0.98 mM, k cat 93 s-1, k cat/K m Arg 630 s-1 mM-1, k cat/K m ATP 94 s-1 mM-1), which correlates with its structure similarity to others AKs (such as Litopenaeus vannamei, Polybetes pythagoricus, and Rhipicephalus sanguineus) and might be related to its important function in the spider's energetic metabolism. Furthermore, the MD and MM/PBSA analysis suggests that EGCG interacted with LlAK, specifically at ATP/ADP binding site (RMSD <1 nm) and its interaction is energetically favored for its binding stability (-40 to -15 kcal/mol). Moreover, these results are supported by fluorescence quenching analysis (K d 58.3 µM and K a 1.71 × 104 M-1). In this context, LlAK is a promising target for the chemical control of L. laeta, and EGCG could be used in combination with conventional pesticides to manage the population of Loxosceles species in urban areas.

Antimicrobial and Antibiofilm Potential of Flourensia retinophylla against Staphylococcus aureus.

Staphylococcus aureus is a Gram-positive bacteria with the greatest impact in the clinical area, due to the high rate of infections and deaths reaching every year. A previous scenario is associated with the bacteria's ability to develop resistance against conventional antibiotic therapies as well as biofilm formation. The above situation exhibits the necessity to reach new effective strategies against this pathogen. Flourensia retinophylla is a medicinal plant commonly used for bacterial infections treatments and has demonstrated antimicrobial effect, although its effect against S. aureus and bacterial biofilms has not been investigated. The purpose of this work was to analyze the antimicrobial and antibiofilm potential of F. retinophylla against S. aureus. The antimicrobial effect was determined using an ethanolic extract of F. retinophylla. The surface charge of the bacterial membrane, the K+ leakage and the effect on motility were determined. The ability to prevent and remove bacterial biofilms was analyzed in terms of bacterial biomass, metabolic activity and viability. The results showed that F. retinophylla presents inhibitory (MIC: 250 µg/mL) and bactericidal (MBC: 500 µg/mL) activity against S. aureus. The MIC extract increased the bacterial surface charge by 1.4 times and the K+ concentration in the extracellular medium by 60%. The MIC extract inhibited the motility process by 100%, 61% and 40% after 24, 48 and 72 h, respectively. The MIC extract prevented the formation of biofilms by more than 80% in terms of biomass production and metabolic activity. An extract at 10 × MIC reduced the metabolic activity by 82% and the viability by ≈50% in preformed biofilms. The results suggest that F. retinophylla affects S. areus membrane and the process of biofilm formation and removal. This effect could set a precedent to use this plant as alternative for antimicrobial and disinfectant therapies to control infections caused by this pathogen. In addition, this shrub could be considered for carrying out a purification process in order to identify the compounds responsible for the antimicrobial and antibiofilm effect.

Biological Activity of Ganoderma Species (Agaricomycetes) from Sonoran Desert, Mexico.

Ganoderma species have been used in folk medicine against different illnesses and are characterized by producing a diversity of bioactive metabolites (triterpenoids, polysaccharides, flavonoids, and phenols) with numerous medicinal effects (anti-proliferative, antioxidant, anti-inflammatory, and antibacterial). This work aims to evaluate ethanolic extracts of fruiting bodies of Ganoderma oerstedii, G. weberianum, and G. subincrustatum strains from the Sonoran Desert in the anti-proliferative activity by the MTT assay on cancer cell lines; anti-inflammatory effect by quantifying nitric oxide (NO) production; antioxidant activity by DPPH, ABTS, and FRAP assays; total phenolic and flavonoid content by Folin-Ciocalteu and AlCl3 method, respectively; antibacterial activity by the broth microdilution method against Escherichia coli and Staphylococcus aureus. Extracts showed anti-proliferative activity with IC50 < 100 µg/mL on the cancer cell lines MDA-MB-231, A549, and HeLa, except G. subincrustatum extract with an IC50 > 100 µg/mL; anti-proliferative activity was not selective, being affected non-cancerous cell line ARPE-19. Extracts showed significant inhibition of NO release in cells stimulated by LPS, up to 60% with G. subincrustatum and G. oerstedii, and 47% with G. weberianum. All tested assays showed moderate antioxidant potential; the most active was G. lucium (control strain) with IC50 of 69 and 30 µg/mL by DPPH and ABTS respectively; and 271 µg Trolox equivalents/g by FRAP. Total phenols and flavonoids ranged from 38 to 56 mg GAE/g and 0.53 to 0.93 mg QE/g, respectively. A significant correlation was found between the antioxidant activities revealed by DPPH, ABTS, and FRAP with total phenol and flavonoid contents. Antibacterial activity was weak against S. aureus (MIC50 > 10 mg/mL). These results demonstrate that tested Ganoderma mushrooms have medicinal potential such as anti-inflammatory and anti-proliferative.

Inhibition of the CYP Enzymatic System Responsible of Heterocyclic Amines Bioactivation by an Asclepias subulata Extract.

Asclepias subulata plant extract has previously demonstrated antiproliferative activity and antimutagenicity against heterocyclic aromatic amines (HAAs) commonly found in cooked meat. The objective of this work was to evaluate the in vitro ability of an ethanolic extract from the medicinal plant Asclepias subulata extract (ASE), non-heated and heated (180 °C), to inhibit the activity of CYP1A1 and CYP1A2, which are largely responsible for HAAs bioactivation. Ethoxyresorufin and methoxyresorufin O-dealkylation assays were performed in rat liver microsomes exposed to ASE (0.002-960 µg/mL). ASE exerted an inhibitory effect in a dose-dependent manner. The half inhibitory concentration (IC50) for unheated ASE was 353.6 µg/mL and 75.9 µg/mL for heated ASE in EROD assay. An IC40 value of 288.4 ± 5.8 µg/mL was calculated for non-heated ASE in MROD assay. However, after heat treatment, the IC50 value was 232.1 ± 7.4 µg/mL. Molecular docking of corotoxigenin-3-O-glucopyranoside, one of the main components of ASE, with CYP1A1/2 structure, was performed. Results show that the interaction of corotoxigenin-3-O-glucopyranoside with CYP1A1/2s' α-helices, which are related with the active site and the heme cofactor, may explain the plant extract's inhibitory properties. Results showed that ASE inhibits CYP1A enzymatic subfamily and may potentially act as a chemopreventive agent by inhibiting bioactivation of promutagenic dietary HAAs.

Association of Different ABO and Rh Blood Groups with the Erythroprotective Effect of Extracts from Navicula incerta and Their Anti-Inflammatory and Antiproliferative Properties.

Previous studies have reported that different blood groups are associated with the risk of chronic degenerative diseases that mainly involve inflammation and neoplastic processes. We investigate the relationship between blood groups and the erythroprotective effect of extracts from Navicula incerta against oxidative damage as a proposal to develop drugs designed for people with a specific blood type related to chronic pathology. The study was carried out through the elucidation of the erythroprotective potential, anti-inflammatory and antiproliferative activity of Navicula incerta. Research suggests that the presence or absence of certain blood groups increases or decreases the abilities of certain phytochemicals to inhibit oxidative stress, which is related to the systemic inflammatory response involved in the development of different types of cancer. The pigment-rich extracts from Navicula incerta inhibit ROO•- induced oxidative stress in human erythrocytes on the A RhD+ve antigen without compromising the structure of the cell membrane. This result is very important, since the A antigen is related to the susceptibility of contracting prostate cancer. Similarly, it was possible to inhibit the proliferation of cervical (HeLa) and prostate (PC-3) carcinoma. The combinatorial analysis of different biological activities can help design phytochemicals as new candidates for preventive drugs treating the chronic degenerative diseases associated with a specific blood group.

Casiopeinas® third generation, with indomethacin: synthesis, characterization, DFT studies, antiproliferative activity, and nanoencapsulation.

Seven new Casiopeinas® were synthesized and properly characterized. These novel compounds have a general formula [Cu(N-N)(Indo)]NO3, where Indo is deprotonated indomethacin and N-N is either bipyridine or phenanthroline with some methyl-substituted derivatives, belonging to the third generation of Casiopeinas®. Spectroscopic characterization suggests a square-based pyramid geometry and voltammetry experiments indicate that the redox potential is strongly dependent on the N-N ligand. All the presented compounds show high cytotoxic efficiency, and most of them exhibit higher efficacy compared to the well-known cisplatin drug and acetylacetonate analogs of the first generation. Computational calculations show that antiproliferative behavior can be directly related to the volume of the molecules. Besides, a chitosan (CS)-polyacrylamide (PNIPAAm) nanogel was synthesized and characterized to examine the encapsulation and release properties of the [Cu(4,7-dimethyl-1,10-phenanthroline)(Indo)]NO3 compound. The results show good encapsulation performance in acidic conditions and a higher kinetic drug release in acidic media than at neutral pH. This result can be described by the Peppas-Sahlin model and indicates a release mechanism predominantly by Fick diffusion.

Standardized phytopreparations and cucurbitacin IIb from Ibervillea sonorae (S. Watson) greene induce apoptosis in cervical cancer cells by Nrf2 inhibition.

ETHNOPHARMACOLOGY RELEVANCE: Ibervillea sonorae (S. Watson) Greene is a plant from northwestern Mexico, known as "Wereke" or "Guareque", used by the Mayo ethnic group to treat diabetes and cancer. Cucurbitacin IIb (CIIb), isolated from I. sonorae has apoptotic and antitumor activity in a model of cervical cancer with the HeLa cell line. One pathway affected by cucurbitacins is Nrf2, a glutathione transferase (GST) transcription factor, important in the regulation of mitochondrial oxidative stress (MOS). A signal of MOS is the change in the mitochondrial membrane potential (ΔΨm), which has been detected in HeLa in the presence of CIIb. Fito-Ison-EtOH (Etanison) and Fito-Ison-EtOAc (Acetison) are phytopreparations from I. sonorae standardized according to their CIIb content (6.7 mg/g and 18.4 mg/g of CIIb, respectively). Etanison and Acetison have been reported to induce morphological changes in HeLa like those induced by CIIb. AIM OF THE STUDY: To evaluate the apoptotic and Nrf2 inhibition activity of the phytopreparations Acetison and Etanison from Ibervillea Sonorae in the HeLa cervical cancer cell line. MATERIALS AND METHODS: Antiproliferative activity was evaluated by the MTT method at 24, 48, and 72 h. For Acetison and Etanison, serial concentrations from 6.25 µg/mL to 100 µg/mL were tested, and for CIIb from 1.56 µg/mL to 50 µg/mL. The expression of Nrf2, caspase 3, and caspase 9 was evaluated by western blot, using concentrations of 30 µg/mL for Acetison, 50 µg/mL for Etanison, and 15 µg/mL for CIIb. Cisplatin was used as a positive control. RESULTS AND CONCLUSIONS: Apoptotic activity of Etanison and Acetison was demonstrated in HeLa, due to the presence of caspase-9 and caspase-3 in western blot assays. Likewise, both the phytopreparations and CIIb showed inhibition of Nrf2, associating apoptotic activity with the inhibition of the GST transcription factor. In this sense, the phytopreparations of I. sonorae, as well as their derivatives, have the potential to obtain and develop anticancer products.

Efficacy of chitosan in the treatment of chronic skin lesions in a horse: A case report.

Consultation was requested for a 7-year-old Gypsy Vanner male horse with a 2-year history of foreskin injury. Upon revision, an ulcer, 153 cm2 in size, with yellowish granules was observed; a RESVECH 2.0 evaluation revealed a score of 32/35 points. Medical history confirmed multiple failed deworming, anti-inflammatory, and antibiotic treatments with different topical therapies and recurrence in summer. Laboratory results confirmed elevated total proteins (8.8 g/dL) and globulins (5.5 g/dL), negative bacterial and fungal cultures, as well as negative coproparasitoscopic findings, and finally, identification of stable fly larvae (Stomoxys calcitrans) in the feces. Microscopy showed disorganized collagen, thickened tissue, polymorphonuclear cells, and acanthosis without neoplastic tissue or parasite remains. Debridement was performed and systemic treatment with ivermectin, penicillin, and non-steroidal anti-inflammatory drugs (NSAIDs) continued. In addition, 2% chitosan gel and films were applied to the entire surface of the lesion for 72 hours on 30 occasions; vector control with nets and insecticides was performed. On day 94, there was a 6 cm2 surface with involvement of the dermal and epidermal layers, moist epithelial tissue, and diffuse edges, with a RESVECH 2.0 evaluation of 6/35 points. Microscopy showed an intact basement membrane, presence of hair follicles, sweat glands, aligned collagen, and angiogenesis. It was concluded that chronic skin lesions in horses represent a diagnostic challenge, and topical chitosan is an adequate treatment due to its biocompatibility and efficacy, in addition to the functional and cosmetic results in dermal regeneration.

Calotropin and corotoxigenin 3-O-glucopyranoside from the desert milkweed Asclepias subulata inhibit the Na+/K+-ATPase activity.

Na+/K+-ATPase is an essential transmembrane enzyme found in all mammalian cells with critical functions for cell ion homeostasis. The inhibition of this enzyme by several cardiotonic steroids (CTS) has been associated with the cytotoxic effect on cancer cell lines of phytochemicals such as ouabain and digitoxin. This study evaluated the inhibitory capacity of cardenolides calotropin and corotoxigenin 3-O-glucopyranoside (C3OG) from Asclepias subulata over the Na+/K+-ATPase activity in vitro and silico. The inhibitory assays showed that calotropin and C3OG decreased the Na+/K+-ATPase activity with IC50 values of 0.27 and 0.87 µM, respectively. Furthermore, the molecules presented an uncompetitive inhibition on Na+/K+-ATPase activity, with Ki values of 0.2 µM to calotropin and 0.5 µM to C3OG. Furthermore, the molecular modeling indicated that calotropin and C3OG might interact with the Thr797 and Gln111 residues, considered essential to the interaction with the Na+/K+-ATPase. Besides, these cardenolides can interact with amino acid residues such as Phe783, Leu125, and Ala323, to establish hydrophobic interactions on the binding site. Considering the results, these provide novel evidence about the mechanism of action of cardenolides from A. subulata, proposing that C3OG is a novel cardenolide that deserves further consideration for in vitro cellular antiproliferative assays and in vivo studies as an anticancer molecule.

Synergistic Interactions between Tocol and Phenolic Extracts from Different Tree Nut Species against Human Cancer Cell Lines.

Tree nuts are rich in polar (phenolic compounds) and non-polar (tocols) antioxidants, with recognized effects in the prevention of diseases such as cancer. These biomolecules possess antiproliferative activity on cancer cells; however, the combined effect of both types of compounds has been scarcely studied, and this approach could give valuable information on the real anticancer potential of tree nuts. In the present study, the antiproliferative activity of pure tocols and phenolic compounds, tocol- and phenolic-rich extracts (TRE and PRE, respectively) from tree nuts and the extracts combinations, was evaluated in four cancer (HeLa, MCF7, PC3, A549) and one control (ARPE) cell lines. The most sensible cell lines were HeLa and MCF7. TRE and PRE from nuts were chemically characterized; γ and δ tocopherols, total tocols, total tocopherols and total phenolic compounds were negatively correlated with cell viability in MCF7 cells. In HeLa cells, only δ and total tocopherols were negatively correlated with cell viability. TRE and PRE had a low effect in reducing cell viability of the cancer cell lines, the most effective extracts were those of emory oak acorn (EOA), pecan nut (PEC) and walnut (WAL), and these were further studied for their pharmacological interactions, using the combination index and the isobologram methods. Combinations of both extracts showed a synergistic and strongly synergistic behavior in the three nuts (EOA, PEC and WAL), with combination indexes between 0.12 and 0.55. These results highlight the need to understand the interactions among components found in complex natural extracts or food products in order to fully understand their bioactivities.

Dogs Detecting COVID-19 From Sweat and Saliva of Positive People: A Field Experience in Mexico.

Context: Molecular tests are useful in detecting COVID-19, but they are expensive in developing countries. COVID-19-sniffing dogs are an alternative due to their reported sensitivity (>80%) and specificity (>90%). However, most of the published evidence is experimental, and there is a need to determine the performance of the dogs in field conditions. Hence, we aimed to test the sensitivity and specificity of COVID-19-sniffing dogs in the field. Methods: We trained four dogs with sweat and three dogs with saliva of COVID-19-positive patients, respectively, for 4.5 months. The samples were obtained from a health center in Hermosillo, Sonora, with the restriction to spend 5 min per patient. We calculated sensitivity, specificity, and their 95% confidence intervals (CI). Results: Two sweat-sniffing dogs reached 76 and 80% sensitivity, with the 95% CI not overlapping the random value of 50%, and 75 and 88% specificity, with the 95% CI not overlapping the 50% value. The 95% CI of the sensitivity and specificity of the other two sweat dogs overlapped the 50% value. Two saliva-sniffing dogs had 70 and 78% sensitivity, and the 95% CI of their sensitivity and specificity did not overlap the 50% value. The 95% CI of the third dog's sensitivity and specificity overlapped the 50% value. Conclusion: Four of the six dogs were able to detect positive samples of patients with COVID-19, with sensitivity and specificity values significantly different from random in the field. We considered the performance of the dogs promising because it is reasonable to expect that with gauze exposed for a longer time to sweat and saliva of people with COVID-19, their detection capacity would improve. The target is to reach the sensitivity range requested by the World Health Organization for the performance of an antigen test (≥80% sensitivity, ≥97% specificity). If so, dogs could become important allies for the control of the COVID-19 pandemic, especially in developing countries.

Antiproliferative activity of standardized herbal phytopreparation from Asclepias subulata.

Background: Several studies have shown that active compounds of Asclepias subulata (cardenolides) have antiproliferative effect on human cancer cells. Cardenolides isolated from A. subulata can be used as active chemical markers to elaborate phytopharmaceutical preparations. To evaluate the antiproliferative effect of a standardized extract of the aerial parts, based on Asclepias subulata cardenolides. Methods: Four standardized extracts were prepared by HPLC-DAD depending on the concentration of calotropin and the antiproliferative activity was measured for the MTT assay, on the A549, MCF-7, HeLa, PC3 and ARPE cell lines. The concentrations of calotropin used for the standardization of the extracts were 10, 7.6, 5 and 1 mg/dL. Results: Standardization of the A. subulata extract based on calotropin at 7.6 mg/g dry weight was achieved and the antiproliferative activity was evaluated over A549, HeLa and MCF-7 cell lines, obtaining proliferation percentages of 3.8 to 13.4% . Conclusions: The standardized extracts of A. subulata at different concentrations of calotropin showed antiproliferative activity against all the cell lines evaluated. The greatest effect was observed against the HeLa cell line.

"Immunoinformatic Identification of T-Cell and B-Cell Epitopes From Giardia lamblia Immunogenic Proteins as Candidates to Develop Peptide-Based Vaccines Against Giardiasis".

Giardiasis is one of the most common gastrointestinal infections worldwide, mainly in developing countries. The etiological agent is the Giardia lamblia parasite. Giardiasis mainly affects children and immunocompromised people, causing symptoms such as diarrhea, dehydration, abdominal cramps, nausea, and malnutrition. In order to develop an effective vaccine against giardiasis, it is necessary to understand the host-Giardia interactions, the immunological mechanisms involved in protection against infection, and to characterize the parasite antigens that activate the host immune system. In this study, we identify and characterize potential T-cell and B-cell epitopes of Giardia immunogenic proteins by immunoinformatic approaches, and we discuss the potential role of those epitopes to stimulate the host´s immune system. We selected the main immunogenic and protective proteins of Giardia experimentally investigated. We predicted T-cell and B-cell epitopes using immunoinformatic tools (NetMHCII and BCPREDS). Variable surface proteins (VSPs), structural (giardins), metabolic, and cyst wall proteins were identified as the more relevant immunogens of G. lamblia. We described the protein sequences with the highest affinity to bind MHC class II molecules from mouse (I-Ak and I-Ad) and human (DRB1*03:01 and DRB1*13:01) alleles, as well as we selected promiscuous epitopes, which bind to the most common range of MHC class II molecules in human population. In addition, we identified the presence of conserved epitopes within the main protein families (giardins, VSP, CWP) of Giardia. To our knowledge, this is the first in silico study that analyze immunogenic proteins of G. lamblia by combining bioinformatics strategies to identify potential T-cell and B-cell epitopes, which can be potential candidates in the development of peptide-based vaccines. The bioinformatics analysis demonstrated in this study provides a deeper understanding of the Giardia immunogens that bind to critical molecules of the host immune system, such as MHC class II and antibodies, as well as strategies to rational design of peptide-based vaccine against giardiasis.

Use of nanosystems to improve the anticancer effects of curcumin.

Curcumin (CUR) is a phenolic compound that is safe for human consumption. It exhibits chemopreventive, antiproliferative, antiangiogenic, and antimetastatic effects. However, these benefits can be hampered due to the lipophilic nature, rapid metabolism, low bioavailability, and fast elimination of the molecule. Considering this, the present work reviews the use of CUR-based nanosystems as anticancer agents, including conventional nanosystems (i.e., liposomes, nanoemulsions, nanocrystals, nanosuspensions, polymeric nanoparticles) and nanosystems that respond to external stimuli (i.e., magnetic nanoparticles and photodynamic therapy). Previous studies showed that the effects of CUR were improved when loaded into nanosystems as compared to the free compound, as well as synergist effects when it is co-administrated alongside with other molecules. In order to maximize the beneficial health effects of CUR, critical factors need to be strictly controlled, such as particle size, morphology, and interaction between the encapsulating material and CUR. In addition, there is an area of study to be explored in the development of CUR-based smart materials for nanomedical applications. Imaging-guided drug delivery of CUR-based nanosystems may also directly target specific cells, thereby increasing the therapeutic and chemopreventive efficacy of this versatile compound.

A Novel Glutathione S-Transferase Gtt2 Class (VpGSTT2) Is Found in the Genome of the AHPND/EMS Vibrio parahaemolyticus Shrimp Pathogen.

Glutathione S-transferases are a family of detoxifying enzymes that catalyze the conjugation of reduced glutathione (GSH) with different xenobiotic compounds using either Ser, Tyr, or Cys as a primary catalytic residue. We identified a novel GST in the genome of the shrimp pathogen V. parahaemolyticus FIM- S1708+, a bacterial strain associated with Acute Hepatopancreatic Necrosis Disease (AHPND)/Early Mortality Syndrome (EMS) in cultured shrimp. This new GST class was named Gtt2. It has an atypical catalytic mechanism in which a water molecule instead of Ser, Tyr, or Cys activates the sulfhydryl group of GSH. The biochemical properties of Gtt2 from Vibrio parahaemolyticus (VpGSTT2) were characterized using kinetic and crystallographic methods. Recombinant VpGSTT2 was enzymatically active using GSH and CDNB as substrates, with a specific activity of 5.7 units/mg. Low affinity for substrates was demonstrated using both Michaelis-Menten kinetics and isothermal titration calorimetry. The crystal structure showed a canonical two-domain structure comprising a glutathione binding G-domain and a hydrophobic ligand H domain. A water molecule was hydrogen-bonded to residues Thr9 and Ser 11, as reported for the yeast Gtt2, suggesting a primary role in the reaction. Molecular docking showed that GSH could bind at the G-site in the vicinity of Ser11. G-site mutationsT9A and S11A were analyzed. S11A retained 30% activity, while T9A/S11A showed no detectable activity. VpGSTT2 was the first bacterial Gtt2 characterized, in which residues Ser11 and Thr9 coordinated a water molecule as part of a catalytic mechanism that was characteristic of yeast GTT2. The GTT2 family has been shown to provide protection against metal toxicity; in some cases, excess heavy metals appear in shrimp ponds presenting AHPND/EMS. Further studies may address whether GTT2 in V. parahaemolyticus pathogenic strains may provide a competitive advantage as a novel detoxification mechanism.

The Dichloromethane Fraction of Croton sonorae, A Plant Used in Sonoran Traditional Medicine, Affect Entamoeba histolytica Erythrophagocytosis and Gene Expression.

Intestinal parasites are a global problem, mainly in developing countries. Obtaining information about plants and compounds that can combat gastrointestinal disorders and gastrointestinal symptoms is a fundamental first step in designing new treatment strategies. In this study, we analyzed the antiamoebic activity of the aerial part of Croton sonorae. The dichloromethane fraction of C. sonorae (CsDCMfx) contained flavonoids, terpenes, alkaloids, and glycosides. The ultrastructural morphology of the amoebae treated for 72 h with CsDCMfx was completely abnormal. CsDCMfx reduced erythrophagocytosis of trophozoites and the expression of genes involved in erythrocyte adhesion (gal/galnac lectin) and actin cytoskeleton rearrangement in the phagocytosis pathway (rho1 gtpase and formin1). Interestingly, CsDCMfx decreased the expression of genes involved in Entamoeba histolytica trophozoite pathogenesis, such as cysteine proteases (cp1, cp4, and cp5), sod, pfor, and enolase. These results showed that C. sonorae is a potential source of antiamoebic compounds.

Therapeutic effects of chitosan in veterinary dermatology: A systematic review of the literature.

Chitosan is a natural polysaccharide with biocompatibility, biodegradability, nontoxicity, antimicrobial, and hemostatic properties. This biopolymer has been used in different pharmaceutical forms; therefore, it has an attractive potential for dermal applications in veterinary medicine. The aim of this review is to assess the healing potential of chitosan, based on its dermatological effects on animals, to enrich the therapeutic options of veterinary clinicians. A systematic review was conducted based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) strategy, retrieving 1,032 studies and selecting 39 after the inclusion and exclusion criteria were applied. The studies included reports with confirmed positive effects (n = 46/99, 46.5 %) (P < 0.05), with positive effects (n = 49.5/99, 49.5 %), and with no effect (n = 4/99, 4 %); none of the studies reported adverse effects. There is an association between frequency of application and a decrease in healing time (P = 0.038); applying chitosan "every 48-72 hours" was the most recommended frequency (n = 10/19, 52.9 %). Chitosan, when applied to skin lesions on animals, produces positive effects on healing, potentially becoming a safe biomaterial for skin treatments in veterinary practice. As an initial protocol, we suggest applying chitosan every 48-72 hours for at least 2 weeks (7 applications).

Antiproliferative activity of standardized phytopreparations from Ibervillea sonorae (S. Watson) Greene.

Ibervillea sonorae (Cucurbitaceae) is a medicinal plant utilized in Northwest Mexico against Diabetes and cancer. This natural product is taken orally, its presentation is capsules containing the plant's dried and powdered caudices. There is no regulation or standardized dosage that allows reproducibility of its pharmacological effects. Cucurbitacins are the main group of compounds found in I. sonorae and are known for their antiproliferative activity in cancer cells. Cucurbitacin IIb (CIIb), one of the compounds present in I. sonorae, has demonstrated in experimental models with HeLa cervical cancer cells an apoptotic and anti-tumoral activity. The objective of this study is to obtain and standardize two phytopreparations of I. sonorae based on their CIIb content, evaluate their antiproliferative activity in cancer cell lines, and compare the results with those obtained with CIIb; expecting to find phytopreparations with anti-cancer potential. APCI-IT-MSn is utilized for the identification of cucurbitacins, FT-ICR-MS/MS for the quantification of CIIb, and the MTT assay for the evaluation of the antiproliferative activity. The CIIb content was 0.67% for Fito-Ison-EtOH and 1.84% for Fito-Ison-EtOAc. In both phytopreparations, six cucurbitacins have been identified, and a seventh one not previously identified. Phytopreparations were more effective against HeLa, with IC50 of 30.0 and 18.6 µg/mL for Fito-Ison-EtOH and Fito-Ison-EtOAc, respectively. This effect is lower than observed on CIIb in HeLa (5.8 µg/mL). There are no significant differences (p > 0.05) in the antiproliferative activity between Fito-Ison-EtOAc and CIIb in A549, LS180, and MDA-MB-231 cells. Phytopreparations of I. sonorae have potential for the development of anti-cancer products.

Optimization of growing conditions for pigments production from microalga Navicula incerta using response surface methodology and its antioxidant capacity.

Navicula incerta is a marine microalga distributed in Baja California, México, commonly used in aquaculture nutrition, and has been extended to human food, biomedical, and pharmaceutical industries due to its high biological activity. Therefore, the study aimed to optimize culture conditions to produce antioxidant pigments. A central composite experimental design and response surface methodology (RSM) was employed to analyze the best culture conditions. The medium (nitrogen-deficient concentrations), salinity (PSU = Practical Salinity Unity [g/kg]), age of culture (days), and solvent extraction (ethanol, methanol, and acetone) were the factors used for the experiment. Chlorophyll a (Chl a) and total carotenoids (T-Car), determined spectroscopically, were used as the response variables. The antioxidant capacity was evaluated by DPPH• and ABTS•+ radical inhibition, FRAP, and anti-hemolytic activity. According to the overlay plots, the optimum growth conditions for Chl a and T-Car production were the following conditions: medium = 0.44 mol·L-1 of NaNO3, salinity = 40 PSU, age of culture: 3.5 days, and solvent = methanol. The pigment extracts obtained in these optimized conditions had high antioxidant activity in ABTS•+ (86.2-92.1% of inhibition) and anti-hemolytic activity (81.8-96.7% of hemolysis inhibition). Low inhibition (33-35%) was observed in DPPH•. The highest value of FRAP (766.03 ± 16.62 µmol TE/g) was observed in the acetonic extract. The results demonstrated that RSM could obtain an extract with high antioxidant capacity with potential applications in the biomedical and pharmaceutical industry, which encourages the use of natural resources for chemoprevention of chronic-degenerative pathologies.