Copaifera langsdorffii Oleoresin-Loaded Nanostructured Lipid Carrier Emulgel Improves Cutaneous Healing by Anti-Inflammatory and Re-Epithelialization Mechanisms.

The skin is essential to the integrity of the organism. The disruption of this organ promotes a wound, and the organism starts the healing to reconstruct the skin. Copaifera langsdorffii is a tree used in folk medicine to treat skin affections, with antioxidant and anti-inflammatory properties. In our study, the oleoresin of the plant was associated with nanostructured lipid carriers, aiming to evaluate the healing potential of this formulation and compare the treatment with reference drugs used in wound healing. Male Wistar rats were used to perform the excision wound model, with the macroscopic analysis of wound retraction. Skin samples were used in histological, immunohistochemical, and biochemical analyses. The results showed the wound retraction in the oleoresin-treated group, mediated by α-smooth muscle actin (α-SMA). Biochemical assays revealed the anti-inflammatory mechanism of the oleoresin-treated group, increasing interleukin-10 (IL-10) concentration and decreasing pro-inflammatory cytokines. Histopathological and immunohistochemical results showed the improvement of re-epithelialization and tissue remodeling in the Copaifera langsdorffii group, with an increase in laminin-γ2, a decrease in desmoglein-3 and an increase in collagen remodeling. These findings indicate the wound healing potential of nanostructured lipid carriers associated with Copaifera langsdorffii oleoresin in skin wounds, which can be helpful as a future alternative treatment for skin wounds.

Enhanced Production of Nitrogenated Metabolites with Anticancer Potential in Aristolochia manshuriensis Hairy Root Cultures.

Aristolochia manshuriensis is a relic liana, which is widely used in traditional Chinese herbal medicine and is endemic to the Manchurian floristic region. Since this plant is rare and slow-growing, alternative sources of its valuable compounds could be explored. Herein, we established hairy root cultures of A. manshuriensis transformed with Agrobacterium rhizogenes root oncogenic loci (rol)B and rolC genes. The accumulation of nitrogenous secondary metabolites significantly improved in transgenic cell cultures. Specifically, the production of magnoflorine reached up to 5.72 mg/g of dry weight, which is 5.8 times higher than the control calli and 1.7 times higher than in wild-growing liana. Simultaneously, the amounts of aristolochic acids I and II, responsible for the toxicity of Aristolochia species, decreased by more than 10 fold. Consequently, the hairy root extracts demonstrated pronounced cytotoxicity against human glioblastoma cells (U-87 MG), cervical cancer cells (HeLa CCL-2), and colon carcinoma (RKO) cells. However, they did not exhibit significant activity against triple-negative breast cancer cells (MDA-MB-231). Our findings suggest that hairy root cultures of A. manshuriensis could be considered for the rational production of valuable A. manshuriensis compounds by the modification of secondary metabolism.

In vitro comparison between antimicrobial and antibiofilm effects of Green Propolis and Baccharis dracunculifolia against Staphylococcus pseudintermedius isolate.

Staphylococcus pseudintermedius is the leading cause of canine pyoderma. Honeybee products are common to treat this and other types of infections. High average annual population loss of bees has been observed. This study evaluated antibacterial and antibiofilm profile of Green Propolis and Baccharis dracunculifolia against S. pseudintermedius and the chemical similarities among both. Ethanolic extracts were produced and chemically characterized. The isolates were subjected to treatment with the extracts in both planktonic and sessile forms. Green propolis minimum inhibitory concentration (MIC) was 0.156 mg / mL, and minimum bactericidal concentration (MBC) was 0.312mg / mL. Baccharis dracunculifolia extract MIC and MBC was 0.312mg / mL and 2.5 mg / mL, respectivelly. Both extracts reduced SD55 formation of biofilm at minimum inhibitory concentration and at 1/8 minimum inhibitory concentration. The results observed in relation to ED99, were similar for both extracts. Besides that, similar chemical indicators between both extracts, including the presence of Artepellin C, suggest that the Baccharis dracunculifolia extract could be an alternative to the Green Propolis extract in the treatment of staph infections.

Long-chain glucomannan supplementation modulates immune responsiveness, as well as intestinal microbiota, and impacts infection of broiler chickens with Salmonella enterica serotype Enteritidis.

The zoonotic pathogen Salmonella enterica serotype Enteritidis (SE) causes severe disease in young chickens. Restriction on antibiotic use requires alternative SE control strategies such as nutritional solutions to improve the resistance of chickens. In this study, chickens were fed long-chain glucomannan (GM) or standard diet and challenged with SE at seven days of age. During 21 days post-infection (dpi), we determined numbers and responsiveness of natural killer (NK) and T cells in ileum and spleen, and SE-specific antibody titers in serum. Microbiota compositions in ileum and caeca were determined, as well as correlations of these with numbers and function of immune cells. Some of the samples in the control group had numerically higher CFUs than the GM-treated group. In addition, the relative abundance of SE based on DNA assessment was significantly lower at 21 dpi upon GM supplementation. At 3 dpi, numbers of intraepithelial NK cells were significantly higher, while activation of intraepithelial NK cells (7 dpi), numbers of intraepithelial cytotoxic CD8+ T cells (14 dpi) and SE-specific antibodies (14 dpi) were numerically higher. Furthermore, relative abundance of the commensal lactic acid bacteria (LAB) significantly increased with GM supplementation post-infection. Higher relative abundance of streptococci was associated with reduced SE in ileal and caecal contents at 21 dpi. Relative abundance of streptococci negatively correlated with SE counts and positively correlated with NK cell activation and SE-specific antibodies, which suggests involvement of the commensal LAB in NK cell responsiveness. These results indicate that GM supplementation modulates the immune system, intestinal microbiota and impacts SE infection of young chickens.

A Brief Overview of Potential Treatments for Viral Diseases Using Natural Plant Compounds: The Case of SARS-Cov.

The COVID-19 pandemic, as well as the more general global increase in viral diseases, has led researchers to look to the plant kingdom as a potential source for antiviral compounds. Since ancient times, herbal medicines have been extensively applied in the treatment and prevention of various infectious diseases in different traditional systems. The purpose of this review is to highlight the potential antiviral activity of plant compounds as effective and reliable agents against viral infections, especially by viruses from the coronavirus group. Various antiviral mechanisms shown by crude plant extracts and plant-derived bioactive compounds are discussed. The understanding of the action mechanisms of complex plant extract and isolated plant-derived compounds will help pave the way towards the combat of this life-threatening disease. Further, molecular docking studies, in silico analyses of extracted compounds, and future prospects are included. The in vitro production of antiviral chemical compounds from plants using molecular pharming is also considered. Notably, hairy root cultures represent a promising and sustainable way to obtain a range of biologically active compounds that may be applied in the development of novel antiviral agents.

Orexin 1 and 2 Receptors in the Prelimbic Cortex Modulate Threat Valuation.

The ability to distinguish between threatening (repulsors), neutral and appetitive stimuli (attractors) stimuli is essential for survival. The orexinergic neurons of hypothalamus send projections to the limbic structures, such as different subregions of the medial prefrontal cortex (mPFC), suggesting that the orexinergic mechanism in the prelimbic cortex (PL) is involved in the processing of fear and anxiety. We investigated the role of orexin receptors type 1 (OX1R) and type 2 (OX2R) in the PL in such processes upon confrontation with an erratically moving robo-beetle in mice. The selective blockade of OX1R and OX2R in the PL with SB 334867 (3, 30, 300 nM) and TCS OX2 29 (3, 30, 300 nM), respectively, did not affect general exploratory behavior or reactive fear such as avoidance, jumping or freezing, but significantly enhances tolerance and approach behavior at the highest dose of each antagonist tested (300 nM). We interpret these findings as evidence for an altered cognitive appraisal of the potential threatening stimulus. Consequently, the orexin system seems to bias the perception of stimuli towards danger or threat via OX1R and OX2R in the PL.

Nonclinical Toxicological Studies of Brazilian Red Propolis and Its Primary Botanical Source Dalbergia ecastaphyllum.

Propolis is one of the most widely used products in traditional medicine. One of the most prominent types of Brazilian propolis is the red one, whose primary botanical source is Dalbergia ecastaphyllum (L.) Taub. Despite the potential of Brazilian red propolis for developing new products with pharmacological activity, few studies guarantee safety in its use. The objective of this study was the evaluation of the possible toxic effects of Brazilian red propolis and D. ecastaphyllum, as well as the cytotoxicity assessment of the main compounds of red propolis on tumoral cell lines. Hydroalcoholic extracts of the Brazilian red propolis (BRPE) and D. ecastaphyllum stems (DSE) and leaves (DLE) were prepared and chromatographed for isolation of the major compounds. RP-HPLC-DAD was used to quantify the major compounds in the obtained extracts. The XTT assay was used to evaluate the cytotoxic activity of the extracts in the human fibroblast cell line (GM07492A). The results revealed IC50 values of 102.7, 143.4, and 253.1 µg/mL for BRPE, DSE, and DLE, respectively. The extracts were also evaluated for their genotoxic potential in the micronucleus assay in Chinese hamster lung fibroblasts cells (V79), showing the absence of genotoxicity. The BRPE was investigated for its potential in vivo toxicity in the zebrafish model. Concentrations of 0.8-6.3 mg/L were safe for the animals, with a LC50 of 9.37 mg/L. Of the 11 compounds isolated from BRPE, medicarpin showed a selective cytotoxic effect against the HeLa cell line. These are the initial steps to determine the toxicological potential of Brazilian red propolis.

Potential Antiglycation and Hypoglycaemic Effects of Toona ciliata M. Roem. and Schkuhria pinnata Lam. Thell. Crude Extracts in Differentiated C2C12 Cells.

Medicinal plants have been identified as a feasible avenue for the development of new potent antidiabetic agents. The phytoconstituent compositions of different Toona ciliata and Schkuhria pinnata extracts were determined and quantified using standard chemical methods after exhaustive extraction. Thereafter, their antioxidant and antiglycation potentials were spectrophotometrically determined. The cytotoxicity profiles of the extracts on C2C12 cells were determined using the MTT assay. Toona ciliata methanol extract resulted in the highest percentage yield (20.83%) and high total phenols and flavonoids content in the methanol and acetone extracts compared to S. pinnata extracts. The acetone extract of T. ciliata showed good activity in the DPPH scavenging and FRAP assays with EC50 values of 1.90 mg/ml and 5.26 mg/ml, respectively. Arbutin's antiglycation ability was outperformed by treatments with the methanol, acetone, and hexane extract of T. ciliata which resulted in 2.49%, 2.79%, and 2.56% glycation, respectively. The hexane extract of T. ciliata was less toxic to C2C12 cells as compared to the other extracts with CC50 value of 402.16 µg/ml. Only the hexane extract of S. pinnata resulted in glucose utilisation of 28.56% which was higher than that of insulin (26.06%) after 6 hours and is therefore considered as the most potent extract with hypoglycaemic potential in this study. Studies are ongoing aimed at identifying drug candidates in this extract that may be employed in the development of hypoglycaemic, antioxidant, and antiglycation agents.

Antioxidant, Antiglycation, and Hypoglycaemic Effect of Seriphium plumosum Crude Plant Extracts.

Diabetes is a severely debilitating metabolic disorder characterised by chronic hyperglycaemia. Traditional medicinal plants provide an important avenue for the development of novel antidiabetic agents. The antidiabetic potential of the methanol, acetone, and hexane extracts of S. plumosum was assessed using different parameters. These included secondary metabolite quantification, hypoglycaemic, cytotoxic effects, and GLUT4 translocation augmentation on C2C12 cells. The methanol extract contained the highest amount of total phenolic and flavonoid compounds and showed enhanced antioxidant activity. The methanol extracts had the best DPPH scavenging (EC50 = 0.72 mg/ml) and ferric reducing powers (EC50 = 2.31 mg/ml). The hexane extract resulted in the highest glucose uptake activity of 35, 77% with respect to all other treatments after a 6-hour exposure period. Immunocytochemistry technique further revealed that the increased glucose utilisation may be due to increased membrane fused GLUT4 molecules in C2C12 cells. The hexane extract was also shown to upregulate the phosphorylation of p70 S6 kinase and Akt1/2. The study highlights a probable insulin-mimetic activity of the hexane extract via the augmentation of Akt1/2 phosphorylation which is involved in the GLUT4 translocation pathway. Furthermore, the study represents the first report on the cytotoxic effect, GLUT4 translocation, and glucose uptake potential of S. plumosum.

Defatting of acetone leaf extract of Acacia karroo (Hayne) enhances its hypoglycaemic potential.

BACKGROUND: Conventional drugs used to treat diabetes are too expensive, toxic and rarely available to rural communities. This study was aimed at investigating the phytochemical differences and hypoglycaemic effects (α-amylase enzyme inhibition, glucose uptake, GLUT4 translocation and phosphorylation of MAPKs) of non-defatted and defatted acetone leaf extract of Acacia karroo. METHODS: Qualitative phytochemical analyses of extracts were determined using standard chemical tests and total phenolic contents using the Folin-Ciocalteu reagent method. Presence of antioxidant constituents was determined using DPPH scavenging and ferric reducing power assays. Alpha amylase enzyme inhibitory potential was determined chromogenically and cytotoxicity of the extracts on C2C12 muscle and 3T3-L1 cells using the MTT assay. Glucose uptake by the cells was determined colorimetrically and the most active extract was evaluated for its ability to translocate GLUT4 and MAPKs phosphorylation potential using immunofluorescence microscopy and dot blot analysis, respectively. RESULTS: Phenols, flavonoids, tannins, saponins and cardiac glycosides were detected in both extracts. Defatting of the plant material resulted in low amounts of phenols (0.432 ± 0.014 TAE/mg), DPPH scavenging activity (EC50 0.40 ± 0.012 mg/ml), low toxicity and high ferric reducing power (EC50 1.13 ± 0.017 mg/ml), α-amylase enzyme inhibition (IC50 30.2 ± 3.037 µg/ml) and glucose uptake by both cells. The defatted extract showed an increase in GLUT4 translocation (at 25 µg/ml) with decrease in Akt expression while in combination with insulin showed a decrease in GLUT4 translocation. A finding, that is implicative that the effect of the extract on GLUT4 translocation in C2C12 cells was not Akt dependent. The defatted extract in the absence and presence of insulin show varying phosphorylation levels of CREB, p38, GSK-3 and ERK2 which are important in cell survival and metabolism. CONCLUSION: This study represents the first report on the hypoglycemic potential of A. karroo and presence of compounds that can be exploited in the search for therapeutics with antidiabetic effect.

Evaluation of a pharmacist-managed electrolyte protocol in outpatients on antiarrhythmic medications.

OBJECTIVE: To evaluate the effectiveness of a pharmacist-managed treatment protocol in achieving and maintaining serum potassium level ([K+]) in the desired range. SETTING: Antiarrhythmic Medications Clinic, The Ohio State University Wexner Medical Center, Columbus, Ohio, from 2009 to 2013. PRACTICE DESCRIPTION: Patients are referred for antiarrhythmic monitoring at this pharmacist-run, electrophysiologist-supervised clinic. Each visit includes medication reconciliation for drug interaction identification, patient interview for potential adverse effects or arrhythmia symptoms, patient education, and drug therapy monitoring through ordering and review of objective testing. PRACTICE INNOVATION: In 2009, a novel, pharmacist-managed electrolyte protocol was established for less than ideal [K+] found during antiarrhythmic monitoring. The protocol was intended to standardize and improve practice, versus pre-protocol management through separate electrophysiology offices. The protocol was designed to maintain [K+] of 4.0-5.0 mmol/L, and it used dietary advice and magnesium and potassium supplementation to normalize [K+]. EVALUATION: The performance of the pharmacist-managed electrolyte protocol was evaluated in consecutive patients seen between June 2009 and July 2013 with [K+] less than 4.0 mmol/L. [K+] during initial visit and laboratory tests were scheduled at weekly intervals after intervention until corrected. Maintenance of [K+] was assessed during the next visit to the clinic. Patients whose management involved pre-protocol between October 2008 and May 2009 at the clinic served as controls. RESULTS: One-hundred ninety-one encounters were evaluated from the post-protocol (treatment) group and 41 encounters from the pre-protocol (control) group. Desired [K+] was reached in 161 (84%) post-protocol patient encounters, compared with 21 (49%) in the control group (P < 0.01). Median time to target was 14 days (range, 3-203 days) in the treatment group and 146 days (range, 7-285 days) in the control group (P < 0.01). Of 125 encounters that received follow-up in the treatment group, 75% remained at desired [K+]. CONCLUSION: A pharmacist-managed electrolyte protocol, implemented as part of a comprehensive antiarrhythmic monitoring service, effectively achieves and maintains desired [K+].

Dam Mycobacterium avium subspecies paratuberculosis (MAP) infection status does not predetermine calves for future shedding when raised in a contaminated environment: a cohort study.

Uptake of Mycobacterium avium subsp. paratuberculosis (MAP) by calves in the first days of life from colostrum, milk and faeces is regarded an important moment of transmission. The objective of this study was to quantify the association between the MAP status of dams as determined by the presence of MAP DNA and antibody in colostrum and that of DNA in faeces and the environment with subsequent MAP shedding of their daughters. A cohort of 117 dam-daughter pairs giving birth/being born on eight commercial dairy farms with endemic paratuberculosis was followed where colostrum, faecal and environmental samples (dust) were analysed for the presence of MAP using an IS900 real-time PCR. Antibodies in colostrum were measured by ELISA. Analysis of dust samples showed that on all farms environmental MAP exposure occurred continuously. In significantly more colostrum samples (48%) MAP DNA was detected compared to faecal samples (37%). MAP specific antibodies were present in 34% of the colostrum samples. In total MAP DNA was present in faecal samples of 41% of the daughters at least once during the sampling period. The association between faecal shedding in the offspring and the dam MAP status defined by MAP PCR on colostrum, MAP PCR on faeces or ELISA on colostrum was determined by an exact cox regression analysis for discrete data. The model indicated that the hazard for faecal shedding in daughters born to MAP positive dams was not significantly different compared to daughters born to MAP negative dams. When born to a dam with DNA positive faeces the HR was 1.05 (CI 0.6; 1.8) and with DNA positive colostrum the HR was 1.17 (CI 0.6; 2.3). When dam status was defined by a combination of both PCR outcomes (faeces and colostrum) and the ELISA outcome the HR was 1.26 (CI 0.9; 1.9). Therefore, this study indicates that neither the presence of MAP DNA in colostrum, MAP DNA in faeces nor the presence of MAP antibodies in colostrum of the dam significantly influences the hazard of MAP shedding in their subsequent daughters up to the age of two years when raised in a contaminated environment.

Cell-wall polysaccharide composition and glycanase activity of Silene vulgaris callus transformed with rolB and rolC genes.

The aim of this research is to investigate the effects of the Agrobacterium rhizogenes rol genes on the composition of cell-wall polysaccharides and glycanase activity in the campion callus. The expression of the rolC gene reduces the yield of campion pectin, while the expression of the rolB or rolC gene inhibits the volumetric production of both pectin and intracellular arabinogalactan. The rol genes are involved in regulating the activity of glycanases and esterases, thereby contributing to the modification of polysaccharide structures, their molecular weight (Mw) and the degree of pectin methyl esterification (DE). The increase in pectin arabinose residue appears to be connected to a decrease in intracellular and extracellular α-l-arabinofuranosidase activity in transgenic campion calluses. In transgenic calluses expressing the rolB and rolC genes, the increase in pectin galactose residue is likely due to a decrease in ß-galactosidase activity. The decrease in the Mw of pectin and its d-galacturonic acid content appears to be connected to an increase in extracellular polygalacturonase activity. Finally, the increase in pectinesterase activity causes a decrease in the DE of pectin. Thus, the expression of rolB and rolC genes in campion callus has a considerable effect on pectin's sugar composition, DE and Mw, while it appears to have an insignificant influence on intracellular and extracellular arabinogalactans.

Bovine Neonatal Pancytopenia is a heritable trait of the dam rather than the calf and correlates with the magnitude of vaccine induced maternal alloantibodies not the MHC haplotype.

Bovine Neonatal Pancytopenia (BNP), a bleeding syndrome of neonatal calves, is caused by alloantibodies absorbed from the colostrum of particular cows. A commercial BVD vaccine is the likely source of alloantigens eliciting BNP associated alloantibodies. We hypothesized that the rare occurrence of BNP in calves born to vaccinated dams could be associated with genetic differences within dams and calves. We found that the development of BNP within calves was a heritable trait for dams, not for calves and had a high heritability of 19%. To elucidate which genes play a role in the development of BNP we sequenced candidate genes and characterized BNP alloantibodies. Alloantigens present in the vaccine have to be presented to the dam's immune system via MHC class II, however sequencing of DRB3 showed no differences in MHC class II haplotype between BNP and non-BNP dams. MHC class I, a highly polymorphic alloantigen, is an important target of BNP alloantibodies. Using a novel sequence based MHC class I typing method, we found no association of BNP with MHC class I haplotype distribution in dams or calves. Alloantibodies were detected in both vaccinated BNP and non-BNP dams and we found no differences in alloantibody characteristics between these groups, but alloantibody levels were significantly higher in BNP dams. We concluded that the development of BNP in calves is a heritable trait of the dam rather than the calf and genetic differences between BNP and non-BNP dams are likely due to genes controlling the quantitative alloantibody response following vaccination.

Antimicrobial activity, toxicity and selectivity index of two biflavonoids and a flavone isolated from Podocarpus henkelii (Podocarpaceae) leaves.

BACKGROUND: Different parts of Podocarpus henkelii have been used in many cultures around the world to treat ailments such as cholera, stomach diseases, rheumatism, cancer, canine distemper in dogs and gall sickness in cattle. The aim of this study was to evaluate the biological activity and toxicity of isolated compounds from Podocarpus henkelii after an earlier study indicated a promising activity in crude extracts against viral pathogens of veterinary importance. METHODS: The antibacterial and antifungal activity of two biflavonoids 7, 4', 7", 4"'-tetramethoxy amentoflavone (TMA), isoginkgetin (IGG) and podocarpus flavone-A (PFA) isolated from the leaves of Podocarpus henkelii were determined using a serial microplate dilution method with tetrazolium violet as growth indicator. The cytotoxicity of compounds TMA and IGG were determined on different cell types using a tetrazolium-based colorimetric cellular assay (MTT). The Ames test was used to determine their mutagenic activities. RESULTS: TMA had reasonable antifungal activity against Aspergillus fumigatus (MIC = 30 µg/ml). IGG had a wide spectrum of activity against four bacterial and two fungal pathogens with much higher selectivity index values obtained for A. fumigatus and Cryptococcus neoformans (SI > 30). PFA had a broad spectrum of activity against Enterococcus faecalis and Pseudomonas aeruginosa (SI > 15) and less activity against the two fungal pathogens. In both the cytotoxicity assays and Ames mutagenicity test using Salmonella typhimurium strains TA98 and TA100, TMA and IGG had no deleterious effect on the different cell types and did not induce mutations in the Ames test. CONCLUSION: Although the antimicrobial activities of the isolated compounds were not that exciting, the compounds had no cytotoxic activity at the highest concentration (1000 µg/ml) tested against all three cell lines. IGG was the most active against E. coli, S. aureus, A. fumigatus and C. neoformans, exhibiting both antibacterial and antifungal activity with good selectivity index values. PFA had a broad spectrum of activity against E. faecalis and P. aeruginosa. The two compounds isolated had low toxicity and no genotoxic activity in the Ames test.

Severe methemoglobinemia due to ingestion of toxicants.

BACKGROUND: Toxin-induced methemoglobinemia is seen in poisoning with oxidizing agents. We report the clinical features and outcome of patients admitted with severe methemoglobinemia due to intentional ingestion of toxicants. METHODS: In this observational case series, patients admitted with toxin-induced methemoglobinemia between September 2011 and January 2014 were identified from the institutional poisoning database. Clinical profile and outcome of patients with methemoglobin concentration greater than or equal to 49% is reported. RESULTS: Of the 824 patients admitted with poisoning, 5 patients with methemoglobin concentration greater than or equal to 49% were included. The implicated compounds were nitrobenzene, benzoylphenylurea, flubendamide and Rishab(TM). One patient refused to name the compound. All patients were managed in the intensive care unit. Altered sensorium [Glasgow coma scale (GCS) < 10] was common (80%); 2 patients presented with a GCS greater than 4. All patients manifested cyanosis, low oxygen saturation and chocolate-brown-colored blood despite supplemental oxygen therapy. The median methemoglobin concentration was 64.7% (range 49.8-91.6%); 2 patients had methemoglobin concentration greater than 70%. One patient needed inotropes. Four patients required mechanical ventilation for 4-14 days. All patients were treated with methylene blue; 4 received more than one dose. Three patients also received intravenous ascorbic acid 500 mg, once daily, for 3 days. Following treatment, there was evidence of haemolysis in all patients; 2 required blood transfusion. All patients survived. CONCLUSION: Patients with severe toxin-induced methemoglobinemia present with altered sensorium and cyanosis and may require ventilatory support and inotropes. Though methemoglobin concentrations greater than 70% are considered fatal, aggressive management with methylene blue and supportive therapy can lead to survival.

Polyphenolic compounds from callus cultures of Iris pseudacorus.

A callus culture of Iris pseudacorus L. (Iridaceae) was established from plant leaves using a modified Murashige and Skoog medium. A derivative of cinnamic acid (lavandoside) (1), a neolignan (dehydrodiconiferyl alcohol-4-O-beta-D-glucopyranoside) (2) as well as three isoflavonoids, tectoridin (3), tectorigenin (4), and iristectorigenin A (5) were isolated from the callus culture. Under normal conditions, the calli accumulated 0.4% DW of polyphenols. The addition of phenylalanine to a concentration of 1 mM resulted in a 1.5-fold increase in isoflavonoid production, allowing the accumulation of 0.69% of polyphenols in the callus dry weight. Tectorigenin, a promising chemotherapeutic and chemopreventive agent for the treatment of carcinomas, was produced in I. pseudacorus calli in high quantities (0.3% DW).

Structural basis of allosteric interactions among Ca2+-binding sites in a K+ channel RCK domain.

Ligand binding sites within proteins can interact by allosteric mechanisms to modulate binding affinities and control protein function. Here we present crystal structures of the regulator of K+ conductance (RCK) domain from a K+ channel, MthK, which reveal the structural basis of allosteric coupling between two Ca2+ regulatory sites within the domain. Comparison of RCK domain crystal structures in a range of conformations and with different numbers of regulatory Ca2+ ions bound, combined with complementary electrophysiological analysis of channel gating, suggests chemical interactions that are important for modulation of ligand binding and subsequent channel opening.

Preliminary Assessment of the Chemical Stability of Dried Extracts from Guazuma ulmifolia Lam. (Sterculiaceae).

We report the results of a preliminary estimation of the stability of the dried extract from bark of Guazuma ulmifolia Lam. ("Mutamba"), with and without added colloidal silicon dioxide (CSD). The physical and chemical properties and the compatibility of CSD in the extract were evaluated for 21 days of storage under stress conditions of temperature (45 ± 2°C) and humidity (75 ± 5%). Thermogravimetry (TG) was supplemented using selective high-performance liquid chromatography (HPLC) for determination of stability of the characteristic constituents (chemical markers), namely, procyanidin B2 (PB2) and epicatechin (EP). The results showed that PB2 is an appropriate compound to be used as a chemical marker in the quality control of dried extracts of G. ulmifolia. The stress study showed that there was no significant difference between the two formulations. However, considering the TG data and the high temperatures involved, the results suggest that CSD increases the stability of the dried extract of G. ulmifolia.

The rolB gene suppresses reactive oxygen species in transformed plant cells through the sustained activation of antioxidant defense.

The rolB (for rooting locus of Agrobacterium rhizogenes) oncogene has previously been identified as a key player in the formation of hairy roots during the plant-A. rhizogenes interaction. In this study, using single-cell assays based on confocal microscopy, we demonstrated reduced levels of reactive oxygen species (ROS) in rolB-expressing Rubia cordifolia, Panax ginseng, and Arabidopsis (Arabidopsis thaliana) cells. The expression of rolB was sufficient to inhibit excessive elevations of ROS induced by paraquat, menadione, and light stress and prevent cell death induced by chronic oxidative stress. In rolB-expressing cells, we detected the enhanced expression of antioxidant genes encoding cytosolic ascorbate peroxidase, catalase, and superoxide dismutase. We conclude that, similar to pathogenic determinants in other pathogenic bacteria, rolB suppresses ROS and plays a role not only in cell differentiation but also in ROS metabolism.