St. John’s Wort Herbal Teas – Biological Potential and Chemometric Approach to Quality Control

Plant Foods for Human Nutrition - St. John’s wort has been used for centuries in traditional medicine of many cultures, and nowadays it is well-known as a clinically important antidepressant...     

Genetic diversity of the pine pathogen Lecanosticta acicola in Slovenia and Croatia

Brown spot needle blight (BSNB), a disease of pine trees caused by the fungus Lecanosticta acicola, has been known in Slovenia since 2008 and in Croatia since 1975. Recent outbreaks in Slovenia prompted this study to compare L. acicola populations in these two neighbouring European countries. Sixty-nine isolates collected from three pine species (Pinus mugo, P. halepensis and P. nigra) were used to determine the phylogenetic relationships, genetic structure, and reproductive strategy of the pathogen. EF1-α sequences showed that Slovenian and Croatian isolates share a common ancestry with individuals from central and northern Europe. Population structure analysis revealed four distinct population clusters of L. acicola in these two countries, generally corresponding to their respective geographic location and host. An unequal ratio of mating types and a low overall genetic diversity in the population indicated a strong influence of asexual reproduction. Although some of the oldest recorded European occurrences of BSNB are from Croatia, this study provided no evidence that the population studied in Croatia was the source of the sampled outbreaks in Slovenia. Recent outbreaks of L. acicola in Slovenia are most likely due to introductions from other, yet to be identified, sources.     

Maize defence mechanisms against the European corn borer,Ostrinia nubilalis Hübner (Lepidoptera: Crambidae)

Maize is arguably the most widely grown crop in the world, but it is often associated with one of its major insect pests, the European corn borer (ECB). The damage caused by this species to maize production is generally variable, but in many cases it is economically significant. This review paper provides an overview of the research findings on the natural plant defence mechanisms against ECB larvae published till now. What is resistance and how it is achieved, what is the chemical response of maize plants to insect feeding and how tolerance can be increased. A short introduction in breeding for resistance and a discussion if the mentioned traits can be used in conventional breeding in order to create maize hybrids less affected by ECB are given.     

The Characterization of Heavy Metals in the Grapevine (Vitis vinifera) Cultivar Rkatsiteli and Wild Blackberry (Rubus fruticosus) from East Serbia by ICP-OES and BAFs

Inductively coupled plasma optical emission spectroscopy, in combination with calculation of various biological factors, was used in this study not only for a simple illustration of the present status of some essential and non-essential metals such as copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), arsenic (As), and cadmium (Cd) in the grapevine cultivar Rkatsiteli and wild blackberry from East Serbia but also for the estimation of plant bioaccumulation potentials. Great majority of detected metal concentrations were in normal ranges except in few cases: Zn concentrations were at the level of deficiency in almost all plant parts, and some Cu and As concentrations were at the levels that could be considered phytotoxic. Biological accumulation factors provided very informative data on metal accumulation and translocation in both plants and pointed to low accumulation rates of metals except in the case of Cu, Zn, and As in some wild blackberry tissues.     

利用SSR快速鉴别花生杂交F1真伪

本研究,我们以6个花生品种为亲本配置杂交组合,田间调查发现亲本间形态表型差异大的杂交F1容易鉴别真伪,而形态表型差异小的则难于鉴别,甚至无法鉴别。为此,我们通过改良Thomson一步法制备DNA模板,建立了一套花生SSR-PCR快速检测体系,并在此基础上利用SSR鉴别花生杂交F1真伪。结果表明,采用Thomson一步法和改良后的一步法提取的DNA模版均能扩展出清晰条带,但改良后制备的DNA模板在4℃下可保存约1个月,未改良的仅能保存一天。利用SSR检测上述群体表明,F1真杂种率为38%～56%,不同亲本间杂交成功率存在差异,同一亲本正反交成功率也存在一定差异。可见,SSR标记用于杂种真伪鉴定具有一定的应用潜力。     

The use of RAPD technique for the identification and classification of Pisum sativum L. genotypes

Summary The genomic DNAs of 42 Pisum sativum genotypes, representing four wild and cultivated subspecies were used as templates in RAPD reactions. Amplification with eight decamer primers generated 149 polymorphic products. Genetic similarities of RAPD profiles were estimated via a coefficient of Jaccard and then the data were processed by cluster analysis (UPGMA). Each genotype was clearly identified and separated from the others. Our results show that RAPD technology is a rapid, precise and sensitive technique for identification of pea genotypes. However, the phylogenetic relationships within the Pisum sativum, which we tested by bootstrap analysis (Wagner parsimony), must be interpreted with caution.     

The influence of surface-treated nano-TiO2 (rutile) incorporation in water-based acrylic coatings on wood protection

The aim of this research was to synthesize surface-treated nano-titanium dioxide (TiO₂) particles and incorporate them into water-based acrylic systems, which could offer long-term protection for UV-sensible wood substrates. To suppress the photocatalytic activity, the surface of TiO₂ nanoparticles in rutile crystal structure was coated with amorphous silica (SiO₂) layer. The amounts of SiO₂ were 5 and 10 wt%, respectively. Formation of SiO₂ layer on TiO₂ surface was analyzed using scanning and transmission electron microscopy. SiO₂ layer thickness increases as a function of precursor loading. In addition, the influence of SiO₂ loading on rutile UV-protective properties was determined. Transparent UV-protective coatings were developed by incorporating surface-treated nano-TiO₂ into water-based acrylic stain. The particle size distribution was determined using dynamic light-scattering measurements, which indicate that the suspension of surface-treated rutile is stable against agglomeration. Furthermore, the color change and ability of protection against UV light of coatings after nanoparticles incorporation were determined. TiO₂, surface treated with 10 wt% of SiO_2, yielded coatings of higher transparency; however, TiO_2, surface treated with 5 wt% of SiO_2, improved UV protection.     

<Emphasis Type="Italic">Lupinus albus</Emphasis> Conglutin Gamma Modifies the Gene Expressions of Enzymes Involved in Glucose Hepatic Production <Emphasis Type="Italic">In Vivo</Emphasis>

Lupinus albus seeds contain conglutin gamma (Cγ) protein, which exerts a hypoglycemic effect and positively modifies proteins involved in glucose homeostasis. Cγ could potentially be used to manage patients with impaired glucose metabolism, but there remains a need to evaluate its effects on hepatic glucose production. The present study aimed to analyze G6pc, Fbp1, and Pck1 gene expressions in two experimental animal models of impaired glucose metabolism. We also evaluated hepatic and renal tissue integrity following Cγ treatment. To generate an insulin resistance model, male Wistar rats were provided 30% sucrose solution ad libitum for 20 weeks. To generate a type 2 diabetes model (STZ), five-day-old rats were intraperitoneally injected with streptozotocin (150 mg/kg). Each animal model was randomized into three subgroups that received the following oral treatments daily for one week: 0.9% w/v NaCl (vehicle; IR-Ctrl and STZ-Ctrl); metformin 300 mg/kg (IR-Met and STZ-Met); and Cγ 150 mg/kg (IR-Cγ and STZ-Cγ). Biochemical parameters were assessed pre- and post-treatment using colorimetric or enzymatic methods. We also performed histological analysis of hepatic and renal tissue. G6pc, Fbp1, and Pck1 gene expressions were quantified using real-time PCR. No histological changes were observed in any group. Post-treatment G6pc gene expression was decreased in the IR-Cγ and STZ-Cγ groups. Post-treatment Fbp1 and Pck1 gene expressions were reduced in the IR-Cγ group but increased in STZ-Cγ animals. Overall, these findings suggest that Cγ is involved in reducing hepatic glucose production, mainly through G6pc inhibition in impaired glucose metabolism disorders.     

Effect of Fucoidan on the Mitochondrial Membrane Potential (ΔΨm) of Leukocytes from Patients with Active COVID-19 and Subjects That Recovered from SARS-CoV-2 Infection

Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, anti-viral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for COVID-19 recovery. This work aimed to determine the ex-vivo effects of treatment with fucoidan (20 µg/mL) on mitochondrial membrane potential (ΔΨm, using a cationic cyanine dye, 3,3′-dihexyloxacarbocyanine iodide (DiOC₆(3)) on human peripheral blood mononuclear cells (HPBMC) isolated from healthy control (HC) subjects, COVID-19 patients (C-19), and subjects that recently recovered from COVID-19 (R1, 40 ± 13 days after infection). In addition, ex-vivo treatment with fucoidan (20 and 50 µg/mL) was evaluated on ΔΨm loss induced by carbonyl cyanide 3-chlorophenylhydrazone (CCCP, 150 µM) in HPBMC isolated from healthy subjects (H) and recovered subjects at 11 months post-COVID-19 (R2, 335 ± 20 days after infection). Data indicate that SARS-CoV-2 infection induces HPBMC loss of ΔΨm, even 11 months after infection, however, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered subjects. Therefore, fucoidan may be a potential treatment to diminish long-term sequelae from COVID-19, using mitochondria as a therapeutic target for the recovery of cellular homeostasis.     

Comparative Studies on Corynebacter1Um Pyogenes Toxin Formation in Monocultures and Mixed Cultures: The Demonstration of a Stimulating Effect of Peptococcus Indolicus and Stuart-Schwan Cocci

The growth and the toxin (i.e. hemolysin) producing capacity of Corynebacterium pyogenes were studied in monocultures and in co-cultures with 1 or more of the organisms frequently accompanying it in summer mastitis in cattle (Peptococcus indolicus, Stuart-Schwan cocci, Bacteroides melaninogenicus subsp. levii, Fusobacterium necrophorum and Streptococcus dysgalactiae) or with organisms seldom associated with summer mastitis (Streptococcus uberis, Streptococcus agalactiae, non-toxic staphylococci and Escherichia coli).Pc. indolicus, and to some extent also Stuart-Schwan cocci, stimulated the growth as well as the hemolysin producing capacity of Gb. pyogenes (Table 1) while Str. dysgalactiae, Str. uberis, Str. agalactiae, E. coli and the majority of the staphylococci reduced these activities. Most F. necrophorum strains stimulated the growth, but not the hemolytic activity. With B. melaninogenicus the results were inconclusive.The effect of Pc. indolicus appeared to be associated with the production of a filterable factor (Tables 2 and 3).Mouse toxicity and hemolytic activity of culture filtrates were closely correlated (Table 4).