Protective Effect of Resveratrol against Hepatotoxicity of Cadmium in Male Rats: Antioxidant and Histopathological Approaches

Cadmium (Cd) is widely used in some industries and emitted from fossil fuels. It is a heavy metal with a number of side effects, including hepatotoxicity. Resveratrol (Rs) is considered an important polyphenol, which is a secondary plant metabolite and has the ability to scavenge free radicals. The study was designed to evaluate the effects of resveratrol on Cd, which induced hepatotoxicity, by the assessment of some histopathological and biochemical alterations. Forty male albino rats were divided into four groups: the 1st group was the control group, the 2nd group was treated with Cd (5 mg/kg), the 3rd group was given Rs (20 mg/kg), and the 4th group was treated with Cd in combination with Rs intraperitoneally for 30 successive days. The results indicate that Cd increased liver enzymes alanine aminotransferase and aspartate aminotransferase (AST and ALT), alkaline phosphatase ALP and gamma-glutamyl transferase (γ-GT) while reducing the total protein level; Cd increased the malondialdhyde (MDA) level while decreasing the levels of other antioxidant enzymes super oxide dismutase, catalase and glutathione peroxidase (SOD, CAT and GPx). Serious congestion and hemorrhage related to the hepatic tissues were noticed in the Cd group, and Rs plays a major role in alleviating histopathological injuries and hepatic oxidative damage. It is clear that Rs has the ability to minimize the hepatotoxicity induced by Cd in male rats.

Caged Dexamethasone/Quercetin Nanoparticles, Formed of the Morphogenetic Active Inorganic Polyphosphate, are Strong Inducers of MUC5AC

Inorganic polyphosphate (polyP) is a widely distributed polymer found from bacteria to animals, including marine species. This polymer exhibits morphogenetic as well as antiviral activity and releases metabolic energy after enzymatic hydrolysis also in human cells. In the pathogenesis of the coronavirus disease 2019 (COVID-19), the platelets are at the frontline of this syndrome. Platelets release a set of molecules, among them polyP. In addition, the production of airway mucus, the first line of body defense, is impaired in those patients. Therefore, in this study, amorphous nanoparticles of the magnesium salt of polyP (Mg-polyP-NP), matching the size of the coronavirus SARS-CoV-2, were prepared and loaded with the secondary plant metabolite quercetin or with dexamethasone to study their effects on the respiratory epithelium using human alveolar basal epithelial A549 cells as a model. The results revealed that both compounds embedded into the polyP nanoparticles significantly increased the steady-state-expression of the MUC5AC gene. This mucin species is the major mucus glycoprotein present in the secreted gel-forming mucus. The level of gene expression caused by quercetin or with dexamethasone, if caged into polyP NP, is significantly higher compared to the individual drugs alone. Both quercetin and dexamethasone did not impair the growth-supporting effect of polyP on A549 cells even at concentrations of quercetin which are cytotoxic for the cells. A possible mechanism of the effects of the two drugs together with polyP on mucin expression is proposed based on the scavenging of free oxygen species and the generation of ADP/ATP from the polyP, which is needed for the organization of the protective mucin-based mucus layer.

The Potential Production of the Bioactive Compound Pinene Using Whey Permeate

Pinene is a secondary plant metabolite that has functional properties as a flavor additive as well as potential cognitive health benefits. Although pinene is present in low concentrations in several plants, it is possible to engineer microorganisms to produce pinene. However, feedstock cost is currently limiting the industrial scale-up of microbial pinene production. One potential solution is to leverage waste streams such as whey permeate as an alternative to expensive feedstocks. Whey permeate is a sterile-filtered dairy effluent that contains 4.5% weight/weight lactose, and it must be processed or disposed of due its high biochemical oxygen demand, often at significant cost to the producer. Approximately 180 million m3 of whey is produced annually in the U.S., and only half of this quantity receives additional processing for the recovery of lactose. Given that organisms such as recombinant Escherichia coli grow on untreated whey permeate, there is an opportunity for dairy producers to microbially produce pinene and reduce the biological oxygen demand of whey permeate via microbial lactose consumption. The process would convert a waste stream into a valuable coproduct. This review examines the current approaches for microbial pinene production, and the suitability of whey permeate as a medium for microbial pinene production.

Identifying Rates of Meadowfoam (Limnanthes alba) Seed Meal Needed for Suppression of Meloidogyne hapla and Pythium irregulare in Soil

Meadowfoam (Limnanthes alba) is a commercial oilseed annual crop grown in Oregon. After extracting oil from seed, the remaining seed meal is rich in the secondary plant metabolite glucolimnanthin, which can be converted into pesticidal compounds such as 3-methoxybenzyl isothiocyanate (ITC) and 3-methoxyphenylacetonitrile (nitrile) in the presence of the enzyme myrosinase. In previous studies, we demonstrated that ITC and nitrile, produced by mixing freshly ground meadowfoam seed with meadowfoam seed meal, are toxic to the plant-parasitic nematode Meloidogyne hapla and the plant pathogen Pythium irregulare. In this study, we evaluated factors that might influence the implementation of meadowfoam seed meal into agricultural production systems for soilborne pathogen and nematode control. Rate-finding experiments demonstrated that a minimum 1.0% seed/seed meal formulation (wt/wt) was necessary to achieve nematode and pathogen suppression; seed meal alone was insufficient for complete control of M. hapla and stimulated the growth of P. irregulare. When this 1.0% seed/seed meal formulation was used, a greater soil amendment rate was required to cause 100% mortality of P. irregulare (1.0% wt/wt) than for M. hapla (0.5% wt/wt). In phytotoxicity experiments, soil amended with the 1.0% seed/seed meal formulation was consistently phytotoxic to wheat, cucumber, and tomato. However, phytotoxic effects were mitigated by a delayed planting into the amended soil. A final assay to monitor concentrations of ITC and nitrile in conjunction with assessing M. hapla and P. irregulare mortality was conducted over a 6-day period in soils amended at 0.5 and 1.0% (wt/wt) with the 1.0% seed/seed meal formulation. The response was rapid, with 100% mortality of both organisms within 2 h after exposure to amended soil. Concentrations of nitrile remained relatively constant over the 6-day period (approximately 0.017 and 0.032 mg/ml at 0.5 and 1.0% amendment rates, respectively), whereas ITC production increased rapidly and peaked 12 to 24 h after amendment (0.083 and 0.171 mg/ml at 0.5 and 1.0% amendment rates, respectively) before returning to near undetectable levels.

Local movements evoked by chemical stimulation of the hind leg in the locust Schistocerca gregaria

The behavioural responses of desert locusts, Schistocerca gregaria, to solutions of four behaviourally relevant chemicals (sodium chloride, sucrose, nicotine hydrogen tartrate and lysine glutamate) applied as droplets to the hind tarsus were analysed. All responses following within 1 s of chemical stimulation were local leg avoidance reflexes, and the probability of eliciting such a response increased in a dose-dependent manner with increasing concentration for all the chemicals tested. Chemical identity, however, critically determined the concentration threshold at which the different chemicals became an effective stimulus. For example, a 2.5 mmol l(−)(1) concentration of the secondary plant metabolite nicotine hydrogen tartrate (NHT), a potent feeding deterrent to locusts, was sufficient to evoke avoidance responses in 50 % of cases, whilst for the nutrients, sucrose and lysine glutamate, 250–500 mmol l(−)(1) of the chemical was needed to induce avoidance behaviour in 50 % of the locusts. NaCl was of intermediate effectiveness, with a 50 % response rate occurring at a concentration of approximately 50 mmol l(−)(1). The latency to the start of the response following stimulation was negatively correlated with the concentration of NaCl, but for the other chemicals concentration had no effect on latency. The duration of the avoidance behaviour decreased with increasing concentration for NaCl and more weakly for NHT, but not for the other chemicals. Adding a subthreshold concentration of sucrose to 50 mmol l(−)(1) NaCl decreased the incidence of response compared with 50 mmol l(−)(1) NaCl on its own. Experiments with other mixtures combining NaCl, sucrose and NHT indicate that the frequency and dynamics of the responses to chemical mixtures cannot be simply predicted from the responses to their individual constituents.