Antimicrobial and toxicological evaluation of Origanum vulgare: an in vivo study

Origanum vulgare has been of great interest in academia and pharma industry due to its antioxidant, antifungal and antitumor properties. The present study aimed to find the anti-MRSA potential and in vivo toxicity assessments of O. vulgare. O. vulgare extract was used to monitor anti-MRSA activity in mice. Following MRSA established infection in mice (Mus musculus), treatment with O. vulgare was continued for 7 days. Autopsies were performed and re-isolation, gross lesion scoring and bacterial load in various organs were measured. Additionally, blood sample was analysed for hematological assays. Toxicity assessment of O. vulgare potential as medicine was done at 200 mg/kg and 400 mg/kg by evaluating liver and kidney functions. Bacterial load and gross lesion in lungs and heart were significantly low compared to positive control following O. vulgare treatment. Likewise, O. vulgare treated groups had hematological, neutrophil and TLC values similar to control groups. Increased AST, ALP and total bilirubin alongwith marked hepatocellular degeneration and distortion around the central vein, inflammatory cell infiltration, and cytoplasmic vacuolization of hepatic cells was observed at higher dose. It is concluded that crude extract of O. vulgare may contain beneficial secondary metabolites and in future may be explored for curing infectious diseases.

Complete wastewater discoloration by a novel peroxidase source with promising bioxidative properties

BACKGROUND Our study aimed to characterize and prospect immobilization strategies for a novel fungal peroxidase - POD (EC 1.11.1.7) and to insert it in the context of pollutant remediation, since these compounds pose risks to human and environmental health. The enzymatic extract was obtained by submerged fermentation of the fungus Trichoderma koningiopsis in an alternative substrate, consisting of fresh microalgal biomass. The immobilization efficiency was evaluated by monitoring the residual activity (RA) and the discoloration potential (DP) of a synthetic dye solution. Concomitantly, the catalytic properties of free POD were explored, and the most promising storage strategy to maintain the enzymatic activity was studied. RESULTS The novel guaiacol peroxidase expressed specific activity of up to 7801 U mg−1 in the free form, showing stability when subjected to up to 80°C in a pH range between 4.0-8.0. Furthermore, the bioproduct immobilized on magnetic nanoparticles expressed up to 689% RA and 100% DP. An increase in the RA of the enzyme, both in free and immobilized form, was also observed after storage for up to 8 months. The synthesized magnetic nanozymes showed good reusability, maintaining 13546 U mg−1 after ten cycles and removing 94% of color in a second batch. Toxicological evaluation with Allium cepa indicated that the enzymatic process of color removal with immobilized POD was essential to eliminate genotoxic effects. CONCLUSION T. koningiopsis peroxidase production and immobilization presented in our work are promising for the enzyme market and for the wastewater treatment technologies, considering its high bioxidative potential.

Histological Features of the Nasal Passage in Juvenile Japanese White Rabbits

Rabbits are sometimes used for intranasal toxicology studies. We investigated the postnatal development of the nasal passage in juvenile Japanese white rabbits from just after birth to 6-week-old to provide information for conducting intranasal toxicological evaluation using juvenile animals. On postnatal day (PND) 1, the nasal passage consisted of the septum with mostly cartilaginous nasal wall and turbinates. The lining squamous, transitional, respiratory, and olfactory epithelia were already distributed similar to adults and were still underdeveloped. The nasal passage gradually expanded with age, as did the nasal wall, including the turbinates formed by endochondral ossification. The maxilloturbinate elongated, during which it branched complexly. The respiratory epithelium takes the form of columnar epithelium together with a reduction in goblet cells. In addition, the olfactory epithelium had clear cytoplasm in the ethmoturbinate, the olfactory nerve bundles thickened, and Bowman’s gland acini increased in size and number. Other tissues, including the vomeronasal organ, nasal-associated lymphoid tissue, and nasolacrimal duct, also developed histologically with age. This investigation characterized the postnatal histological development of the nasal passage in Japanese white rabbits, providing basic knowledge regarding the histological examination and rationale for appropriate study design of intranasal toxicology studies in juvenile rabbits.

Biomedical Applications of Nanoparticles

In recent years, there has been significant growth and burgeoning interest in utilizing nanoparticles for various biomedical applications, including medical diagnostics, targeted drug delivery, tissue engineering, regenerative medicine, and biomedical textiles. In particular, nanoparticles functionalized with biological molecules have unique properties and are very effective in medical diagnostics. Besides that, nanoparticles have a wide range of therapeutic applications, including the development of nanodrug delivery systems, the design of novel drugs, as well as their contribution to the design of therapeutic materials. This chapter provides an overview of recent advancements in the biomedical applications of nanoparticles. Finally, this chapter discusses the challenges of the toxicological evaluation of engineered nanoparticles and the importance of conducting detailed studies on the synthesis of future nanomaterials to develop cutting-edge technologies for addressing a wide range of biomedical issues.

Hybrid skin chips for toxicological evaluation of chemical drugs and cosmetic compounds

Hybrid skin models for safety tests of drugs and cosmetics for topical application.

Accidental monensin poisoning in buffaloes in Bahia, Brazil

ABSTRACT: Monensin is an ionophore antibiotic (IA) widely used for growth promotion and weight gain in the production of ruminants. However, it has caused intoxication in several species, including buffaloes, mainly because of the ignorance or disrespect of the recommendations for use in each animal species. The objective of this study was to describe, for the first time, clinical-epidemiological and anatomopathological data of an outbreak of accidental poisoning by monensin in buffalos and rediscuss the recommendation of the use of IA in the production of this species. The outbreak affected 21 adult buffaloes after consumption of remains from a feed formulated on the farm and whose constituents were mixed by hand. Clinical and first death signs were observed 24 hours after ingestion of this food. In general, the clinical picture was characterized by muscle weakness, tremors, difficulty in locomotion, and decubitus. Fifteen buffaloes presented clinical signs of poisoning (71.5% morbidity), followed by death (100% lethality), after acute to subacute evolution (<24h to 96h). Laboratory tests indicated elevated serum activity of creatine phosphokinase and aspartate aminotransferase enzymes. Three buffaloes underwent necropsy, and samples from several organs were collected for histopathological examination. The main injuries found were hyaline degeneration and multifocal segmental necrosis in the skeletal and cardiac striated muscles (myopathy and degenerative-necrotic multifocal multifocal-necrotic cardiopathy). The diagnosis was confirmed by the toxicological evaluation of suspected ration remains, which detected 461.67mg/kg of monensin. The death of 71.5% buffaloes in this lot occurred due to a succession of errors, which included faults in the formulation of the ration and, above all, due to the use of monensin in a highly sensitive species. Despite the possible beneficial effects of IA use as a dietary supplement for buffaloes, we are of the opinion that IAs should never be used in bubalinoculture since any increment in production does not compensate for the imminent risk of death due to a small safety margin for this species and the absence of antidotes.

Antibacterial activity and toxicological evaluation of Anogeissusleiocarpus and Psidium guajava on Escherichia coli and Staphylococcus aureus

The study was carried out to determine the antibacterial activities and toxicological evaluation of Anogeissusleiocarpus and Psidiumguajava on Escherichia coli and Staphylococcus aureus isolated from clinical samples. The plants leaves were extracted using Hexane, Methanol, Ethanol and Water. Various concentrations (50, 25, 12.5 and 6.25mg/ml) of the crude extract of the plants were prepared and their antibacterial activity against Staphylococcus aureus and E. coli was determined using Agar well (Diffusion) method. Toxicity of the plants was evaluated, acute toxicity test, kidney and liver function tests. The result revealed that at 50mg/ml concentration, the leaf extract of Psidiumguajava was active against Staphylococcus aureus and E. coli exhibiting the highest zones of inhibition of 19mm and 9mm respectively. Whereas The leaf extract of Anogeissusleiocarpus only inhibited the growth of Staphylococcus aureus recording highest zone of inhibition of 15mm at a concentration of 50mg/ml. The plant extracts were found to be non-toxic as the LD50 was above 5000mg/kg and the biochemical parameters evaluated for both liver and kidney function tests revealed values that are within normal range. Hence the study established that consumption of the leaves of P.guajava for medicinal purpose can be said to be innocuous, as such the plant could be regarded as a potential candidate in the search of potent and harmless plants of therapeutic value.