Khaled Abo-EL-Sooud

PURPOSE: The antibacterial properties of silver nanoparticles (AgNPs) are extensively identified. In large quantities, they might be harmful. So many fields of nanotechnology have shown a great deal of interest in the development of an environmentally friendly, efficient method for synthesizing metal nanoparticles. Because of its antibacterial and antifungal properties toward a wide range of microbes, chitosan silver nanoparticles (AgNPs@Cs) constitute a newly developing class of bio-nanostructured hybrid materials. Furthermore, the use of photothermal therapy (PTT) has been suggested as a means of elimination of germs. These light-stimulated treatments are minimally invasive and have a few side effects. In the present work, the antibacterial effect of AgNPs at low concentrations; prepared by chemical and green methods as antimicrobial and photothermal agents in photothermal therapy; with laser irradiation were explored as combined treatment against MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae.

METHODS: Silver nanoparticles were produced in two ways. First, by sodium borohydrides, second, by chitosan (as a natural eco-friendly reducing, and capping agent). The nanostructure of AgNPs and AgNPs@Cs was confirmed by UV-visible spectrometer, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIRs), and direct light scattering (DLS). The antibacterial activity of the prepared nanoparticles and the laser irradiation was tested against three bacterial species of zoonotic importance; MRSA, Pseudomonas aeruginosa, and Klebsiella pneumoniae; and was evaluated by measuring their minimum inhibitory concentrations (MIC).

RESULTS: Silver nanoparticles produced by the two methods had spherical shapes with nearly the same particle size. The analysis of DLS showed that AgNPs were very stable with zeta potential - 28.8 mv, and 47.7 mv by chemical and chitosan synthesis, respectively. Furthermore, AgNPs@Cs showed higher antibacterial activity toward the tested bacterial species than AgNPs by chemical method. Additionally, the bacterial viability using photothermal laser therapy was reduced compared to laser and AgNPs alone. The bactericidal activities were higher when laser diode was coupled with AgNPs@Cs than by chemical reduction.

CONCLUSION: The laser combined treatment had a higher antimicrobial effect than AgNPs alone or laser irradiation alone.

AIM OF THE WORK: The study was conducted to evaluate the influence of theophylline pre-treatment on serum pharmacokinetics and milk elimination of tylosin following single intramuscular (IM) administrations in lactating goats.

METHODS AND RESULTS: In a cross-over study, tylosin was injected via intramuscular (IM) at a single dose of 15 mg/kg b.wt. After a one-month washout period goats received theophylline at a daily IM dose of 2 mg/kg b.wt. for seven consecutive days then tylosin was injected IM dose of 15 mg/kg b.wt. two hours after the last theophylline dosing. Blood samples were collected before and at 0.25, 0.5, 0.75, 1, 2, 4, 6, 8, 10, 12, and 24 h post-injection. Samples were left to clot and then centrifuged to yield serum. Milk samples were collected before and at 0.5, 1, 2, 4, 6, 8, 10, 12, 24, 48, and 72 h post-injection from each goat by hand milking. Tylosin serum concentrations were determined by high-performance liquid chromatography (HPLC). Tylosin concentrations versus time were analyzed by a noncompartmental method. Tylosin C significantly declined from 1.73 ± 0.10 to 1.01 ± 0.11 µg/ml, and attained T values of 2 and 1 h, respectively in theophylline-pretreated goats. Moreover, theophylline pretreatment significantly shortened the elimination half-life (t) from 6.94 to 1.98 h, t from 0.62 to 0.36 h and the mean residence time (MRT) from 8.02 to 4.31 h, also Vz/F and AUCs decreased from 11.91 to 7.70 L/kg and from 12.64 to 4.57 µg*h/ml, respectively, consequently, theophylline enhanced the clearance (Cl/F) of tylosin from the body. Similarly, tylosin milk concentrations were significantly lower in theophylline-pretreated goats than in goats that received tylosin alone and were detected up to 24 and 72 h in both groups, respectively. Moreover, the t and AUCs were significantly decreased from 14.68 ± 1.97 to 4.72 ± 0.48 h, and from 181 to 67.20 µg*h/ml, respectively.

CONCLUSIONS: The withdrawal period for tylosin in goat milk is at least 72 h. Theophylline pretreatment significantly decreases serum and milk tylosin concentrations to subtherapeutic levels, which could have serious clinical consequences such as failure of therapy. This means that after administering tylosin to goats, milk from these animals should not be consumed for at least 96 h to ensure that the milk is free from residues of the antibiotic.

BACKGROUND AND OBJECTIVES: Little is known about the implications of titanium dioxide nanoparticles (TiONPs) and cadmium chloride (Cd) co-exposure on the male reproductive system in mammals. As a result, this study researched the effects of oral TiONPs and/or Cd exposure on male reproduction and testicular functions. Additionally, a mitigation trial with co-enzyme Q10 (CoQ10) has also been conducted.

METHODS: In a 60-day experiment, seven experimental groups, each containing 10 male Sprague Dawley rats, were orally given distilled water (control), corn oil (vehicle control), CoQ10 (10 mg/kg b.wt), TiONPs (50 mg/kg b.wt), Cd (5 mg/kg b.wt), TiONPs + Cd, and TiONPs + Cd + CoQ10. Then, sperm quality, male sex hormones, oxidative stress indications, Ti and Cd testicular residues, testes and accessory gland architecture, and apoptotic and inflammatory markers in rat testes were assessed.

RESULTS: TiONPs and/or Cd exposure negatively impacted body weight, weight gain, testicular weights, semen quality, serum reproductive hormones, oxidative stress parameters, and Caspase-3 and tumor necrosis factor (TNF-α) immunoreactions. Histopathological changes were recorded in testicular, seminal vesicle, and prostatic tissues. Yet, co-administration of CoQ10 with TiONPs and Cd substantially mitigated these adverse consequences. The most notable aspect is that it effectively lowered testicular tissue Ti and Cd levels. It also improved oxidant status, hormonal profile, and sperm picture. CoQ10 minimized the testicular damage implied by histological examination. Furthermore, CoQ10 significantly diminished TiONPs and Cd-induced Caspase-3 and TNF-α immunoexpression in testicular tissue.

CONCLUSION: As a result, CoQ10 could be utilized as a safe remedy to protect male reproductive physiology from TiONPs and Cd damage.