Magnesium Supplementation Alleviates the Toxic Effects of Silica Nanoparticles on the Kidneys, Liver, and Adrenal Glands in Rats

Concerns regarding the possible hazards to human health have been raised by the growing usage of silica nanoparticles (SiNPs) in a variety of applications, including industrial, agricultural, and medical applications. This in vivo subchronic study was conducted to assess the following: (1) the toxicity of orally administered SiNPs on the liver, kidneys, and adrenal glands; (2) the relationship between SiNPs exposure and oxidative stress; and (3) the role of magnesium in mitigating these toxic effects. A total of 24 Sprague Dawley male adult rats were divided equally into four groups, as follows: control group, magnesium (Mg) group (50 mg/kg/d), SiNPs group (100 mg/kg/d), and SiNPs+ Mg group. Rats were treated with SiNPs by oral gavage for 90 days. The liver transaminases, serum creatinine, and cortisol levels were evaluated. The tissue malondialdehyde (MDA) and reduced glutathione (GSH) levels were measured. Additionally, the weight of the organs and the histopathological changes were examined. Our results demonstrated that SiNPs exposure caused increased weight in the kidneys and adrenal glands. Exposure to SiNPs was also associated with significant alterations in liver transaminases, serum creatinine, cortisol, MDA, and GSH. Additionally, histopathological changes were significantly reported in the liver, kidneys, and adrenal glands of SiNPs-treated rats. Notably, when we compared the control group with the treated groups with SiNPs and Mg, the results revealed that magnesium could mitigate SiNPs-induced biochemical and histopathologic changes, confirming its effective role as an antioxidant that reduced the accumulation of SiNPs in tissues, and that it returns the levels of liver transaminases, serum creatinine, cortisol, MDA, and GSH to almost normal values.

Hepatotoxic effect of tramadol and O-desmethyltramadol in HepG2 cells and potential role of PI3K/AKT/mTOR

1. The aim of this study was to compare the in vitro cytotoxic effect of tramadol and M1 metabolite in HepG2 cell line, the underlying mechanism, and PI3K/AKT/mTOR as potential target.2. Concentrations representing therapeutic level for tramadol (2 µM) and M1 metabolite (0.5 µM) were used. In addition, other increasing concentrations representing higher toxic levels were used (6, 10 µM for tramadol and 1.5, 2.5 µM for M1 metabolites). Cytotoxicity was assessed at 24, 48 and 72 h.3. Both tramadol and M1 metabolites were able to produce cytotoxicity in a dose and time dependent manner. Insignificant difference was detected between cells exposed to tramadol and M1 metabolite at therapeutic concentrations. Tramadol-induced apoptotic and autophagic cell death while M1 metabolite-induced apoptosis only. For PI3K/AKT/mTOR pathway, the therapeutic concentration of tramadol was only able to increase phosphorylation of AKT while higher toxic concentrations were able to increase phosphorylation of whole pathway; Meanwhile, M1 metabolite was able to increase the phosphorylation of the whole pathway significantly in therapeutic and toxic concentrations.4. In conclusion, both tramadol and M1 are equally cytotoxic. Apoptosis and autophagy both mediate hepatic cell death. PI3K/AKT pathway is involved in apoptosis induction while autophagy is regulated through mTOR independent pathway.

Crucial Role of PLGA Nanoparticles in Mitigating the Amiodarone-Induced Pulmonary Toxicity

BACKGROUND

Amiodarone (AMD) is a widely used anti-arrhythmic drug, but its administration could be associated with varying degrees of pulmonary toxicity. In attempting to circumvent this issue, AMD-loaded polymeric nanoparticles (AMD-loaded NPs) had been designed.

MATERIALS AND METHODS

AMD was loaded in NPs by the nanoprecipitation method using two stabilizers: bovine serum albumin and Kolliphor® P 188. The physicochemical properties of the AMD-loaded NPs were determined. Among the prepared NPs, two ones were selected for further investigation of spectral and thermal analysis as well as morphological properties. Additionally, in vitro release patterns were studied and kinetically analyzed at different pH values. In vitro cytotoxicity of an optimized formula (NP4) was quantified using A549 and Hep-2 cell lines. In vivo assessment of the pulmonary toxicity on Sprague Dawley rats via histopathological and immunohistochemical evaluations was applied.

RESULTS

The developed NPs achieved a size not more than 190 nm with an encapsulation efficiency of more than 88%. Satisfactory values of loading capacity and yield were also attained. The spectral and thermal analysis demonstrated homogeneous entrapment of AMD inside the polymeric matrix of NPs. Morphology revealed uniform, core-shell structured, and sphere-shaped particles with a smooth surface. Furthermore, the AMD-loaded NPs exhibited a pH-dependent and diffusion-controlled release over a significant period without an initial burst effect. NP4 demonstrated a superior cytoprotective efficiency by diminishing cell death and significantly increasing the IC50 by more than threefold above the pure AMD. Also, NP4 ameliorated AMD-induced pulmonary damage in rats. Significant downregulation of inflammatory mediators and free radicle production were noticed in the NP4-treated rats.

CONCLUSION

The AMD-loaded NPs could ameliorate the pulmonary injury induced by the pure drug moieties. Cytoprotective, anti-fibrotic, anti-inflammatory, and antioxidant properties were presented by the optimized NPs (NP4). Future studies may be built on these findings for diminishing AMD-induced off-target toxicities.

Appraisal of amiodarone-loaded PLGA nanoparticles for prospective safety and toxicity in a rat model

AIMS

Amiodarone (AM) is a highly efficient drug for arrhythmias treatment, but its extra-cardiac adverse effects offset its therapeutic efficacy. Nanoparticles (NPs)-based delivery system could provide a strategy to allow sustained delivery of AM to the myocardium and reduction of adverse effects. The primary purpose was to develop AM-loaded NPs and explore their ameliorative effects versus off-target toxicities.

MATERIALS AND METHODS

Polymeric NPs were prepared using poly lactic-co-glycolic acid and their physicochemical properties were characterized. Animal studies were conducted using a rat model to compare exposure to AM versus that of the AM-loaded NPs. Biochemical evaluation of liver enzymes, lipid profile, and thyroid hormones was achieved. Besides, histopathological changes in liver and lung were studied.

KEY FINDINGS

Under optimal experimental conditions, the AM-loaded NPs had a size of 186.90 nm and a negative zeta potential (-14.67 mV). Biochemical evaluation of AM-treated animal group showed a significant increase in cholesterol, TG, LDL, T4, and TSH levels (ρ < 0.05). Remarkably, the AM-treated group exhibited a significant increase of liver enzymes (ρ < 0.05) coupled with an obvious change in liver architecture. The AM-loaded NPs displayed a reduction of liver damage and enzyme levels. Lung sections of the AM-treated group demonstrated thickening of interalveolar septa, mononuclear cellular infiltration with congested blood vessels, and heavy collagenous fibers deposition. Conversely, less cellular infiltration and septal thickening were observed in the animal lungs treated with the AM-loaded NPs-treated.

SIGNIFICANCE

Our findings demonstrate the competence of the AM-loaded NPs to open several exciting avenues for evading the AM-induced off-target toxicities.