Metabolomics as a tool to evaluate the toxicity of formulations containing amphotericin B, an antileishmanial drug

Hyaluronic acid-Amphotericin B Nanocomplexes: a Promising Anti-Leishmanial Drug Delivery System

The development of an effective amphotericin B (AmB) formulation to replace actual treatments available for leishmaniasis, which present serious drawbacks, is a challenge. Here we report the development of hyaluronic...

Seasonal variation in serum metabolites of northern European dogs

Background

Metabolic profiling identifies seasonal variance of serum metabolites in humans. Despite the presence of seasonal disease patterns, no studies have assessed whether serum metabolites vary seasonally in dogs.

Hypothesis

There is seasonal variation in the serum metabolite profiles of healthy dogs.

Animals

Eighteen healthy, client‐owned dogs.

Methods

A prospective cohort study. Serum metabolomic profiles were assessed monthly in 18 healthy dogs over a 12‐month period. Metabolic profiling was conducted using a canine‐specific proton nuclear magnetic resonance spectroscopy platform, and the effects of seasonality were studied for 98 metabolites using a cosinor model. Seasonal component was calculated, which describes the seasonal variation of each metabolite.

Results

We found no evidence of seasonal variation in 93 of 98 metabolites. Six metabolites had statistically significant seasonal variance, including cholesterol (mean 249 mg/dL [6.47 mmol/L] with a seasonal component amplitude of 9 mg/dL [0.23 mmol/L]; 95% confidence interval [CI] 6‐13 mg/dL [0.14‐0.33 mmol/L], P < .008), with a peak concentration of 264 mg/dL (6.83 mmol/L) in June and trough concentration of 236 mg/dL (6.12 mmol/L) in December. In contrast, there was a significantly lower concentration of lactate (mean 20 mg/dL [2.27 mmol/L] with a seasonal component amplitude of 4 mg/dL [0.42 mmol/L]; 95% CI 2‐6 mg/dL [0.22‐0.62 mmol/L], P < .001) during the summer months compared to the winter months, with a peak concentration of 26 mg/dL (2.9 mmol/L) in February and trough concentration of 14 mg/dL (1.57 mmol/L) in July.

Conclusions and Clinical Importance

We found no clear evidence that seasonal reference ranges need to be established for serum metabolites of dogs.

Turning weakness into strength: Albumin nanoparticle-redirected amphotericin B biodistribution for reducing nephrotoxicity and enhancing antifungal activity

As the gold standard treatment for invasive fungal infection, amphotericin B (AmB) is limited by its severe nephrotoxicity. It has been shown that AmB complex with albumin in vivo forms a sub-10 nm nanocomplex within kidney excretion size range and eventually induces the nephrotoxicity. This study presents an approach to take advantage of the "weakness" of such unique interaction between AmB and albumin to form AmB nanocomplex beyond the size range of kidney excretion. Herein, a novel strategy was developed by directly assembling molecular BSA into larger-sized nanostructures with the reconstructed intermolecular disulfide bond and hydrophobic interaction. The rich binding sites of AmB within BSA nanostructures enabled the efficient AmB loading and forming nanoparticle (AmB-NP) which exceeds the size range of kidney excretion (~ 60 nm). We found nanoassembly with BSA redirected biodistribution of AmB with a 2.8-fold reduction of drug accumulation in the kidney and significantly improved its renal impairment in mice. Furthermore, we found that nanoassembly with BSA significantly increased the biodistribution of AmB in brain and endowed it 100-folds increase in pharmacological effect against meningoencephalitis caused by common fungal pathogen Cryptococcus neoformans. Together, this study not merely overcomes the nephrotoxicity of AmB using its "weakness" by a nanoassembly method, and provides a new strategy for reducing toxicity of drugs with high albumin binding rate in vivo.

Metabolomics Based Study of the Antileishmanial Activity of Xanthium strumarium Leaf Extract on Promastigotes Phases of Leishmania major by Proton NMR Spectroscopy

BACKGROUND

Xanthium strumarium L. is extensively used as a traditional herb to treat many diseases and is also known as a source of phytochemicals. It has been used traditionally to treat trypanosomiasis, malaria fever, eczema, cancer, ulcer, fever, herpes headache, and skin lesion such as leishmaniasis. In this preliminary study, nuclear magnetic resonance (NMR)-metabolomics approaches was used to evaluate the inhibitory effects and metabolic alterations caused by leaf extract of X. strumarium on the stationary phases of promastigotes in Leishmania major.

METHODS

The promastigotes were cultured in Biochemistry Laboratory at Pasteur Institute of Iran in 2017, stationary phases were obtained from 5 to 6 day-old cultures and treated with different concentrations of the plant's extract. Antileishmanial activity was assayed by MTT method and cell metabolites were extracted. ¹H NMR spectroscopy was applied, and outliers were separated using multivariate statistical analysis.

RESULTS

The most affected metabolic pathways in the experimental groups were limited to amino sugar and nucleotide sugar metabolism, cyanoamino acid metabolism, starch and sucrose metabolism, butanoate metabolism, and galactose metabolism.

CONCLUSION

The ethanolic leaf extract of X. strumarium is a potent growth inhibitor of Leishmania major and can affect vital metabolic pathways of Leishmania promastigotes. The assay provided new perspectives on the development of novel treatment strategies for leishmanial activity derived from natural products.