Multiplatform Metabolomics to Understand the Imidacloprid-Induced Toxicity in Drosophila.

Neonicotinoids, the class of insecticides used for crop protection, are subjected to vigilance due to their pernicious impacts. Imidacloprid (IMD) is one of the most representative insecticides of the neonicotinoid family, which has shown unfriendly consequences for non-target species. Metabolomics, a multidisciplinary approach, is being used in toxicological research to understand the metabolic responses to toxicant exposure by utilizing modern analytical techniques. Yet, no solitary analytical technique can cover the broad metabolite spectrum, but a multi-technique metabolomics platform can aid in analyzing the majority of the metabolites. In the present study, an effort has been made to identify the differential metabolites in Drosophila after exposure to IMD at 2.5 and 25 ng/mL using liquid chromatography-high-resolution mass spectrometry (LC-HRMS), gas chromatography-MS (GC-MS), and NMR-based untargeted metabolomics. Multivariate pattern recognition analysis helped in identifying/recognizing 19 (LC-HRMS), 7 (GC-MS), and 13 (NMR) differential metabolites mainly belonging to the category of amino acids, sugars, fatty acids, and organic acids. The pathway analysis of differential metabolites predominantly showed impact on aminoacyl-tRNA biosynthesis, amino acid metabolism, and glycerophospholipid metabolism. Among these, arginine and proline metabolism was observed to be the common metabolic pathway perturbed in Drosophila due to IMD exposure. The multiplatform metabolomics based on LC-HRMS, GC-MS, and NMR analysis with an advanced level of statistical analysis can provide insights into potential perturbations in the metabolome of IMD-exposed Drosophila.

Synthesis, characterisation and anti-tumour activity of biopolymer based platinum nanoparticles and 5-fluorouracil loaded platinum nanoparticles.

A facile and green synthesis of platinum nanoparticles [gum kondagogu platinum nanoparticles (GKPtNP)] using biopolymer- gum kondagogu was developed. The formation of GKPtNP was confirmed by ultraviolet (UV)-visible spectroscopy, scanning electron microscopy-energy dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, Zeta potential, Fourier transform infrared, inductively coupled plasma mass spectroscopy. The formed GKPtNP are well dispersed, homogeneous with a size of 2-4 ± 0.50 nm, having a negative zeta potential (-46.1 mV) indicating good stability. 5-Fluorouracil (5FU) was loaded onto the synthesised GKPtNP, which leads to the development of a new combination of nanomedicine (5FU-GKPtNP). The in vitro drug release studies of 5FU-GKPtNP in pH 7.4 showed a sustained release profile over a period of 120 min. Agrobacterium tumefaciens induced in vitro potato tumour bioassay was employed for screening the anti-tumour potentials of GKPtNP, 5FU, and 5FU-GKPtNP. The experimental results suggested a complete tumour inhibition by 5FU-GKPtNP at a lower concentration than the GKPtNP and 5FU. Furthermore, the mechanism of anti-tumour activity was assessed by their interactions with DNA using agarose gel electrophoresis and UV-spectroscopic analysis. The electrophoresis results revealed that the 5FU-GKPtNP totally diminishes DNA and the UV-spectroscopic analysis showed a hyperchromic effect with red shift indicating intercalation type of binding with DNA. Over all, the present study revealed that the combined exposure of the nanoformulation resulted in the enhanced anti-tumour effect.

Binding Studies of Andrographolide with Human Serum Albumin: Molecular Docking, Chromatographic and Spectroscopic Studies.

BACKGROUND: Human serum albumin acts as a carrier protein to a variety of drugs and aids their transport. Andrographis paniculata, a herbal plant has been used as a source of traditional medicine in the Asian countries. Among the various constituents of this plant, andrographolide is the most active and is being used from centuries in the treatment of many chronic and infectious diseases. OBJECTIVE: The present study was designed to evaluate the interaction and binding affinity of andrographolide with HSA, by molecular docking, chromatographic and spectral studies. METHODS: Andrographolide was docked with crystal structure of human serum albumin (1AO6) using Auto Dock Vina software and the interactions were analyzed by a visualizing software py- MOL. For further characterization and confirmation, andrographolide (3x10-5 M) and HSA (0.001, 0.005, 0.01, 0.02, 0.04 M) sample mixtures were incubated at 37°C for 3h in a metabolic shaker, followed by centrifugation. The supernatant and the filtrate were analyzed by UV spectroscopy, HPLC, CD and FTIR spectral analysis. RESULTS: The docking studies revealed that andrographolide interacted with HSA and formed hydrogen bonds with Trp 214, Arg 218 and Lys 444 amino acid residues. The UV spectral analysis revealed a decrease in the absorption peak of HSA due to its interaction with andrographolide. A new peak was observed at retention time 7.45 min by HPLC analysis and the Bmax was found to be 7.5 ± 0.4 mg protein with a Kd value of 1.89 mM, indicating interaction of andrographolide with HSA. The CD spectra results suggested, a marginal decrease in the negative ellipticity without any significant shift in peak, indicating the stabilization of the HSA-andrographolide complex. The FTIR analysis of the andrographolide-HSA mixture showed a peak at wave number 1637 cm-1 (a shift of amide I groups from 1646 cm-1) and 1016 cm-1 which corresponded to the ligand, confirming the complex formation. CONCLUSION: The molecular docking studies demonstrated the interactions of andrographolide to the crystal structure of HSA. The chromatographic and spectroscopic analysis confirmed the binding of andrographolide with HSA and their complex formation. Overall the present studies conclude the binding of andrographolide to HSA protein, favoring its pharmacokinetics.