RESUMO
BACKGROUND: The progression of chronic pancreatitis (CP), an inflammatory disease of the pancreas, causes pancreatic stones to form within the pancreatic ductal lumen/parenchyma, which occurs via protein plug formation. Pain is the most common symptom that necessitates clinical attention, and pain relief is the therapeutic goal for these patients. Endoscopic therapy and surgery are complimentary forms of therapy for pain relief. This study was envisaged to clarify the mechanism by which protein plug/soft stones form in pancreatic ducts prior to undergoing calcification. METHODS: Protein plugs were obtained from twenty CP patients undergoing therapeutic ERCP for stone removal. Pancreatic juice was obtained from five CP patients without stones. Proteins were isolated by TCA/acetone precipitation, SDS PAGE and 2-D gel electrophoresis to determine the protein profile. Protein spots from the 2-D gel were excised and subjected to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) for identification. The effect of altered pH and elevated concentrations of trypsin on pancreatic juice protein was assessed by SDSâPAGE to determine the protein profile. Differentially expressed protein bands were excised and subjected to MALDI-TOF. In silico analysis was performed by docking lithostathine with the calcite molecule using AutoDock Vina and PyMOL to clarify their interaction during stone formation. RESULTS: Twenty-three and twenty-nine spots from 2D gels of protein plugs and pancreatic juice, respectively, revealed that lithostathine (Reg1A) was the only protein in the protein plugs, whereas digestive enzymes and lithostathine were identified in pancreatic juice. Altered pH levels and increased trypsin concentrations in the pancreatic juice caused a protein to degrade via an unknown mechanism, and this protein was identified as chymotrypsin C (CTRC) by MALDI-TOF. Docking studies showed that the binding affinity of calcite was higher with the cleaved lithostathine, explaining the deposition of calcium that was observed around the protein plugs after calcified stones were formed through precipitation. CONCLUSION: Our results suggest that chymotrypsin C (CTRC) is degraded in an acidic environment, leading to the precipitation of lithostathine in the ductal lumen.
RESUMO
Green synthesis of organic Pt-nanocomposite was accomplished using carboplatin as a precursor and novel biopolymer - gum kondagogu (GK) as a reducing agent. The synthesised GK stabilised organic Pt-nanocomposite (GKCPt NC) was characterised by different analytical techniques such as ultraviolet-visible spectroscopy, nanoparticle analyser, scanning electron microscopy and energy dispersive X-ray analysis, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma optical emission spectrophotometer. The XRD pattern established the amorphous nature of GKCPt NC. TEM analysis revealed the homogeneous, monodisperse and spherical nature, with Pt metal size of 3.08 ± 0.62â nm. The binding energy at 71.2 and 74.6â eV show the presence of metallic platinum, Pt(0) confirmed by XPS studies. Further, in vitro radical scavenging and antitumour activity of GKCPt NC have been investigated. In comparison to GK and carboplatin, GKCPt NC showed superior 1, 1-diphenyl-2-picrylhydrazyle activity of 87.82%, whereas 2, 2-azinobis-(3-ethylbenzthinzoline-6-sulphonic acid) activity was 38.50%, respectively. In vitro studies of the antitumour property of GK, GKCPt NC and carboplatin were evaluated by potato disc tumour bioassay model. The efficacy of synthesised GKCPt NC concentration (IC50) on tumour inhibition was found to be 2.04-fold lower as compared to carboplatin. Overall, the synthesised GKCPt NC shows both antitumour and antioxidant properties when compared to the original drug - carboplatin and might have promising applications in cancer therapy.