In Silico, In Vitro and Ex Vivo Evaluation of the Antihyperglycaemic, Antioxidant and Cytotoxic Properties of Coccinia grandis L. Leaf Extract.

Research background: Coccinia grandis L. is traditionally used for the treatment of diabetes mellitus. Since the scientific evidence and mechanism of action have not yet been extensively investigated, this study aims to evaluate the antidiabetic and cytotoxic effects together with the optimisation and development of a scale-up process design for higher yields of bioactive phytocompounds from C. grandis. Experimental approach: The in silico study was conducted to predict the binding affinity of phytocompounds of C. grandis for α-amylase and α-glucosidase enzymes involved in the pathophysiology of diabetes with pharmacokinetic assessment. Response surface methodology was used to determine the optimum total phenolic content (TPC), total flavonoid content (TFC), total tannin content (TTC) and antioxidant activities (DPPH and FRAP) in 17 different experimental runs in which the parameters of microwave-assisted extraction such as temperature (50-70 °C), power (400-1000 W) and time (15-45 min) were varied. The phytocompounds were purified and identified using column chromatography, thin-layer chromatography (TLC), UV-visible spectroscopy, Fourier transform infrared spectroscopy (FTIR) and liquid chromatography-mass spectrometry (LC-MS). The in vitro antidiabetic activity was determined by α-amylase and α-glucosidase enzymatic inhibitory assays, while cytotoxic investigations were done by measuring haemolytic activity, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) and chorioallantoic membrane (CAM) assays. Results and conclusions: The reported major bioactive compounds have shown an excellent binding affinity for α-amylase and α-glucosidase enzymes in the range of -14.28 to -36.12 kJ/mol with good pharmacokinetic properties and toxicities ranging from low to medium. The bioactive constituents such as total phenols, total flavonoids, total tannins and antioxidant activities such as DPPH and FRAP were found to be high and dependent on the optimised microwave-assisted extraction parameters such as temperature, time and power: 55 °C, 45 min and 763 W, respectively. Sixteen compounds were identified by FTIR and LC-MS spectra in the plant sample after preliminary identification, purification and TLC. The percentage of enzyme inhibition depended on the concentration of the extract (7.8-125.0 µg/mL) and was higher than that of acarbose. The haemolytic activity was in accordance with ISO standards and low toxicity was observed in the MTT and CAM assays in the range of 7.8-125.0 µg/mL, suggesting its potential use as an antidiabetic drug and for functional food development. Novelty and scientific contribution: The results of the study open up new opportunities for researchers, scientists and entrepreneurs in the food and pharmaceutical sectors to develop antidiabetic foods and medicines that help diabetics to better control their condition and maintain overall health.

High fibroin-loaded silk-PCL electrospun fiber with core-shell morphology promotes epithelialization with accelerated wound healing.

Silk fibroin (SF) is a widely explored biopolymer for wound-healing applications due to the presence of amino acids in the biodegradable polymer chain with superior mechanical properties. Herein, a high SF-loaded fibrous matrix along with poly(ε-caprolactone) (PCL) was fabricated using electrospinning of emulsion and blend compositions to modulate nanostructure morphology. A comparative study of the physicomechanical properties of electrospun fibers with emulsion (eS7P3) and homogenous blend (bS7P3) was performed as well. In both compositions, SF loading of up to 70% was successfully achieved in the spun fibers while emulsion yielded core-shell morphology, and the blend resulted in monolith fiber architecture as evidenced by TEM microscopy. Further characterization revealed superior mechanical properties in S7P3 fiber with core-shell morphology, as compared to those in the monolith in terms of a higher degree of crystallinity with Young's modulus of 60 MPa under tensile test and nanoindentation modulus of 1.59 ± 0.8 GPa. Further, eS7P3 nanostructure morphology containing silk in the core with a thin outer layer of PCL facilitated relatively faster biodegradation in the lysozyme medium, as compared to that in the monolith. Owing to the presence of a hydrophobic shell, protein adsorption on the fibrous mat presented slow but steady kinetics up to 24 h. When the scaffold was seeded with human placenta-derived mesenchymal stem cells (hPMSCs), in vitro study confirmed that the eS7P3 structure had marginally higher cell proliferation with superior cell infiltration than the monolith. Further, in vivo study involving a rodent model showed the potential of the eS7P3 fiber substrate with a core-shell structure for accelerating full-thickness wound healing by inducing hair follicle and wound closure with less scar formation after 15 days.

Role of nanofibers on MSCs fate: Influence of fiber morphologies, compositions and external stimuli.

In regenerative medicine, self-regulated tissue regeneration is perceived by Mesenchymal Stem Cells (MSCs) fate due to their tissue-specific differentiation, which is an emerging yet promising tool for therapeutics. MSCs with their innate nature like secretion of bioactive molecules, multilineage differentiation and proliferation supported tissue repair. MSCs interact with extracellular matrix (ECM) components like collagen, glycosaminoglycans (GAGs), proteoglycans and various proteins that are present in the form of nanofibers representing variable matrix elasticity along with topographies and bioactive cues. Synthetic nanofibers also showed to mimic native tissue microenvironment and supported regeneration owing to structural resemblance with ECM for anchorage-dependent cells. Different nanofibers generated using various polymer precursors and their resultant scaffolds, architectures, compositions etc. were studied for their influence on MSCs activities to improvise cell-cell and cell-material interactions. Electrospinning, popular nanotechnology for fiber formation based on electrohydrodynamic theory, is widely used for many applications due to its simplicity, efficacy and environmentally friendliness. Electrospun nanofibers were extensively investigated to understand the influence of material towards manipulating stem cells based on regenerative medicine. Subsequently, the influence of different solutions and process parameters were studied for nanofiber structure repeatability and emphasized on fiber properties such as diameter, mechanical properties, degradation rate, and porosity. Recent approaches towards scale-up for nanofiber production by electrospinning and other novel techniques are also presented briefly. The fate of MSCs, while seeded on nanofibers under external stimuli viz. electrical, mechanical, magnetic and electromagnetic field, is reviewed to find the niche for differentiation pathways. Further, several external stimuli presented as important factors motivating cellular differentiation in combination with specific conditions without the use of any chemical cues.