Structural insights into the binding mode and conformational changes of BSA induced by bixin and crocin

Development of high internal phase emulsions with noncovalent crosslink of soy protein isolate and tannic acid: Mechanism and application for 3D printing

In this study, we propose a design strategy using soy protein isolate (SPI)-tannic acid (TA) complexes crosslinked through noncovalent interactions to develop high internal phase emulsions (HIPEs) for 3D printing materials. The results of Fourier transform infrared spectroscopy, intrinsic fluorescence, and molecular docking analyses indicated that the dominant interactions occurring between the SPI and TA were mediated by hydrogen bonds and hydrophobic interactions. The secondary structure, particle size, ζ-potential, hydrophobicity and wettability of SPI was significantly altered by the addition of TA. The microstructure of HIPEs stabilized by SPI-TA complexes exhibited more regular and even polygonal shapes, thereby allowing the protein to form a dense self-supporting network structure. When the concentration of TA exceeded 50 μmol/g protein, the formed HIPEs remained stable after 45 days of storage. Rheological tests revealed that the HIPEs exhibited a typical gel-like (G' > G'') and shear-thinning behavior, which contributed to preferable 3D printing behavior.

Multispectroscopic, virtual and in vivo insights into the photoaging defense mediated by the natural food colorant bixin

An upsurge in early onset of photoaging due to repeated skin exposure to environmental stressors such as UV radiation is a challenge for pharmaceutical and cosmeceutical divisions. Current reports indicate severe side effects because of chemical or synthetic inhibitors of matrix metalloproteases (MMPs) in anti-skin aging cosmeceuticals. We evaluated the adequacy of bixin, a well-known FDA certified food additive, as a scavenger of free radicals and its inhibitory mechanism of action on MMP1, collagenase, elastase, and hyaluronidase. The anti-skin aging potential of bixin was evaluated by several biotechnological tools in silico, in vitro and in vivo. Molecular docking and simulation dynamics studies gave a virtual insight into the robust binding interaction between bixin and skin aging-related enzymes. Absorbance and fluorescence studies, enzyme inhibition assays, enzyme kinetics and in vitro bioassays of human dermal fibroblast (HDF) cells highlighted bixin's role as a potent antioxidant and inhibitor of skin aging-related enzymes. Furthermore, in vivo protocols were carried out to study the impact of bixin administration on UVA induced photoaging in C57BL/6 mice skin. Here, we uncover the UVA shielding effect of bixin and its efficacy as a novel anti-photoaging agent. Furthermore, the findings of this study provide a strong foundation to explore the pharmaceutical applications of bixin in several other biochemical pathways linked to MMP1, collagenase, elastase, and hyaluronidase.

Strategies to meet the global demand for natural food colorant bixin: A multidisciplinary approach

Bixin is an apocarotenoid derived from Bixa orellana L. well known as a food colorant along with its numerous industrial and therapeutic applications. With the current surge in usage of natural products, bixin has contributed immensely to the world carotenoid market and showcases a spike in its requirement globally. To bridge the gap between bixin availability and utility, owed to its bioactivity and demand as a colouring agent in industries the sustainable production of bixin is critical. Therefore, to meet up this challenge effective use of multidisciplinary strategies is a promising choice to enhance bixin quantity and quality. Here we report, an optimal blend of approaches directed towards manipulation of bixin biosynthesis pathway with an insight into the impact of regulatory mechanisms and environmental dynamics, engineering carotenoid degradation in plants other than annatto, usage of tissue culture techniques supported with diverse elicitations, molecular breeding, application of in silico predictive tools, screening of microbial bio-factories as alternatives, preservation of bixin bioavailability, and promotion of eco-friendly extraction techniques to play a collaborative role in promoting sustainable bixin production.

Crocin induces autophagic cell death and inhibits cell invasion of cervical cancer SiHa cells through activation of PI3K/AKT

Background

Cervical cancer is a prevalent tumor mainly induced by Human Papilloma Virus (HPV). Autophagy was inactivated with HPV to promote cancer progression. Here we explored the effects of crocin on cervical cancer cells, mainly on autophagy and apoptosis.

Methods

SiHa cells were treated with crocin, and proliferation, metastases, apoptosis and autophagy were measured using a CCK-8 assay, transwell migration assay, flow cytometry and immunofluorescence. Protein levels were measured using western blotting. The antitumor effects of crocin were validated in female BALB/c nude mice injected with SiHa cells.

Results

The result showed that 2, 4, 8 and 16 mM of crocin significantly reduced the viability of SiHa cells within 24 h. Subsequently, 0, 1, 2 and 4 mM crocin concentrations were used in later experiments. Treatment with crocin reduced invasive cells, while increasing autophagic and apoptotic cells dose-dependently. The enhanced apoptosis and autophagy were partly validated by an increase in cleaved caspase-3/caspase-3, cleaved caspase-9/caspase9, LC3B II/I, Beclin1 and ATG7. AMPK and mTOR were inactivated with crocin treatment, while PI3K was activated. These results indicated that crocin might promote autophagy and apoptosis by inactivating AMPK and mTOR signaling. Tumor progression was inhibited in mice treated with 50 mg/kg/d of crocin, which was demonstrated by smaller tumor volumes, less VEGF expression, more intense caspase-3 staining and increased LC3B II/I in the tumor tissues.

Conclusions

Crocin inhibited the progression of cervical cancer in vitro and in vivo, possibly through inactivation of AMPK and mTOR, inhibition of proliferation and invasion, and promotion of autophagy and apoptosis. These results support the potential therapeutic value of crocin in treating cervical cancer.

Understanding the molecular interaction of human argonaute-2 and miR-20a complex: A molecular dynamics approach

Argonaute-2 (AGO2), a member of the Argonaute family, is the only member possessing catalytic and RNA silencing activity. In here, a molecular dynamics (MDs) simulation was performed using the crystal structure of human AGO2 protein complex with miR-20a. miR-20a is involved with various kind of biological process like heart and lung development, oncogenic process, etc. In precise, MD simulation was carried out with AGO2 protein complex with wild type, two mutant sites and four mutant sites in guided microRNA (miRNA). It has been noted that root-mean-square deviation (RMSD) of atomic positions of nucleic acid for wild type and two mutant sites guided miRNA has the same pattern of fluctuations, which stabilizes around 0.27 nm after 2 ns. Cα atom of AGO2 protein in the complex shows that this complex with wild type and two mutant site mutation duplex has a stable RMSD value after 20 ns, ranging between 0.14 and 0.21 nm. From the root-mean-square fluctuation (RMSF), we observed an increased pattern of fluctuations for the atoms of four mutant complex of AGO2-miR-20a complex. This increased RMSF of non-mutated nucleic acids is contributed by U-A bond breaking at the site of the nucleotide of U2 of guided miRNA, as observed from the duplex structure taken at different time steps of the simulation. Superimposed structure of the miRNA-mRNA duplex for the three complexes depicts that the three miRNA-mRNA duplexes are stable during the simulation. Current work demonstrates the possible correlations between the conformational changes of this AGO2-miR-20a duplex structure and the interactions of different atoms.

Probing the Protein-Protein Interaction Network of Proteins Causing Maturity Onset Diabetes of the Young

Protein-protein interactions (PPIs) play vital roles in various cellular pathways. Most of the proteins perform their responsibilities by interacting with an enormous number of proteins. Understanding these interactions of the proteins and their interacting partners has shed light toward the field of drug discovery. Also, PPIs enable us to understand the functions of a protein by understanding their interacting partners. Consequently, in the current study, PPI network of the proteins causing MODY (Maturity Onset Diabetes of the Young) was drawn, and their correlation in causing a disease condition was marked. MODY is a monogenic type of diabetes caused by autosomal dominant inheritance. Extensive research on transcription factor and their corresponding genetic pathways have been studied over the last three decades, yet, very little is understood about the molecular modalities of highly dynamic interactions between transcription factors, genomic DNA, and the protein partners. The current study also reveals the interacting patterns of the various transcription factors. Consequently, in the current work, we have devised a PPI analysis to understand the plausible pathway through which the protein leads to a deformity in glucose uptake.

Mutational analysis of microbial hydroxycinnamoyl-CoA hydratase-lyase (HCHL) towards enhancement of binding affinity: A computational approach

Improving the industrial enzyme for better yield of the product is important and a challenging task. One of such important industrial enzymes is microbial Hydroxycinnamoyl-CoA hydratase-lyase (HCHL). It converts feruloyl-CoA to vanillin. We place our efforts towards the improvement of its catalytic activity with comprehensive computational investigation. Catalytic core of the HCHL was explored with molecular modeling and docking approaches. Site-directed mutations were introduced in the catalytic site of HCHL in a sequential manner to generate different mutants of HCHL. Basis of mutation is to increase the interaction between HCHL and substrate feruloyl-CoA through interatomic forces and hydrogen bond formation. A rigorous molecular dynamics (MD) simulation was performed to check the stability of mutant's structure. Root mean square deviation (RMSD), root mean square fluctuation (RMSF), dynamic cross correlation (DCCM) and principal component analysis (PCA) were also performed to analyze flexibility and stability of structures. Docking studies were carried out between different mutants of HCHL and feruloyl-CoA. Investigation of the different binding sites and the interactions with mutant HCHLs and substrate allowed us to highlight the improved performance of mutants than wild type HCHL. This was further validated with MD simulation of complex consisting of different mutants and substrate. It further confirms all the structures are stable. However, mutant-2 showed better affinity towards substrate by forming hydrogen bond between active site and feruloyl-CoA. We propose that increase in hydrogen bond formation might facilitate in dissociation of vanillin from feruloyl-CoA. The current work may be useful for the future development of 'tailor-made' enzymes for better yield of vanillin.