Impact of bisphenol A and analogues eluted from resin-based dental materials on cellular and molecular processes: An insight on underlying toxicity mechanisms.

Dental resin systems, used for artificial replacement of teeth and their surrounding structures, have gained popularity due to the Food and Drug Administration's (FDA) recommendation to reduce dental amalgam use in high-risk populations and medical circumstances. Bisphenol A (BPA), an endocrine-disrupting chemical, is an essential monomer within dental resin in the form of various analogues and derivatives. Leaching of monomers from resins results in toxicity, affecting hormone metabolism and causing long-term health risks. Understanding cellular-level toxicity profiles of bisphenol derivatives is crucial for conducting toxicity studies in in vivo models. This review provides insights into the unique expression patterns of BPA and its analogues among different cell types and their underlying toxicity mechanisms. Lack of a consistent cell line for toxic effects necessitates exploring various cell lines. Among the individual monomers, BisGMA was found to be the most toxic; however, BisDMA and BADGE generates BPA endogenously and found to elicit severe adverse reactions. In correlating in vitro data with in vivo findings, further research is necessary to classify the elutes as human carcinogens or xenoestrogens. Though the basic mechanisms underlying toxicity were believed to be the production of intracellular reactive oxygen species and a corresponding decline in glutathione levels, several underlying mechanisms were identified to stimulate cellular responses at low concentrations. The review calls for further research to assess the synergistic interactions of co-monomers and other components in dental resins. The review emphasizes the clinical relevance of these findings, highlighting the necessity for safer dental materials and underscoring the potential health risks associated with current dental resin systems.

Unraveling the interaction of bisphenol A with collagen and its effect on conformational and thermal stability.

Evidence suggests the association of bisphenol A (BPA) with increased collagen (COL) expression in the development of fibrosis. Ultraviolet and fluorescence spectra on collagen-BPA interaction showed that 100 ng/ml of BPA initiated loosening of protein backbone through unfolding with exposure of tyrosine residues resulting in an intermediate "Molten Globule" state, which later aggregated with 1 µg/ml of BPA indicated with an apparent red-shift. Conformational changes with CD and ATR-FTIR showed disappearance of negative band with broadening and shifting of peptide carbonyl groups. Light scattering findings with TEM images presented initial dissolution followed by unordered thick fibrillar bundles with 30 µg/ml BPA. The complex was pH sensitive, with calorimetric thermogram revealing increased thermal stability requiring 83°C to denature. Hydrogen bonds of 2.8 Å with hydrophobic interactions of BPA in all grooves of collagen molecule with same pattern and binding energy (-4.1 to -3.9 kcal/mol) confirmed the intensity of aggregate formation via in-silico docking.

Elucidating the inhibitory mechanism of yeast α-glucosidase by phytocompounds from Scoparia dulcis through in vitro and in silico approach.

Antidiabetic activity of herb Scoparia dulcis Linn (SD) used in traditional medicine is well established, yet, the molecular mechanism is not understood. In this study, in vitro α-glucosidase inhibitory effects of SD aqueous extract and its kinetics were investigated and in silico analysis was carried out. SD showed potent inhibition of α-glucosidase with low IC50value (30 µg/mL). Enzyme kinetics analysis revealed the inhibition to be a mixed type of inhibition. From literature screening, we found that six compounds of SD to exhibit potent anti-diabetic activity, namely apigenin, betulinic acid, hispidulin, luteolin, scopadulcic-acid-B and scutellarein. These compounds were subjected to molecular docking. Docking studies revealed scopadulcic acid B and betulunic acid to show optimum binding constant and low free energy. Molecular dynamics simulation was carried out to further understand the interaction and stability between glucosidase and ligands of SD. Taken together, the study reveals that the potency of SD is due to synergistic effect of active phytochemicals in it and suggest that their properties can be utilized for anti-diabetic treatment strategies.Communicated by Ramaswamy H. Sarma.

Comparative evaluation of Emblica officinalis as an etchant and an MMP inhibitor with orthophosphoric acid and chlorhexidine on the microshear bond strength of composite resin: an ex vivo study.

OBJECTIVES: This study aimed to evaluate Emblica officinalis (Indian gooseberry or amla) as an acid etchant and matrix metalloproteinase (MMP) inhibitor, and to compare its effect on the microshear bond strength of composite resin with orthophosphoric acid (OPA) and 2% chlorhexidine (CHX) as an acid etchant and MMP inhibitor, respectively. MATERIALS AND METHODS: The etching effect and MMP-inhibiting action of amla on dentin samples were confirmed by scanning electron microscopy (SEM) and gelatin zymography, respectively. Dentinal slabs (3 mm thick) from 80 extracted human molars were divided into 10 and 20 samples to form 2 control groups and 3 experimental groups. Groups 1, 2, and 4 were etched with OPA and groups 3 and 5 with amla juice. An MMP inhibitor was then applied: CHX for group 2 and amla extract for groups 4 and 5. Groups 1 and 3 received no MMP inhibitor. All specimens received a standardized bonding protocol and composite resin build-up, and were subjected to microshear bond strength testing. The force at which the fracture occurred was recorded and statistically analyzed. RESULTS: Amla juice had a similar etching effect as a self-etch adhesive in SEM and 100% amla extract was found to inhibit MMP-9 by gelatin zymography. The microshear bond strength values of amla were lower than those obtained for OPA and CHX, but the difference was not statistically significant. CONCLUSIONS: Amla has a promising role as an acid etchant and MMP inhibitor, but further studies are necessary to substantiate its efficacy.