Brushite cements are known for excellent osteoconductive and degradation properties, however, its widespread use is limited due to rapid setting time and poor mechanical properties. The eggshell derived calcium phosphates exhibits improved physical and biological properties due to the presence of biologically relevant ions. In this study, eggshell derived brushite cement (EB) was fabricated using β-tricalcium phosphate synthesized from eggshells. The presence of trace elements in EB prolonged its setting time. The size of brushite crystals in EB was found to be smaller than the pure brushite cement (PB) leading to increased initial compressive strength and higher in vitro degradation rate. The L6 and MG63 cell lines exhibited good biocompatibility with the cement at the end 72 h. In vivo studies of the cements were performed in rat calvarial defect model. Micro CT analysis showed faster degradation and accelerated bone formation in EB filled defect. Histological studies revealed infiltration of inflammatory cells into the implant site for both the cements till 6th week. However, inflammation was found to be significantly reduced at the 12th week in EB compared to PB leading to complete bone bridge formation. Multi-ion substituted EB seems to be a potential bone substitute material with a reasonable setting time for ease of handling, higher mechanical strength, minimal inflammatory response and higher bone regeneration.

Background: Pioglitazone is an effective drug for the treatment of type 2 diabetes. The drug was suspended from Indian market in June 2013 due to the risk of bladder cancer but was reintroduced in July 2013 because its benefits outweighed the risks. The risks associated with pioglitazone can be minimized if its dose is reduced. Hypothesis: Ellagic acid, a polyphenolic antioxidant, is reported to reduce blood sugar in diabetic rats. The mechanism of anti-diabetic action of ellagic acid is not known. Drugs with same pharmacological action but different mechanism may act in synergistic way when combined together. The combination of ellagic acid with pioglitazone could enhance its activity and hence reduce its dose. Study design and methods: Diabetes was induced in Wistar rats by intraperitoneal administration of 175 mg of nicotinamide/kg body weight in combination with 65 mg of streptozotocin/kg body weight and then fed with high fat diet for 4 weeks (Group II-VII). Non-diabetic rats were fed with normal chow diet (Group I). Group I and II received vehicle only whereas group III to VII received ellagic acid, pioglitazone or their combination. The treatment was given orally once a day for 21 days. Results: The induction of type 2 diabetes in rats caused increase in blood glucose, LDL, triglyceride, and cholesterol and decrease in HDL. The diabetic rats showed improvement in hyperglycemia, dyslipidemia, liver and kidney function markers after treatment with ellagic acid, pioglitazone or their combinations. A combination of 10 mg of ellagic acid/kg BW with 10 mg of pioglitazone/kg BW resulted in significant improvement in all the biochemical parameters when compared to any of the individual treatment. The treatment of diabetic rats with the same combination significantly increased the expression levels of GLUT4, PPAR-gamma and adiponectin in skeletal muscle. Conclusion: The present study indicates that the dose of pioglitazone, required to achieve normoglycemia in diabetic rats, can be reduced by two folds by combining it with ellagic acid. The combinations reported here can be superior, since dose associated side effects and toxicity of the pioglitazone can be reduced.

Carbonated apatite has a chemical composition quite similar to biological apatite found in native bone. The incorporation of carbonate (CO2-3) ions groups into the apatitic crystal structure can tailor its crystallinity, solubility and biological activity that benefit the bone repair and regeneration. In this study, we report a simple and elegant method of synthesizing carbonated calcium deficient hydroxyapatite (ECCDHA) nanoparticles from egg shell wastes and its efficacy has been compared with synthetic calcium deficient hydroxyapatite (SCDHA) nanoparticles. Egg shell contains about 94% of calcium carbonate. Fourier transform infrared (FT-IR) spectroscopy results confirmed the carbonate substitution in the apatite as B-type and CHNS/O elemental analysis showed 6 wt.% of carbonate content in ECCDHA. Energy dispersive spectroscopy (EDS) analysis confirmed the presence of biologically relevant elements such as magnesium, strontium, fluoride, potassium etc., in ECCDHA inherited from the egg shell. In vitro cell culture studies confirmed that the ECCDHA is cellular compatible and it has enhanced cell adhesion and proliferation of L6 myoblast cells as compared to SCDHA. The potential of ECCDHA suitable for bone drug applications was tested with an antibiotic drug, doxycycline. The results showed higher drug loading and releasing for ECCDHA as compared to SCDHA during the period of study. Based on these results, the ECCDHA may be considered as a potential bone substitute and drug carrier system.

Polydimethyl siloxane (PDMS) is an excellent implant material for biomedical applications, but often fails as it is prone to microbial colonization which forms biofilms. In the present study CuO, CTAB capped CuO, and ZnO nanoparticles were tested as nanofillers to enhance the antibiofilm property of PDMS against Staphylococcus aureus and Escherichia coli. In general S. aurues (Gram positive and more hydrophobic) favor PDMS surface than glass while E. coli (Gram negative and more hydrophilic) behaves in a reverse way. Incorporation of nanofillers renders the PDMS surface antibacterial and reduces the attachment of both bacteria. These surfaces are also not cytotoxic nor show any cell damage. Contact angle of the material and the cell surface hydrophobicity influenced the extent of bacterial attachment. Cell viability in biofilms was dependent on the antimicrobial property of the nanoparticles incorporated in the PDMS matrix. Simple regression relationships were able to predict the bacterial attachment and number of dead cells on these nanocomposites. Among the nanocomposites tested, PDMS incorporated with CTAB (cetyl trimethylammonium bromide)-capped CuO appears to be the best antibacterial material with good cyto-compatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1075-1082, 2017.

Coumarins are natural polyphenol lactones comprising of fused rings of benzene and α-pyrone. The current study demonstrates the inhibitory effect of coumarins with various substitutions on Mycobacterium smegmatis mc2 155. We also demonstrate the effect of pomegranate (Punica granatum) extract containing ellagic acid, on M. smegmatis as well as their affect on MtbFtsZ (FtsZ from Mycobacterium tuberculosis). The ellagic acid extracts from pomegranate peels inhibit mycobacteria with a MIC of 25 μM and 0.3 to 3.5 mg/mL, respectively, but failed to inhibit the polymerization of MtbFtsZ. However, the coumarins were shown to inhibit the polymerization and GTPase activity of the protein as well as have an inhibitory affect on M. smegmatis mc2 155. Docking of the most active coumarin (7-Dimethyl-4-methyl coumarin with MIC of 38.7 μM) to the GTP binding site suggests that it interacted with the G103 residue. Based on the docking results two mutants of varying activity (G103S and G103A) were constructed to elucidate the interaction of MtbFtsZ and coumarins. Mutation of G103 with Serine (a bulky group) results in an inactive mutant and substitution with alanine produces a variant that retains most of the activity of the wild type. There is a disruption of the protofilament formation of the MtbFtsZ upon interaction with coumarins as demonstrated by TEM. The coumarins increase the length of Mycobacteria five times and MtbFtsZ localization is disturbed. The mutant proteins altered the GTPase and polymerization activity of coumarins as compared to wild type protein. The results here support that coumarins inhibit proliferation of Mycobacteria by targeting the assembly of MtbFtsZ and provide the possible binding site of coumarins on MtbFtsZ. This study may aid in the design of natural products as anti-mycobacterial agents. The currently reported GTP analogs for FtsZ are toxic to the human cell lines; natural coumarins targeting the GTP binding site of MtbFtsZ may hold promise as an important drug lead for tuberculosis treatment.

Background and purposeFerulic acid, an anti-oxidant phytochemical present in several dietary components, is known to produce wide range of pharmacological effects. It is approved for use in food industry as a preservative and in sports food. Previous reports from our lab have shown synergistic interaction of ferulic acid with metformin in cell lines and diabetic rats. The purpose of this review is to compile information about anti-diabetic activity of ferulic acid in in vitro and in vivo models with special emphasis on activity of ferulic acid when combined with metformin. The mechanism of synergistic interaction between ferulic acid and metformin is also proposed after carefully studying effects of these compounds on molecules involved in glucose metabolism.MethodsScientific literature for the purpose of this review was collected using online search engines and databases such as ScienceDirect, Scopus, PubMed and Google scholar.ResultsFerulic acid forms resonance stabilized phenoxyl radical which scavenges free radicals and reduce oxidative stress. It improves glucose and lipid profile in diabetic rats by enhancing activities of antioxidant enzymes, superoxide dismutase and catalase in the pancreatic tissue. Combining ferulic acid with metformin improves both, in vitro glucose uptake activity and in vivo hypoglycemic activity of the latter. It is possible to reduce the dose of metformin by four folds (from 50 to 12.5 mg/kg body weight) by combining it with 10 mg of ferulic acid/kg body weight in diabetic rats. Ferulic acid improves glucose uptake through PI3-K pathway whereas metformin activates AMPK pathway to improve glucose uptake.ConclusionThe synergistic interaction of ferulic acid and metformin is due their action on parallel pathways which are involved in glucose uptake. Due to synergistic nature of their interaction, it is possible to reduce the dose of metformin (by combining with ferulic acid) required to achieve normoglycemia. Since the dose of metformin is reduced, the dose associated side effects of metformin therapy can be reduced.

The complexes containing diethylamino substituents exhibit promising cytotoxicity against the estrogen receptor (ER) negative MDA-MB-231 breast cancer cell line.

The dual effect of FtsZ inhibition and oxidative stress by a group of 1,2-dihydroquinolines that culminate in bactericidal effect on mycobacterium strains is demonstrated. They inhibited the non-pathogenic Mycobacterium smegmatis mc(2) 155 with MIC as low as 0.9 μg/mL and induced filamentation. Detailed studies revealed their ability to inhibit polymerization and GTPase activity of MtbFtsZ (Mycobacterial filamentous temperature sensitive Z) with an IC50 value of ∼40 μM. In addition to such target specific effects, these compounds exerted a global cellular effect by causing redox-imbalance that was evident from overproduction of ROS in treated cells. Such multi-targeting effect with one chemical scaffold has considerable significance in this era of emerging drug resistance and could offer promise in the development of new therapeutic agents against tuberculosis.

Polyphenols are secondary metabolites formed in plants as a defense mechanism. More than 8000 polyphenols have been established naturally in food, including wine, tea, coffee, cocoa, vegetables, cereals, and fruits. Epidemiological studies advocate that dietary polyphenols beneficially prevent CVD and related metabolic disorders. Antioxidantive property, vasodilation and vascular protection, antiinflammation, antifibrotic, antiapoptotic, and metabolic activities were linked to the mechanistic properties of preventing CVD, type-2 diabetes, and obesity. Based on the observed health benefits of polyphenol, it may act as a potential alternative and additive therapy; and the use of nanotechnology in improving its bioavailability and efficiency will be a promising approach in preventing the noncommunicable diseases. Nanoformulations include liposomal formulations, nanoemulsions, lipid nanocapsules, emulsions, inclusion complexes, gels, and so on. In the chapter, we discuss the various nanotechnological applications to improve the functionalities of polyphenols and their mechanism of action in preventing CVD and related metabolic disorders.

The methanol extract of pomegranate peels was re-extracted with ethyl acetate. It was then evaporated to dryness. It was found to have a profound effect on the glucose uptake in L6 myotubes. The major constituents of this extract were ellagic acid and its glycosides and so further studies were carried out with pure commercial ellagic acid. Its effect on glucose uptake and expression of genes involved in the insulin signalling were investigated individually and in combination with a commercial drug, pioglitazone. They interact synergistically to increase insulin stimulated glucose uptake. Ellagic acid increases the expression of glucose transporter type 4 (GLUT4) and peroxisome proliferator-activated receptor gamma (PPAR-γ). Activation of the latter by pioglitazone upregulates adiponectin, but when combined with pure ellagic acid, this upregulation is achieved at lower concentrations of the drug. The current study proves that insulin sensitising activity of pioglitazone can be enhanced at low doses by combining it with ellagic acid.

Tetracalcium phosphate (TTCP) is the most basic phase among the calcium phosphate bioceramics. TTCP has been used as self setting bone cement and its relatively high surface pH seems to be very beneficial for cell adhesion and bone formation. Various attempts have been made to improve the cement properties for the ease of use during the surgical procedures. The effect of citric acid (CA) on the setting properties, apatite forming ability, strength and biological behavior of TTCP based bone cement has been studied in detail in the present study. The cement formulation containing 15 % CA has been found to have setting time between 9 and 16 min suitable for bone cement. It also showed complete conversion to apatite phase and highest compressive strength after 28 days of immersion in phosphate buffer at physiological conditions. Cell culture studies using rat skeletal muscle cells confirm higher cell viability in the CA containing cements compared to the pure cement without CA content. The results suggest that self-hardening tetracalcium phosphate based bone cement modified with CA holds a promise for its use in orthopaedic and trauma surgery.

Naturally occurring phytochemicals with reported antibacterial activity were screened for their ability to inhibit the bacterial cell division protein Escherichia coli FtsZ. Among the representative compounds, coumarins inhibit the GTPase and polymerization activities of this protein effectively. Further screening with ten coumarin analogs we identified two promising candidates, scopoletin and daphnetin. The former is found to inhibit the GTPase activity of the protein in a noncompetitive manner. Docking of these coumarins with the modeled protein indicate that they bind to T7 loop, which is different from the GTP-binding site (active site), thereby supporting the experimental data. Lowest binding energy is obtained with scopoletin. 3D QSAR indicates the need for groups such as hydroxyl, diethyl, or dimethyl amino in the 7th carbon for enhanced activity. None of the coumarins exhibited cytotoxicity against NIH/3T3 and human embryonic kidney cell lines. The length of Bacillus subtilis increases in the presence of these compounds probably due to the lack of septum formation. Results of this study indicate the role of coumarins in halting the first step of bacterial cell division process.

•Benzoquinone analog is identified as an activator of insulin receptor tyrosine kinase.•Modification of this molecule provided potent and specific activators of receptor.•Vanadium mimics insulin actions by inhibiting protein tyrosine phosphatases.•Specific activators of protein tyrosine phosphatase 1B have been designed.•Identification of such small molecules provided an opportunity to replace insulin.