Synergistic Antioxidant and Antibacterial Activity of Curcumin-C3 Encapsulated Chitosan Nanoparticles.

BACKGROUND: Recent studies have focused on the nanoformulations of curcumin to enhance its solubility and bioavailability. The medicinal properties of curcumin-C3 complex, which is a combination of three curcuminoids (curcumin, demethoxycurcumin and bisdemethoxycurcumin) is less explored. OBJECTIVE: The aim of this study was to prepare curcumin-C3 encapsulated in chitosan nanoparticles, characterize and evaluate their antioxidant and antibacterial potential. METHODS: Ionic gelation method was used to prepare curcumin-C3 nanoparticles and was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy and nanoparticle tracking analysis. In vitro assays were performed to assess drug release, antioxidant and antibacterial activities. RESULTS: Curcumin-C3-chitosan nanoparticle showed an increased entrapment efficiency of >90%, drug release and improved antioxidant potential. Moreover, curcumin-C3-chitosan nanoparticle showed stronger inhibition of Escherichia coli and Staphylococcus aureus. CONCLUSION: Chitosan is a suitable carrier for curcumin-C3 nanoparticle and can be used as a drug delivery system in the treatment of inflammatory and bacterial diseases.

Curcumin-C3 Complexed with α-, ß-cyclodextrin Exhibits Antibacterial and Antioxidant Properties Suitable for Cancer Treatments.

BACKGROUND: The curcumin-C3 (cur-C3) complex obtained from Curcuma longa rhizome is a combination of three curcuminoids, namely, curcumin, dimethoxycurcumin, and bisdemethoxycurcumin. Cur and curcuminoids have been extensively researched for their wide range of therapeutic properties against inflammatory diseases, diabetes, and cancer. OBJECTIVE: In spite of their extensive medicinal properties, cur and curcuminoids have poor solubility and bioavailability due to their hydrophobicity. This limitation can be overcome by complexing cur-C3 with natural cyclic oligosaccharides, such as Cyclodextrin (CD). METHODS: In this study, cur-C3 and CD (α, ß) inclusion complexes (ICs) were prepared with different molar ratios and characterized by nuclear magnetic resonance, Fourier transform infrared spectroscopy, X-ray diffraction, and transmission electron microscopy. RESULTS: The cur-C3 cyclodextrin ICs showed an increased entrapment efficiency of 97.8% and improved antioxidant activity compared to cur and can be used as an antioxidant to reduce cancer-related oxidative stress. Additionally, α- CD ICs of curcumin-C3 caused an increase in growth inhibition of Staphylococcus aureus. CONCLUSION: Our findings suggest that both α- and ß-CDs are suitable carriers for cur-C3 and can be used as an effective treatment for cancer-associated oxidative stress and as a preventive treatment for nosocomial infections and pneumonia.

The Comparative Studies of Binding Activity of Curcumin and Didemethylated Curcumin with Selenite: Hydrogen Bonding vs Acid-Base Interactions.

In this report, the in vitro relative capabilities of curcumin (CCM) and didemethylated curcumin (DCCM) in preventing the selenite-induced crystallin aggregation were investigated by turbidity tests and isothermal titration calorimetry (ITC). DCCM showed better activity than CCM. The conformers of CCM/SeO3(2-) and DCCM/SeO3(2-) complexes were optimized by molecular orbital calculations. Results reveal that the selenite anion surrounded by CCM through the H-bonding between CCM and selenite, which is also observed via IR and NMR studied. For DCCM, the primary driving force is the formation of an acid-base adduct with selenite showing that the phenolic OH group of DCCM was responsible for forming major conformer of DCCM. The formation mechanisms of selenite complexes with CCM or DCCM explain why DCCM has greater activity than CCM in extenuating the toxicity of selenite as to prevent selenite-induced lens protein aggregation.

Comparison of safety and efficacy between fondaparinux and nadroparin in non-ST elevation acute coronary syndromes.

BACKGROUND: American College of Cardiology/American Heart Association/European Society of Cardiology (ACC/AHA/ESC) guidelines gave fondaparinux a class I recommendation for use in patients with non-ST elevation acute coronary syndromes (NSTE-ACS) undergoing invasive or conservative strategy. Nadroparin is one of the common anticoagulants used in NSTE-ACS in China. Accordingly, this study compared the safety and efficacy between fondaparinux and nadroparin in patients with NSTE-ACS. METHODS: In this prospective, randomized, open-label, and single center study, a total of 300 patients with NSTE-ACS were randomized to receive either fondaparinux (group F, n = 150, 2.5 mg/d) or nadroparin (group N, n = 150, 0.1 ml/10 kg q12 h) for a mean of 4 days. The primary safety endpoint was the incidence of major or minor bleeding at 9 days that was not related to coronary artery bypass grafting (CABG). The primary efficacy endpoints included death, myocardial infarction, or recurrent ischemia at 9 days. All patients underwent a 180-day follow-up. RESULTS: Baseline characteristics were well matched between the two groups. There was a non-significant 28% relative risk reduction in the primary safety endpoint in group F compared with group N (4.7% vs. 6.7%, HR 0.72, 95%CI 0.42-1.65, P = 0.38). The primary efficacy endpoint was 8.0% in group F and 10.0% in group N (HR, 0.82, 95%CI 0.54-1.71, P = 0.49). The composite of the safety and efficacy endpoints at 9 days (10.0% vs. 16.0%, HR 0.61, 95%CI 0.31-1.10, P = 0.10), 30 days (14.0% vs. 17.9%, HR 0.72, 95%CI 0.47-1.16, P = 0.21), or 180 days (18.7% vs. 27.3%, HR 0.65, 95%CI 0.38-1.11, P = 0.11) showed a non-significant trend toward a lower value in group F. CONCLUSION: Fondaparinux resulted in a nonsignificant risk reduction in patients with NSTE-ACS in both bleeding and ischaemic events during short- and long-term follow-up compared with nadroparin.

Ditopic complexation of selenite anions or calcium cations by pirenoxine: an implication for anti-cataractogenesis.

This study investigated whether and how pirenoxine (PRX) interacts with selenite or calcium ions, as these two ions have been proven respectively a factor leading to the formation of lens cataract. UV, NMR, and isothermal titration calorimetry (ITC) analysis indicated that PRX could bind maximum up to six selenite anions and the binding site preference was concentration dependent with the peripheral binding first followed by the π-π interactions with the aromatic moiety; while for calcium cation interaction the 3-carboxylate and ß-ketoimine functional groups were responsible for chelating calcium ions. The results obtained by MP2/6-31+G(d) molecular orbital calculations provided theoretical evidence in support of the π-π interactions between selenite and the PRX aromatic framework, and further analysis of the binding energies with the aromatic moiety indicates that these interactions take place most likely at the benzoquinone (ring I) π-system. The calcium binding preferences with PRX were also determined based on the stabilization energy obtained by B3LYP/6-31+G(d) calculations, showing the binding preferences were site 2 > site 1 > site 3 > ring II, consistent with the experimental data. The in vitro study of the reduction of selenite or calcium ions-induced lens turbidity by PRX with ditopic recognition properties was thus demonstrated. These results may provide a rationale for using PRX as an anti-cataract agent and warrant further biological studies.

Photophysical and electrochemical properties of new ortho-metalated complexes of rhodium(III) containing 2,2'-dipyridylketone and 2,2'-dipyridylamine. An experimental and theoretical study.

Two new ortho-metalated rhodium(III) complexes of the formula [Rh(ppy)(2)(L)](+), ppy = 2-phenylpyridine and L = 2,2'-dipyridylketone (dpk) (), 2,2'-dipyridylamine (HDPA) () have been synthesized and subjected to X-ray diffraction crystal structural, photophysical and electrochemical studies. Density functional theory calculations have also been performed to get rationalizations of the optical orbitals and redox orbitals concerning photophysical and electrochemical data. Complex exhibits the triplet ligand-to-ligand charge transfer ((3)LLCT) [pi(ppy)-pi*(dpk)] phosphorescence at 77K (520 nm) and at room temperature (555 nm), while complex shows triplet ligand centred ((3)LC) [pi-pi*(ppy)] phosphorescence only at 77K (460 nm). Both complexes and have similar irreversible oxidation potentials (+1.19 V for and +1.15 V for vs. Fc/Fc(+)). These two complexes show different characteristics in the reduction process: a reversible process occurs for at -1.31 V, while an irreversible process is observed for 2 at -1.85 V.