Introducing curcumin as an electrochemical DNA hybridization indicator and its application for detection of human interleukin-2 gene

Yellow-emitting carbon dots as fluorescent sensors for the rapid determination of curcumin

The non-standard use of curcumin could cause some adverse drug reactions, such as diarrhea, nausea and skin allergies. Thus, the curcumin determination was fundamental to disease treatment and prevention. Herein, a facile and efficient fluorescent probe was developed based on carbon dots, which was prepared through hydrothermal method (o-phenylenediamine and N-isopropylacrylamide as the reaction raw materials). Characteristics of the as-fabricated carbon dots (NCDs) were studied through some analysis techniques, such as UV-vis absorption spectroscopy, transmission electron microscopy, Fourier transform infrared instrument, X-ray photoelectron spectroscopy and fluorescence spectrophotometer. Fluorescence quenching phenomenon could be observed after addition of curcumin. This as-prepared fluorescent probe displayed a significant response for the determination of curcumin with a satisfactorily lower detection limit of 0.017 μM and a considerable linear range of 0.5-50 μM compared to reported literatures. Because of the preeminent repeatability and anti-jamming capability, the as-developed CDs suggested mighty potentiality for actual applications of curcumin detection in real samples and temperature sensing.

Curcumin Electrochemistry-Antioxidant Activity Assessment, Voltammetric Behavior and Quantitative Determination, Applications as Electrode Modifier

Curcumin (CU) is a polyphenolic compound extracted from turmeric, a well-known dietary spice. Since it has been shown that CU exerts beneficial effects on human health, interest has increased in its use but also in its analysis in different matrices. CU has an antioxidant character and is electroactive due to the presence of phenolic groups in its molecule. This paper reviews the data reported in the literature regarding the use of electrochemical techniques for the assessment of CU antioxidant activity and the investigation of the voltammetric behavior at different electrodes of free or loaded CU on various carriers. The performance characteristics and the analytical applications of the electrochemical methods developed for CU analysis are compared and critically discussed. Examples of voltammetric investigations of CU interaction with different metallic ions or of CU or CU complexes with DNA as well as the CU applications as electrode modifiers for the enhanced detection of various chemical species are also shown.

Wearable Natural Rubber Latex Gloves with Curcumin for Torn Glove Detection in Clinical Settings

Glove tear or perforation is a common occurrence during various activities that require gloves to be worn, posing a significant risk to the wearer and possibly others. This is vitally important in a clinical environment and particularly during surgical procedures. When a glove perforation occurs (and is noticed), the glove must be replaced as soon as possible; however, it is not always noticeable. The present article is focused on the design and development of a novel fluorescence-based sensing mechanism, which is integrated within the glove topology, to help alert the wearer of a perforation in situ. We hypothesized that natural rubber gloves with curcumin infused would yield fluorescence when the glove is damaged, particularly when torn or punctured. The glove design is based on double-dipping between Natural Rubber Latex (NRL) and an inner layer of latex mixed with curcumin, which results in a notable bright yellow-green emission when exposed to UV light. Curcumin (Cur) is a phenolic chemical found primarily in turmeric that fluoresces yellowish-green at 525 nm. The tear region on the glove will glow, indicating the presence of a Cur coating/dipping layer beneath. NRL film is modified by dipping it in a Cur dispersion solution mixed with NRL for the second dipping layer. Using Cur as a filler in NRL also has the distinct advantage of allowing the glove to be made stronger by evenly distributing it throughout the rubber phase. Herein, the optimized design is fully characterized, including physicochemical (fluorescence emission) and mechanical (tensile and tear tests) properties, highlighting the clear potential of this novel and low-cost approach for in situ torn glove detection.

Electrochemically activated pencil lead electrode as a sensitive voltammetric sensor to determine gallic acid

An electrochemical sensor for the determination of some polyphenolic compounds such as Gallic acid (GA) and Galloyl esters was developed using the activated pencil lead electrode (APLE). At first, a study has been made of the optimum conditions for electrochemical activation of the pencil lead electrode. Potentiodynamic and potentiostatic strategies were investigated for activation of the pencil lead electrode and the results show that the potentiodynamic pretreatment gives better performance toward measurement of the polyphenolic compounds. Electrochemical properties of GA were investigated using chronoamperometry and cyclic voltammetry; and some thermodynamic and kinetic variables such as α, n _α, and D were calculated. Sensitive differential pulse voltammetry (DPV) technique was applied for the determination of Gallic acid and Galloyl esters in different samples. Enhanced oxidation peak currents of Gallic acid were observed at APLE when compared with non-activated PLE. The calibration graph has two linear ranges of 0.49-24.3 µM and 0.07-0.83 mM, and the obtained limit of detection for S/N = 3 was 0.25 µM. Adsorptive stripping differential pulse voltammetry (AdSDPV) was also conducted to determine Gallic acid and Galloyl esters in sub-micromolar concentration range. Using the AdSDPV method, the limit of detection was improved and calculated to be 5.2 nM. The proposed method was successfully applied for quantification of the total concentration of Gallic acid and Galloyl esters in a variety of real samples such as black and green tea, and mango juice samples, and desirable recovery values indicated the good accuracy of the developed sensor.

Phytochemicals toward Green (Bio)sensing

Because of numerous inherent and unique characteristics of phytochemicals as bioactive compounds derived from plants, they have been widely used as one of the most interesting nature-based compounds in a myriad of fields. Moreover, a wide variety of phytochemicals offer a plethora of fascinating optical and electrochemical features that pave the way toward their development as optical and electrochemical (bio)sensors for clinical/health diagnostics, environmental monitoring, food quality control, and bioimaging. In the current review, we highlight how phytochemicals have been tailored and used for a wide variety of optical and electrochemical (bio)sensing and bioimaging applications, after classifying and introducing them according to their chemical structures. Finally, the current challenges and future directions/perspective on the optical and electrochemical (bio)sensing applications of phytochemicals are discussed with the goal of further expanding their potential applications in (bio)sensing technology. Regarding the advantageous features of phytochemicals as highly promising and potential biomaterials, we envisage that many of the existing chemical-based (bio)sensors will be replaced by phytochemical-based ones in the near future.

The role of curcumin and its derivatives in sensory applications

Curcumin has recently attracted much attention due to the wide range of its physiological actions such as anti-tumor, anti-inflammatory, anti-thrombotic, anti-diabetic and anti-microbial effects. This phytochemical can be used as a sensing material for the detection of chemicals due to its optical properties as a fluorescent polyphenol. Curcumin and its derivatives can make complexes with many cations such as Cu²⁺, Fe²⁺, Hg²⁺, Pt²⁺, Re³⁺ and Al³⁺via bearing 1,3-diketones with keto-enol isomerization. The complexation of curcumin with certain metal ions leads to its solubility in water and producing various hues of colors as well as cytotoxic and antimicrobial effects. Curcumin can also form complexes with certain metal ions and thus serve as a chelating agent for anions such as ClO^-, CN^-, F^- and S^2-. Moreover, conjugation of curcumin with some organic compounds such as cysteine and poly-glycerol acrylate provides an efficient fluorescence detection system for picric acid and 2-vinyl pyridine in aqueous media. In this review, we focused on curcumin as a key element in a membrane composition of chemical sensors. In addition, the latest sensing platforms based on curcumin and its derivatives are briefly described.

Y75B8A.8 (HC8) protein of Haemonchus contortus: A functional inhibitor of host IL-2

Interleukin 2 (IL-2) is an important immune regulatory factor in the immune response of the host. However, little is known about the inhibitor of host IL-2 in Haemonchus contortus infection. In this study, we found that globin domain-containing protein (HCGB) and Protein Y75B8A.8 (HC8) from H contortus excretory and secretory products are two binding proteins of IL-2 in goats. The yeast two-hybrid screening further validated the positive interactions of IL-2 with HCGB and HC8. Meanwhile, we found that HC8 had inhibitory effects on IL-2-induced peripheral blood mononuclear cell (PBMC) proliferation, while HCGB did not. Furthermore, transcriptional analysis revealed that HC8 could block the IL-2-activated signalling pathway. Our results showed that HC8 was a functional inhibitor of goat IL-2.

Effects of dexmedetomidine on TNF-α and interleukin-2 in serum of rats with severe craniocerebral injury

Background

Dexmedetomidine is a highly selective adrenergic receptor agonist, which has a dose-dependent sedative hypnotic effect. Furthermore, it also has pharmacological properties, and the ability to inhibit sympathetic activity and improve cardiovascular stability during an operation. However, its protective effect on patients with severe craniocerebral injury in the perioperative period remains unclear.

Method

Eighty adult male SD rats were used and divided into two groups (n = 40, each group): dexmedetomidine injury group (experimental group), and sodium chloride injury group (control group). Models of severe craniocerebral injury were established in these two groups using the modified Feeney’s free-fall method. As soon as the establishment of models was succeed, rat in the experimental group received 1 μg of dexmedetomidine (0.1 ml), while each rat in the control group was given 0.1 ml of 0.9% sodium chloride. Blood was sampled from an incision at the femoral vein to detect TNF-α and IL-2 levels at 1, 12, 24,36,48 and 72 h after establishing the model in the two groups.

Results

After severe craniocerebral injury, TNF-α levels of rats were lower in every stage and at different degrees in the experimental group than in the control group (P < 0.05), while IL-2 levels were lower in the experimental group to different extents (P < 0.05).

Conclusion

Dexmedetomidine protects the brain of rats with severe craniocerebral injury by reducing the release of inflammatory mediators.