Interdigitated capacitive biosensor based on molecularly imprinted polymer for rapid detection of Hev b1 latex allergen

Allergen protein detection was performed by a surface imprinted layer combined with an interdigitated capacitance (IDC) transducer that allowed label-free measurements. The immobilized imprinted polymers are the probes that bind to rubber allergen proteins extracted from products such as rubber gloves. Copolymers made from methacrylic acid–vinylpyrrolidone–dihydroxyethylene-bisacrylamide (MAA–NVP–DHEBA) are soluble in aqueous solution and eliminate the denaturation of protein. When deposited as a coating onto an IDC microelectrode transduction system, such materials lead to sensors that produce capacitance responses that are clearly dependent on the concentration of the latex protein (10–900 ng ml⁻¹) in pH 7.4 buffer. The biosensor can detect Hev b1 within minutes and with a detection limit of 10 ng ml⁻¹. Different but related hevein allergenic proteins isolated from natural rubber latex from the rubber tree (Hev b1, Hev b2, and Hev b3) were distinguished by the imprinted material, depending on the dimension and conformation of these proteins with a selectivity factor of 4. They recognized Hevea latex proteins better than non-Hev b proteins, such as lysozyme, ovalbumin, and bovine serum albumin, by a factor of 2. Moreover, the sensor exhibited good operational stability of up to 180 days when used continuously at room temperature.     

Evaluation of In Vitro α‐Amylase and α‐Glucosidase Inhibitory Potentials of 14 Medicinal Plants Constituted in Thai Folk Antidiabetic Formularies

The sporadic increase in the occurrence and prevalence of diabetes mellitus have compelled and vigorous search for alternative anti‐diabetic therapeutic approach from medicinal plants and its bioactive. One of the major approach employed is the reduction of gastrointestinal glucose levels through the inhibition of carbohydrate digesting enzymes notably α‐amylase and α‐glucosidase. In this study, the ethanol extracts of 14 selected plants from Mor Porn's recipe were screened for their α‐amylase and α‐glucosidase inhibitory activity. The ethanolic extract from the stem of Vitex glabrata displayed the highest percentage inhibitory activity of 84.98 ± 0.59 and 84.71 ± 1.51 against α‐glucosidase and α‐amylase enzymes, respectively. Chemical investigation of the active extract of V. glabrata indicated that pentacyclic triterpenes were the major compounds responsible for the activity. The result obtained from this study suggests the potential use of V. glabrata as an alternative natural source for the treatment of diabetes mellitus.