Nanoporous Carbon Materials as Solid Contacts for Microneedle Ion-Selective Sensors.

Continuous sensing of biomarkers, such as potassium ions or pH, in wearable patches requires miniaturization of ion-selective sensor electrodes. Such miniaturization can be achieved by using nanostructured carbon materials as solid contacts in microneedle-based ion-selective and reference electrodes. Here we compare three carbon materials as solid contacts: colloid-imprinted mesoporous (CIM) carbon microparticles with ∼24-28 nm mesopores, mesoporous carbon nanospheres with 3-9 nm mesopores, and Super P carbon black nanoparticles without internal porosity but with textural mesoporosity in particle aggregates. We compare the effects of carbon architecture and composition on specific capacitance of the material, on the ability to incorporate ion-selective membrane components in the pores, and on sensor performance. Functioning K+ and H+ ion-selective electrodes and reference electrodes were obtained with gold-coated stainless-steel microneedles using all three types of carbon. The sensors gave near-Nernstian responses in clinically relevant concentration ranges, were free of potentially detrimental water layers, and showed no response to O2. They all exhibited sufficiently low long-term potential drift values to permit calibration-free, continuous operation for close to 1 day. In spite of the different specific capacitances and pore architecture of the three types of carbon, no significant difference in potential stability for K+ ion sensing was observed between electrodes that used each material. In the observed drift values, factors other than the carbon solid contact are likely to play a role, too. However, for pH sensing, electrodes with CIM as a carbon solid contact, which had the highest specific capacitance and best access to the pores, exhibited better long-term stability than electrodes with the other carbon materials.

Antidiabetic Potential and Antioxidant Activity of Olea europaea subsp. Cuspidata (Indian Olive) Seed Extracts.

The aim of the present study was to evaluate the antioxidant and antidiabetic potential of Indian olive seed extracts. Plant seeds were sequentially extracted with n-hexane, chloroform, methanol, and water. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging and alpha-amylase inhibitory activities of extracts were carried out. Olea europaea methanolic extract (MEOE) and aqueous extract (AEOE) were orally administered to normoglycemic and alloxan-treated diabetic rats so as to determine their hypoglycemic effect. High-performance liquid chromatography (HPLC) analysis showed gallic acid, ferulic acid, quercetin, and vanillic acid in MEOE. It was found that the methanolic and aqueous extracts exhibited the maximum DPPH and alpha-amylase inhibition activities, respectively. MEOE and AEOE exerted a significant decline in the fasting blood sugar in diabetic animals (p < 0.05); however, they did not cause hypoglycemia in nondiabetic animals. Treatment with MEOE and AEOE reduced the aggravated liver and kidney function biomarkers. Aggravated levels of oxidative stress biomarkers including superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and malondialdehyde (MDA) were restored by treatment with MEOE. Moreover, MEOE improved the count of islets of Langerhans in the pancreas, fatty changes, and enlarged sinusoidal spaces in the liver and necrosis of the glomerulus and tubular cells of the kidney in diabetic rats. This study showed that the African olive seed extract effectively managed experimental diabetes and restored the normal functions and histology of the liver and kidney in diabetic rats through the reduction of oxidative stress.

Morphological and Molecular Identification of Paramphistomum epiclitum from Buffaloes in Pakistan.

INTRODUCTION: Little is known about the genetic and morphological characters of Paramphistomum epiclitum. For the first time in Pakistan, adult flukes were morphologically characterized and the sequence variation in the nuclear ribosomal DNA (rDNA) region, including the first internal transcribed spacers (ITS1) and the 5.8S gene of the Paramphistomum epiclitum were studied. METHODS: Adult amphistomes were examined by light microscopy and sequences of ITS1 and 5.88S rDNA genes were obtained. RESULTS: Twenty adult flukes were measured, 13.17 ± 1.19 mm in length and 5.28 ± 1.34 mm in width. Seventeen adult flukes were sequenced and high sequence variability was observed in 5' end of ITS1 region. The 5.8S and 3' end of ITS1 sequences had 100% identity among the samples. A comparative analysis revealed that different types and numbers of repeats were found within each ITS1 region. The 3' end of ITS1 region from P. epiclitum showed 98% homology with P. cervi from China and formed a subclade with genetic distance of 0.1663. The 5.8S gene showed 100% identity within Paramphistomidae family and formed a sub-clade with P. epiclitum, P. leydeni, P. cervi and Cotylophoron cotylophorum species isolated from China, India and Uruguay. CONCLUSION: This work provides new information on morphological identity and genetics of P. epiclitum from Pakistan.

Antioxidant and alpha amylase inhibitory activities of Fumaria officinalis and its antidiabetic potential against alloxan induced diabetes.

Fumaria officinalis belongs to family papaveraceae and is traditionally used to treat hypertension, hepatitis and diabetes. The current study was conducted to evaluate in vitro and in vivo antidiabetic activity of Fumaria officinalis. Aerial parts of the plant were sequentially extracted with n-hexane, chloroform, methanol and water. Phytochemical analysis was carried out on all extracts. Antioxidant activity was determined by 2,2-diphenyl-1-picryl hydrazyl (DPPH) inhibition method. In vitro alpha-amylase inhibitory activity was performed on all extracts by using dinitrosalicylic acid. Effect of aqueous and methanolic extracts of F. officinalis on blood glucose was evaluated in normo-glycaemic rats and alloxan induced diabetic rats. Glimepiride 0.2 mg/kg was used as standard therapy in diabetic rats. Results showed that methanolic extract exhibited the maximum percentage inhibition of DPPH (86.30%) and alpha-amylase inhibition (94.01%) at 500 µg/ml and 16 mg/ml concentration respectively. Administration in normo-glycaemic rats did not show any significant decrease in blood glucose level at 500 and 750 mg/kg dosage. Aqueous and methanolic extracts exhibited a significant hypoglycaemic effect (p˂0.05) at all doses. A significant increase in the body weight and an improvement in liver and kidney function tests of diabetic rats were observed. These extracts also reduced the damage to the cells of glomeruli, interstitial inflammation, necrosis of tubular cells and thrombosis in the kidney, the enlargement of sinusoids and steatosis in the liver of diabetic rats. This study concludes that F. officinalis may have antidiabetic potential possibly due to its antioxidant and alpha-amylase inhibitory activities.