No abstract

Single-stranded DNA (ssDNA) is a prerequisite for electrochemical sensor-based detection of parasite DNA and other diagnostic applications. To achieve this detection, an asymmetric polymerase chain reaction method was optimised. This method facilitates amplification of ssDNA from the human lymphatic filarial parasite Wuchereria bancrofti. This procedure produced ssDNA fragments of 188 bp in a single step when primer pairs (forward and reverse) were used at a 100:1 molar ratio in the presence of double-stranded template DNA. The ssDNA thus produced was suitable for immobilisation as probe onto the surface of an Indium tin oxide electrode and hybridisation in a system for sequence-specific electrochemical detection of W. bancrofti. The hybridisation of the ssDNA probe and target ssDNA led to considerable decreases in both the anodic and the cathodic currents of the system's redox couple compared with the unhybridised DNA and could be detected via cyclic voltammetry. This method is reproducible and avoids many of the difficulties encountered by conventional methods of filarial parasite DNA detection; thus, it has potential in xenomonitoring.

Objective: The present study was designed to evaluate the bioavailability of nano encapsulated DDA (nano-DDA) in experimental diabetic rats. Methods:Polycaprolactone was used as a polymer to encapsulate 14-deoxy-11, 12-didehydroandrographolide (DDA) using solvent evaporation technique in order to improvise the bioavailability of the drug. Male albino wistar rats were induced with single intraperitoneal injection of nicotinamide (110 mg/kg) followed by streptozotocin (45 mg/kg) to induce experimental diabetes. Free DDA and nano-DDA were orally administered to the experimental diabetic rats for 45d and blood glucose level was monitored periodically. After one week washout period, free DDA and nano-DDA were orally administered to the rats and blood samples were collected at predetermined intervals. Plasma concentration of DDA was determined by highperformance liquid chromatography (HPLC). Pharmacokinetic analysis was carried out to determine the oral bioavailability.Results: 50 mg of nanoparticle-containing 9.4 mg of DDA exhibited a significant decrease in blood glucose level (105.6±2.99 mg/dL), on par with the free drug administered (50 mg/kg). The nano-DDA accomplished a significant increase in Cmax (961.7±8.78ng) and area under the curve (AUC) (2631±6.98 h X ng/ml) than free DDA. A significant increase in the oral bioavailability was witnessed for nano-DDA (absolute bioavailability% = 34.94±0.231%), which was 10.8 times higher than the free DDA (3.234±0.062 %) and substantiated a slow and sustained drug release from the polymer matrix. Conclusion:Our results substantiated that nanoencapsulation of DDA, enhanced the oral bioavailability of DDA than the free drug in vivo. Nano-DDA can thus serve as a bioactive molecule in the quest for new antidiabetic nano drug discovery.