Chemosensing of honeybee parasite, Varroa destructor: Transcriptomic analysis.

Chemosensing is a primary sense in nature, however little is known about its mechanism in Chelicerata. As a model organism we used the mite Varroa destructor, a key parasite of honeybees. Here we describe a transcriptomic analysis of two physiological stages for the Varroa foreleg, the site of primary olfactory organ. The transcriptomic analysis revealed transcripts of chemosensory related genes belonging to several groups. These include Niemann-Pick disease protein, type C2 (NPC2), gustatory receptors (GRs), ionotropic receptors (IRs), sensory neuron membrane proteins (SNMPs) and odorant binding proteins (OBP). However, no insect odorant receptors (ORs) and odorant co-receptors (ORcos) were found. In addition, we identified a homolog of the most ancient IR co-receptor, IR25a, in Varroa as well as in other members of Acari. High expression of this transcript in the mite's forelegs, while not detectable in the other pairs of legs, suggests a function for this IR25a-like in Varroa chemosensing.

Evaluation of in vitro enzymatic and non-enzymatic antioxidant properites of leaf extract from Alpinia Purpurata (Vieill.) K. Schum / 中国结合医学杂志

<p><b>OBJECTIVE</b>To evaluate the enzymatic and non-enzymatic antioxidants of leaf extract from Alpinia purpurata.</p><p><b>METHODS</b>One gram of fresh leaf of Alpinia purpurata was grinded in 2 mL of 50% ethanol and centrifuged at 10,000×g at 4°C for 10 min. The supernatant obtained was used within 4 h for various enzymatic antioxidants assays like superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), ascorbate oxidase, peroxidase, polyphenol oxidase (PPO) and non-enzymatic antioxidants such as vitamin C, total reduced glutathione (TRG) and lipid peroxidation (LPO).</p><p><b>RESULTS</b>The leaf extract of Alpinia purpurata possess antioxidants like vitamin C 472.92±6.80 μg/mg protein, GST 372.11±5.70 μmol of 1-chloro 2,4 dinitrobenzene (CDNB)-reduced glutathione (GSH) conjugate formed/min/mg protein, GPx 281.69±6.43 μg of glutathione oxidized/min/mg protein, peroxidases 173.12±9.40 μmol/g tissue, TRG 75.27±3.55 μg/mg protein, SOD 58.03±2.11 U/mg protein, CAT 46.70±2.35 μmol of H2O2 consumed/min/mg protein in high amount whereas ascorbate oxidase 17.41±2.46 U/g tissue, LPO 2.71±0.14 nmol/L of malondialdehyde formed/min/mg protein and PPO 1.14±0.11 μmol/g tissue in moderate amount.</p><p><b>CONCLUSION</b>Alpinia purpurata has the potential to scavenge the free radicals and protect against oxidative stress causing diseases. In future, Alpinia purpurata may serve as a good pharmacotherapeutic agent.</p>