Guar gum-enhanced emission of gold nanoclusters for α-glucosidase activity detection and anti-diabetic agents screening in plant extracts.

The development of efficient fluorescent methods for α-glucosidase (α-Glu) detection and α-Glu inhibitor screening plays a critical role in the therapy of type 2 diabetes (T2D). Herein, guar gum (GG), a high-abundant and non-toxic natural polymer originated from the seeds of a drought-tolerant plant, Cyamposis tetragonolobus, was found to be able to enhance the fluorescence emission of gold nanoclusters (AuNCs) probe. The emission enhancement effect was achieved by using GG at very low concentrations (<1.0 wt%) and presented in a viscosity-dependent manner through increasing solvent reorientation time and inhibiting intramolecular motions of AuNCs. Furthermore, the enhanced emission of the AuNCs was quenched by Fe3+via dynamic quenching and then restored by α-Glu. Accordingly, a fluorimetric method was proposed for the determination of α-Glu. Owing to the fluorescence enhancement effect of GG on the AuNCs probe, the detection limit of the approach was 0.13 U L-1 and the detection range was up to 5 orders of magnitude from 0.2 to 4000 U L-1, which was much better than most current α-Glu detection methods. The approach was further applied to α-Glu inhibitors screening from natural plant extracts, providing great prospects for the prevention and treatment of T2D.

Clinical effects of electrical stimulation therapy on lumbar disc herniation-induced sciatica and its influence on peripheral ROS level.

OBJECTIVE: To study the clinical effects of electrical stimulation therapy on lumbar disc herniation-induced sciatica and its influence on peripheral reactive oxygen species (ROS) level. METHODS: 100 patients with lumbar disc herniation-induced sciatica were selected, and were randomly divided into the control and research group. The control group was treated with traction and other basic therapies, while the research group was treated with electrical stimulation. The pain degrees, peripheral ROS levels and clinical effects prior to treatment and at 4 weeks after treatment were examined. RESULTS: The total cure-remarkable-effectiveness rate of patients in research group was higher than that in control group (p<0.05). Before treatment, the pain rating index (PRI), present pain intensity (PPI) and visual analogue scale (VAS) score had no statistically significant differences between the two groups. After treatment, PRI, PPI and VAS scores in the two groups were lower than those prior to treatment; these indexes in research group were lower than those in control group, and the differences were statistically significant (p<0.05). After treatment, the peripheral ROS levels in the two groups were lower than those before treatment; it was lower in research group than that in control group (p<0.05). CONCLUSION: Electrical stimulation has a significant effect in the treatment of lumbar disc herniation-induced sciatica, which can effectively reduce the pain, alleviate the clinical symptoms and signs of patients, regulate the peripheral ROS level, and prevent the oxidative damage of myocardial tissues.

Structural determination and antioxidant activity of a polysaccharide from the fruiting bodies of cultured Cordyceps sinensis.

A water-soluble polysaccharide named CPS1 had been isolated from C. sinensis mycelium by hot water extraction, ethanol precipitation, anion-exchange, and gel-permeation chromatography. UV spectra, FTIR spectra, partial acid hydrolysis, PMP precolumn derivation, periodate oxidation and Smith degradation studies were conducted to elucidate its structure. The results indicated that CPS1 was a glucomannogalactan with the monosaccharide composition of glucose: mannose: galactose = 2.8: 2.9: 1. The total carbohydrate content of CPS1 was 99.0%. The weight-average molecular weight was 8.1 x 10(3) Da. The results predicted (1-->2) and (1-->4)-linkage of mannose, (1-->3)-linkage of galactose, (1--> ) and (1-->3, 6)-linkage of glucose composed the backbone of CPS1. CPS1 was also evaluated for its antioxidant activity in vitro, including scavenging effects on the hydroxyl radicals, the reducing power, Fe(2+)-chelating activity, scavenging effect on superoxide radicals, as well as the inhibition of hydrogen peroxide induced haemolysis. CPS1 showed a high antioxidant effect, especially scavenging effect of hydroxyl radicals, the reducing power and Fe(2+)-chelating activity. The results provide scientific support for the antioxidant activity and indicated a connection between antioxidant activity and reparation of renal failure.