Antifatigue effects and antioxidant activity in polysaccharide fractions from Chinese yam bulbils.

Polysaccharides are the principal component in Chinese yam (Dioscorea opposita Thunb.) bulbils. The properties and antifatigue of polysaccharides from yam bulbils (PYB) were identified and compared. Their molecular weights (PYB-1 and PYB-2) were approximately 145 and 11 kDa, respectively, with active ß-configurations. Meanwhile, the antifatigue activities of PYBs were tested in mice via exhaustive swimming tests (EST). The EST results indicated that PYB-1 and PYB-2 significantly prolonged swimming time in mice (p < .05). Associated with this increase was a rise in hepatic glycogen content and antioxidant enzyme (superoxide dismutase (SOD), glutathione peroxidase (GSH-Px)) activity, along with a decline in blood urea nitrogen, lactic acid, and malondialdehyde levels. The results showed that molecular weight might contribute to the antifatigue effects of PYBs. Additionally, antioxidant tests showed that PYB-1 had stronger free-radical scavenging activity than PYB-2. Taken together, the findings indicated that PYBs exhibited effective antifatigue and antioxidant activities providing additional evidence supporting the use of PYBs as functional food ingredients for relieving fatigue.

A c-MWCNTs/AuNPs-based electrochemical cytosensor to evaluate the anticancer activity of pinoresinol from Cinnamomum camphora against HeLa cells.

A sensitive, simple, label-free electrochemical cytosensor was developed to evaluate the anticancer activity of pinoresinol against human cervical carcinoma (HeLa) cells. HeLa cells were immobilised on carboxylated multi-walled carbon nanotubes (c-MWCNTs)/gold nanoparticles (AuNPs) nanocomposite-modified glassy carbon electrodes. Scanning electron microscopy, transmission electron microscopy, Fourier transform-infrared spectroscopy, and X-ray diffractometry were used to characterise the morphology, crystallinity, and composition of the nanocomposites. Cyclic voltammetry was used to characterise and optimise the cytosensor. Both c-MWCNTs and AuNPs increased the electron-transfer rate between the HeLa cells and the electrode, retaining good cell compatibility. The concentration of HeLa cells immobilised on the nanocomposite electrode exhibited a good correlation with the impedance values determined by electrochemical impedance spectroscopy in the range of 102-106 cells/mL (detection limit of 102 cells/mL) with R2 = 0.975. HeLa cells were then immobilised on the nanocomposite electrode at a concentration of 104 cells/mL, and it was used as a cytosensor. The anticancer activity of pinoresinol from Cinnamomum camphora was evaluated by determining the median inhibitory concentration using the proposed cytosensor. For comparison, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and fluorescent imaging were simultaneously performed, which confirmed the results of the cytosensor. The cytosensor is promising for future applications in anticancer drug screening.