Lianfu Zhang

Anti-fatigue activity of polysaccharide fractions from Lepidium meyenii Walp. (maca)

The two fractions of polysaccharide MPS-1 and MPS-2 were extracted from Lepidium meyenii Walp. (maca) by water, and purified using a DEAE-52 and a Sephadex G-100 column. The molecular weight (MW) of MPS-1 was 7.6kDa, and the MW of MPS-2 was 6.7kDa. The MPS-1 was composed of xylose, arabinose, galactose and glucose, with the mole ratio 1:1.7:3.3:30.5; the MPS-2 was composed of arabinose, galactose and glucose, with the mole ratio 1:1.3:36.8. The IR spectrum implied that only α-pyranose existed in MPS-1, and both α-pyranose and β-pyranose existed in MPS-2. The anti-fatigue activities of MPS-1 and MPS-2 were measured by the forced swimming test, along with the determination of blood lactate (BLA), urea nitrogen (BUN), lactic dehydrogenase (LDH) activity and liver glycogen (LG). The results indicated that both MPS-1 and MPS-2 presented dose-dependently positive effects on the fatigue related parameters. Additionally, MPS-2 has a better anti-fatigue effect than MPS-1.

Highly efficient trans–cis isomerization of lycopene catalyzed by iodine-doped TiO2 nanoparticles

Highly efficient trans–cis isomerization of lycopene was achieved in the presence of a novel iodine-doped titanium dioxide (I-TiO2) catalyst. The catalyst was prepared via a hydrothermal route and subsequent vacuum calcination and was characterized with thermogravimetric analysis, X-ray diffraction, nitrogen adsorption–desorption isotherms, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy techniques. Factors that affected the reaction parameters, such as the reaction temperature, the concentration of substrate, the weight of the catalyst and the reaction time, were investigated in detail. Application tests showed that the catalyst was highly active in the isomerization of lycopene in a heterogeneous reaction, and the conversion of all-trans-lycopene exceeded 80% after 2 h of reaction at 75 °C in ethyl acetate. Moreover, the catalyst displayed no significant loss of activity after five cycles of reuse.

Lycopene: Heterogeneous Catalytic E/Z Isomerization and In Vitro Bioaccessibility Assessment Using a Diffusion Model.

Highly efficient heterogeneous catalytic E/Z isomerization of lycopene was achieved using an iodine-doped titanium dioxide (I-TiO2 ) catalyst prepared by sol-gel method. The effects of reaction temperature and reaction time were investigated in detail. The maximum total Z-ratio of lycopene exceeded 78% after 2 h of refluxing at 75 °C in ethyl acetate. Moreover, lycopene samples with a series of total Z-ratios were prepared and the bioaccessibility of these samples was estimated using a diffusion model, the results showed that the bioaccessibility of lycopene markedly increased conforming to a linear regression model with increasing of the total Z-ratio of lycopene from 3.6% to 78.5%. Furthermore, the specific role of the microstructure and melting point of 3.6% and 78.5% total Z-ratio of lycopene was also investigated to understand the probable mechanism for the enhanced bioaccessbility of (Z)-lycopenes.

Effect of drying methods on physico-chemical properties and antioxidant activity of Dendrobium officinale

The present study aimed to investigate the effect of different drying methods, i.e., sun drying (SD), hot air drying (AD), vacuum drying (VD), infrared radiation drying (IR), and freeze drying (FD) on the physico-chemical properties of Dendrobium officinale. The results revealed that different drying methods showed significant differences in the color retention, water soluble polysaccharide content, total phenolic content, total flavonoid content, fatty acids, and antioxidant activities. FD, VD, IR and AD led to higher retention of bioactive compounds and better antioxidant activities, and FD showed the best. However, with respect to the water-soluble polysaccharides content, the characteristic components in D. officinale, AD was better than FD. The results showed that the quality of D. officinale depends on the drying method applied. Considering the retention of polysaccharide content and drying processing duration, AD is a promising treatment for D. officinale.

Polysaccharides from Diaphragma juglandis fructus: Extraction optimization, antitumor, and immune-enhancement effects

This study discusses the optimization of the microwave-assisted extraction of polysaccharides from Diaphragma juglandis (DJPs). One main fraction (DJP-2) was successfully purified by ion-exchange chromatography and gel-permeation chromatography. The results showed that the optimal extraction conditions with DJP extraction yield of 4.7 ± 0.28% were water to raw material ratio of 20 mL/g, extraction time of 40 min, and microwave extraction power of 400 W. Bioassays indicated that DJP-2 could effectively suppress the proliferation of HepG2 and BGC-82 cell lines. In addition, DJP-2 could significantly enhance phagocytosis; stimulate the production of NO, tumor necrosis factor-α (TNF-α), and interleukins (IL-6 and IL-1β); and promote their corresponding mRNA expression levels in a dose-dependent manner. Meanwhile, CR3, MR, and TLR2 were confirmed to be the major membrane receptors of DJP-2 on RAW 264.7. All these results indicated that DJP-2 could be a potential antitumor and immunomodulatory agent in the field of pharmacology.

Preparation and characterization of Dendrobium officinale powders through superfine grinding

BACKGROUND Dendrobium officinale has been used in China for several thousand years as a health food and has become one of the most expensive tea materials worldwide as a result of extremely scarce resources in the wild and an increasing demand. Hence, it is very important to improve the depth and width of its application. In the present study, the physico-chemical, surface chemistry and thermal properties of micron range particles and coarse particles prepared by superfine grinding and shear pulverization were investigated. RESULTS As the particle size decreased, the specific surface area of D. officinale powders increased significantly. Microscopy observations confirmed that superfine grinding effectively changed the original structure of D. officinale. The Fourier transform infrared spectroscopy spectra depicted the characteristic bands shifted in terms of absorbance and/or wave number as the powder particle size decreased. The crystallinity and intensity of the crystal peaks of D. officinale powders increased as the particle size decreased. Moisture sorption isotherms suggested that superfine powders were more unstable as a result of the increase in surface area, as well as the exposure of polar groups. CONCLUSION The results of the present study suggest that superfine grinding may provide new methods of processing for D. officinale with respect to further enhancement of its application value.

Protective Effects of Lepidium meyenii (Maca) Aqueous Extract and Lycopene on Testosterone Propionate‐Induced Prostatic Hyperplasia in Mice

The inhibitory effect of maca extractant, lycopene, and their combination was evaluated in benign prostatic hyperplasia (BPH) mice induced by testosterone propionate. Mice were divided into a saline group, solvent control group and testosterone propionate‐induced BPH mice [BPH model group, solvent BPH model group, benzyl glucosinolate group (1.44 mg/kg), maca group (60 mg/kg), lycopene treated (15, 5, and 2.5 mg/kg), maca (30 mg/kg) combine lycopene treated (7.5, 2.5, and 1.25 mg/kg), and finasteride treated]. Benzyl glucosinolate was used in order to evaluate its pharmacological activity on BPH to find out whether it is the major active component of maca aqueous extract. Finasteride was used as positive control. The compounds were administered once for 30 successive days. Compared with solvent BPH model group, BPH mice fed with maca (30 mg/kg) and lycopene (7.5 mg/kg) combination exhibited significant reductions in the prostatic index, prostatic acid phospatase, estradiol, testosterone, and dihydrotestosterone levels in serum. They also had similar histological compared with those aspects observed in the mice in the solvent control group. The results indicated that combination of maca and lycopene synergistically inhibits BPH in mice. Copyright

Effects of Different Drying Methods on Physico-Chemical Properties of Dendrobium Officinale

Dendrobium officinale has been used in China for several thousand years as a health food and a source of nutrients. The aim of this study was to investigate the effects of different drying methods on the characterization of D. officinale. The physico-chemical properties, i.e color retention, shrinkage rate, functional components contents, moisture sorption isotherms and FTIR spectrum of D. officinale samples through sun drying (SD), oven drying (OD), vacuum drying (VD), infrared radiation drying (ID) and freeze drying (FD) were investigated. The results revealed that different drying methods showed significant difference on color retention, shrinkage rate and water soluble polysaccharides content of D. officinale, but not total dendrobine or protein content. As can be seen from the FTIR spectra, no new chemical bonds were produced between different dried D. officinale samples. In the same water activity, the moisture content in freeze dried samples at equilibrium was slightly higher compared with other four samples. FD samples presented the best quality in color and shrinkage protection, but with respect to the water-soluble polysaccharides content for D. officinale, OD, VD and ID samples were better than FD samples, and OD ones was the highest. The results showed that the quality of dried D. officinale depends on the drying method and conditions. Considering the retention of polysaccharide content, OD is considered promising for drying D. officinale.