Jinglei Li

Antihyperlipidemic and hepatoprotective properties of selenium modified polysaccharide from Lachnum sp.

Hyperlipidemia is one of the major health problem people suffering throughout the world, which is also a major risk factor for chronic heart disease that can lead to death. The current study was designed to investigate antihyperlipidemic and hepatoprotective effects of selenium modified exopolysaccharide of Lachnum sp. (SeLEP-1b) on high-fat induced mice model. Nitric acid-sodium selenite (HNO3-Na2SeO3) method was used to selenize pure LEP-1b. FT-IR and 13C NMR results confirmed the modification of LEP-1b into SeLEP-1b. The main structure of SeLEP-1b was similar to the original structure of native LEP-1b and Se(O)OH group was attached to the O-6 position of C-6 in LEP-1b. Oral administration of LEP-1b and SeLEP-1b (200mg/kg) notably reduced the serum and liver lipids, atherogenic index, and enhanced the activities of antioxidant enzymes of hyperlipidemic mice, aswell improved the histopathological status of hepatic tissues. Hence, SeLEP-1b showed better effects than LEP-1b at the same doses. SeLEP-1b demonstrated promising lipid-lowering and liver protecting activities, which may be considered as a novel compound to treat hyperlipidemia and also act as a hepatoprotective agent.

Antioxidant activity and flavor compounds of hickory yogurt

ABSTRACT Hickory milk and reconstituted milk (about 12 g/100 g total solid) were mixed in the proportion of 3:7 by volume to prepare hickory milk yogurt. Cow milk yogurt was used as control. The acidity and total count of lactic acid bacteria of hickory milk yogurt were not significantly different from cow milk yogurt (p > 0.05). Compared with cow milk yogurt, hickory milk yogurt had higher total solids, fat, crude protein, and amino acids, but lower ash and not-fat solids. Sensory evaluation showed that the appearance and flavor scores of hickory milk yogurt had no significant difference from cow milk yogurt (p > 0.05), but the texture score was significantly higher (p < 0.05). IC50 values in relation to 1,1-diphenyl-2-picrylhydrazyl scavenging activity and inhibition of lipid peroxidation (46.88 and 26.70 g/L) of hickory milk yogurt were significantly lower than those of cow milk yogurt which suggested that the antioxidant activity of hickory milk yogurt was significantly higher than cow milk yogurt (p < 0.05). There were 30 and 28 kinds of volatile compounds identified in hickory milk yogurt and cow milk yogurt, respectively. Compared with cow milk yogurt, the concentration of acetaldehyde, hexanal, nonanal, 2-nonanone, caproic acid, heptylic acid, and nonanoic acid in hickory milk yogurt increased significantly, and the concentration of benzaldehyde, 2,3-pentanedione, 2,3-butanedione, 3-hydroxy-2-butanone, acetic acid, butyric acid, and benzoic acid decreased significantly (p < 0.05).

Anticoagulant activity of a sulfated Lachnum polysaccharide in mice with a state of hypercoagulability

A sulfated polysaccharide, designated as SLEP-1, was obtained after sulfation of the exopolysaccharide (LEP-1) which was isolated from Lachnum. The degree of substitution (DS) of sulfate group of SLEP-1 was 1.97. SEM images of SLEP-1 revealed laminated structure in mesh. UV, FT-IR and 13C NMR spectra indicated that the LEP-1 was sulfated successfully. The result of the anticoagulant activity in vitro showed that both of LEP-1 and SLEP-1 could effectively prolong activated partial thromboplastin time (APTT) and thrombin time (TT) of the normal mice plasma, in which SLEP-1 was more effectively than those of LEP-1, and dose-effect relationships were found. According to the bleeding time (BT), clotting time (CT), APTT, PT, prothrombin time (TT), fibrinogen (FIB), AT-III activity and FXa concentration of the hypercoagulable mice, it indicated that SLEP-1 (30mg·kg-1 and 90mg·kg-1) had strong inhibitory effect on intrinsic coagulation pathway, which could also enhance fibrinolytic activity. It may constitute an anticoagulant drug of interest in anticoagulant therapy.

Immunoregulatory effect assessment of a novel melanin and its carboxymethyl derivative

A novel melanin with low molecular weight (LIM205, 522Da) was isolated from the fermentation broth of Lachnum sp. and its carboxymethyl derivative (CLIM205) was prepared. The immunoregulatory effects of LIM205 and CLIM205 in immuno-compromised mice induced by cyclophosphamide were investigated. The results demonstrated that both LIM205 and CLIM205 could significantly increase the thymus and spleen indices, specific and nonspecific (including carbon clearance ability) immunity, humoral and cellular immunity of mice. Treatment with LIM205 and CLIM205 could increase activities of SOD, GSH-PX, CAT and decrease content of MDA in the mice. Furthermore, for all animal tests, the immunoregulatory activities of CLIM205 were more prominent than that of LIM205. In conclusion, our findings suggested that the natural products LIM205, as well as its carboxymethyl derivative CLIM205, had significant immunoregulatory activities, which might be a promising source of immunoregulator in healthcare field.

Physicochemical properties, immunostimulatory activity of the Lachnum polysaccharide and polysaccharide-dipeptide conjugates

The physicochemical properties and the immunoregulatory actions in vitro of an exopolysaccharide from Lachnum (LEP) and its conjugation with a dipeptide (LEP-RH) were investigated aiming to improve their functional characteristics. The structure characteristic of the LEP and LEP-RH were determined via FT-IR and NMR. The physicochemical properties were evaluated by scanning electron microscopy (SEM), rheometer, and differential scanning calorimeter (DSC). SEM results showed that LEP-RH had a rough surface and relatively loose distribution that different from LEP. Rheological studies of LEP and LEP-RH at the same concentration indicated that LEP and LEP-RH have similar shear-thinning behaviors and gel-like structures, while LEP-RH has a better thermal stability than LEP. Bioassay results showed that treatment with the higher dosage (200 μg/mL) of LEP and LEP-RH stimulated the proliferation, cytokine secretion (IL-2, IL-6 and TNF-α) of RAW264.7 macrophages.

Synergistic antitumor effect of polysaccharide from Lachnum sp. in combination with cyclophosphamide in hepatocellular carcinoma

Combination therapy with chemotherapeutics is attracting increasing attention as an important treatment option for hepatocellular carcinoma (HCC) due to its complex pathological characteristics. In this study, as a new therapy strategy, combination treatment of LEP-2a (a non-toxic polysaccharide from Lachnum sp.) with cyclophosphamide (CTX) was investigated. Results showed that combination treatment with LEP-2a and CTX processed a significantly synergistic anti-tumor effect in H22 tumor-bearing mice through Fas/FasL mediated caspase-dependent death pathway and mitochondria apoptosis pathway. Moreover, our study indicated that LEP-2a played a crucial role in enhancement of immune response, inhibition of tumor angiogenesis and down-regulation of survival associated proteins. Notably, side effects induced by CTX were relieved after LEP-2a treatment. These results support the conception that LEP-2a has the potential as an ideal adjuvant agent for a more effective combination therapy with CTX against HCC.