Polysaccharides from Tetrastigma hemsleyanum Diels et Gilg: optimum extraction, monosaccharide compositions, and antioxidant activity.

The optimization of extraction of Tetrastigma hemsleyanum Diels et Gilg polysaccharides (THP) using ultrasonic with enzyme method and its monosaccharide compositions and antioxidant activity were investigated in this work. Single-factor experiments and response surface methodology (RSM) were performed to optimize conditions for extraction, and the independent variables were (XA) dosage of cellulase, (XB) extraction time, (XC) ultrasonic power, and (XD) ratio of water to the material. The extraction rate of THP was increased effectively under the optimum conditions, and the maximum (4.692 ± 0.059%) was well-matched the predicted value from RSM. THP was consisted of mannose, glucuronic acid, rhamnose, galacturonic acid, glucose, galactose, and arabinose, while glucose was the dominant (26.749 ± 0.634%). According to the total antioxidant capacity assay with the FRAP method, DPPH, and hydroxyl radical scavenging assay, THP showed strong antioxidant activity with a dose-dependent behavior. The results indicated that THP has the potential to be a novel antioxidant and could expand its application in food and medicine.

[Study on effect of total flavanones of Sedum sarmentosum on apoptosis of hepatic stellate cells and its mechanism].

OBJECTIVE: To study the effect of total flavanones of Sedum sarmentosum (SSTF) on the apoptosis of rat hepatic stellate cells (HSC-T6) and its mechanism. METHOD: Different concentrations of SSTF and HSC-T6 cells were co-cultured for different period of time. The MTT assay was used to detect the inhibitory effect of SSTF on the proliferation of HSC-T6 cells. The flow cytometry Annexin-V/PI double staining method was adopted to detect SSTF's effect on HSC-T6 cell apoptosis. Western blotting and Real-time PCR methods were applied to observe the effect on the protein and mRNA expressions of apoptosis-related cytokines Bcl-2, Bax and Caspase-3. RESULT: SSTF significantly inhibited HSC-T6 cell proliferation and induced cell apoptosis in a dose and time dependent manner. According to Western blotting result, SSTF promoted apoptosis by inhibiting Bcl-2, Bax and promoting the protein expression of Caspase-3; according to a further Real-time PCR study, Bcl-2 mRNA levels can inhibit Bcl-2 and promote Bax and Caspase-3 expressions. CONCLUSION: SSTF has the effect of promoting the apoptosis of HSC-T6 mainly by inhibiting Bcl-2 and promoting protein and mRNA expressions of Bax and caspase-3.

[Study on supension culture and quantitative determination of total ginsenosides from the crown gall of Panax quinquefolium].

The influences of different cultural node on the crown gall culture of Panax quinquefolium and its ginsenosides contents were studied. The faster growth rate was obtained in suspension culture. And the dry weight (DW) of crown gall and the accumulation of total ginsenoside content reached 0. 776 g DW/flask and 19.4 mg/flask, which were 111% and 64% higher than solid culture, respectively. The results also indicated that the utilization (by percentage) of sucrose was 91.8%. The investigation provided useful information for following researches on fermentation culture and large-scale production of ginsenosides.

The growth characteristics and ginsenosides isolation of suspension-cultured crown gall of Panax quinquefolium.

The growth characteristics and ginsenosides isolation of the suspension-cultured crown gall of Panax quinquefolium were studied. The result showed that the maximum biomass of cultures was 18.6 g/L (dry weight) and the content of ginsenosides reached its maximum level of 620.4 mg/L on the 27th day. The utilization rates of sugar, phosphorus, nitrogen in NH4+ and nitrogen in NO3- were 91.8%, 100%, 81% and 97%, respectively. Four compounds were isolated from the suspension-cultured crown gall and their structures were elucidated as pseudoginsenoside F11 (I), ginsenoside Rd (II), ginsenoside Rb1 (llI) and ginsenoside Rb3 (IV).