This study optimizes the extraction process and explores the antioxidant activity of Gastrodia elata polysaccharides, aiming to provide theoretical reference for the extraction, development, and application of the polysaccharides. Polysaccharides were extracted from G. elata by an ultrasonic-assisted method with deep eutectic solvents. The extraction process was optimized by single factor and response surface tests. The antioxidant activity of polysaccharides was evaluated by DPPH and ABTS⁺ free radical scavenging rates. The optimal deep eutectic solvents were composed of choline chloride and lactic acid at a molar ratio of 1:2. The optimal extraction conditions were the ultrasonic treatment at 50 ℃ for 48 min, a solid-to-liquid ratio of 1:38, and a water content of 42%. Under these conditions, the polysaccharide yield reached (19.88±0.93)%. The results of antioxidant activity experiment in vitro showed that the scavenging rates of G. elata polysaccharides on DPPH and ABTS⁺ free radicals were up to (26.39±1.47)% and (30.61±0.16)%, respectively, which indicated that the polysaccharides extracted by the deep eutectic solvents had a certain antioxidant ability. The extracted polysaccharides can be further studied and developed as a potential natural antioxidant.
Polysaccharides/pharmacology* ; Gastrodia/chemistry* ; Antioxidants/pharmacology* ; Deep Eutectic Solvents/chemistry* ; Solvents/chemistry*

Objective To study the in vitro anti-tumor activity of dendritic cells (DCs) loading with antigen produced by radiofrequency ablation of tumor lysate in situ combined with cytokine-induced killer cells (CIK).Methods CIK ceils derived from BALB/C mouse spleen and DCs derived from bone marrow were prepared,and experimental model of murine colon carcinoma were established for radiofrequency ablation.The supernatant of tumor tissue in situ lysis after repeated freezing and thawing were tested by lowry protein quantitative statutory,amounting to a final concentration of 5 μg/ml,then load to the first 5 days of culture DCs (Ag-DC),2 days later,co-cultured with CIK cells after the first seven days of culture 48 h (Ag-DC-CIK).Flow cytometry was used to analyze costimulatory molecules on the surface of the cells,and CCK-8 assay to detect in vitro cytotoxic activity.Results The DCs loading with antigen resulted in an increase in the proportion of CD86 + CD11 c +,MHC Ⅱ + CD11 c + and MHC Ⅱ + CD80 + cells.The main effector cells of CIK cells were CD3 + NK1.1 + cells.The percentage of CD3 + NK1.1 + cells was 1.45％ on the first day of the culture ; while when they had been cultured for 7 days,the percentage CD3 + NK1.1 + significantly increased to 36.9％.The cytotoxicity of Ag-DC-CIK cells toward C26 cells was much more efficient than that of DC-CIK,CIK cells.The cytotoxic activity of the former was significantly lower than the latter and the same target ratio.When the ratios of effector cells to target cells were 5 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (74.9 ± 3.5) ％,; while the DC-CIK was (71.2 ± 2.1) ％ and the CIK cells was (68.7 ± 2.9) ％.The difference was statistically significant(F =7.007,P =0.007).When the ratios of effector cells to target cells were 10 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (82.3 ± 4.5) ％,while the DC-CIK cells was (77.1 ± 5.1) ％,and the CIK cells was (72.7 ± 2.8) ％.The difference was statistically significant (F =7.727,P =0.005).When the ratios of effector cells to target cells were 20 ∶ 1,the cytotoxic activity of Ag-DC-CIK cells against C26 cells was (83.2 ± 1.9) ％,while the DC-CIK cells was (77.2 ± 4.2) ％,and the CIK cells was (73.0 ± 2.6) ％.The difference was statistically significant (F =16.594,P =0.000).Conclusion DCs loading with antigen produced by radiofrequency ablation of tumor in situ pyrolysis products can improve in vitro cytotoxic activity combined with CIK cells,which can provide a new comprehensive cancer treatment strategy.