Optimization of green deep eutectic solvent (DES) extraction of Chenopodium quinoa Willd. husks saponins by response surface methodology and their antioxidant activities.

Quinoa saponins have outstanding activity, and there are an increasing number of extraction methods, but there are few research programs on green preparation technology. The extraction conditions of quinoa saponins with deep eutectic solvents (DESs) were optimized by single-factor experiments combined with response surface methodology. The antioxidant capacity of saponins extracted by DESs and traditional methods was evaluated by the DPPH clearance rate, iron ion chelation rate and potassium ferricyanide reducing power. The results show that the optimal DES is choline chloride: 1,2-propylene glycol (1 : 1), and its water content is 40%. The optimal extraction conditions were as follows: the solid-to-solvent ratio was 0.05 g mL-1, the extraction time was 89 min, and the extraction temperature was 75 °C. Under these conditions, the extraction of quinoa saponins by DES was more effective than the traditional extraction methods. The saponins extracted by DES and traditional methods were analyzed by UPLC-MS, and five main saponins were identified. Quantitative analysis by HPLC-UV showed that Q1 (m/z = 971) and Q2 (m/z = 809) had higher contents of saponins. In vitro antioxidant experiments showed that all DES saponin extracts showed good antioxidant capacity. This study provides new insight into the development and utilization of quinoa saponins.

[Insulin-like growth factor-1 induced activation and expression of signal transducers and activators of transcription-3 in scleral fibroblast of guinea pigs].

OBJECTIVE: To investigate the expression of signal transducers and activators of transcription 3 (STAT3) in sclera fibroblast of guinea pigs for understanding whether STAT3 signaling transduction pathway induced by the insulin-like growth factor-1 (IGF-1) was constitutively activated. METHODS: Immunocytochemical staining was used to determine the protein levels of STAT3 and P-STAT3 (activated STAT3) in scleral fibroblasts. RT-PCR was used to detect the mRNA of STAT3. The effects of IGF-1 on scleral fibroblast proliferation were measured by MTT assay. RESULTS: Immunocytochemical staining and RT-PCR revealed that STAT3 protein and mRNA were over-expressed in the cells which contained constitutively activated STAT3 signaling transduction pathway (t=-6.925, -10.179 and 9.363; P<0.001). The results of MTT showed that IGF-1 induced fibroblasts proliferation significantly at concentrations of 0.5, 1.0, 10.0 microg/L (P<0.05). CONCLUSION: STAT3 signaling transduction pathway is constitutively activated in the treated scleral cells by IGF-1, suggesting that STAT3 signaling transduction pathway may play a critical role in the occurrence of myopia and sclera remodeling.