ABSTRACT
@#Objective To optimize the extraction process of flavonoids from Broussonetia papyrifera leaves and explore the antioxidant effect of flavonoids on mouse epidermal stem cells.Methods The extraction process of flavonoids from Broussonetia papyrifera leaves was optimized by single factor experiment,including the liquid-solid ratio(15:1,20:1,25:1,30:1and 35:1),sodium hydroxide(NaOH) concentration(0.2%,0.4%,0.6%,0.8% and 1.0%),pH value(2.5,3.0,3.5,4.0and 4.5) and extraction temperature(60,65,70,75 and 80℃).Based on the results of single factor experiment,the optimal extraction process was determined by orthogonal test with the mass fraction of flavonoids as the evaluation index.CD49f~+/CD71~-mouse epidermal stem cells were isolated and cultivated by immunomagnetic bead method,and the effects of flavonoids on the cell relative viability and the contents of reduced glutathione(GSH) and malondialdehyde(MDA) were detected.Results The optimal extraction conditions of flavonoids were liquid-solid ratio of 30:1,0.6% NaOH,pH 4.5and extraction temperature of 75 ℃.Under these conditions,the average mass fraction of flavonoids extracted was 1.47%.Compared with the negative control group,when the flavonoids final concentration was 25 and 50 μg/mL,the cell relative viability increased significantly(F=1.427 and 13.747 respectively,each P <0.01);when the final concentration of flavonoids was 12.5,25 and 50 μg/mL,the content of GSH increased significantly(F=0.044,0.291 and 2.577 respectively,each P <0.05) and the content of MDA decreased significantly(F=3.568,4.909 and 1.400 respectively,each P <0.05).Conclusion The optimized extraction process of flavonoids from B.papyrifera leaves was stable and reliable,which is beneficial to the reuse of remaining stock solution after processing,and the extracted flavonoids can promote the proliferation of mouse epidermal stem cells and perform antioxidant activity.
ABSTRACT
Urolithiasis is a common disease with wide ranging effects, with oxalate stones being the most prevalent type. Existing clinical diagnostic methods rely on complex instruments and professionals, are difficult to distinguish between stone types, and have insufficient sensitivity. Moreover, high-sensitivity point-of-care testing (POCT) methods remain scarce. We constructed a rapid homogeneous dual fluorescence and binary visualization analysis system to diagnose oxalate urolithiasis because oxalate can efficiently reduce Cu2+ to Cu+, which can be selectively competitively recognized by both calcein and cadmium telluride quantum dots (CdTe QDs). Under optimized conditions, the system exhibited high sensitivity to oxalate ranging from 10 pM to 10 nM within 3 min. Following that, visualized test strips of calcein and QDs were generated by inkjet printing; oxalate concentrations as low as 10 nM can be easily identified by reading the quenching distance on the strip. We then analyzed 66 clinical urine samples: 11 healthy, 10 oxalate-negative, and 45 oxalate-positive samples. The fluorescence and visual mode results were highly consistent with clinical computed tomography (CT) images and clinical diagnostics. Therefore, our analysis strategy has the potential to use POCT for the assessment of oxalate urolithiasis.
