Plant morphology, physiological characteristics, accumulation of secondary metabolites and antioxidant activities of Prunella vulgaris L. under UV solar exclusion

BACKGROUND: Prunella vulgaris L. has been an important medicinal plant for the treatment of thyroid gland malfunction and mastitis in China for over 2000 years. There is an urgent need to select effective wavelengths for greenhouse cultivation of P. vulgaris as light is a very important factor in P. vulgaris growth. Here, we described the effects of natural light (control) and UV solar exclusion on the morphological and physiological traits, secondary metabolites contents and antioxidant activities of P. vulgaris. RESULTS: The results showed that UV solar exclusion resulted in remarkable alterations to morphological and biomass traits; significantly reduced the chlorophyll a, chlorophyll b and total chlorophyll contents; significantly enhanced the ratio of chlorophyll a to b; and significantly increased the carotenoid and anthocyanin contents in P. vulgaris. UV solar exclusion significantly increased the catalase (CAT) and peroxidase (POD) activities, increased superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities and slightly decreased the glutathione (GSH) content. UV solar exclusion significantly increased the soluble sugar and H2O2 contents and increased the soluble protein content but significantly decreased the proline content and slightly decreased the MDA content. The secondary metabolite contents (total phenolics, rosmarinic acid, caffeic acid, hyperoside, ursolic acid and oleanolic acid) and in vitro antioxidative properties (DPPH· and ABTS·+scavenging activities) were significantly increased in P. vulgaris spicas under UV solar exclusion. Additionally, the total polysaccharide and total flavonoids contents were slightly increased by UV solar exclusion. The salviaflaside content was significantly reduced by UV solar exclusion. CONCLUSION: Our study demonstrated that P. vulgaris activates several antioxidant defence systems against oxidative damage caused by UV solar exclusion.

Generation of Water-In-Oil-In-Water (W/O/W) Double Emulsions By Microfluidics / 分析化学

Novel compartment microparticles produced with double emulsion droplets as templates provide a protected internal space for material encapsulation. The effect of three-phase flow rate on the micro-droplet generation of double emulsion mechanism is available for reference to produce precise size and highly monodisperse particles. The influence of three-phase flow rate on the formation mode and size of the emulsion droplets was mainly investigated by making use of experiment and numerical simulation. The size of compound droplets decreases and the frequency increases with the increasing outer fluid flow rate. The monodispersity of the double emulsion reduces due to transition from dripping to narrowing jetting regime. Outer droplet size increases with the increasing flow rate of the middle fluid, whereas inner droplet size is the opposite. The frequency increases and then stabilizes,which leads to a widening regime. When Q2/Q1>6, multi-core type double emulsion droplets are produced. Droplet coalescence occurs when surfactant is not considered. As Q1 increases,there is an increasing tendency for inner drop size. The outer drop size is proportional to the sum of the inner and middle flow rate,and that is regardless of Q1/Q2. For drop size,ratio of core-shell and internal structure are precisely controlled by adjusting three-phase flow rate respectively.