干旱胁迫对光果甘草幼苗根系MDA含量及保护酶POD、CAT活性的影响

实验室用甘露醇模拟不同程度干旱胁迫,观测光果甘草幼苗根系膜脂过氧化水平受影响的情况。结果表明当干旱胁迫程度由-0.5 MPa上升到-1.0 MPa时,甘草根系MDA的含量随干旱胁迫程度的增强而升高,同时甘草幼苗根系POD活性下降,而CAT的活性则呈现升高趋势。说明干旱胁迫程度由轻度转为中度后,甘草幼苗的根系产生了膜脂过氧化作用。POD与CAT这两种保护酶活性也随之产生变化,POD活性先升后降,而CAT活性则持续上升,二者相互配合协同作用,以维持和保护甘草幼苗根系细胞膜的完整性,降低膜脂过氧化水平。

光果甘草毛状根培养过程中对活性氧清除能力和总黄酮含量的变化

采用化学发光法,分析了光果甘草(GlycyrrhizaglabraL.)毛状根培养过程中对3种活性氧(ROS:O2÷、HO·和H2O2)清除能力的动态变化,并测定了培养过程中总黄酮含量的动态变化。实验结果表明,毛状根在对数生长期(20～28d)对3种ROS都有很强的清除能力,在生长停滞期(29～40d)对HO·和H2O2的清除能力仍维持较高的水平,而对O2÷的清除能力随培养时间的延长逐渐下降。总黄酮含量在对数生长期呈现增加的趋势,至31d时达到最高含量(0.78%),随培养时间的延长含量逐渐降低。

Effect of Hoechunyangkyeok-San Extract on Melanogenesis

Forsythia fructus has been shown to have antioxidative, anti-inflammatory, antibacterial, anti-aging and whitening effects. Hoechunyangkyeok-san (Forsythia viridissima-prescription) is a traditional herbal medicine, which has been clinically used for treating febrile and inflammatory disorders. This work was carried out to investigate the skin whitening effects of Forsythia viridissima-prescription extract (a hydrolyzed extract of Hoechunyangkyeok-san: SID White HYC) on skin. The effects of SID White HYC were assessed the melanin contents in B161 melanoma cells and the pigmented equivalent with HMB45 and Fontana Masson staining in 3D skin model. Then, we examined the expression of major pigment enzymes regulating melanin synthesis and melanosome transport related proteins in B16F1 cells. SID White HYC significantly inhibited the melanin synthesis (56.7% and 30.6% inhibition at 100 μg/mL, intracellular and secreted, respectively) in B16F1 cells and 3D skin model. In addition, western blotting analysis showed that SID White HYC reduced the expression of melanin synthesis and melanosome transport related proteins in B16F1 cells. In clinical trials, the cream containing 0.05% SID White HYC showed skin depigmentation effect without any irritation. These results suggest that SID White HYC may be useful inhibition of melanogenesis and melanosome transport. Therefore, SID White HYC may have potential as a skin-whitening ingredient in cosmetics.

三种药用甘草凋落物的水浸提液对根腐病病原菌的影响

以根腐病病原菌尖孢镰刀菌和腐皮镰刀菌为试材,采用外源添加法,分析了这2种病原菌对3种药用甘草根腐病的致病性能,研究了3种药用甘草凋落物(叶片)的水浸提液对尖孢镰刀菌和腐皮镰刀菌菌丝生长和产孢的影响,以期探究甘草凋落物与根腐病发生之间的内在联系。结果表明:尖孢镰刀菌和腐皮镰刀菌对3种药用甘草具有很强的致病性,可引起典型的根腐病害症状。在0.005~0.020 g·mL^(-1)的浓度范围内,光果甘草和乌拉尔甘草叶片的水浸提液显著促进了2种病原菌的生长和繁殖,二者对尖孢镰刀菌的菌落直径和孢子量的促进效果最高分别可达14.06%、10.58%、24.50%和48.39%,对腐皮镰刀菌的菌落直径和孢子产量的促进效果最高分别可达8.79%、12.25%、17.11%和25.13%。胀果甘草叶片水浸提液对2种病原菌的菌丝生长和产孢则表现出"低促高抑"的特点,其最高使尖孢镰刀菌的菌落直径和孢子量分别显著增加了3.63%和14.86%,使腐皮镰刀菌的菌落直径和孢子量分别显著增加6.64%和16.58%。3种药用甘草叶片水浸提液对该2种病原菌生长和繁殖促进效果的强弱顺序依次为乌拉尔甘草>光果甘草>胀果甘草。综上所述,甘草叶片作为凋落物在农田中的大量积累可能是造成甘草连作背景下根腐病频发的主要原因,建议每年在叶片枯落前进行茎叶收割并及时移出农田。