闹羊花素Ⅲ对斜纹夜蛾细胞系的活性及作用机理

研究了闹羊花素Ⅲ对斜纹夜蛾Spodoptera litura离体培养细胞（SL细胞）的活性，并测定了对SL细胞Na⁺、K⁺和葡萄糖吸收以及对4龄幼虫血细胞数量的影响。结果表明：以400 µg/mL 和200µg/mL闹羊花素Ⅲ处理SL细胞，24 h后细胞的相对死亡率为79.00% 和56.69%，处理后8 h，16 h，24 h和48 h的LC₅₀分别为240.09 µg/mL，173.45 µg/mL，113.56 µg/mL和73.40 µg/mL；闹羊花素Ⅲ处理SL细胞后10 min，细胞对离子的吸收迅速增加，30 min后吸收作用逐渐减弱；处理后3天内细胞对葡萄糖的吸收迅速增加，4～5 天后，细胞对葡萄糖的吸收基本停止。以叶碟法和注射法处理4龄幼虫，8 h后幼虫血细胞数量显著降低，随处理时间增加，幼虫血细胞数量又逐渐增加。

Bioactivity of rhodojaponin-Ⅲ on Spodoptera litura cells and its mechanism

Bioactivity and effect of rhodojaponin-Ⅲ on the Spodoptera litura cell (SL cell) and cell absorptivity of Na⁺, K⁺ and glucose were tested, and the effect on the cell amount of the 4th instar larvae of S. lituran was also studied. The resulted showed that when treated with 400 μg/mL and 200 μg/mL, the mortalities after 24 h treatment were 79.00% and 56.69%, respectively. The LC₅₀ to S. litura cell at 8, 16, 24 and 48 h after treatment were 240.09, 173.45, 113.56 and 73.40 mg/mL, respectively. Treated with rhodojaponin-Ⅲ, S. litura cells started to absorb Na⁺ and K⁺ rapidly in no less than 10 min, and 30 min later the absorbability wore off ; S. litura cells started to absorb glucose rapidly within 3 days, and in 4－5 days S. litura cells almost stopped uptaking glucose. Treated by leaf disc and injecting, the cell amount of the 4th instar larvae of S. litura receded observably, and recovered gradually as the treatment time extended.