title: The cytotoxicology of momordicins I and II on Spodoptera litura cultured cell line SL-1.
abstract: Momordicin I and II are secondary metabolites from bitter melon (Momordica charantia L.) that are toxic to the Spodoptera litura ovary cell line (SL-1 cell). Both momordicin I and II significantly inhibited SL-1 cells proliferation. IC50 values after 24 h were 8.35 and 82.31 µg/mL, 6.11 and 77.49 µg/mL for 36 h, 4.93 and 49.42 µg/mL for 48 h for cells treated by momordicin I and II, respectively. IC50 values of the azadirachtin A control were 149.63, 54.54 and 23.66 µg/mL at 24, 36 and 48 h respectively, indicating that the cytotoxicity of momordicin I was significantly higher than that of momordicin II and azadirachtin A. Using inverted phase contrast microscopy we found that after 24 h exposure to momordicin I and II, cell shapes changed to circular, swelling increased, adherence ability declined and the cellular membrane bubbled. After 48 h exposure to momordicin I, most cells were suspended and dead; vacuole deformation and cytoplasm leakage indicated that momordicin I was more toxic to the cytoskeleton than momordicin II. Cells treated with momordicin I and II inhibited glucose absorption by 23.04 and 13.38% after 48 h and 47.60 and 20.92% after 60 h. Flow cytometry analysis suggested that SL-1 cells treated with momordicin I and II dramatically accumulated during the G2/M phase of the cell cycle, and total cell protein content increased by 56.93 and 35.81% respectively after 48 h treatment. Following treatment with momordicin I and II the karyotheca dissolved, the chromatin condensed abnormally and the nucleoli were damaged, migrated, or disappeared. The PI fluorescent value by FCM showed that the relative fluorescent intensity of SL-1 cells induced by momordicin I and II increased to 521.45 and 370.17, higher than 135.04 induced by control group treatment for 48 h. This indicated significant damage to the cytomembrane. Overall, the results demonstrate that suppression of cytoskeletal function, interference of mitotic figures and destruction of nuclear structure are effects of momordicin I and II exposure. These effects play major roles in momordicin I and II inhibition of SL-1 cells growth. The mode of action by which momordicins inhibit insect cell growth and development may be useful in the development of novel pest control formulations containing cucurbitane-type triterpene glycosides.
authors.affiliation: Laboratory of Insect Ecology, The College of Natural Resource and Environment, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Liu
authors.affiliation: Institute of Traditional Chinese Medicine and Natural Products, College of Pharmacy, Jinan University, Guangzhou 510632, China.
authors.forename: Guo-Cai
authors.initials: GC
authors.lastname: Wang
authors.affiliation: Laboratory of Insect Ecology, The College of Natural Resource and Environment, South China Agricultural University, Guangzhou 510642, China.
authors.forename: Mao-Xin
authors.initials: MX
authors.lastname: Zhang
authors.affiliation: Laboratory of Insect Ecology, The College of Natural Resource and Environment, South China Agricultural University, Guangzhou 510642, China. Electronic address: gzhbling@scau.edu.cn.
authors.forename: Bing
authors.initials: B
authors.lastname: Ling
mesh_terms: D000818:Animals; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002460:Cell Line / Q000187:drug effects; D002463:Cell Membrane Permeability / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D019476:Insect Proteins / Q000378:metabolism; D036701:Limonins / Q000494:pharmacology; D018411:Spodoptera / Q000166:cytology* / Q000187:drug effects*; D013261:Sterols / Q000494:pharmacology*
chemical_list: D019476:Insect Proteins; D036701:Limonins; D013261:Sterols; C000605971:momordicin II; C506900:momordicine I; D005947:Glucose; C010329:azadirachtin
keywords: Cell cycle; Cell proliferation; Momordica charantia L.; Momordicin I; Momordicin II; SL-1 cell