Cytotoxicity analysis of active components in bitter melon (Momordica charantia) seed extracts using human embryonic kidney and colon tumor cells.
Bitter melon (Momordica charantia) seed extracts (BMSE) have been used as traditional medicine for treating various ailments, although in many cases, the active component(s) are unidentified. In this study, bitter melon seeds were extracted in water, ethanol, or ethanol: water (1:1). The aqueous seed extracts (BMSE-W) exhibited marked cytotoxicity towards human embryonic kidney 293T (HEK293T) and human colon tumor 116 (HCT1116) cells. The activity in BMSE-W was unaffected by heat and proteinases treatments, and eluted in the total volume of size-exclusion HPLC, suggesting the small, organic nature of the active component(s). Gas chromatographic-mass spectrometic (GC-MS) analysis of the HPLC fractions identified methoxy-phenyl oxime (MPO) as a major active component. Acetophenone oxime, a commercially available structural homolog of MPO, demonstrated cytotoxicity comparable with that of the BMSE-W. The oxime functional group was found to be critical for activity. Increased poly-(ADP-ribose)-polymerase and beta-actin cleavage, and chromatin condensation observed in treated cells suggested apoptosis as a plausible cause for the cytotoxicity. This study, for the first time, identified a cytotoxic oxime in BMSE-W.
Laboratory of Biochemistry, Northwest Missouri State University, 800 University Drive, Maryville, MO 64468, USA.
Elizabeth S
ES
Chipps
Renuka
R
Jayini
Shoko
S
Ando
April D
AD
Protzman
M Zubayed
MZ
Muhi
M Abdul
MA
Mottaleb
Ahmed
A
Malkawi
M Rafiq
MR
Islam
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects; D045325:HCT116 Cells; D057809:HEK293 Cells; D006801:Humans; D029777:Momordica charantia / Q000737:chemistry*; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry
D000972:Antineoplastic Agents, Phytogenic; D010936:Plant Extracts