Corchorusin-D, a saikosaponin-like compound isolated from Corchorus acutangulus Lam., targets mitochondrial apoptotic pathways in leukemic cell lines (HL-60 and U937).
OBJECTIVE
The presence of triterpene saponins in Corchorus acutangulus Lam. has been reported. However, no studies concerning biological activity of the plant extracts have been done so far. In the present study, the anti-leukemic activity of the methanol extract of aerial parts (ME) of C. acutangulus has been investigated, and efforts have been made to identify the active ingredient responsible for this activity.


METHODS
The anti-leukemic activity of ME, its fractions and corchorusin-D (COR-D), the active ingredient, was investigated in leukemic cell lines U937 and HL-60 using cell viability and MTT assays. The molecular pathways leading to the activity of COR-D were examined by confocal microscopy, flow-cytometry, caspase and Western blot assays.


RESULTS
ME, its n-butanolic fraction and COR-D inhibited cell growth and produced significant cytotoxicity in leukemic cell lines U937 and HL-60. COR-D produced apoptotic cell death via mitochondrial disfunction and was found to pursue the intrinsic pathway by inciting the release of apoptosis-inducing factors (AIFs) from mitochondria. COR-D-induced translocation of Bax from cytosol to mitochondria facilitating caspase-9 activation and up regulation of downstream pathways leading to caspase-3 activation and PARP cleavage, which resulted in the subsequent accumulation of cells in the sub-G0 phase followed by DNA fragmentation.


CONCLUSIONS
COR-D possesses significant anti-leukemic activity in U937 and HL-60 cell lines by acting on the mitochondrial apoptotic pathways. Since the necrotic body formation is low after COR-D treatment, the occurrence of inflammation in in vivo systems could be reduced, which represents a positive indication in view of therapeutic application.
Mallick
Sumana
S
Drug Development Division, Indian Institute of Chemical Biology [Unit of Council of Scientific & Industrial Research, India], 4 Raja S.C. Mullick Road, Kolkata, India.
Ghosh
Papiya
P
Samanta
Suman K
SK
Kinra
Sumita
S
Pal
Bikas C
BC
Gomes
Aparna
A
Vedasiromoni
Joseph R
JR
D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000502:physiology; D015153:Blotting, Western; D020169:Caspases / Q000378:metabolism; D002467:Cell Nucleus / Q000187:drug effects / Q000648:ultrastructure; D049109:Cell Proliferation / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D032381:Corchorus / Q000737:chemistry; D053938:DNA Fragmentation / Q000187:drug effects; D005434:Flow Cytometry; D006027:Glycosides / Q000737:chemistry / Q000494:pharmacology*; D018922:HL-60 Cells; D006801:Humans; D007938:Leukemia / Q000188:drug therapy* / Q000473:pathology; D008564:Membrane Potentials / Q000187:drug effects; D000432:Methanol; D018613:Microscopy, Confocal; D008928:Mitochondria / Q000187:drug effects*; D051336:Mitochondrial Membranes / Q000187:drug effects; D010936:Plant Extracts / Q000494:pharmacology; D011064:Poly Adenosine Diphosphate Ribose / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*; D014315:Triterpenes / Q000737:chemistry / Q000494:pharmacology*; D020298:U937 Cells
D000972:Antineoplastic Agents, Phytogenic; D051017:Apoptosis Regulatory Proteins; D006027:Glycosides; D010936:Plant Extracts; D014315:Triterpenes; C067483:corchorusin D; D011064:Poly Adenosine Diphosphate Ribose; D020169:Caspases; D000432:Methanol