Antiproliferative properties of Padma Lax and its components ginger and elecampane.
BACKGROUND
Padma Lax (PL) is a multi-component herbal laxative, derived from traditional Tibetan medicine. It has been used in the treatment of constipation dominant irritable bowel syndrome. Beyond its purgative and bowel-regulating properties we found it to exhibit antiproliferative properties.


METHODS
C6 tumor cells were incubated with either an ethanolic or aqueous extract of PL. Cell proliferation, cell cycle, percentage of apoptotic cells, caspase-3/-7 activity as well as mitochondrial membrane potential were determined.


RESULTS
Ethanolic extracts of PL inhibited cell proliferation in a dose- and time-dependent manner (half max concentration: 384.4 mug/ml after 48 h of incubation). Aqueous extracts were less effective. Ginger and elecampane were the active components of PL in respect to its antiproliferative action and were found to act synergistically. Supplementing the culture medium with polyamines could not override the cytostatic action of PL. Incubation of C6 cells with PL in the presence of catalase proved that the PL effect was specific and not due to oxidative stress. PL had no effects on the cell cycle at a low dose but arrested cells in G1 at high concentrations. Reduction of cell numbers was found to be due to apoptosis. The caspase- 3/-7 pathway was not involved in the PL-induced cell death. However, mitochondrial membrane potential was lost during the course of incubation with PL indicating a mitochondrial- but not caspase-mediated induction of apoptosis.


CONCLUSIONS
PL exhibits antiproliferative properties which may be beneficial to prevent constipation-related cancer. This study may also contribute to a future development of a new herbal-based antiproliferative treatment.
Hofbauer
Sebastian
S
Division of Animal Physiology, Department of Cell Biology, University of Salzburg, Austria.
Kainz
Verena
V
Golser
Leopold
L
Klappacher
Michaela
M
Kiesslich
Tobias
T
Heidegger
Wilhelm
W
Krammer
Barbara
B
Hermann
Anton
A
Weiger
Thomas M
TM
D002455:Cell Division / Q000187:drug effects*; D002478:Cells, Cultured; D003248:Constipation / Q000150:complications / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D000431:Ethanol; D020939:Zingiber officinale; D006801:Humans; D007414:Intestinal Neoplasms / Q000209:etiology / Q000517:prevention & control; D038861:Medicine, Tibetan Traditional / Q000379:methods*; D008517:Phytotherapy; D010936:Plant Extracts / Q000494:pharmacology*; D013997:Time Factors
D010936:Plant Extracts; C066069:Padma 28; D000431:Ethanol