Nv. Rajeshkumar et R. Kuttan, Protective effect of Picroliv, the active constituent of Picrorhiza kurroa, against chemical carcinogenesis in mice, TER CAR MUT, 21(4), 2001, pp. 303-313
Cancer chemoprevention of chemically induced tumours by Picroliv, an iridoi
d glycoside mixture purified from Picrorhiza kurroa, was studied on 20-meth
ylcholan-threne (20-MC)-induced sarcoma model and 7,12-dimethylbenz[a]anthr
acene (DMBA)-initiated papilloma formation in BALB/c mice. Administration o
f Picroliv (100 and 200 mg/kg, p.o) inhibited the sarcoma development by 47
and 53% as estimated on day 200 after 20-MC administration. Control animal
s started dying of tumour burden 76 days after 20-MC administration and all
animals were dead by day 170, while 60 and 66% of the animals survived in
the Picroliv treated group, 100 and 200 mg/kg, respectively. Picroliv exhib
ited anti-tumour-promoting activity on a two-stage carcinogenesis test on m
ouse skin using DMBA as an initiator and croton oil as a promoter. Topical
application of Picroliv (I and 5 mg/mouse) 30 minutes prior to that of crot
on oil application resulted in a 50 and 60% reduction in the number of anim
als that developed papillomas, and 48 and 64% reduction in the number of pa
pillomas per mouse. There was also a delay in the onset of first skin tumou
r in the group of animals treated with Picroliv. Oral administration of Pic
roliv (150 mg/kg, p.o.) prior to DMBA application delayed the onset of papi
llomas and the percent of mice (60%) with tumours indicates that Picroliv i
nhibited the tumour initiation induced by DMBA. Picroliv administration was
also found to increase the life span of transplanted Dalton's Lymphoma Asc
ites (DLA) and Ehrlich Ascites Carcinoma (EAC) harboring mice and reduced t
he volume of transplanted solid tumours. (C) 2001 Wiley-Liss, Inc.