Carcinogenicity studies of masheri: pyrolysed tobacco product, in vitamin-A-deficient Sprague Dawley rats.
The carcinogenicity of long-term feeding of masheri extract to animals in a vitamin-A-sufficient (SLO+) and deficient (SLO-) state was studied in Sprague Dawley rats by feeding daily dose of 3 mg extract over a period of 21 months. The phase I activating enzymes, the glutathione (GSH)/glutathione S-transferase (GST) detoxification system, and the hepatic and circulating levels of vitamins A and C were also monitored at 12 and 21 months. It was observed that the phase I enzyme activities were significantly higher in SLO+ than in SLO- rats at both 12 months and 21 months. Moreover, the SLO- masheri-treated animals also showed a decreased in the GSH/GST detoxification system while the reverse was observed in SLO+ group. Masheri extract treatment significantly lowered the hepatic and circulating levels of vitamin A while a concurrent increase was observed in the vitamin C level. The extract was found to be tumorigenic in both the SLO+ and SLO- groups. Benign tumours were observed in the SLO+ group while a high incidence of malignant tumours of the lung were observed in the SLO- group upon treatment with masheri extract.
Ammigan
N
N
Carcinigenesis Division, Cancer Research Institute, Tata Memorial Centre, Parel, Bombay, India.
Nair
U J
UJ
Lalitha
V S
VS
Bhide
S V
SV
D000236:Adenoma / Q000139:chemically induced; D000818:Animals; D001579:Benzopyrene Hydroxylase / Q000378:metabolism; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000633:toxicity*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D006358:Hot Temperature; D008099:Liver / Q000187:drug effects / Q000201:enzymology; D008168:Lung / Q000187:drug effects / Q000201:enzymology; D008175:Lung Neoplasms / Q000139:chemically induced; D008297:Male; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D010212:Papilloma / Q000139:chemically induced; D010936:Plant Extracts / Q000633:toxicity*; D010947:Plants, Toxic; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced; D013997:Time Factors; D014026:Nicotiana; D014030:Tobacco, Smokeless / Q000633:toxicity; D014801:Vitamin A / Q000097:blood / Q000378:metabolism; D014802:Vitamin A Deficiency / Q000378:metabolism*
D002273:Carcinogens; D010936:Plant Extracts; C057607:masheri; D014801:Vitamin A; D003577:Cytochrome P-450 Enzyme System; D001579:Benzopyrene Hydroxylase; C019781:benzphetamine N-demethylase; D010089:Oxidoreductases, N-Demethylating; D005978:Glutathione