Arecoline tumorigenicity in Swiss strain mice on normal and vitamin B deficient diet.

Arecoline, a major alkaloid present in betel nut, was administered daily by gavage feeding to Swiss male and female mice at a dose of 1 mg/day/mouse five times a week, either alone or in combination with KNO3 or KNO3 + lime. Swiss mice of both sexes kept on a vitamin B complex-deficient diet were tested in a similar manner and compared with those receiving a normal diet. In the mice receiving a normal diet it was observed that arecoline induced tumors in 40% of males but failed to produce tumors in any of the females. Arecoline tumorigenicity in females was evident only when they received a vitamin B-deficient diet. Arecoline tumorigenicity was not evident in males when they were treated simultaneously with KNO3 + lime and kept on a normal diet. However, the same treatment administered to male mice kept on a vitamin B complex-deficient diet induced tumors in 39%.

Long-term feeding study in C17 mice administered saccharin coated betel nut and 1,4-dinitrosopiperazine in combination.

The observations on the effect of 3 agents--1,4-dinitrosopiperazine, betel nut and saccharin fed to C17 mice in combination is presented in this report. A total of 119 inbred mice of both sexes were put on long-term feeding trials. Group I consisted of 34 mice given a standard diet; group II of 32 mice fed an experimental diet containing saccharin coated betel nut powder at 10% concentration; group III of 29 mice given 0.2 ml aqueous solution of 0.1% 1,4-dinitrosopiperazine by intubation daily and group IV of 24 mice fed a combination of the experimental diet together with intubation of 1,4-dinitrosopiperazine. Feeding was continued for 40 weeks at which time all mice were given a standard diet and water ad libitum, and then observed for their full life-span. The commonest neoplasm found was squamous cell carcinoma of the forestomach in groups III and IV. Male mice were more susceptible to the treatment than female mice. In female mice reticular cell neoplasm--Type A of the uterus was the commonest tumour and was more common in group III than in group IV. The diet of saccharin coated betel nut failed to potentiate the carcinogenicity of 1,4-dinitrosopiperazine.

Protection by testosterone propionate against the nephrotoxicity of 2-aminoanthraquinone in Fischer rats.

The role of gonadal hormones in the nephrotoxicity of the hepatocarcinogen 2-aminoanthraquinone (2-AAQ) was investigated. Intact and castrated four week old Fischer rats of both sexes and castrated female rats with subcutaneous implants of testosterone propionate pellets were fed 2% 2-AAQ in a Wayne meal diet. After 12 weeks of ad libitum feeding the animals were then given control diet. Based on survival, body, liver and kidney weights, and the histopathological evaluation of the kidneys, castrated female rats given testosterone propionate were afforded the greatest protective effect against the nephrotoxicity of 2-AAQ.

Betel quid chewing and oral cancer: experimental studies on hamsters.

Betel quid ingredients--betel nut, betel leaf, lime, catechu and tobacco--were tested separately and in various combinations for carcinogenicity, using hamster cheek pouch as the experimental site. The four modes of administration used were (1) tri-weekly painting of the cheek pouch with aqueous extracts of test materials, (2) deposition of replaceable wax pellets containing the test material, (3) gelatin capsules containing the powdered material and (4) insertion of natural material into the pouch for trauma and direct exposure. Untreated controls and standard carcinogen DMBA-treated controls were also maintained. A total of 317 young adult golden Syrian hamsters (Mesocricetus auratus) used for the experiments were killed in two age groups: 6-12 months and 13-24 months, only when signs of general debility were observed. In the untreated controls, animals were free of any malignancy. In the experimental series, various betel quid ingredient combinations under test induced both oral and gastric lesions ranging from massive atypia and precancerous lesions to frank carcinomas. Maximum lesions were observed in the groups receiving betel nut, lime and tobacco combinations and in the polyphenol fraction of betel nut containing major tannins. The mode of administration of test material resulted in distinct differences; tri-weekly paintings giving oral lesions in the range of 22-23% and gastric lesions 39-48%; the same material given either through the replaceable gelatin capsule or in natural form induced 69% oral lesions and 63 to 82% gastric lesions. Overall evaluation of the data of all the four series confirms the potent carcinogenicity of betel nut, particularly its tannin-containing polyphenolic fraction and its combination with lime and tobacco. Maximum oral lesions induced in the hamsters by continuous exposure to capsules and natural material, highlight the direct relationship of frequency of chewing in habitual chewers with oral carcinogenesis. The high incidence of gastric (forestomach) lesions invites special attention.

Carcinogenicity of betel quid ingredients: feeding mice with aqueous extract and the polyphenol fraction of betel nut.

Male mice of inbred strains Swiss and C17 were fed daily 5 times a week by intragastric tube 0.1 ml of betel-nut aqueous extract, betel-leaf aqueous extract and the polyphenol fraction of betel nut. Male mice of corresponding strains fed 0.1 ml of distilled water served as controls. Treated and control mice were kept under observation and killed when moribund. Betel-nut aqueous extract induced tumours of the gastrointestinal tract in 58% Swiss mice and 25% C17 mice. The polyphenol fraction by the same route induced tumours at other sites in 17% of the mice. Betel-leaf aqueous extract failed to induce any tumour in the treated mice, which supports an earlier report of the lack of any carcinogenic principle in betel leaf, an essential constituent of betel quid. Results are discussed in relation to the relevant literature.

N-Formylation of an aromatic amine as a metabolic pathway.

1. Feeding 2-aminoanthraquinone (2-AAQ) in the diet to Fischer rats led to nephrotoxicity in females, caused by deposits of crystalline material in the kidney tubules. 2. This material consisted of 2-AAQ, N-acetyl-2-AAQ and N-formyl-2-AAQ. N-Formyl-2-AAQ was also identified in the ether extract of urine of rats fed 2-AAQ. 3. This represents the first case of identification of the N-formyl derivative of a primary aromatic amine as a metabolite in vivo.

Toxicological study of Semecarpus anacardium nut extract.

Toxicological study was carried out in rats with chloroform-soluble fraction of the nuts of Semecarpus anacardium to determine its safe non-toxic dose. The fraction produced toxicity at all levels tested (50-400 mg/kg) but the extent of toxicity was found dose-dependent. At lower doses this fraction induced partial growth inhibition over 36 days and higher doses proved fatal within 6 days. It was observed that 230 mg/kg caused 50% mortality in rats and this value is 1380 mg/m2 when expressed for body surface area. This work will be of some use in the cancer chemotherapy study of the fraction.

Experimental studies on betel nut and tobacco carcinogenicity.

Sun-dried Mangalore betel nut extracts in water and in DMSO, and sun-cured Vadakkan tobacco extract in DMSO, were tested for their carcinogenic potency. Inbred Swiss and C17 mice and golden hamsters were used for the experiments. Control animals treated with either DMSO or water did not show any changes at the sites of administration. On subcutaneous administration of betel nut extract, 60% of Swiss mice developed transplantable fibrosarcomas at the site of injection. Skin application of DMSO extracts of tobacco and of betel nut separately did not result in skin lesions in C17 mice; but when a mixed DMSO extract of tobacco and betel nut was used, skin papilloma and epidermoid carcinoma developed in some animals. Similarly, hamster cheek pouches painted with a DMSO extract of tobacco alone did not develop malignant atypia whereas those painted with a DMSO extract of betel nut showed early malignant changes. DMSO extract of a mixture of tobacco and betel nut positively increased the incidence of early malignant changes in the hamster cheek pouch, indicating the enhancing effect of betel nut in carcinogenesis.

Effect of partial hepatectomy on tumor incidence and metabolism of mice fed thioacetamide.

Six-week-old male Swiss mice were given 0.03% thioacetamide (TAA) in the diet 24, 72, and 168 hours after partial hepatectomy. TAA-treated mice from all three groups were killed when they were 4, 9, and 13 months old. Intact and partially hepatectomized animals on normal diets served as controls. None of the controls evidenced neoplasms at any age. All three experimental groups developed liver tumors earlier than did intact mice treated with the TAA diet. Progressive metabolic studies on the livers or tumor tissues of treated mice showed that the levels of glucose-6-phosphatase, fructose-1,6-diphosphatase, and glycogen decreased significantly in the 4-month-old treated group when there was no significant alteration in liver histology. These parameters were lowest in the tumor tissues of treated mice.