Anticarcinogenic effects of some Indian plant products.

The anticarcinogenic properties of some commonly consumed spices and leafy vegetables were investigated. The effects of feeding the plant products on the induction of squamous cell carcinomas in the stomachs of Swiss mice by feeding benzo[a]pyrene(B[a]P) and on the induction of hepatomas in Wistar rats by feeding 3'-methyl-4-dimethylaminoazobenzene (3'MeDAB) were investigated. Among the nine plant products tested, cumin seeds (Cuminum cyminum Linn) and basil leaves (Ocimum sanctum Linn) significantly decreased the incidence of both B[a]P-induced neoplasia and 3'MeDAB-induced hepatomas. Poppy seeds (Papaver somniferum Linn) significantly inhibited B[a]P-induced neoplasia alone, while the other plant products, asafoetida, kandathipili, turmeric, drumstick leaves, solanum leaves and alternanthera leaves were ineffective. These results suggest that cumin seeds, basil leaves and to a lesser extent poppy seeds, which are all widely used in Indian cooking, may prove to be valuable anticarcinogenic agents.

Genotoxic effects of some foods & food components in Swiss mice.

A number of commonly consumed foods and food components in south India were screened for their genotoxic effects on Swiss mice. Salted, sundried and oil fried vegetables and fishes induced chromosomal aberrations, sperm head abnormalities and micronuclei production, which were comparable to the effect of the positive control viz., 20-methylcholanthrene. Spices like Cissus quadrangularis (an indigenous herb used in certain south Indian dishes) and pyrolysed cumin and aniseeds showed moderate effects. Calamus oil, widely used in pharmaceuticals was highly effective. All the three parameters of genotoxicity gave similar results.

An evaluation of the tumour affinity of the radioactive cobalt chelate of tallysomycin S10b in lymphoma-bearing mice.

The tumour affinity of the radioactive cobalt chelate of tallysomycin S10b (Tlm S10b), a promising structural analogue of Bleomycin, was assessed using a mouse lymphoma model. The highest concentrations (%dose/gram tissue) were observed in the kidneys, followed by the tumour (4.1%/g 1 h p.i.) at 1 h, 4 h and 48 h. The tumour had the highest concentration among all tissues at 24 h. The biodistribution profile of 60Co-Tlm S10b was distinctly different from that obtained with 60CoCl2, demonstrating the in vivo stability of the chelate. More than half of the chelate (56.8% of the injected dose) was excreted in the urine at 1 h. The highest tumour/non-tumour ratios were obtained for blood (41.3, 4 h), bone (30.5, 4 h) and muscle (29.2, 48 h). Scintigraphy at 24 h, using 57Co-Tlm S10b, showed the tumour, liver, kidney and bladder clearly. The similarities and differences exhibited by Co-Tlm S10b with reference to the literature on cobalt chelates of Bleomycin and naturally occurring tallysomycin (A + B) are discussed.

Mutagenic activity of south Indian food items.

Dietary components and food dishes commonly consumed in South India were screened for their mutagenic activity. Kesari powder, calamus oil, palm drink, toddy and Kewra essence were found to be strongly mutagenic; garlic, palm oil, arrack, onion and pyrolysed portions of bread toast, chicory powder were weakly mutagenic, while tamarind and turmeric were not. Certain salted, sundried and oil fried food items were also mutagenic. Cissus quadrangularis was mutagenic, while 'decoctions' of cumin seeds, aniseeds and ginger were not. Several perfumes, essential oils and colouring agents, which are commonly used were also screened and many of them exhibited their mutagenic potential by inducing the 'reverse mutation' in Salmonella typhimurium tester strains.

Presence of polycyclic aromatic hydrocarbons in some South Indian food components.

South Indian food dishes, comprising several deep fried items have been proved to be mutagenic. Polycyclic aromatic hydrocarbons (PAHs) such as, benzo(a)pyrene, chrysene and dibenzanthracene, which are potent and proven carcinogens have been identified and quantified in several of the commonly consumed South Indian food dishes and food components. Most of the pyrolysed items contained PAHs in appreciable quantities. PAHs were detected in significant levels in salted, sundried and oil fried vegetables and fishes. Some of the raw and uncooked food components also revealed the presence of PAHs.

Mutagenicity of nitrosated food items.

Several food items, commonly consumed in South India, after nitrite treatment under simulated gastric conditions were found to be mutagenic in Salmonella typhimurium tester strain TA 100. Dichloromethane extracts containing the volatile nitroso compounds and ethyl-acetate extracts with the non-volatile nitroso compounds of some of the food items exhibited mutagenicity.

Plant products as protective agents against cancer.

Out of various spices and leafy vegetables screened for their influence on the carcinogen-detoxifying enzyme, glutathione-S-transferase (GST) in Swiss mice, cumin seeds, poppy seeds, asafoetida, turmeric, kandathipili, neem flowers, manathakkali leaves, drumstick leaves, basil leaves and ponnakanni leaves increased GST activity by more than 78% in the stomach, liver and oesophagus, - high enough to be considered as protective agents against carcinogenesis. Glutathione levels were also significantly elevated in the three tissues by these plant products. All of them except neem flowers, significantly suppressed (in vivo) the chromosome aberrations (CA) caused by benzo(a)pyrene in mouse bone marrow cells. Multiple CA and exchanges reflecting the severity of damage within a cell were significantly suppressed by these nine plant products. The results suggest that these nine plant products are likely to suppress carcinogenesis and can act as protective agents against cancer.