Effect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp, a Beninese food condiment.

Smoked shrimp is a food condiment widely used in Beninese local cooking practices. A previous study revealed that this product is highly contaminated with polycyclic aromatic hydrocarbons (PAH). The present study explored possibilities to reduce PAH levels in shrimp smoked using cottage industry smoking techniques with barrel and chorkor kilns, by replacing wood by charcoal from Acacia auriculiformis and Mangifera indica, as fuels. Results showed that only shrimp smoked using acacia charcoal in a chorkor kiln had PAH levels (benzo[a]pyrene = 5 µg kg(-1) and sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene = 28 µg kg(-1)) in accordance with a European standard of 5 and 30 µg kg(-1), respectively, and suitable physicochemical characteristics for good storage (moisture content = 11.9% ± 1.5%; water activity = 0.46 ± 0.03). However, further investigations still needs to be done to reduce the duration of product contact with combustion gasses in order to reduce the PAH content of smoked shrimp to safer levels, largely below standards.

Inhibitory effects of citrus fruits on the mutagenicity of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid treated with nitrite in the presence of ethanol.

It has been shown that the mutagenicity of 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid (MTCCA), a mutagen precursor in soy sauce treated with nitrite, was strongly increased when it was treated with nitrite in the presence of alcohols. We found that the mutagenicity of MTCCA treated with 50 mM nitrite at pH 3, 37 degrees C for 60 min in the presence of 7.5% ethanol was reduced by the addition of citrus fruits sudachi (Citrus sudachi), lemon (C. limon) and yuzu (C. junos), to the reaction mixture. The mutagenicity-reducing activity per weight of flavedos (outer colored portions of peel) of the citrus fruits was considerably higher than that of the juices. The juices of the other citrus fruits commercially available in Japan also had mutagenicity-reducing activity against the nitrite-treated MTCCA. Among the many components of citrus fruits, dietary fibers lignin and pectin showed strong antimutagenic activity in the reaction mixture, suggesting that the mixed fractions of these components including lignin, pectin, D-limonene, naringin, hesperidin, ascorbic acid and citric acid reduce the mutagenicity of MTCCA in the reaction mixture containing nitrite and ethanol.

Mutagenicity of soy sauce treated with nitrite in the presence of ethanol or alcoholic beverages.

The mutagenicity induced by soy sauce after reaction with 50 mM nitrite at pH 3, 37 degrees C, for 60 min in the presence of 1.25-10% ethanol was reduced in proportion to the ethanol concentration. The mutagenicity of soy sauce treated with nitrite was also reduced in the presence of commercial alcoholic beverages, Japanese sake, wine, 'shochu', whiskey and brandy, but not beer, in proportion to the concentration. The mutagenicity of nitrite-treated tyramine, which is a major precursor of a mutagen in soy sauce treated with nitrite, was strongly reduced in the presence of ethanol, n-propanol or isopropanol and more strongly reduced in the presence of methanol, but was increased twofold in the presence of the sugars glucose or sucrose. The reduction of the mutagenicity of nitrite-treated tyramine required simultaneous treatment of tyramine with ethanol and nitrite. The mutagenicity of tyramine treated with nitrite was clearly reduced in the presence of shochu and whiskey, similarly to ethanol. Analysis by high-performance liquid chromatography revealed that the reduction of the mutagenicity of nitrite-treated tyramine in the presence of ethanol resulted from the reduced production of mutagenic 3-diazotyramine from tyramine.

Carcinogenicity testing of some constituents of black pepper (Piper nigrum).

In mice, injection of safrole, tannic acid or methylcholanthrene (MCA) during the preweaning period induced tumors in different organs. Safrole and tannic acid (constituents of black pepper) were weak carcinogens when compared with MCA which was used as a carcinogenic control substance. Force feeding of d-limonene (one of the pepper terpenoids) for a long time to the mice which were injected with any of the above 3 substances reduced their carcinogenic activity, while force feeding of piperine (one of black pepper alkaloids) was ineffective.

Carcinogenicity of lifelong administration of capsaicin of hot pepper in mice.

Capsaicin was administered in a semisynthetic powdered diet at 0.03125% level for the lifespan of Swiss mice starting from 6 weeks of age. As a result of C treatment, tumors of the cecum were induced in 22% of females and 14% of males, whereas the corresponding tumor incidences in untreated female and male controls were both 8%. Histopathologically, the tumors were classified as benign polypoid adenomas. Capsaicin is the main pungent principle of hot pepper, which is consumed in high quantities by humans worldwide. The capsaicin content of some chili varieties ranges up to 0.53%.

Modulatory influences of clove (Caryophyllus aromaticus, L) on hepatic detoxification systems and bone marrow genotoxicity in male Swiss albino mice.

Modulatory effects observed due to clove administration (0.5%, 1% and 2% w/w in the diet) to Swiss albino mice for 10, 20 and 30 days in the hepatic levels of cytochrome P-450 (Cyt. P-450), cytochrome b5 (Cyt. b5), aryl hydrocarbon hydroxylase (AHH), glutathione S-transferase (GST), DT-diaphorase (DTD), acid soluble sulfhydryl (SH) content and radiation-induced malondialdehyde (MDA) formation were recorded. Enhanced GST, Cyt. b5 and SH levels were observed in all the treatment groups, excepting those maintained on a 0.5% diet for 10 days which did not show significant increase in the GST and SH levels as compared to their respective controls. Significant reduction in Cyt. P-450 and MDA levels was observed in all groups at 30 days duration. While AHH levels remained unaltered by clove administration, DTD activity was elevated by 1% and 2% clove diets at 30 days duration. An in vivo bone marrow micronucleus assay demonstrated that administration of 0.5% and 2% clove diets for 10 days neither significantly induced micronuclei nor could effectively modulate the 7, 12-dimethylbenz[a]anthracene genotoxicity in mice. The results suggest whole cloves as potential chemopreventive agents.

Carcinogenic effect of force-feeding an extract of black pepper (Piper nigrum) in Egyptian toads (Bufo regularis).

50 male and 50 female Bufo regularis were treated, by force-feeding, with an extract of black pepper, at a dose level of 2 mg, 3 times a week for 5 months. The first tumors appeared after 2 months. Liver tumors (hepatocellular carcinomas, lymphosarcomas and fibrosarcomas) were found in 12 males and 18 females. Metastatic deposits of hepatocellular carcinomas were registered in the spleen, kidney, fat body and ovary.

Comparison of the inhalation toxicity of kretek (clove cigarette) smoke with that of American cigarette smoke. II. Fourteen days, exposure.

The comparative repeat dose toxicity of American cigarettes and kreteks (Indonesian cigarettes containing approximately 60% tobacco and 40% shredded clove buds) was assessed by exposure of groups of five male and five female rats to equivalent (approximately 2 mg/l in terms of total particulate matter) concentrations of smoke from each type of cigarette over 15 consecutive days. The smoke was delivered "nose only" using an HRC Rodent Smoking Machine (Mark IV). For each type of cigarette, three doses were used. These were achieved by regulating the daily total duration of exposure to smoke. The different doses used were 2 x, 4 x and 6 x, 15-min exposures, presented daily over a period of approximately 6 h. Inter-group comparisons were made between American and kretek groups which received the same daily durations of smoke exposure. Higher doses of smoke resulted in reduced bodyweight gains and food consumption in male groups; the response of female groups was not as clear. At the highest dose, male rats exposed to kretek smoke gained significantly more weight by comparison with males exposed to American smoke. Higher doses of smoke tended to increase water consumption in both sexes of groups exposed to American smoke; kretek smoke produced no obvious effect. Smoke exposures produced the expected responses in certain haematological and blood biochemical parameters attributed to exposure to CO and the irritants present in cigarette smoke. Such responses were, however, confined largely to the groups exposed to American smoke. Macroscopic pathological findings attributed to smoke inhalation were confined to the lungs, and consisted of minimal to moderate discolouration and incomplete collapse of the lung.(ABSTRACT TRUNCATED AT 250 WORDS)

Carcinogenesis induced by black pepper (Piper nigrum) and modulated by vitamin A.

Painting and feeding of mice with 2mg of an extract from black pepper on 3 days a week for 3 months results in a significant increase of the number of tumor-bearing mice. Tumor incidence is reduced in those groups of experimental animals receiving 5 or 10mg Vitamin A-palmitate twice weekly for 3 months by feeding or painting during and subsequent to application of pepper extract. Feeding of mice with powder of black pepper in diet (50g/3kg food) has no impact on carcinogenesis.

Clastogenic effects produced by black pepper in mitotic cells of Vicia faba.

Black pepper, as is well known, is an important spice widely used in the cooking and processing of meat and fish. The aim of the present investigation was to evaluate the clastogenic potential of black pepper. This was accomplished by treating root meristems of Vicia faba with aqueous extracts of black pepper. Examination of the treated roots showed the presence of chromatid breaks, chromosome breaks, gaps and exchanges. Statistically significant differences from controls were observed. Experiments to evaluate its clastogenic potential in mouse systems are in progress and the results will be published elsewhere.

Augmenting effect of a nonmutagenic fraction in soy sauce on mutagenicity of 3-diazotyramine produced in the nitrite-treated sauce.

When 25 kinds of Japanese soy sauce at a concentration of 5% were incubated with 50mM sodium nitrite (pH 2) at 37 degrees for 1 hr, the reaction mixtures induced 34-834 (average 368 +/- 228) revertants per microliter of soy sauce equivalent in Salmonella typhimurium strain TA100 in the absence of S9 mix. The mutagen(s) formed was very unstable under natural daylight and a fluorescent lamp but quite stable under a yellow lamp as well as in the dark. In addition to the known precursors, i.e., tyramine and 1-methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid, 1-methyl-1,2,3,4-tetrahydro-beta-carboline, which caused weak mutagenesis, was found in the soy sauce. However, the sum of the activities of the three mutagen-precursors after nitrite treatment accounted for only a part of the mutagenicity of nitrite-treated soy sauce. There was in the soy sauce a factor which increased ninefold the mutagenicity of nitrite-treated tyramine, 3-diazotyramine. Therefore, tyramine was considered the principal precursor of the mutagen produced in the nitrite-treated soy sauce. These three precursors together with the mutagenicity augmentation accounted for all the mutagenicity of nitrite-treated sauce. The mutagenicity-augmenting factor in the soy sauce was nonmutagenic before and after nitrite treatment and was stable to heat and light irradiation.

Cytotoxicity of extracts of spices to cultured cells.

The cytotoxicity of the extracts from eight different spices used in the Indian diet was determined using Dalton's lymphoma ascites tumor cells and human lymphocytes in vitro and Chinese Hamster Ovary cells and Vero cells in tissue culture. Alcoholic extracts of the spices were found to be more cytotoxic to these cells than their aqueous extracts. Alcoholic extracts of several spices inhibited cell growth at concentrations of 0.2-1 mg/ml in vitro and 0.12-0.3 mg/ml in tissue culture. Ginger, pippali (native to India; also called dried catkins), pepper, and garlic showed the highest activity followed by asafetida, mustard, and horse-gram (native to India). These extracts also inhibited the thymidine uptake into DNA.

Carcinogenicity testing of black pepper (Piper nigrum) using the Egyptian toad (Bufo regularis) as a quick biological test animal.

Milled black pepper (Piper nigrum) force-fed to Egyptian toads as a suspension in amphibian saline or injected subcutaneously in the dorsal lymph sac as an ethanol extract, induced primary tumours in the liver and secondary tumours in other organs (kidney and spleen). When applied to the skin of experimental animals as an ethanol extract, black pepper induced primary tumours in the liver and secondary tumours in the ileum and stomach. Tumours of the liver were diagnosed as hepatocellular carcinomas and those of the other organs as metastases of the primary liver tumours. It is speculated that one or more constituents of black pepper may be responsible for tumour induction in the organs of the Egyptian toad Bufo regularis.

Tumour-promoting effect of chilli extract in BALB/c mice.

In 50% of BALB/c mice pretreated with atropine, tongue tumours were induced by fortnightly application of DMN-OAc (2 mg/kg) on the tongue. When DMN-OAc + TPA was used for the initiation-promotion protocol, tumours were observed on the tongue, the site of application, in only 10% of animals. In the same group, stomach tumours were obtained in 63% of mice, denoting that initiation-promotion could be successfully used to induce stomach tumours. Using a protocol of DMN-OAc + chilli as a promoter, we observed induction of stomach tumours. The promoter effect of chilli extract was also seen in the BHC-induced hepato-carcinogenesis system. It thus appears that, in BALB/c mice, chilli acts as a promoter in stomach and liver carcinogenesis.